VULNERABILITY MAPS: AN USEFUL TOOL FOR ESIA

1         ABSTRACT

Due to several reasons such as: the increasing demand of energy, the regional energy integration and the transport
costs decrease using pipelines; Oil & Gas pipelines projects are more and more often and ambitious all over the
world. Sometimes these projects are developed in very sensitive areas like tropical forests, wetlands, coastal zones,
among others. Environmental and Social Impact Assessments for this type of linear projects should be able to
identify the right of way sectors where the impacts will be more important according to the social and
environmental local context, in order to design and implement better environmental & social management plans.
Integration of the detailed Sensitivity Maps and the Impacts Assessment for the key project activities give a
measure of the Impact Significance for each sector of the pipeline and is also represented on Vulnerability Maps,
developed using a GIS tool. In this paper, the designed methodology is explained step by step and the case study
presented is a gas pipeline project in a primary forest of the Peruvian Amazonia.

This work presents the development of a methodology that integrates the Sensitivity Analysis based on local
context with the results of the Impact Assessment of the Project, which allows understanding the Significance of
the impacts in each sector of the pipeline. This methodology was applied in a project for the construction of a gas
pipeline in a primary forest in the Peruvian Amazonia. Hereafter, the methodology applied to the case study, an
example of its partial results and the general conclusions obtained from the study are detailed below.

The methodology of the Significance Analysis is applied to the most important environmental and social impacts
that were identified as a result of the interaction of the relevant actions of a Project for the installation, operation
and abandonment of a gas pipeline and the environmental and social aspects or factors. The development of the
methodology included the revision of the best international practices references (such as IPIECA, ARPEL, World
Bank, IFC) for similar linear Environmental and Social Impact Assessments projects, as well as the consideration of
applicable case studies.

The objective of the analysis is to determine the priority zones in the pipeline right of way to be considered in the
Environmental Management Plan according to the results of the impact assessment magnitudes and the different
existing sensitive areas at local level.


The developed methodology is applicable to the 3 phases of the project (construction, operation and abandonment)
and starts with the development of a detailed Environmental and Social Baseline of the pipeline right of way and
the Impact Assessment (quantification of the impacts magnitude). On the other hand, the application of this
methodology is circumscribed only to those relevant actions and environmental and social aspects according to the
particularity of each project.

Hereafter, the sequence of steps for the application of the methodology is presented:

    1.   Identification of relevant Impacts, Aspects and Actions;
    2.   Development of Sensitivity Maps by each Environmental and Social Aspect;
    3.   Significance Calculation;
    4.   Development of Vulnerability Maps;
    5.   Significance Description;
    6.   General Conclusions.
This methodology is partly supported by the GIS tool for the development of the Sensitivity and Vulnerability
Maps. In the following sections, the methodology steps are detailed as well as its application to the case study.


The impacts quantification was performed according to the V. Conesa Fernández – Vítora methodology, based on
the Leopold Matrix that uses 10 parameters to calculate the importance of a given impact and the range of possible
values is +/- 13 a +/- 100. From the results of the quantification of the magnitude of all the actions on all the
environmental and social aspects, available in the impact matrix, impacts of greater magnitude were selected. In
this particular case the adopted selection criteria was impacts with a magnitude value above or equal to -31.

In consequence, according to the adopted criteria, the selected impacts were:

   Alteration of the structural stability;                        Alteration of the terrestrial fauna abundance
   Increase of the erosion process;                                and composition;
   Alteration of the floristic abundance and                      Potential affectation to the public health;
  composition;                                                     Temporal limitation in the performance of the
   Alteration of the vegetal cover;                                traditional activities;
   Displacement of the terrestrial fauna;                         Disturbance to the local daily life; and
   Alteration of the scenic quality;                              Alteration of archaeological evidences.

According to the criteria for the selection of magnitude values of the mentioned impacts and regarding to the
opinion of experts, the selected environmental and social factors for the analysis were:

     Geology and Geomorphology;                                   Socioeconomical and Sociodemographic; and
     Terrestrial Flora and Fauna;                                 Sociocultural.

The relevant actions of the project related to the selection of impacts and factors were:

     Deforestation and clearing actions;                          Presence of labor force; and
     Air traffic;                                                 Soils movement and leveling       of
     Use of vehicles and heavy equipments;                         surface.
     Installation of gas pipeline and optical fiber;
     Use of power generators;


According to the most relevant environmental and social aspects for the project, the Sensitivity Maps by
Environmental or Social Aspect were developed for the area of the project.

The resulting maps divided the area of the Project, and therefore also the pipeline right of way, in sections or
sectors with 4 categories of sensitivities by factor: Very High, High, Medium, and Low.

The following Sensitivity Maps were developed:

     Erosive Processes Sensitivity Map;                           Social Sensitivity Map; and
     Biological Sensitivity Map;                                  Archaelogical Sensitivity Map.

Afterwards, the calculation of the Significance of the impact by aspect was performed considering, on one side, the
different levels of Sensitivity of each environmental and social factor, and on the other side, the results of the
quantification of the impact magnitude of the selected actions that were previously enumerated.

The Significance is defined as the interaction between the Magnitude of the impact and the Sensitivity, and allows
to know the importance of the impact in each sector of the pipeline, according to the considered aspect and its

The Significance expression is: Significance = Magnitude Value * Sensitivity Value. The Magnitude value of each
considered impact was multiplied by the 4 values of Sensitivity, obtaining a Significance value for each of the
Sensitivity values by factor.

On the other hand, it was developed a general table of Significance values in order to classify the obtained values
into categories. The table was elaborated from the multiplication of the possible Magnitude values (from 11 to 100)
and the possible Sensitivity values by aspect (from 1 to 4). The resultant values were classified in 5 categories (See
next figure).

Table Nº 1: Table of Calculation and Classification of Significance Values

                                SMALL                                                                                      MEDIUM                                                                                                                           LARGE                                                                                                                        CRITICAL
            13   14   15   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39   40   41   42   43   44   45   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60   61   62   63   64   65   66   67   68   69   70   71   72   73   74   75   76   77   78   79   80   81   82   83   84   85   86   87   88   89   90   91   92   93   94   95   96   97   98   99   100

 LOW 1      13   14   15   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39   40   41   42   43   44   45   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60   61   62   63   64   65   66   67   68   69   70   71   72   73   74   75   76   77   78   79   80   81   82   83   84   85   86   87   88   89   90   91   92   93   94   95   96   97   98   99   100

MEDIUM 2    26   28   30   32   34   36   38   40   42   44   46   48   50   52   54   56   58   60   62   64   66   68   70   72   74   76   78   80   82   84   86   88   90   92   94   96   98 100 102 104 106 108 110 112 114 116 118 120 122 124 126 128 130 132 134 136 138 140 142 144 146 148 150 152 154 156 158 160 162 164 166 168 170 172 174 176 178 180 182 184 186 188 190 192 194 196 198                                                     200

 HIGH 3     39   42   45   48   51   54   57   60   63   66   69   72   75   78   81   84   87   90   93   96   99 102 105 108 111 114 117 120 123 126 129 132 135 138 141 144 147 150 153 156 159 162 165 168 171 174 177 180 183 186 189 192 195 198 201 204 207 210 213 216 219 222 225 228 231 234 237 240 243 246 249 252 255 258 261 264 267 270 273 276 279 282 285 288 291 294 297                                                                     300

V. HIGH 4   52   56   60   64   68   72   76   80   84   88   92   96 100 104 108 112 116 120 124 128 132 136 140 144 148 152 156 160 164 168 172 176 180 184 188 192 196 200 204 208 212 216 220 224 228 232 236 240 244 248 252 256 260 264 268 272 276 280 284 288 292 296 300 304 308 312 316 320 324 328 332 336 340 344 348 352 356 360 364 368 372 376 380 384 388 392 396                                                                              400

As a result of the analysis of the Significance, it was possible to obtain tables of Significance for the selected actions,
in the case of more than one impact by factor, the maximum magnitude value obtained was considered.


The Significance values were also represented in Vulnerability Maps by action or group of actions of the project
with similar magnitude of impact, which allows knowing the Significance in each sector of the pipeline according
to the corresponding sensitivity. Those maps were developed by a GIS tool, performing a spatial analysis between
the GIS layer of the pipeline and the sensitivity layers of each aspect. In this way, it was possible to obtain for each
case, a group of pipeline sectors linked with the sensitivity attribute of the area, which was then multiplied by the
magnitude values, obtaining for each sector the Significance of the impact associated to the analyzed factor. The
maximum and minimum values of magnitude of the actions were taken in order to reduce the quantity of maps to
be generated considering the high amount of actions of the project with similar magnitude values.


As final step of the process, within the analysis by aspect, it was performed a description of the Significance of the
impact referring to the result and particularly to the zones and critical points of the pipeline on which specific
prevention and mitigation measures must be applied.

3.7              GENERAL CONCLUSIONS

As final step of the process, a summarized analysis is performed including the actions and aspects that comprise
impacts of greater Significance, mentioning the critical zones of the pipeline in common with all or more than one
of the analysis performed by aspect.
4           RESULTS
Hereafter, a summary of the performed analysis on the Geology and Geomorphology environmental aspect is
presented for the case study. According to the used methodology, the Geology and Geomorphology factor has
been selected as a relevant aspect for the analysis on which the action Deforestation and Clearing produces the
following impacts with greater values of magnitudes:

         Alteration of the Structural Stability (Magnitude -35);
         Increment of the erosive processes (Magnitude -31).


From the Erosive Process Sensitivity Map, the categories of sensitivity and the results of the quantification of the
impact magnitude for the Deforestation and Clearing actions, it was possible to perform the calculation of
Significance for the 4 levels of Sensitivity, obtaining the Significance values and the Vulnerability Map for Erosive
Processes – Deforestation and Clearing Action (See Below).

Table Nº 2: Significance Values for the Deforestation and Clearing Actions

                     Action                                   Significance Value according to Sensitivity level

                                                     Low                  Medium                 High              Very High

        Deforestation and Clearing Action     35 (not significant)        70 (Low)           105 (Medium)         140 (Medium)

It is worth mentioning that given the classification of Significance values, the Magnitude value of the mentioned
action shows values of a medium Significance for sectors with High and Very High Sensitivity.

Figure Nº 1: Erosive Process Sensitivity Map and Erosive Process Vulnerability Map – Deforestation
and Clearing Action


In general terms, it will be performed a deforestation and clearing of the areas destined to the right of way, camps,
soil storage areas, temporal roads access, among other facilities of the project (a total of 198 ha) which could
generate the destabilization of the land in the zones of high slope. Also, the deforestation and clearing actions will
foster the increment of the erosive processes in the slope zones given the lack of vegetation and the foliage
protection. The pipeline will go through sectors with High and Very High Sensitivity of erosive processes. These
zones are, in general, high and medium hills with strong slopes. The high zones were water courses starts are the
zones with higher sensitivity. Although these zones have lithologies of strong cohesion, the combination of the
strong slopes and the high precipitations throughout the year, turn these sectors sensitive to erosive processes. The
sites in which the impacts will have greater significance (medium) correspond to the areas with moderate and
strong slopes to be deforested.

Based on the results of the Significance calculation and its graphics representation through the Erosive Processes
Vulnerability Map - Deforestation and Clearing actions, it was possible to detect that the pipeline generally goes
through zones of Low to Medium Significance considering the impact action of Deforestation and Clearing on the
factor Geology and Geomorphology. It is worth mentioning certain zones of medium Significance in which Very
High to High Sensitivity areas due to erosive process predominate:

       Zone 2: This zone fundamentally comprises an area of Dense and Semi-dense Primary Amazonian Forest,
        with a geomorphology of Very High Sensitivity to erosive process. The following points stand out: H30 and
        H31 that present scarps with signs of landslides with medium Significance values;
       Zone 3: The pipeline goes along the whole longitude of the area zones of Very High Sensitivity to erosive
        processes. Point H08 is a site with two signs of erosion, one of them is very important and partly presents
        non cohesive lithology which is a characteristic of medium Significance;
       Zone 3: This zone has a 2840 m longitude going through a primary forest with a High and Very High
        Sensitivity to erosive processes. The following points represent the medium Significance that dominate the
        zone H07: stream crossing and H06: 60 m hill with a slope of 50%;
       Zone 5: Most part of this trajectory (1206 m) has a High Sensitivity to erosive processes. Points H03, H04
        correspond to the ascents and descents to two order 3 streams, quite sharp with not stable slopes.

The designed methodology has allowed identifying the sectors of the layout with greater Significance that must be
considered in the Environmental Management Plan. The interaction of the results of the analysis performed by
aspects shows that the Deforestation and Clearing action is the one that accumulated the highest Significance
value, presenting the following values according to the considered factor.

       Geology and Geomorphology: Medium;
       Flora and Fauna: High and;
       Socioeconomical and Sociodemographic: High.

On the other hand, it can be noticeable actions that generate disturbance and noises such as: Air Traffic, Vehicle
Use, Heavy Machinery and Equipments, Foreign Presence, Electric Power Generation and Soil Movement and
Leveling. Those actions will produce impacts of Medium Significance on the Biological and Social aspects.

Finally, certain zones of the pipeline right of way with similar levels of Significance for all or more than one of the
analyzed aspects stand out:

       Zone 1: This zone is characterized by sectors with High and Medium Significance for the impacts produced
        on the Biological, Social and Archaeological aspects, given the presence of archaeological sites, fishing
        communities and areas of Very High Biological Sensitivity;
       Zone 2: This zone will be characterized by the potential presence of impacts with high Significance in the
        Geology and Geomorphology, Biological and Social factors, given the High Sensitivity to Erosive Processes,
        the presence of hunting and fishing areas and the High Biological Sensitivity;
       Zone 3 to Zone 6: They are characterized by a Very High Biological and Erosive Process Sensitivity,
        combined with areas of social use for fishing, plant harvest and use as pastureland.
These areas must be considered especially during the application of the Environmental and Social Management
Plan in order to prevent and minimize the identified and quantified impacts.


       D.S. 015-2006-EM - Reglamento para la Protección Ambiental en las Actividades de Hidrocarburos;
       Estudio de Impacto Ambiental Semidetallado del Sistema de Línea de Conducción Cashiriari 2 – Planta de
        Gas Malvinas, Lote 88, Pluspetrol – ERM Perú;
   Evaluación de Impacto Ambiental Gasoducto, Costa Azul – El Florido, Shell - ERM México;
   Metodología de Evaluación de Área de Influencia e Impactos desarrollada por ERM Brasil;
   Evaluación de Impacto Ambiental y Social para la Perforación de Pozos en el Yacimiento Cañadón
    Minerales, OXY – ERM Argentina;
   Estudio de Impacto Ambiental y Social para la Operación del Yacimiento Caimancito, Pluspetrol – ERM
   Lineamientos para el Desarrollo de Evaluaciones de Impactos Ambientales y Sociales, Pluspetrol – ERM
   Asesoramiento para la Gestión Corporativa de la Biodiversidad en Petrobras Energía S.A., ERM Argentina;
   ERM IA Guidance - ERM Approach - 2009 02 09 “ERM Way”, Minerva – ERM IA&P Practice;
   Anexo II Resolución 398 CONAMA - Brasil
   Efectos Ambientales Producidos por la Deforestación y Erosión – Guía Ambiental #5, ARPEL;
   Social Impact Assessment- 2004, IPIECA ;
   Environmental Assessment Sourcebook Volume III - Guidelines for Environmental Assessment of Energy
    and Industry Projects – World Bank Technical Paper Nº 154, World Bank;
   General Environmental Guidelines - 1998, IFC
   Environmental, Health, and Safety Guidelines for Onshore Oil and Gas Development) – 2007. IFC.

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