Estimating Pollutant Loads Caroni River Bolivar, Venezuela

1
Estimating Pollutant Loads Caroni RiverBolivar,
Venezuela

• Global Applications of GIS Technology
• Lee Sherman

2
Location

• Rio Caroni is in Southeast Venezuela in the State
  of Bolivar. Focus is the segment which flows
  between Guri Lake and the Orinoco River.

3
Objectives

• Three main objectives
• Estimate pollutant loads (sediment and nutrients)
  to the river segment in question.
• Incorporate load estimations into a Water Quality
  Model (WASP) to predict water quality downstream.
• Recommend improvements.
• The idea is to predict the impact of the Lower
  Caroni Development program on water quality.
• My focus is on estimating pollutant loads the
  rest will be done by Miguel Acevedo at UNT.

4
Interesting aspects of this project

• Exploring the versatility and limitations of GIS
  technology
• Is GIS only as useful as the quality of data we
  are working with?
• LIDAR vs. GTOPO30
• Working with global data is exciting
• What kinds of global data are available?
• How useful are they?

5
Approach

• Delineate watersheds for streams contributing to
  the river segment
• Define hydrologic properties for each watershed
  (area, time of concentration, runoff coefficient
  or curve number)
• Obtain precipitation data for region and compute
  runoff flow
• Assign Expected Mean Concentrations based on land
  use
• Compute mean annual loads W QC

6
Data received from Dr. Acevedo includes

• Hydrography
• Land Use
• Soils
• Vegetation
• Water Body Extents
• Population
• Roads, Other

7
Challenges immediately evident

• No elevation data!
• Watershed delineation?
• Dataset complete for only one segment!
• Files and Attributes in Spanish!
• No hablo español!
• Unknown Coordinate System!
• How will I project?

8
GTOPO30 Data

• 1-KM DEM
• LZW Licensing?
• Converted to grid with Arcinfo using Imagegrid
  command
• Overlayed countries layer from HW 3 (geographic
  coordinates)
• Trial and error projecting

9
HYDRO1K Data

• Result of processing global DEM
• Hydrography Basins more available
• Used Arctoolbox to import these interchange
  (.eoo) files Conversion Tools/ Import to
  Coverage
• Projected to match data
• Resolution is too low for objectives
• Back to the drawing board

10
Next steps

• Use hydrography and GIS to estimate watershed
  areas (or obtain other source of elevation data
  i.e. topographic maps)
• Assign hydrologic properties to areas
• Obtain precipitation data and compute flows
• Use land use data to assign expected mean
  concentrations
• Estimate average loads

11
Conclusions

• Working with limited data is extremely
  challenging
• Global data is very useful for large-scale
  applications but was too coarse for my needs.
• GIS will still be a useful tool in terms of
  computing hydrologic parameters, areas, EMCs,
  etc.

12
Questions?