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Advancements in GIS and Hydrologic Modeling Adjusting

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Advancements in GIS and Hydrologic Modeling Adjusting Powered By Docstoc
					  Advancements in GIS and Hydrologic
Modeling: Adjusting Measured Flow Data
 from Urbanized Watersheds and a case
        study of the SBC-LTER
February 19, 2002


R. Ed Beighley
Marine Science Institute
University of California, Santa Barbara




                                          http://sbc.lternet.edu/
Research Goal…
 Develop a model to adjust measured
 streamflow data from a watershed
 urbanized during and/or after gauging
 to represent specified fixed land use
 conditions.
Urbanization...
                                                 Baltimore, MD




 Washington D.C.




• USGS Stream Gauge
 1997 MD Dept. of Planning Land Use/Land Cover
Phases of Research…
 Develop high spatial and temporal land
  use data
 Develop relationships between
  measures of urbanization and trends in
  streamflow
 Develop GIS adjustment model
Urbanization Effects…
 Dominant Factors that Cause Peak
  Discharge to Change
    Physical change in land use
         • From What? – To What?
    Spatial arrangement
         • Affects timing/superposition of sub-
           area contributions at gauge
         • Top-Down, Uniform, Bottom-Up
Urbanization Effects…
 Change in Land Use (From What? - To What?)
          B1                           B2
 A1                          A2




1951                          1963

   Qp(A1) > Qp(B1)                Qp(A2)  Qp(B2)
 Increase in Peak Discharge (Qp) from:
    Agriculture to Residential < Forest to Residential
    Qp(A2) - Qp(A1) < Qp(B2) - Qp(B1)
Urbanization Effects…
                     Urbanization Effects
                     •   Impervious Area 
                     •   Infiltration 
                     •   Runoff Volume 
                     •   Time of Concentration 
                     •   Volume and Timing Change
                               Superposition

              Peak Discharge?
          A                        B

                         Or
Urbanization Case Study...
Spatial/Temporal Land Use...



1951 Aerial Photograph



     What Happened
       Between?


1997 MD Dept. of Planning
Spatial/Temporal Land Use...
 GIS Linked Tax Map Data
           - Year Built
           - Land Use
           - Lot Size
Spatial/Temporal Land Use...
                                     Temporal Change in Land Use Distribution
                   80%
                                       Agricultural      Residential          Urban
                                       Forested          Commercial
                   70%


                   60%
Percent Land Use




                                                               1997 MD Dept. of Planning
                   50%
                                                               Reference Points
                         1951 Aerial Photograph
                   40%
                         Reference Points

                   30%


                   20%


                   10%
                                                             White Marsh, Maryland
                   0%
                     1950    1955    1960     1965    1970    1975     1980     1985   1990   1995   2000
Measures of Urbanization...
 Measures used to infer trends in discharge
   Loss of Forested Land (- 5%)
   High-Density Development (+ 5%)
   Overall Urbanization (+ 10%)
Measured Precipitation...
                                     Spatial Variability of Measured Precipitation near the Watts Branch
                                                  Streamflow Gauge at Rockville, Maryland
                              15.0                                                                       10,000
                                        Rockville, 187705
                                        Potomac, 187272
                              12.5      Brighton Dam, 181125
Measured Precipitation (cm)




                                                                                                                  Measured Discharge (m 3/s)
                                        Boyds, 181032
                                        Laurel, 185111
                              10.0      Damascus, 182335
                                        Watts Branch Discharge

                               7.5                                                                       1,000



                               5.0



                               2.5



                               0.0                                                                       100
                                          Mar-1977             Jul-1978        Aug-1979       Oct-1980

                                                            Annual Maximum Discharge Events
GIS Adjustment Procedure…
Historical Land Use Conditions:   Design Storm: Fixed Distribution
      CN(x,t) and Imp(x,t)         and Varying Magnitude (PS(t))




Hydrologic Model                        Adjust Magnitude of PS(t)

                                              No

 Simulated Peak                     Does Simulated = Measured
 Discharge (Qs(t))                 Peak Discharge (Qs(t) = Qp(t))?

                                             Yes       Move to
                                                      Adjustment
                                                      Procedure
GIS Adjustment Procedure…

    …         Design Storm: PS(t) Calibrated with Measured
               Annual Maximum Discharge Series (QP(t))




  Fixed Land Use:               Hydrologic
CN(x,tA) and Imp(x,tA)            Model




                         Adjusted Annual Maximum
                          Discharge Series (QA(t))
                      GIS Adjustment Procedure…
                                      1000    Measured and GIS Adjusted Annual Maximum Discharges
                     1000                                                                           1000
                                                  Watts Branch at Rockville, MD                            White Marsh Run at White Marsh, MD



                      100 100
Discharge, (m 3/s)




                                                                                                     100
                       Discharge, (m 3/s)




                       10                    10                                                       10


                                                         Increase in Urbanization
                                                           57% Onset to current                                Increase in Urbanization
                                                           45% During gauging                                    39% During gauging
                         1                                                                             1
                         19551 1960                    1965    1970   1975    1980   1985    1990      1960 1965 1970 1975 1980 1985 1990 1995 2000
                              1955                            1960           1965           1970          1975       1980       1985      1990
                                                              Time (Years)                                              Time (Years)
                                                                                              Time (Years)

                                            Q p (t ), Varying Land Use       Q a (t ), Yr-2000 Land Use         Observed Signal        2000 Signal
                   GIS Adjustment Procedure…
                           Measured and GIS Adjusted Flood Frequency Distributions
                   1,000                                                              1,000
                            Watts Branch at Rockville, MD                                          White Marsh Run at
                                                                                                    White Marsh, MD

                            Development Pattern:                                              Development Pattern:
                    100          Top-Down                                              100      Middle/Uniform
Discharge (m3/s)




                                                                   Discharge (m3/s)
                                                                                                            2-yr Flood  12%
                                                                                                           + 4.0 m3/s (150 cfs)
                     10                     2-yr Flood  65%                            10
                                          + 12.4 m3/s (440 cfs)

                                  Increase in Urbanization
                                    57% Onset to current                                         Increase in Urbanization
                                    45% During gauging                                             39% During gauging
                      1                                                                  1
                            1               2        10     100                               1              2       10      100

                                  Return Period (Years)                                            Return Period (Years)
                       1,000
                                      Based on GIS Adjusted Discharges for Year-2000 Land Use Conditions

                                      Based on Measured Discharges with Varying Land Use Conditions
Conclusions (Part 1)...
 Spatial and temporal aspects of urbanization
  are incorporated in GIS adjustment method
 GIS Adjusted discharges are representative
  of a fixed land use conditions
 Failure to adjust discharges from urbanized
  watersheds can result in under estimating
  design floods
SBC – LTER Study Region...

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 Arroyo Hondo                         Arroyo Burro
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                 Refugio                                                                    #


                 El Capitan                Mission                                                  #
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                                                  Santa Monica                                                      #
                                                       Franklin
                                                                                            Rincon
                                                    Carpinteria                                                                     #




   N

                                                                               10          0                    10 Kilometers
Hydrologic Modeling…
 Compile/Develop Spatial Data
    Topography (DEM)
    Drainage Network (Stream and Drains)
    Soil Survey Geographic (SSURGO) Database
    Land Use (Digital Images and Parcels)
 Develop Model Framework (schematic)
    Sub-divide watershed
    Determine spatially averaged parameters
 Estimate Rainfall Coverage
    Rain Gauge Network
    Orographic Enhancement
Drainage Network...
                      Mission Creek Watershed
                          @ Montecito St.
                        SBC-LTER ID: MC00




                  N
                      1   0   1 Kilometers
Drainage Network...
                      Mission Creek Watershed
                          @ Montecito St.
                        SBC-LTER ID: MC00


                      Digital Elevation Model




                  N
                      1    0   1 Kilometers
Drainage Network...
                      Mission Creek Watershed
                          @ Montecito St.
                        SBC-LTER ID: MC00


                      Digital Elevation Model
                      Digitized Streams (NHD)




                  N
                      1    0   1 Kilometers
Drainage Network...
                      Mission Creek Watershed
                          @ Montecito St.
                        SBC-LTER ID: MC00


                      Digital Elevation Model
                      Digitized Streams (NHD)
                      Digitized Storm Sewers




                  N
                      1    0   1 Kilometers
Drainage Network...
                      Mission Creek Watershed
                          @ Montecito St.
                        SBC-LTER ID: MC00


                      Digital Elevation Model
                      Digitized Streams (NHD)
                      Digitized Storm Sewers
                      Inferred Drainage Network
                      and Watershed Boundary

                  N
                      1    0   1 Kilometers
Soil Properties...
                         Mission Creek Watershed
                             @ Montecito St.
                           SBC-LTER ID: MC00


                         SSURGO Soils Properties
                         Soils texture (clay, loam)
                         Permeability
                         Depth*




                     N
                         1   0    1 Kilometers
Soil Properties...
                         Mission Creek Watershed
                             @ Montecito St.
                           SBC-LTER ID: MC00


                         SSURGO Soils Properties
                         Soils texture (clay, loam)
                         Permeability
                         Depth*
                         Shallow Soils over Bedrock
                         0 - 1.5 meters


                     N
                         1   0    1 Kilometers
Land Use Information...
                      Mission Creek Watershed
                          @ Montecito St.
                        SBC-LTER ID: MC00

                      Generalized Land Use
                          Residential
                          Commercial/Industrial
                          Infrastructure
                          Mixed Urban
                          Agriculture
                          Shrub/Brush
                          Forest
                          Riparian




                  N
                      1     0     1 Kilometers
Land Use Information...
                      Mission Creek Watershed
                          @ Montecito St.
                        SBC-LTER ID: MC00



                      City and County Zoning
                          Res. Low Density
                          Res. Medium Density
                          Res. High Density
                          Commercial
                          Agriculture
                          Recreation
                          Open Lands

                  N
                      1    0    1 Kilometers
High-Resolution Land Use...
                               Santa Barbara City
                             Parcel Boundaries and
                              Zoning Information

                            Low Density
                            Residential


                             “IMPERVIOUS AREA”



                            Medium Density
                            Residential
 0.1   0   0.1 Kilometers
Model Schematic...
                            Mission Creek Watershed
                                @ Montecito St.
                              SBC-LTER ID: MC00

                            Sub-Divisions:
                            Similar Hydrologic Properties
                    %
            %               SBC-LTER Sample Sites

        %



    %


                        N
                            1   0   1 Kilometers
                %
Rainfall Coverage…
                        40
                                   Ridge                                  Gauge EL
                                                 Water Year 2001                                   #

                        35         Coast                                   1000 m

                                                                                                                #
                        30
Monthly Rainfall (cm)




                                                                               #                        #
                        25                                                                                  #




                        20
                                                                                     #

                        15                                                                     #         Gauge
                                                                                                        EL 30 m
                        10


                        5


                        0
                             Sep     Oct   Nov   Dec   Jan   Feb   Mar   Apr   May       Jun           Jul          Aug
Orographic Enhancement…
 Precipitation distributed to each pixel, Pi, by:


                                                m

  P    i
            a E i  b Ai  c   ek w k
                                               k 1

  where a, b and c are storm specific regression coefficients; Ei
  and Ai are elevation and aspect, respectively; ei is the
  regression residual at gauge k; wi is the inverse-distance-
  squared weight for gauge k; and m is the number of gauges
  used in the weighting procedure (Taschner et al, 2001).
HEC-HMS Model...


  Sub-Basin Properties:     Junctions:
    Drainage Area              Flow Connections
    Flow Length
    Roughness
    Slope
                            Channel Properties:
    - Rain Gauge Wts.
                              Cross-Sect. Shape
                              Length
                              Roughness
                              Slope



                            SBC-LTER Sample Site, MC00,
                            Mission Cr. @ Montecito St.
                            Outlet
  HEC-HMS Model Schematic
Hydrologic Model…
 HEC-HMS Model
    Spatially averaged parameters
    Event based
 Surface Response
    Impervious surfaces
    Infiltration excess (after initial losses)
 Subsurface Response
    Rapid shallow soil flow (interflow)
    Slower groundwater discharge (baseflow)
 Flow Routing
    Overland
    Channel
HEC-HMS Model Results...
                       Mission Creek at Mission St.
                       USGS Gauge No. 11119745
                              Jan 10-12, 2001

                HEC-HMS Simulation


                     Initial Conditions: Dry
                  Storm Rainfall  15 cm (6 in)




            USGS Gauge Data
HEC-HMS Model Results...
                            Mission Creek at Mission St.
                            USGS Gauge No. 11119745
                                 March 4-7, 2001

                     Initial Conditions: Wet
                 Storm Rainfall  19 cm (7.5 in)
                                HEC-HMS Simulation




          USGS Gauge Data
Hydrologic Modeling…
 Few Storm Events Dominate
   Storm flow volume 90% of annual discharge
   Storm flow occurs 10% of the year
   Runoff-Rainfall ratio  25%
   Mar 4-7, 2001 event  60% of annual Q
Future Modeling…                                                            P    Conceptual Model
 Reservoir Model w/ Source-to-Sink Routing                                                ET
                                                                           I                           Surface
    Spatially distributed
    Efficient computations                                               Storage (t, Min, Max)
                                                                                                       Rapid Subsurface
    Few model coefficients                                                 R
                                                                                                       (Steep-shallow
                                                                                                  ET   soils over rock)
    Enhanced linkage between data & models
    Applicable for large scale modeling efforts                          Storage (t, Min, Max)

                                                                                                       Groundwater
 Response shape based on spatially distributed:
 flow velocities; attenuation coefficients; and
 loss parameters
                                                                                         Surface Runoff
                                      Source A                                           Rapid Interflow
                                                                                         Groundwater




                                                              Discharge
                                                                                         Source A Hydrograph



                                            Flowpath:
                                         Source A to Outlet


                                     Outlet Discharge from Source A                         Time
Hydrograph Separation...
              400                                                                                    25
                        Mission Creek at Montecito St.
              350

                                                                                                     20
              300
                                                                              Silica




                                                                                                          Discharge (m3/s)
              250                                                             Stream Discharge
                                                                                                     15
Silica (µM)




              200                                            Hydrograph Components:
                                                              Overland (CO; QO)
                                                                                                     10
              150                                             Shallow Soil (CS; QS)
                                                              Ground Water (CGW; QGW)
              100
                                                   3-Component Mixing Model                          5

               50
                                            C  C Q  C Q  C Q /Q
                                             T           O   O        S   S       GW    GW       T

                0                                                                                    0
                3-Mar      4-Mar    5-Mar        6-Mar        7-Mar       8-Mar        9-Mar     10-Mar
Water Quality Modeling...
               140                                                               14

                                         Mission Creek at Montecito St.
               120                                                               12



               100                                                 Stream Flow   10
                                                                   NO3




                                                                                      NH4 or PO4 (µM)
                                                                   NH4
Nitrate (µM)




                80                                                 PO4           8



                60                                                               6



                40                                                               4



                20                                                               2



                 0                                                               0
                 3-Mar   4-Mar   5-Mar   6-Mar   7-Mar    8-Mar     9-Mar    10-Mar

				
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