Report Template

Categorization of West Coast Fresh Water System SINCLAIR KNIGHT MERZ Categorization of West Coast Fresh Water System Document history and status Revision Final Date issued 31 October 2006 Reviewed by Mal Horner Approved by Lyndsay Chapple Date approved 27 October 2006 Revision type Final Distribution of copies Revision Final Copy no Quantity 1 Issued to ADB – Axel Hebel Printed: Last saved: File name: Author: Project manager: Name of organisation: Name of project: Name of document: Document version: Project number: 30 October 2006 29 October 2006 11:32 AM COCS_60_059-RPT-0057 (FINAL) Categorization of Westcoast Freshwater System.doc Tony Mc Donald, Erik van der Zee Lyndsay Chapple Asian Development Bank ETESP Package 6 Extension Categorization of West Coast Fresh Water System Final COCS-60-059 SINCLAIR KNIGHT MERZ Categorization of West Coast Fresh Water System SINCLAIR KNIGHT MERZ Categorization of West Coast Fresh Water System Contents 1. Introduction – This Report 1.1 1.2 1.3 Observations – Pre flight Survey Team and Invitees Purpose of the Field Trip 1 1 1 2 2. 3. Rationale Background Information 3.1 3.2 3.3 3.4 3.5 Other Studies Land System zones Nearshore Coastal Condition Rainfall for West coast Weather During Survey 3 4 4 4 5 6 6 4. Methodology 4.1 4.1.1 4.1.2 4.1.3 7 7 7 7 7 Data Collection Type of photography Camera GPS and laptop computer 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 Flight preparation Base line mapping data Water body identification Photo flight Flight safety Processing of aerial photography Covered land area Determination of changes in river mouths and estuaries Constraints Mapping & imagery: SPOT, Quickbird & Norwegian Data Tidal Variance Hand Held Camera Noise Levels during the Flight Security 7 9 9 9 9 9 10 10 10 10 11 11 11 12 4.10.1 4.10.2 4.10.3 4.10.4 4.10.5 5. Findings 5.1 5.1.1 5.1.2 13 13 13 13 Observations – Pre and During Flight Coastal Terrestrial SINCLAIR KNIGHT MERZ i Categorization of West Coast Fresh Water System 5.2 5.2.1 5.2.2 5.2.3 5.2.4 5.2.5 5.2.6 5.2.7 5.2.8 5.2.9 Post flight Imagery Observations 14 Quality and clarity of the imagery 14 Comparison of Vertical Imagery 14 Number of Rivers in the Study 14 Overall Comparison between the two land system zones 14 Comparative Quantitative Summary: Western Barisan & Meulabou Embayment 15 Quantification of Major Differences 16 Applying Engineering Solutions 17 Conservation Issues Involved 18 Livelihoods and Conservation 18 5.3 Presentation of Study 19 6. Recommendations 6.1 6.2 6.3 6.4 Period of coastline reestablishment Ongoing measurement of coastal change River Mouth Management Policy Survey Methodology 20 20 20 20 20 Appendix A Appendix B B.1 B.2 B.2.1 B.2.2 B.2.3 List of Participants for Helisurvey Observations 23 24 24 25 25 27 28 Comparative Summary: Western Barisan - Meulaboh Embayment Western Barisan Zone Blocked Rivers Semi Blocked Rivers Open Rivers B.3 B.3.1 B.3.2 B.3.3 Meulaboh Embayment Zone Blocked Rivers Semi Blocked Rivers Open Rivers 29 29 30 31 Appendix C C.1 C.2 Analysis from Satellite Imagery & Helicopter Photography 32 32 34 Western Barisan Coastal Headlands & Lowlands Area Meulaboh Embayment Figures Figure 1 - Average Monthly Rainfall for West Coast Figure 2 –Study area with location of rivers/ wate bodies Figure 3 - Change of Krueng Raba River (Lhoknga) over time 6 after 6 after 18 SINCLAIR KNIGHT MERZ ii Categorization of West Coast Fresh Water System Tables Table 1 - Different combinations of camera and flight parameters Table 2 - Comparison of Change in River Status by Land System Zone over Time Table 3- Comparison of Key Differences Table 4 - Quantitative Summary Western Barisan Zone Table 5 - Quantitative Summary Meulaboh Embayment Zone Table 6 - Western Barisan Zone: Blocked Rivers Table 7 - Western Barisan Zone: Semi Blocked Rivers Table 8 - Western Barisan: Open Rivers Table 9 - Meulaboh Embayment Zone: Blocked Rivers Table 10 - Meulaboh Embayment Zone: Semi Blocked Rivers Table 11 - Meulaboh Embayment Zone: Open Rivers 8 15 16 24 24 25 27 28 29 30 31 SINCLAIR KNIGHT MERZ iii Categorization of West Coast Fresh Water System Acronyms ADB Bapedalda BAPPEDA BRR EMS FFI GIS GPS KAP ME SLR SPOT TOR’s UNHCR USAID WB WWF Asian Development Bank Badan Pengendalian Dampak Lingkungan Daerah (Regional Environmental Impact Management Agency) Badan Perencanaan Pembangunan Daerah (Agency for Regional Development Planning) Agency for Rehabilitation and Reconstruction of Aceh and Nias Extended Mission Sumatra (of ADB) Flora and Fauna International Geographic Information System Global Positioning System Kecamatan Action Plan Meulaboh Embayment Single Lens Reflex Satellite Probatoire d’Observation de la Terre Terms of Reference United Nations High Commissioner for Refugees United States Agency for International Development Western Barisan Coastal Headlands and Lowlands World Wildlife Fund SINCLAIR KNIGHT MERZ iv Categorization of West Coast Fresh Water System 1. Introduction – This Report This report details the summary background and the findings of a rapid aerial assessment survey completed on the West Coast Freshwater Rivers and Estuaries. On Saturday 12th August 2006 a team of 18 who comprised individuals from several agencies involved in the reconstruction and rehabilitation program in Aceh flew the coast from Banda Aceh to Meulaboh, in order to complete the survey. The flight was made using the 18 seat, Russian piloted, MI 8 United Nations helicopter using the regular flight route along the coast. 1.1 Observations – Pre flight Numerous KAP’s had identified the requests from communities to dredge estuaries, to “drain” recently established wetlands, and to plant primary dunes with coconut / casuarina spp. All these issues, while livelihood related, also require some analysis from a broad environmental perspective. Some stakeholders predicted that any blocked rivers and freshwater lagoons were a natural effect of the tsunami whereby the naturally formed riverbank-levee had been destroyed and thus the intensity and volume of the river flow was dissipated. Specific studies and TOR’s developed as a result the KAP planning process and subsequent field team recommendations generally amounted to a mix of ICZM components; the appropriate management of estuary (opening), ecological restoration of wetlands and estuaries, integrated estuary management plans, environmental education, pollution and catchment management. It was envisaged that these TOR’s could be applied to accompany any implementation of mechanical work to estuaries or river dynamics. 1.2 Survey Team and Invitees While trying to manage the numbers of people on board the flight it was identified that it would be valuable to incorporate as many organizations as was feasible by extending invitations to all interested stakeholders for the survey flight. Therefore, invitations were extended to representatives from BRR, BAPPEDA, Bapedalda, FFI, WWF, ADB-EMS and ETESP partners, the Dutch Sea Defence Project team and the USAID team concerned with environmental issues associated with the West Coast road. One member from the Lhoknga Life Saving Project also doubled as a photographer. Frank Wilkinson, known for his February 2005 report for the UNHCR that recorded the Tsunami coastal damage and discussed the variance in wave dynamics and associated geomorphology phenomena, was also invited for the survey. His observations and contributions to general discussions offered considerable contextual input for the group. SINCLAIR KNIGHT MERZ 1 Categorization of West Coast Fresh Water System Seven members of the SP/EM team were busily involved in a range of tasks associated with data collection. 1.3 Purpose of the Field Trip The purpose of the field trip was to complete a rapid assessment of river mouths and estuaries along the West Coast to gain a clearer picture of the status of the water bodies. Consultation from various stakeholders had indicated that rivers along the coast were blocked. Some players identified the need for dredging work and others indicated that emergent wetlands had considerable value. The Field Trip was undertaken to take a pictorial record of the coast to enable some assessment of the river mouth and estuary status. SINCLAIR KNIGHT MERZ 2 Categorization of West Coast Fresh Water System 2. Rationale The Kecamatan Action Planning KAP work completed for the Asian Development Bank (ADB), Earthquake and Tsunami Emergency Support Project (ETESP), by the Spatial Planning and Environmental Management (SP/EM) component team had clearly revealed that one of the most significant environmental problem along the west coast concerned the status of river flow, most particularly where sandbars appeared to block flows through river mouths and estuaries, and, as a consequence, freshwater wetland lagoons had begun to built up behind the primary sand dune / ridges. While there appeared to be a high correlation between these problems and the tsunami, it was recognised there were also catchment management problems that contributed to the river flows, the origins of which are associated with legal or illegal forest clearance programs and plantation development and/or timber concessions, and more general resource management. SP/EM phase 2 will continue the KAP work in tsunami affected areas further south along the west coast, and also on the islands of Simeulue and in Nias. It was considered that replication of this rapid field survey could be worth considering for phase 2 (ETESP 24). Prior to the KAP survey work, river mouths and estuaries had been identified as amongst the most sensitive “no-go” areas from an environmental perspective. However these areas are also the prime places for fishing boat mooring and associated fishing activities. Post tsunami many NGOs have supported communities with donated fishing boats and there is a steady call from communities for blocked river mouths to be opened using large machinery. Pre survey theories as to why the river mouths were blocked varied. Basically, river flow needed to be greater than the wave and littoral current-action in order to find a path thru the strandline. SINCLAIR KNIGHT MERZ 3 Categorization of West Coast Fresh Water System 3. Background Information The survey covered a number of administrative areas that comprised three Kabupatens (Aceh Besar, Aceh Jaya, Aceh Barat) and 11 Kecamatans. A map to outline this information appears as Figure 2. 3.1 Other Studies The work of others has been of great value to this rapid assessment. In February 2005 the UNHCR supported a rapid assessment of coastal damage by Frank Wilkinson. His subsequent report offered a clear summary of the situation at that time. The RePPPRoT Map Series (1987) was used to contribute to the determination of land systems. Long et.al. (2006) completed an assessment of post tsunami coastal conditions, with a view to conservation values, for the entire province of Aceh. By applying modelling techniques, a component of the Dutch Sea Defence project (Marchland, 2006) offered some insights into vulnerability of coastal regions. The broader work of this important Dutch funded study is investigating the implication of (a) further earthquakes, (b) subsequent wave activity and (c) vulnerability of people’s livelihood to these variables. On going collaboration with this project is considered to be an important component for the next phase of SP/EM. 3.2 Land System zones The study area incorporated two land system zones; the (i) Western Barisan Coastal Headlands and Lowlands and (ii) Meulaboh Embayment. The Western Barisan Coastal Headlands and Lowlands (WB) zone can be characterised by the appearance of protruding layers of the Barrisan Range consisting of a variety of parent materials including massive calcareous rock formations, hills and mountains (near Leupung) and isolated rocky headlands (old volcanic sediments) near Calang. In between these hills, hillocks and mountains, interspersed flat alluvial valley bottoms with meandering river systems occur adjacent to the coast. Where the coastal area is wide enough, a varied series of repetitive narrow beach ridges and swale formations with sandy soils between the hills have formed. Agriculture potential in this zone is low when compared to the extensive marine and alluvial lowlands of northern coasts of Aceh. The Meulaboh Embayment (ME) zone can be characterised as a wave-dominated beach barriersystem which blocks drainage of meandering rivers and inland backswamps which can be interpreted as being former lagoons. Near Calang the depth of the embayment is 100 metres, while nearer Meulaboh it is approximately 2000 metres. The long shore current drift causes a highly SINCLAIR KNIGHT MERZ 4 Categorization of West Coast Fresh Water System energetic environment with waves depositing tonnes of coarse sandy material along the primary beaches. Due to tsunami impact this coastal environment has been completely disrupted: sedimentation and deposition are still not balanced and estuary layout is still changing shape. Since the alluvial plains of the embayment are very flat, river gradients are low and sedimentation is slow. This results in low level energy river systems finding their way across plains, terraces and Meander belts and these rivers do not produce high levees1. Therefore they tend to flood before they can break though the blocking beach ridge in the estuarine river mouth. The Dutch Coastal Defence project advises a no-building zone of 200 m along the whole shore, with no reconstruction activities in or near the estuaries until the “sea is ready for it”. Agricultural capability in these ME lowlands is mainly determined by the extent of highly productive alluvial floodplains. Mixed home gardens (kebun) occur on the levees with an intercropping of a variety of annual and perennial crops. Sometimes there are small estates, or paddy fields in depressions (former oxbows). The lower and wetter backswamp areas of the floodplains are mainly used for rainfed rice followed by another crop. These alluvial floodplains were only affected by the tsunami in the near coastal areas near estuaries. At present, in some areas, the salinity has been diluted and translocated by river flow and rain water and, in several of them, they are productive again. However, in many areas poor drainage and high salinity still pose serious restrictions to agricultural rehabilitation and detailed analyses of drainage options are required. The floodplains and former tidal backswamps behind the beach barriers gradually merge into swamp lands which include peat forest and peat domes. In many places the fringes of these peat domes have been logged, drained and cultivated. 3.3 Nearshore Coastal Condition The land system and form on-shore will influence and be reflected in the nearshore characteristics. A previous ADB study (Long et al 2006) of coastal conditions post tsunami surveyed the near shore region of the study area. One output of this work aimed to map the benthos and marine groups along the Aceh coast with a view to identifying conservation values. The mapping for Aceh Jaya reveals the occurrence of sporadic hard sea bed accompanied by course sands, a high count for the presence of macro algae, which is associated with a high loss of coral material. The greatest biodiversity within the benthos groups along the west coast appear to be in Aceh Jaya, a part of the WB land system zone. 1 Source: Notes from RePPPRoT Map Series 1987. SINCLAIR KNIGHT MERZ 5 Categorization of West Coast Fresh Water System From Calang to Meulaboh the seabed of the near shore was reported to almost entirely comprise course sands, devoid of coral reefs. The sandy seabed was unremarkable or not noteworthy. The inference from the work was that this status was either the result of tsunami or depleted from prior management practices. 3.4 Rainfall for West coast The average yearly rainfall for the west coast of Aceh from Loknga to Blangpidie (89 km southeast of Meulaboh) was 3.2 m as per figure 1 below. Rainfall was high throughout the year and peaked from September to November where over a third of a meter of rain on average fell each month during this period. 400 350 300 250 200 150 100 50 0 Jan Rainfall (cm) Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Figure 1 - Average Monthly Rainfall for West Coast Rainfall characteristics in the west coast region of Aceh means that intense rain events are normal and flash flooding can commonly result. As illustrated by the graph, there are two periods of relative dry, the months of January - February and June are comparatively low in rainfall. This issue emerged to be of relevance in the data collected. 3.5 Weather During Survey The weather during the time of the heli-survey flight was highly favourable. Overall it was a day of predominantly calm conditions with light winds. In contrast, the days either side of the survey saw some low lying cloud cover, gusting high winds and associated heavy sea activity. SINCLAIR KNIGHT MERZ 6 KECAMATAN LOCATION MAP 760000 610000 780000 800000 820000 840000 610000 Lhok Nga 590000 Leupung Lhoong 570000 Jaya Kabupaten Pidie 550000 Sampoiniet Kabupaten Aceh Jaya Setia Bakti 530000 Krueng Sabee 510000 Panga 510000 Teunom Kabupaten Aceh Barat 490000 490000 Sabang Banda A ceh Aceh Besar Bireun Bener Meri ah Aceh Tengah Aceh Barat Legend Kabupaten boundary Kecamatan boundary Pidie Aceh Jaya Arongan Lambalek Kecamatan under study River or estuary of interest 470000 470000 Samatiga Nagan Raya Gayo Lues Aceh Barat Daya Johan Pahlawan 0 7,500 ± ETESP - SP/EM EAR THQUAKE AND TSUNAMI EMER GENCY SUPPORT PR OJECT Meureubo 15,000 m 760000 ADB GRANT No. 002 INO INDONESIA 780000 Last u pdate: 26 O ct 2006 AF 800000 820000 840000 Fig. 2 Kecamatan map with survey locations 530000 550000 570000 590000 Kabupaten Aceh Besar Categorization of West Coast Fresh Water System SINCLAIR KNIGHT MERZ v Categorization of West Coast Fresh Water System 4. 4.1 Methodology Data Collection 4.1.1 Type of photography Two types of photography were taken: near vertical (outbound from Banda Aceh) and oblique (inbound to Banda Aceh). Vertical photography is taken with the lens axis perpendicular to the earth surface, whereas oblique photography is taken with the lens axis non-perpendicular to the earth surface. 4.1.2 Camera Two Canon digital SLR’s were used: Canon EOS 20D (for the majority of photos) and Canon EOS 350D along with several single lens pocket digitals. The focal distance of the Canon cameras varied between 18 and 200 mm The rear of the helicopter has a hinged inspection / cargo port that was left open for the out-bound journey to enable taking the vertical photography. 4.1.3 GPS and laptop computer Two Garmin 60 CX GPS units were used to record the track flown, one connected to a laptop with OziExplorer tracking software (freeware) and the other one as a stand-alone unit. Both GPS units had an external antenna that was mounted on the windshield of the helicopter cockpit. The recorded flight track was displayed in real time using the OziExplorer software, overlaid on a map with the areas of interest marked on it. This was used to provide navigational instructions to the helicopter pilots. 4.2 Flight preparation An initial meeting was held with those involved, in order to hear what people from the different organisations wanted from the survey and to specifically try to achieve as much as was possible within the time frame. The areas of interest were marked on thirteen image base-maps derived from either Norwegian aerial photography or SPOT 5 satellite imagery at scale 1:15,000. Ideally the planned flight path should have been marked on this map and converted to a geo-referenced map used in OzieExplorer. In this way the pilot could be guided in order to cover the appropriate area. This is especially important for the vertical photography. Decisions needed to be taken about the exposure interval for each frame. This is determined by a calculation which is a function of a number of parameters: SINCLAIR KNIGHT MERZ 7 Categorization of West Coast Fresh Water System Camera: focal length and lens angle Camera resolution (size of image in pixels) Flying height Flying speed Photo overlap: to avoid gaps and taking redundant images, the overlap should be between 30% and 70%. An overlap of more than 50% would provide for observing the images stereoscopically (3D). Position of image: portrait (longer side perpendicular to flight direction) or landscape (longer side parallel to flight direction). Table 1 shows a number of combinations of parameters, with variable focal length. The other parameters can be of course varied as well, albeit within certain limits. Table 1 - Different combinations of camera and flight parameters Focal length [mm] Lens angle [deg] Camera resolution [pixels] Flying height [m] Flying speed [km/h] Photo overlap [%] Ground resolution [m] Exposure interval [sec] landscape 49 28 4 Area covered width [km] 3.2 1.9 0.3 portrait length [km] 18 31 200 101 70 12 3504x2336 3504x2336 3504x2336 2,000 2,000 2,000 250 250 250 30 30 30 1.5 0.8 0.1 32 19 3 4.8 2.8 0.4 Before and after the flight each camera recorded a photograph of the GPS time, so the camera and GPS times were synchronized. The time interval for recording GPS coordinates was set to 10 sec. Although not done for this survey, the tide should be considered as well for appropriate timing of future photo flights. Timing for the flight was determined by helicopter and flying team availability. Initially some time was spent on preparation of a flight plan and calculation of time interval between adjacent photographs in order to create approx. 30% overlap between succeeding photos. Stereo (3D) photography was not considered at this stage. On the basis of this calculation the height of approx. 2,000 m (6,600 ft) was decided upon. SINCLAIR KNIGHT MERZ 8 Categorization of West Coast Fresh Water System 4.3 Base line mapping data In total four different data sets were used to assist this survey. This data is referred to in this report as; (a) June 2003 SPOT, (b) Quickbird, (c) June 2005 Norwegian aerial photography and (d) August 2006 images. 4.4 Water body identification Prior to the flight a log consisting of 13 A3 maps was developed to identify all river that were thought to be along the route. This process identified some 46 discrete water bodies. 4.5 Photo flight Photography was recorded along the coastal strip incorporating river mouths, estuaries and wetlands. The out-journey was flown at approx. 2,000 m (6,600 ft) during which mainly vertical images were captured, the return journey was flown at approx. 500 m (1,650 ft) above sea level and 500 m from the coast to capture oblique shots of each river mouth / estuarine situation. 4.6 Flight safety At the rear of the helicopter there is a large cargo hatch. This hatch can be partially opened using a small trap door. This small trapdoor was to be open during the flight so that images could be recorded by someone lying on his stomach and pointing the camera vertically. For safety reasons the photographer was to be tied in a harness. As this small trap door was open for the entirety of the flight, it was deemed necessary that all passengers were to remain with safety belts on. 4.7 Processing of aerial photography Upon return to the office, the GPS data and photography were downloaded, and the metadata of the photography, at least photo ID, data and time, was extracted with help of the software package “EXIFextracter” (freeware). After synchronizing the photo time with the GPS time, the position of each photograph was determined by interpolation of the photo time between two subsequent GPS recordings. A total of over 1,400 images were the work of three photographers, out of which a selection was used and assembled to obtain appropriate coverage of the areas of interest. After initial processing, the approximate position of each photograph was adjusted visually using an existing map or geo-referenced image as a reference with the assistance of appropriate GIS software. As will be noted below under Constraints, there were difficulties in stitching of some images, especially when the individual photographs were not taken vertically. In such a situation it is impossible to make an exact fit. However, although the stitching was not perfect, it was found that it was good enough for interpretation and comparison purposes. Specialised image processing SINCLAIR KNIGHT MERZ 9 Categorization of West Coast Fresh Water System (remote sensing) software would provide for better tools for a more exhaustive central projection, giving better results. The position of oblique photos is indicated with help of a symbol. This symbol can be hyperlinked to the oblique photograph itself. 4.8 Covered land area Using the June 2004 SPOT satellite imagery as baseline data, it was initially decided to identify all rivers along the planned flight route. However, due to image overlap and the number of images taken, the data collected almost offers a contiguous coverage of the coastline from Lhoknga to Meulaboh, including post tsunami freshwater lagoons and estuary development. 4.9 Determination of changes in river mouths and estuaries Changes in river mouths and estuaries were visually determined by comparing the helicopter photography of August 2006 with the aerial photography of June 2005 or, if not available, Quick Bird satellite imagery of the first quarter of 2005, and SPOT satellite imagery of December 2004. 4.10 Constraints 4.10.1 Mapping & imagery: SPOT, Quickbird & Norwegian Data The use of the pre tsunami2 SPOT 5 satellite imagery as a tool to determine possible pre-tsunami characteristics and conditions was limited. The pixel size is 10 m and therefore begins to loose visual accuracy below 1:25,000. However, this was improved by merging the panchromatic imagery (with 5 m resolution) with that of the multi-spectral imagery (with 10 m resolution). It was also recognized that general weather conditions (cloud etc) could distort the situation or compromise clarity, and therefore, the quality of the images. This was particularly a problem with some of the June 2003 SPOT imagery. However, this did not present as a problem for the actual helisurvey imagery as the weather was ideal. The post tsunami SPOT Imagery (30 December 2004) for Kecamatan Lhoong is panchromatic (black and white) only. This imagery, although offering a higher resolution and therefore a higher level of detail, is not as easy as multi spectral imagery to classify landform and features post tsunami. For reasons unknown to the survey team, the Norwegian aerial photography (June 2005) excluded a number of key kecamatans, namely Leupung, Jaya, Sampoiniet and Samatiga. As this 2 Pre-tsunami SPOT 5: W coast N of Lamno: June 2003; S of Lamno: June 2004 SINCLAIR KNIGHT MERZ 10 Categorization of West Coast Fresh Water System photography was of a very good quality, these exclusions depreciated the potential quality of any analysis. Due to the dense canopy coverage read from the SPOT imagery, it is difficult to determine river flow status, most particularly, for example, in the case of minor rivers. Almost all of the rivers surveyed had no designated name on the mapping. To overcome this identification problem, all rivers were given a numeric registration. 4.10.2 Tidal Variance All the August 2006 survey imagery was captured over a variable point in time according to the flight path, there is a limitation that the imagery will alter depending upon the particular point in the tidal cycle. The flight took 1 hour 15 minutes north to south and approximately the same in return after a 30-minute break. Within this time frame it was considered that, although there was change in tidal affect over the near 3-hour period, this potentially had limited visual influence on the findings. As previously indicated, the timing of the flight was determined by helicopter and crew availability. 4.10.3 Hand Held Camera The aerial survey was completed with the photographer in a loose harness, using a hand held camera and shooting from an open hatch in the floor of the helicopter. In a number of places where the landform featured headland protrusions, particularly where there were no visible water bodies identified with the pre tsunami SPOT imagery, the flight path did not include these areas in detail. Therefore, as the flight path did not fly over the full extent of the coastline, in some places the photographer changed the angle of the lens to capture other adjacent and relevant features including the full extent of inundation. Unfortunately the geo-referencing method used results in loss of accuracy when the camera angle deflects more from the vertical, and both stitching of the imagery and the end product can be slightly inaccurate. Although more appropriate software is available to handle this problem it was not yet available at time of processing. This problem of image compatibility was partially solved by manually reconfiguring the image. 4.10.4 Noise Levels during the Flight It was known before hand that it would be almost impossible to verbally communicate during the flight. In order to overcome this inability to verbally communicate, a system of hand signals combined with the use of pre made signs printed on A4 pages was produced in order to be able to relay messages between the pilot and the team. These pages were shared with the pilot at pre flight the meeting. SINCLAIR KNIGHT MERZ 11 Categorization of West Coast Fresh Water System As a result of the high noise levels inside the helicopter, for the great part of the journey, there was virtually no verbal communication. This was a great hindrance to the sharing of observations between the survey team. 4.10.5 Security To enable the taking of vertical images through the trap door all passengers were to remain with safety belts on. This safety status meant that there could be very limited sharing of observations and interaction between passengers, something that had been a feature of a survey previous (17th February 2006) to observe the impact of the king tide upon recently completed housing, general infrastructure and livelihood activity. SINCLAIR KNIGHT MERZ 12 Categorization of West Coast Fresh Water System 5. Findings 5.1 Observations – Pre and During Flight A number of those who took part in the survey had regularly flown the Banda Aceh – Meulaboh route before. Frequently people had recorded observations on these journeys and there was a sharing of general observations and what to expect before the party left the airport. When the survey reached Meulaboh the entire group took a 40-minute break when there was a further opportunity to discuss. 5.1.1 Coastal The inshore west coast is a highly dynamic body of water and there appears to be both accretion and erosion progressing in different situations. Turbidity was present at a number of river mouths indicating steady river flow. This turbidity coincided with the prominent littoral currents. These currents appeared to vary in direction, running north or south. Turbidity could be a combined indication of sediment load and/or a near shore response to the river flow as it enters the aggressive and dynamic, predominantly course sandy conditions of the near shore coast. 5.1.2 Terrestrial In some places up to 250m of coastline has been lost in a very uniform manner, particularly along long straight beach sections as in the ME. In others, a larger loss was visible but it is considered that this was influenced by landform, particularly in the WB system. As the team had spent the previous days looking at the SPOT data baseline material an immediate difference was the magnitude of the water bodies adjacent to the primary dune and/or strandline. Concentrations of new settlement appeared along the fringe of some of these water bodies. In some places stands of uniformly mature trees which appeared to be dead, have been affected by either salt and/or the permanent inundation of water. In many cases river mouths are well sealed with the height of the primary dune or bank uniform with the predominant strandline. There was a lateral build-up of parallel freshwater bodies over, in some cases, up to 15 km in length. In such cases the build-up occurs until the fluvial movement can link to another river outlet. This phenomena occurred mostly along the ME coast. The river channels adjacent to this estuary appear to be, in general, very broad and shallow. In such a situation it appears that the tsunami had caused sand sedimentation to occur across the flood plain which would contribute to the estuary blockage. SINCLAIR KNIGHT MERZ 13 Categorization of West Coast Fresh Water System 5.2 Post flight Imagery Observations A detailed analysis of pre and post tsunami imagery is included in Appendix C. 5.2.1 Quality and clarity of the imagery For a hand held camera operating out of a small hatch in the helicopter the quality of the images are excellent. The resolution, the focus, and the depth of field all clearly offer a precise record of the ground conditions. The validity and economic efficiency of this technique for gathering quick and accurate data is well recommended. 5.2.2 Comparison of Vertical Imagery The most revealing images are those vertical shots that have been rectified and compared against the earlier images (pre tsunami SPOT imagery, pre tsunami QuickBird imagery or June 2005 Norwegian aerial photography). The data from the three major sources were collated and comparisons made. The analysis of this data was basically completed by eye and is relatively subjective. However, various measurements were made to pinpoint loss of coastline, degree of accretion or area of inundation. More exhaustive analysis of these images could assist in understanding and predicting, with some degree of confidence, the time that will be necessary for the coastline to reach a balance post tsunami. 5.2.3 Number of Rivers in the Study Each river has been given a subjective label of being either a major or a minor water course. This status was determined by the width, length and size of the catchment area. This determination was considered necessary as the general maps of the west coast issued by government agencies do not make reference to the minor river systems. A typical example of the results of this shortfall can be seen in the rivers identified in the MCRMP report (Long el at 2006). The SP/EM analysis of mapping, particularly the December 04 images, indicated that the coast had a greater number of rivers that that documented by Long et al, who simply accessed government agency mapping. For the sake of accuracy in dealing with the imagery, it was decided that this survey would register all visible flowing water bodies under either a major or a minor categorization. (A comparison table including a quantification of the major and minor water bodies appears in Appendix B). 5.2.4 Overall Comparison between the two land system zones The major surveyed differences noted between the WB and the ME was the difference in the number and characteristics of rivers and water bodies. The meandering plain and parallel ridge and swale land form adjacent to the primary sand dunes of the ME, enabled joining together of rivers / water bodies. The joining of river bodies, changing of river mouth positions, and, in general, the more dynamic situation in the ME. The data supports the notion that rivers in this land system zones are routinely blocked. SINCLAIR KNIGHT MERZ 14 Categorization of West Coast Fresh Water System Two combinations of comparative images were assembled. Analysis revealed that there was a need to deal with rivers that had meandered, had their levee bank broken by the tsunami and/or were joined. In places, four water courses may have joined together, and, from the images, only one of them may have been flowing in August 06. There are approximately 46 individual (minor and major) rivers in the WB which, and, after accounting for joined river status, this figure was reduced to 35. In the ME, the total number was 30 which was reduced to 13 joined or composite flows as of August 06. The conclusion reached with these rivers, particularly in the ME, is that there is a constant dynamic with these river bodies, particularly close to the coast. Comparative Quantitative Summary: Western Barisan & Meulabou Embayment The following summary Table 2 is derived from the observations of each river. A more detailed tabulation is presented in Appendix B. Table 2 is subjective and is constructed on the assumption that the status of rivers in August 2006 determined the starting point for analysis. The table indicates that the total number of rivers has changed. This change of status simply refers to whether the river flowed to the sea, or merged with another river. A subjective distinction has also been made between the major and minor rivers. Minor rivers were determined by a diminishing river width and small “catchment” area. A number of rivers appeared to be either spring fed and/or auxiliary watercourses for estuarine areas. For the sake of this survey, each river was determined as it was observed to be flowing to the sea. A further distinction was necessary to categorise rivers that were semi-blocked. It is considered that some rivers were either affected by high tidal movement and/or rainfall events. The mouth of these rivers was commonly “semi-close” with a shallow bar. This category can be viewed as being both closed and open, depending upon routine fluctuations in tide and rainfall events. Table 2 - Comparison of Change in River Status by Land System Zone over Time Western Barisan Meulaboh Embayment Jun 04 O major 4 minor 2 major 9 minor 8 major 6 minor 29 Aug 06 1 major 7 minor 3 major 0 minor 2 major 0 minor 13 Dec 04 1 major 6 minor 1 major 1 minor 4 major 0 minor 13 Jun 04 0 major 1 minor 2 major 1 minor 4 major 7 minor 15 5.2.5 Dates Blocked Semi-blocked Open Total # rivers Aug 06 3 major 20 minor 4 major 4 minor 4 major 0 minor 35 Dec 04 2 major 9 minor 0 major 1 minor 8 major 12 minor 32 SINCLAIR KNIGHT MERZ 15 Categorization of West Coast Fresh Water System Table 2 assists in observing the emerging pattern and trends. The table highlights the change in number of water bodies that have reached the coast since June 2004. While it is clear that the tsunami has caused more rivers to be blocked, the variance in the figures indicate the changing nature of the coastline is a situation that cannot whole be attributed to the effect of the tsunami. The seasonal rainfall dynamic no doubt has a great impact upon the position and character of river mouths. The total number of rivers flowing in both zones has changed in number, regardless of characteristic, and the greatest area of variance appears to be in the WB system. There are also more rivers in the WB, (reflecting the catchment topography) and, it is therefore inferred that, a greater number of minor rivers exist there. There are a diminishing number of minor rivers open or semi-opened in both land systems. This finding suggests that the flow of the minor rivers in both the WB and the ME are dependent upon seasonal rains. The low point in the average seasonal rainfall occurs in June and this is supported by the survey observations. In the WB there three major rivers blocked, four semi blocked and only four major rivers open. In the ME there is one major river blocked, three semi blocked and two out of four major rivers open. 5.2.6 Quantification of Major Differences Table 3 offers a summary of the quantifiable facts from the survey. The changes over time in the three categories which summarise river status is a key finding. Of interest also is the differences in the number of [major] rivers and the absence of reference to minor rivers which are mapped and presented as official mapping. Additional summary tables are assembled as Appendix B. (MCRMP refers to Long et al 2006). Table 3- Comparison of Key Differences No. Indicators River grouping based on Land System Western Barisan Meulaboh Embayment Aceh Jaya-Aceh Barat (From Calang to Meulaboh) 30 1 Category Aceh Besar-Part of Aceh Jaya (From Lhoknga to Calang) 46 2 3 Number of river/ water bodies Number of major rivers a. SP/EM data b. MCRMP data 11 5 4 4 SINCLAIR KNIGHT MERZ 16 Categorization of West Coast Fresh Water System River grouping based on Land System 4. Number of minor river/ coastal wetlands a. SP/EM data b. MCRMP data 35 - 26 - 5. a. August 06 Major river blocked 3 2 0 1 1 0 b. Dec 04/June 05 c. June 04 6. a. August 06 Minor river blocked 20 9 4 7 6 1 b. Dec 04/June 05 c. June 04 7. Major river blocked on August06, close to settlement 2 8 Major river semi-blocked on August06, close to settlement 1 4 9 Minor river blocked on August06, close to settlement 3 14 6 Although the pre tsunami SPOT imagery does not have the resolution and clarity of the later data, it is apparent from this data that some of the inundated areas / wetlands along the west Coast existed pre-tsunami. The conclusion from the survey is that the combination of both the at times ephemeral minor rivers with the key major flows means that there is considerable dynamic constantly in place along the west coast affecting river flows and, along with it, both the emergence and decline of wetlands. 5.2.7 Applying Engineering Solutions One river in particular was of interest in this survey. The mouth of River #1 (Krueng Raba of Lhoknga) was severely affected by the tsunami (see Fig. 3). Images post tsunami reveals a massive loss of coast, and vegetation with the mouth of the river almost closed. During the later part of 2005 (see Fig. 3 (b)) a groin was installed to assist in the reopening of the river mouth. This effect of this groin is clearly visible in August 2006 (see Fig. 3 (c)). The status of this river mouth is a good example of the hydrological dynamics involved along the coast. In order to document further the developments an additional image was taken of this river mouth on 20th October 2006 (see SINCLAIR KNIGHT MERZ 17 Categorization of West Coast Fresh Water System Fig. 3 (d)). For two days prior to the photo, intense rainfall had occurred in the catchment and it was expected that this would change dramatically the mouth. The suite of four photos that follow highlight the ongoing changes to this river. In August 2006 the river mouth almost appears to be semi-blocked and in October opened. However the rehabilitation of the river is not all positive. Adjacent and immediately up river from the groin a new sand bar has established itself within the river, making the river narrow. It is considered that this sand bar is a side affect from the groin. 5.2.8 Conservation Issues Involved In some places the KAP consultation work received requests from some communities for wetland areas to be drained. There are significant ecological values associated with the post tsunami emergence of the wetland areas. However, consultation processes has identified that where settlement is close to affected areas, and/or where land tenure and or livelihood issues coincide with the inundation, there is a need for long term support to communities to assist decision making on these issues. There is a reported large gap in understanding of the environmental values involved in these water bodies, both at the community and institutional level. It can be seen from the imagery that some inundated areas / wetlands in the lower river (river flood plain) will be difficult to be drained. In some areas there appears to be a pronounced subsidence in land profile, a phenomena that is reported to have been more pronounced on the island of Nias than in Aceh. Regardless, there is evidence of subsidence along the west coast, and these areas require long-term management solutions. Such situations may require that the areas be given a conservation / protection land status, and revegetation programs be implemented. Replanting with nipah (Nipah Friticans), which is tolerant of the variable saline and fresh water condition, is the appropriate way in which to rehabilitate and, in the long term, protect this land. Along the length of the coast, there have been some small scale replanting initiatives conducted by NGO’s. There is a massive ongoing need to continue replanting with coconut and Casuarina spp, particularly along the vulnerable beach areas. Although the west coast is a highly dynamic and aggressive body of water, there are some very secluded and protected areas that maybe suitable for planting with mangrove, assuming that the appropriate “muddy” soil profiles are still present. 5.2.9 Livelihoods and Conservation Appropriate studies of individual areas can offer the opportunity to embrace a synthesis of both livelihood and conservation based land use. Conservation and maintenance of wetland can enhance ecological biodiversity, providing improved habitat and along with that, community based SINCLAIR KNIGHT MERZ 18 Categorization of West Coast Fresh Water System SINCLAIR KNIGHT MERZ Categorization of West Coast Fresh Water System fisheries. To support livelihoods, it is necessary to seek sustainable solutions that could include for example, caged fishery culture etc. 5.3 Presentation of Study This study is presented on a CD-ROM that is included in this report. This will enable ongoing use of the imagery. The material includes: Index A which includes all rivers surveyed; Comparative Maps – A series of 55 maps visually comparing the pre tsunami status of all rivers with that in August 2006. In addition, over 100 oblique images reveal a clear picture of the river status. These images are referenced in the GIS to their particular location on the map. A one page graphical summary of the predominant conditions across each land system zone. This report. SINCLAIR KNIGHT MERZ 19 Categorization of West Coast Fresh Water System 6. Recommendations 6.1 Period of coastline reestablishment The survey has found that the west coast is still in a very high state of flux. A period of accretion, re-definition of coastline and establishment of general equilibrium will require, according to some estimates, up to five years (Wilkinson, F., personal communication). It is therefore recommended that limited infrastructure investment activity be instituted along the coastal boundary until there has been some settlement. Post tsunami application of a 200m buffer is endorsed by the KPA environmental management team. 6.2 Ongoing measurement of coastal change It is clear that to have a confidant management of the dynamic nature around river mouths and estuaries, data needs to be more accurately measured, assessed, shared amongst relevant players and management options discussed. It is recommended that monitoring and evaluation of sensitive areas be given priority. 6.3 River Mouth Management Policy While this report recommends a minimal approach to infrastructure initiatives along the coast, the data from the survey recognises that, in August 2006, there were three major rivers blocked in WB and one in ME. If close to settlement, such a situation will always caused difficulties and there will be requests for hard and instant engineering solutions; it is recommended that each case needs to be carefully surveyed. A good example of this situation can be seen for River #1 (Krueng Raba of Lhoknga; see also Fig. 3). Before any proposed infrastructure initiative it is necessary that the geomorphology and hydrology of each individual river needs to be assessed. There is a need to promote an appropriate environmental management policy, management procedures and action plan if deemed necessary. Conducting an engineering study of river mouth and coast area elevation of adjacent river mouth and inundation area, especially blocked or semi-blocked river mouth, which is closed to human settlement and disturbed other livelihood (fishing boat accessibility). 6.4 Survey Methodology A number of improvements can be recommended in the way that this survey was implemented: Ideally the camera should be mounted to the helicopter to avoid extreme deflection off the vertical. Proper flight planning will optimize the number of photos taken and a better coverage of the areas of interest. SINCLAIR KNIGHT MERZ 20 Categorization of West Coast Fresh Water System To monitor developments in the river mouths, a program of regular surveys needs to be implemented which means that aerial photography could be taken every 6 months and the results shared with relevant communities. SINCLAIR KNIGHT MERZ 21 Categorization of West Coast Fresh Water System REFERENCES Long. B.G., Hamdani, A., Andrews, G, Courboules, J., Ibros, Z., Sinaga, M., Scott, P.J.B., Siregar, A., and Mansyur, K (2006) Aceh Nearshore Atlas and Draft Marine Zonation Plan. Marine and Coastal Resources Management Project [Asian Development Bank Loan No. 1770-Indo (SF)] Department of Fisheries, Jl M.T. Haryono Kav. 52-53 Jakarta Selatan, Indonesia. Marchland, M., (2006), Vulnerability Assessment, Sea Defence Project, Banda Aceh. RePPPRoT Map Series 1987. Wilkinson, Frank (2005) Coastal Design and Tsunami Mitigation, United Nations High Commissioner for Refugees, Aceh, Indonesia. SINCLAIR KNIGHT MERZ 22 Categorization of West Coast Fresh Water System To monitor developments in the river mouths, a program of regular surveys needs to be implemented which means that aerial photography could be taken every 6 months and the results shared with relevant communities. SINCLAIR KNIGHT MERZ 21 Categorization of West Coast Fresh Water System Appendix A List of Participants for Helisurvey Date: Saturday 12th August, 2006 Helicopter: UNHAS 18 seater Crew: UNHAS crew of three Participants: Nr. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 BAPPEDA USAID / ADB Lhoknga Life Save Project FFI BRR Dutch Sea Defence BAPEDALDA Organisation ADB - SPEM Person Syarifuddin David Lloyd Scott Henderson Erik van der Zee Handoko Prastiyo Roma C. Manurung Tony McDonald Pak Said Mustafa Pak Mufti Eric Claassen Pak Yogi Pak Webi Soesmarjanto Frank Wilkinson (Pak Lucianto) Carsten Huttche Peter Ellison SINCLAIR KNIGHT MERZ 23 Categorization of West Coast Fresh Water System Appendix B Observations B.1 Comparative Summary: Western Barisan - Meulaboh Embayment Table 4 and Table 5 categorise rivers by both “individual” and “joined” status. The distinction of rivers being jointed was necessary in order to account for the changing river characteristics. The tables refer to three categories; blocked, semi-blocked and open. These differences were determined by the August 2006 data. Changes by category assist in explaining the dynamic nature of the existing coastline. Table 4 - Quantitative Summary Western Barisan Zone December 04 Rivers Summary Western Barisan Blocked June 04 SPOT/ QuickBird/ Norwegian aerial photography 13 individual rivers, 11 joined groups 2 x major (R30, 39) 9 x minor (R8, 19, 24, 35, 37-38, 41-42, 43, 44, 46) 1 individual river/ joined groups 1 x minor (R23) August 06 4 individual rivers/ joined groups 4 x minor (R15, 19, 20-21, 37-38) 27 individual rivers, 23 joined groups 3 x major (R12, 30, 39) 20 x minor (R6, 8, 9, 10, 11, 14, 15, 16, 19, 2021, 23, 24-25, 27, 28, 35, 37-38, 41-42, 43, 44, 46) 12 individual rivers, 8 joined groups 4x major (R1, 2-5, 31-32, 34) 4 x minor (R13, 33, 36, 40) Semi- blocked 11 individual rivers/ joined groups 2 x major (R12, 45) 9 x minor (R13, 23, 24, 35, 40, 41-42, 43, 44, 46) Open 19 individual rivers, 14 joined groups 8 x major (R1, 2-5, 17-18, 22, 26, 30, 31-32, 34) 6 x minor (R6, 16, 27, 28, 33, 36) 23 individual rivers, 19 joined groups 8x major (R1, 2-5, 17-18, 22, 26, 31-32, 34, 45) 12 x minor (R10, 11, 13, 14, 15, 16, 2021, 27, 28, 33, 36, 40) 5 individual rivers, 4 joined groups 4 x major (R17-18, 22, 26, 45) Table 5 - Quantitative Summary Meulaboh Embayment Zone Rivers Summary Meulaboh Embayment Blocked Pre tsunami SPOT 1 individual rivers June 05 Norwegian aerial photography 12 individual rivers = 7 joined groups August 06 16 individual rivers = 8 joined groups SINCLAIR KNIGHT MERZ 24 Categorization of West Coast Fresh Water System Rivers Summary Meulaboh Embayment Pre tsunami SPOT June 05 Norwegian aerial photography 1 x major (R54-55), 1 x minor river (R47) 6 x minor (R47- 48, 60-62, 69, 71-72, 73,74) 9 individual rivers, 2 joined groups 1 x major (R49-53) 1 x minor (R65-68) 8 individual rivers, 4 joined group 4 major (R57-59, 63-64, 70,75-76,) 6 individual rivers, 2 joined group 2 major (R56, 63-64); August 06 1 x major (R54-55), 7 x minor (R47- 48, 60-62,65-68, 69, 71-72, 73,74) Semi- blocked 5 individual rivers, 3 joined groups 2 x major (R54-55, 63-64), 1 x minor (R47-48) 8 individual rivers, 3 joined groups 3 x major (R49-53, 70, 75-76) Open 23 individual rivers, 11 joined groups 4 x major (R49-53, 57-59,70, 75-76) 7 x Minor (R48, 6062, 65-68, 69, 71-72, 73, 74) B.2 Western Barisan Zone Rivers/ water bodies # 1-46 B.2.1 Blocked Rivers 27 individual rivers were blocked, out of which 23 can be classified as associate (consisting of 3 major and 20 minor associate rivers); see Table 6. Table 6 - Western Barisan Zone: Blocked Rivers Blocked Rivers: Major River # 12 June 04 Semi-blocked, very narrow 20m mouth, flushing channel ~ 20m, Open at northern estuarine lagoon (400m), protected by primary san dune Semi-blocked at southern estuarine lagoon (1200m), protected by sand dune, river mouth channel 15m Dec 04 (post tsunami) SPOT River mouth wider 110m, scouring, flood plane destroyed, Destroy sand dune and estuarine lagoon and blocked. Blocked, loss estuarine lagoon, loss of coastal area 50-100m, subsidence on land ward/ inundation. August 06 Blocked with deposition along river course, low energy seasonal river? Blocked, more depression to northern area, inundation, have drainage channel at northern about 400m from previous river mouth, close to settlement Blocked, loss estuarine lagoon, loss of coastal area 50-100m, re-establish new coast line with primary sand dune, subsidence on land ward/ inundation, close to settlement 30 39 SINCLAIR KNIGHT MERZ 25 Categorization of West Coast Fresh Water System Blocked Rivers: Minor River # 6 June 04 Open with low water depth and small drainage channel Semi-blocked, sand dune and sand bar around river mouth Semi-blocked, sand dune protection Dec 04 (post tsunami) SPOT Lost of dunes and coast line 300m. Blocked behind 450m of previous river mouth, lost of sand dune & coast line 250m. Completely destroy of coastal sand dunes and swampy area Open, broadening river mouth, destroy sand dune & estuarine lagoon, remove coast line 350m to landward. Open, completely destroy of coastal sand dunes and swampy area Open, completely destroy of coastal sand dunes and swampy area Open and depression Open and depression Blocked and depression/ inundation, relatively have a channel to R18 Open, lost coastal area and depression Semi-blocked Blocked at R24 & open at R25, depression 1500m Open, lost of coastal area 150m, Open, destroy estuarine lagoon and sand dune, lost of coastal area 150m, Blocked, lost of coastal area 60-280m, river mouth move to the south but still blocked. Blocked, depression/ inundation August 06 Blocked, loss of coast line 150m, growing up of new sand dune, tambak inundation. Close to settlement Blocked, lost 150m of coat line, broad inundation of adjacent swampy area, tambak, and paddy field, close to settlement. Blocked, lost 120m of coat line, broad inundation of adjacent swampy area & tambak, grow up new primary sand dune, close to settlement. Completely blocked by sand dune, depression area with broadening of inundation, close to settlement 8 9 10 Semi-blocked, estuarine lagoon (700m) protected by sand dune 11 ? (unidentify) Completely blocked by sand dune, depression with inundation, close to settlement Completely blocked by sand dune, destroy estuarine lagoon, depression with inundation, close to settlement Blocked, far to settlement Blocked, far to settlement Blocked by new sand dunes, depression, close to settlement, relatively have a channel to R18 Blocked by new sand dune, loss of coast (250-400m), depression and inundation of adjacent area, close to settlement, Blocked, small and short river with narrow catchment area Blocked with new sand dunes, lost of coastal area 380m and levees, depression Blocked with new primary sand dune, reestablish coastal area such previous tsunami, close to settlement Blocked with new primary sand dune, reestablish coastal area, lose coastal area 100m, close to settlement Blocked, subsidence of landward, inundation to southern ward 14 Semi-blocked, estuarine lagoon (1km) protected by sand dune, sand bar around river mouth Blocked Open Blocked and swampy area as lagoon formation. Relatively have a channel to R18 Blocked with very small drainage channel to the sea. Semi-blocked Semi-blocked at 24 & blocked at 25 Open 15 16 19 20-21 23 24-25 27 28 Open at southern estuarine lagoon (600m) Semi-blocked with river mouth wide 30m, estuarine lagoon (450 m) protected by sand dune Blocked, separate river mouth, 35 37-38 Blocked, separate river mouth, depression/ inundation/ far to settlement SINCLAIR KNIGHT MERZ 26 Categorization of West Coast Fresh Water System Blocked Rivers: River # 41-42 June 04 Semi-blocked, small river, canopy cover Semi-blocked, small river, canopy cover Semi-blocked, small river, canopy cover Semi-blocked, small river, canopy cover Dec 04 (post tsunami) SPOT Blocked, low depression, loss of coastal area 2550m Blocked, low depression, loss of coastal area 30100m Blocked, depression, broad inundation. Blocked by road dam, more depression/ inundation August 06 Blocked, depression/ inundation, close to settlement Blocked, move rive mouth to the south and create estuarine lagoon (400m) depression/ inundation, close to settlement Blocked by road dam, might be subsidence and broad inundation, close to settlement Blocked, may be low depression, close to settlement 43 44 46 B.2.2 Semi Blocked Rivers 12 individual rivers were semi-blocked, out of which 8 can be classified as associate (consisting of 4 major and 4 minor associate rivers); see Table 7. Table 7 - Western Barisan Zone: Semi Blocked Rivers Semi Blocked Rivers: Major Krueng Raba 1 River open, spur to the north, also indication of seasonal closure. Loss of almost 300m of coast in places. Canopy/ vegetation destroyed, , Open post (R4, R5), estuary / lagoon destroyed, loss of coastline, lost completely river 2 & 3, Open, broad river mouth, lost coastal area 200m, depression the northern. R31 river mouth open 170m and R32 150m of new river mouth Open to northern ward, river mouth wide 240m, lost coastal area 150, depression, inundation Semi-blocked, accretion, reestablishment of old coastline continues, river mouth narrow/ with large bar (river 130 m with drainage channel 15m). close to settlement Some coastline accretion & definition in north direction, R5 blocked, R4 semi-blocked & depression/ inundation at adjacent, R2&R3 emerging, close to settlement R32 semi-blocked (drainage channel 8m, river mouth 80m) R31 blocked, inundation and depression to northern ward, close to settlement. River # June 04 December 04 (post tsunami) SPOT August 06 Krueng Geupu 2,3, 4&5 31-32 Open in between R2-3 (50m), sand bar around drainage channel, sand dune protecting estuarine lagoon (100m width, 5km length) Open with depression of sand bar to the river mouth (drainage channel 25m) 34 Open, 500m river mouth wide, sand bar at the middle river mouth Semi-blocked, river mouth wide 50m, broad river wide from 60 to 80m, re-establish new coast line with primary sand dune, wide beach sand, depression/ inundation of adjacent area, close to settlement. SINCLAIR KNIGHT MERZ 27 Categorization of West Coast Fresh Water System Semi Blocked Rivers: Minor River # 13 June 04 Semi-blocked & almost no flow, drainage line / Depression & tambak, December 04 (post tsunami) SPOT Open, broad river mouth and swampy area, loss of coastal definition, 100m loss in places. Open, broadening river mouth, loss of dune system & coastal define, depression, Open, river mouth move to the north, 80 m wide, lost coastal area 80-200m Open, broadening river mouth (85m), scouring along entire river course, some 50m loss of coastline, August 06 Semi blocked, new sandbar establishment, northern direction, land settlement in evidence. 33 Open, bar current to the north, lagoon mouth, Semi-blocked, alignment almost restored, inundation, semi-blocked in same position. 36 Open, 25 m river mouth wide. Semi- blocked & the same position of river mouth with post tsunami, depression/ inundation close to settlement Semi-blocked, river mouth wide 15m, drainage channel 8m, Inundated lagoon area developed with old river course visible, coast almost stable. 40 Semi-blocked, small river, canopy cover. NB: 2,3,4,5 should be recognised as one system. Parallel with coast, estuary B.2.3 Open Rivers 5 individual rivers were open, out of which 4 can be classified as associate (only major rivers): see Table 8. Table 8 - Western Barisan: Open Rivers Open Rivers: Western Barisan Major river, Lamno River # 17-18 June 04 Pre tsunami the river open, flowed out at R17. Alluvial delta build up, Parallel Troughs & depressions, tambak, limited settlement. Large open river, river mouth 125m, Open with 150 m wide river mouth, depression / south east defined by foothills, tambak, open to sea, December 04 (post tsunami) SPOT Huge loss of coast line and delta (1800m). Scouring, River Open in low depth mouth. River mouth broader post tsunami, open, no loss of coast, deposits on paddy. Open, broad of river mouth 500m, depression, loss of coast, vegetation, tambak, river definition still clear. August 06 Complete realignment of the river. Open on R18, blocked on R17. Narrow catchment area. 22 Mouth settled & become narrow, some settlement of coast / large water bodies. Open with very narrow drainage channel (50m) due to sand bar, broad river mouth, loss of coastal area 350m, new coast line establish, depression, inundation, close to settlement. 26 SINCLAIR KNIGHT MERZ 28 Categorization of West Coast Fresh Water System Open Rivers: Western Barisan River # 45 June 04 Semi blocked, river mouth wide 60 with drainage channel 20m . December 04 (post tsunami) SPOT Open, defined by limestone foothills, depression/ broad inundation, scouring to bedrock in places & settlement, huge impact incatchment. August 06 Open, loss of coastal area 100m, river mouth wide 60m, re-established on broad plane/delta. Depression, broad inundation, close to settlement. B.3 Meulaboh Embayment Zone Rivers/ water bodies # 47-75 B.3.1 Blocked Rivers 16 individual rivers were blocked, out of which 8 can be classified as associate (consisting of 1 major and 7 minor associate rivers); see Table 9. Table 9 - Meulaboh Embayment Zone: Blocked Rivers Blocked Rivers: Meulaboh Embayment Major (R54) June 04 River # June 05 Norwegian aerial photography Semi-blocked on R54, draining to south, connected with long parallel lagoons Small catchment, unclear course, depression, R47 blocked Open on R48, small catchment. 60-62 Open, connecting with line parallel lagoon, each line more discrete & separate channel. Open, connecting with line parallel lagoon, each line more discrete & separate channel. Open, drainage line connecting parallel lagoon Blocked, Inundation merging with R55 also blocked Connection to 48 & blocked. Inundation & wider. Tsunami backwash All connected, Inundation, becomes wider. Blocked. Blocked, inundation of adjacent area Blocked, some longitudinal parallel lagoon to R55 Close to settlement Blocked with less inundation. Maybe subsidence. Close to settlement Connected with R47 & blocked. Blocked, many small drainage lines connecting parallel lagoons. August 06 54-55 Minor River 47-48 65-68 Semi blocked, depression to land ward, broadening drainage channel (±130200m of each) with low depth Blocked, depression to land ward, broadening drainage line connecting parallel lagoon with R68 Blocked, many small drainage lines connecting parallel lagoons. Close to settlement Blocked, inundation & lagoon building, many small drainage lines connecting parallel lagoons Close to settlement 69 SINCLAIR KNIGHT MERZ 29 Categorization of West Coast Fresh Water System Blocked Rivers: Meulaboh Embayment June 04 River # June 05 Norwegian aerial photography August 06 71-72 Line parallel lagoon, each line relatively discrete & separate channel, open drainage channel. Open, drainage line connecting parallel lagoon withR72 Loss coast line 100m, blocked, depression to land ward, broadening inundation Lost coast line 150 m, blocked, depression to land ward, broadening drainage line connecting parallel lagoon with R72 Blocked, broadening river area, depression R71 blocked, R72 opened, grown up some small drainage lines connecting parallel lagoons. Close to settlement Blocked, inundation & lagoon building, many small drainage lines connecting parallel lagoons Close to settlement Blocked, broadening river area from70 to 150m, low depression Close to settlement 73 74 Open B.3.2 Semi Blocked Rivers 8 individual rivers were semi-blocked, out of which 3 can be classified as associate (all major rivers); see Table 10. Table 10 - Meulaboh Embayment Zone: Semi Blocked Rivers Semi-Blocked Rivers: Meulaboh Embayment Major river (R50) June 05 River # June 04 Norwegian aerial photography Semi blocked or minor open on R52, others are blocked, depression, no major loss of coast line. Semi block or very minor opening in R52 Open, almost universal subsidence, loss of levee, & coast of 250m. Open mouth with loss of coastal definition / primary sand dune. Small delta almost lost. Turbid water. Mouth almost silted, coastline reestablishment. Close to settlement Semi open on R76 (river mouth 200m & drainage channel 40m). Two large lagoons, opening to south - growing larger. R75 small delta line. Close to settlement August 06 49-53 Open on R53, the rest are blocked, parallel, lagoon, connection to major river of R50 R53 open & partial drainage for R49-R52 Semi open on R53, inundation & wide lagoon formation, tidal influence, highly dynamic situation. Close to settlement Major river 70 Major river, Open with tambak & Kebun. Major river (R76) 75-76 Open. Two large lagoons, opening to south. R75 small delta line SINCLAIR KNIGHT MERZ 30 Categorization of West Coast Fresh Water System B.3.3 Open Rivers 6 individual rivers were open, out of which 2 can be classified as associate (all major rivers); see Table 11. Table 11 - Meulaboh Embayment Zone: Open Rivers Open Rivers: Meulaboh Embayment Major river (R56) River # 56 (57-59) Major river (R64) 64 (6364) June 04 Open, broad 500m estuary, with links to other drainage lines. R63 semi blocked; R64 open, river mouth width 500m but drainage channel 100m, connected with estuarine lagoon R63 June 05 Norwegian aerial photography R56 Open but smaller lines blocked (R57-59) with loss of levee & subsidence. Open both R63 & R64, depression toward estuarine lagoon of R63, August 06 Open, redefining of coastline, R57-59 blocked. Close to settlement Open at R64 , R63 blocked, drainage channel 100m, redefining of coast line, inundation & merged with R63, close to settlement SINCLAIR KNIGHT MERZ 31 Categorization of West Coast Fresh Water System Appendix C Analysis from Satellite Imagery & Helicopter Photography C.1 River/ Water body # Western Barisan Coastal Headlands & Lowlands Area Pre tsunami Evidence of seasonal & tidal influences Less evidence Condition in August 06 Open/ Blocked Semi-Blocked (Krueng Raba) 2-3 4-5 Fully Blocked Semi Blocked (Krueng Geupu) 6 7 Blocked Open Lost of coast line & estuarine lagoon & emergent of new sand dune Lost of coast line & emergent of new sand dune to rebuild estuarine lagoon Lost of coast line 150m & rebuild a new emergent of sand dune Lost of coast line adjacent meandering/ swampy mouth area, including mangrove Lost of coast line adjacent river mouth & swampy area flushing Abrasion (lost of coastal area) & create some inundation of adjacent. Abrasion (lost of coastal area) & create some inundation of adjacent. Lost of coast line & emergent of new sand dune Emergent new sand dune Lost of coast line, emergent new small sand dune Lost of coast line & emergent of new sand dune Lost of coast line & emergent of new sand dune emergent of new sand dune Abrasion (lost of coastal area) & create some inundation of adjacent. Abrasion (lost of coastal area) & create some inundation of adjacent. Lost of coast line & emergent of new sand dune Abrasion (lost of coastal area) Abrasion (lost of coastal area) Minor river & or estuarine lagoon Major river & estuarine lagoon Less evidence seasonal opening Inundating of kebun Inundating of paddy field & tambak Close to settlement Close to settlement Post Tsunami (Dec 04) SPOT open Erosion/Accretion (lost of coast/ emergent coast) Emergent of sand dune Major/ Minor River/ Meandering Major river Inundation of adjacent area - Relatively Close to Settlement Close to settlement Livelihood interfere May influence fisherman boat to & from landing at river edge. Kebun May influence fishing boat from landing on river edge Paddy field & tambak Tambak disturbance Tambak & kebun disturbance Remarks Relatively close to pre tsunami condition (June 04) open 1 Blocked estuarine lagoon) Krueng Geupu of Leupung Open in between R3-4. (Mouth destroyed) Open R4 & R5 Swampy area/ meandering swampy area/ meandering Less evidence Tidal influence Inundating of tambak Inundating of tambak & kebun close to settlement close to settlement Lhoong - open open Semi Blocked Open with huge broadening of swampy drain channel Blocked at land ward open Open with wide river mouth open Open with wide river mouth Open open Open open open Open with the shallow river mouth, turbid Blocked open open open 8 9 10 11 12 13 14 15 16 17-18 18 19 20 21 22 Blocked Blocked Blocked Blocked Blocked Semi-Blocked Blocked Blocked Blocked Blocked Open Blocked Blocked Blocked Semi-Blocked (Narrowing river mouth) Blocked Blocked Semi-Blocked, narrowed river mouth Minor river Minor river Meandering/ swampy area Meandering/ swampy area Major river Swampy area with meandering Swampy area with meandering Swampy area with meandering Swampy area with meandering Major river Swampy area with minor river Minor river with swampy area Minor river with swampy area Minor river Major river Less evidence Less evidence Less evidence Less evidence Tidal & seasonal influence Tidal & seasonal influence Less evidence Less evidence Tidal & seasonal influence Less evidence seasonal opening Less evidence Less evidence Tidal & seasonal influence Seasonal influence Inundating of paddy field & tambak Inundating of tambak & kebun Inundating of tambak & kebun Inundating of tambak & kebun Inundating of adjacent river mouth area Inundating adjacent swampy area, including tambak Inundating adjacent swampy area, including tambak Inundating adjacent swampy area Inundating adjacent swampy area Inundating adjacent swampy area Inundating adjacent swampy area Inundating adjacent swampy area Inundating adjacent swampy area, including paddy fied & kebun Inundating adjacent swampy area, including paddy fied & kebun Increasing of inundation area Close to settlement close to settlement close to settlement close to settlement Close to settlement Close to settlement Close to settlement Close to settlement Far to settlement Close to settlement Close to settlement Close to settlement Close to settlement Close to settlement Close to settlement Tambak & paddy field disturbance Tambak & kebun disturbance Tambak & kebun disturbance Tambak & kebun disturbance Tambak & kebun disturbance Tambak disturbance Tambak & kebun disturbance kebun disturbance Tambak disturbance Tambak & kebun disturbance kebun disturbance Paddy field & kebun disturbance Paddy field & kebun disturbance Settlement, paddy field & kebun disturbance kebun disturbance paddy field & kebun disturbance Settlement, paddy field, tambak & kebun disturbance More depression Semi Blocked Semi Blocked Semi Blocked ? open Semi Blocked Semi Blocked Blocked Open Open Blocked Blocked Blocked Blocked Open 23 24-25 26 Abrasion (lost of coastal area) Abrasion (lost of coastal area) Abrasion (lost of coastal area) 750 m Swampy area Swampy area Major river Possibly seasonal influence Less evidence Seasonal influence Inundating adjacent swampy area, including kebun Inundating adjacent swampy area, including paddy fied, tambak, & kebun Far to settlement Far to settlement Close to settlement Semi Blocked Semi Blocked-Blocked open Semi Blocked Blocked at R24 & open at R25 Open, broad of river mouth 500m SINCLAIR KNIGHT MERZ 32 Categorization of West Coast Fresh Water System Condition in August 06 River/ Water body # Open/ Blocked Blocked, moving of the river mouth to the south ward Blocked Open Blocked Semi-Blocked Semi-Blocked Semi-Blocked Blocked Pre tsunami Evidence of seasonal & tidal influences Less evidence of seasonal influence Less evidence Possibly seasonal influence Possibly seasonal influence Possibly seasonal influence Possibly seasonal influence Possibly seasonal influence Post Tsunami (Dec 04) SPOT Open Erosion/Accretion (lost of coast/ emergent coast) Emergent new sand dune Major/ Minor River/ Meandering Minor river Inundation of adjacent area Inundation of adjacent swampy area, including tambak Inundation of adjacent swampy area, including tambak Inundation of adjacent swampy area Enlarge of inundation of adjacent swampy area, including tambak Enlarge of inundation of adjacent swampy area, including kebun & settlement Enlarge of inundation of adjacent swampy area, including kebun & settlement Enlarge of inundation of adjacent swampy area, including kebun, paddy field & settlement Inundation of adjacent swampy area, including kebun Inundation of adjacent swampy area Relatively Close to Settlement Close to settlement Livelihood interfere Settlement, tambak disturbance Remarks (June 04) Blocked 27 28 29 30 31-32 33 34 35 Lost of coastal area Lost of coastal area & destroyed swampy lagoon Lost of coast line & emergent of new sand dune Lost of coastal area Lost of coast line & emergent of new sand dune emergent of new sand dune with a wide sand beach Lost of coast line & emergent of new sand dune Lost of coast line & emergent of new sand dune emergent of new sand dune Minor river Lagoon Major river Major river Minor river Major river Minor river with wide flood plain area Minor river Close to settlement Close to settlement Close to settlement Close to settlement Close to settlement Close to settlement Settlement, tambak disturbance Settlement, tambak disturbunce Settlement & kebun disturbance Settlement & kebun disturbance Kebun, paddy field, & settlement disturbance Kebun disturbance Open open Open open open open Open Open Open Blocked Open Open Open Blocked 36 Semi- Blocked & move of river mouth to northern part Blocked Possibly seasonal influence Close to settlement Open Open 37-38 Minor river with huge area of fluvio marine & flood plain in adjacent Major river with estuarine lagoon Less evidence Far to settlement - Wide coastal lowland flood plain; Ecological disturbance Blocked Blocked 39 Blocked emergent of new sand dune Possibly seasonal influence Enlarge of inundation of adjacent swampy area, including kebun, paddy field & settlement Inundation of adjacent swampy area, including kebun & settlement Inundation of adjacent area Inundation of adjacent area Inundation of adjacent area Enlarge of inundation of adjacent swampy area, including kebun, tambak, paddy field & settlement Enlarge of inundation of adjacent swampy area, including kebun Inundating of paddy field Close to settlement Kebun, paddy field, & settlement disturbance Kebun & settlement disturbance Kebun & paddy field disturbance Kebun & paddy field disturbance Kebun & paddy field disturbance Kebun, paddy field, tambak, & settlement disturbance Kebun & settlement disturbance Paddy field disturbance Wide flood plain beside river ; in Calang Calang Open Blocked 40 41-42 42 43 44 Semi-Blocked Blocked Blocked Blocked Blocked by temporary dam for road Open Blocked emergent of new sand dune emergent of new sand dune emergent of new sand dune - Minor river Minor river Minor river Minor river Swampy area with small flushing channel to the sea Major river Minor river Possibly seasonal influence Less evidence Less evidence Less evidence Possibly tidal & seasonal influence Close to settlement Close to settlement Close to settlement Close to settlement Close to settlement Semi Blocked Semi Blocked NA NA Semi Blocked Open Blocked Blocked Blocked Open 45 46 Lost of coast line, emergent of new sand dune, & enlarge river wide. - Close to settlement Close to settlement Semi Blocked Semi Blocked Open Blocked SINCLAIR KNIGHT MERZ 33 Categorization of West Coast Fresh Water System C.2 River/ Water body # Meulaboh Embayment Pre tsunami Post Tsunami (June 05) Norwegian Aerial Photograph Blocked Condition in August 06 Open/ Blockeding Erosion/Accretion (lost of coast/ emergent coast) Major/ Minor River/ Meandering Evidence of seasonal & tidal influences Seem to be seasonal opening during wet season (west monsoon) - Inundation of adjacent area Relatively Close to Settlement Livelihood interfere Remarks (June 04) 47-48 Blocked Blocked as a coastal back swamp/ reservoir Semi Blocked Emergent of sand dune minor river Meandering & longitudinal connection to down stream of major river Major river (R50) with longitudinal estuarine lagoon to the south ward (R51-53) Major river with less longitudenal estuarine lagoon to the south ward Minor river Major river Minor river, R57 connected with R56, 58, 59 Minor river Flushing place of longitudinal back swamp from river #58 The mouth of longitudinal back swamp minor river , connected with R64. Major river Minor river Mouth of swampy area Major river Inundating of paddy field close to settlement Close to settlement (ca. 50 m). close to settlement Paddy field disturbance Wide flood plain area; Southern Calang Wide area of fluvio-marine land system Wide flood plain area in adjacent river mouth Wide area of fluvio-marine land system Wide area of fluvio-marine land system Wide area of fluvio-marine land system; Teunom River Blocked 49 - Inundating of kebun Enlarging of estuarine lagoon as swampy reservoir Enlarge of estuarine lagoon as swampy reservoir Increasing number of longitudinal back swamp Inundating of paddy field Inundating of paddy field Inundating of paddy field Inundation of coastal lowland Inundating of paddy field Inundating of paddy field during wet season Inundating of paddy field & less use of land during wet season Inundating of paddy field & less use of land during wet season Inundating of paddy field, kebun, & less use of land during wet season Inundating of paddy field, kebun, & less use of land during wet season Inundating of settlement area Inundating of settlement area Enlarging of estuarine lagoon Kebun disturbance Might be disturbed of out & in going boat to the river Paddy field disturbance Paddy field disturbance Blocked Blocked 50-53 Emergent of sand dune Less evidence Open in 53 Semi Blocked on R53 54 55 56 57-59 58 59 60-62 63 Blocked Blocked Open (Teunom River) Blocked Blocked Blocked Blocked Blocked (Arongan River) Open (Woyla River) Blocked Blocked Open/Semi Blocked (Bubon River) Blocked Blocked Blocked Open (Krueng Cangkui) Semi Blocked (Krueng Meurebo) Emergent of sand dune Emergent of sand dune emergent of coast line at both side of river mouth Emergent of sand dune Emergent of sand dune Emergent of sand dune Emergent of sand dune Emergent of sand dune Emergent of sand dune Emergent of sand dune Emergent of sand dune Less evidence Less evidence Seasonal opening Seasonal opening Less evidence Less evidence Seem to be seasonal opening Less evidence Seasonal opening Less evidence Seasonal opening Less evidence Less evidence Less evidence Less evidence Seasonal influence close to settlement close to settlement close to settlement far to settlement far to settlement far to settlement Far to settlement close to settlement close to settlement close to settlement close to settlement close to settlement close to settlement close to settlement close to settlement close to settlement close to settlement Blocked Semi Blocked open open open Semi Blocked Open Semi Blocked Blocked Blocked open Semi Blocked Blocked Blocked Blocked Open Open Semi Blocked Blocked Open Blocked Blocked Blocked Open Open Paddy field disturbance Paddy field disturbance Paddy field disturbance Paddy field disturbed as well as Fishing boat access to the river Paddy field disturbance Paddy field disturbance Paddy field disturbance Might be disturbed of out & in going boat to the river Paddy field disturbance Paddy field disturbance Might be disturbed of out & in going boat to the river Wide area of fluvio-marine land system Wide area of fluvio-marine land system - 64 65-68 69 70 71-72 73 74 75 76 Wide flood plain area; open Open Open open Open Open Open Open Open Lost of coast line & growing a new emergent of sand dune Lost of coast line & rebuild a new emergent of sand dune emergent of sand dune Lost of coast line & rebuild a new emergent of sand dune Mouth of swampy area Mouth of swampy area Minor river Minor river Major river SINCLAIR KNIGHT MERZ 34