Estimation of Runoff

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Estimation of Runoff nonpoint source pollution
using GIS techniques
By
Abedalrazq Khalil
Utah State University
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Estimation of Runoff and nonpoint source
pollution using GIS techniques
Introduction

• NPS pollutants are spread over broad areas
  encompassing hundreds, thousands or even millions
  of hectares of soil millions of liters of water
  and/or millions of cubic meters of air.
  Characteristically, NPS pollutants are
  ubiquitous, but are generally low in
  concentration consequently, their impact upon
  human health, plants and animals is chronic in
  nature.
• The ability to model NPS pollutants provides an
  assessment tool for optimizing the utility of the
  environment by sustaining its use with minimal
  detrimental consequences.
• GIS serves as a means of storing, manipulating
  and displaying the tremendous volumes of spatial
  data associated with NPS pollutants.

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Estimation of Runoff and nonpoint source
pollution using GIS techniques
Objective

• Both nitrogen (N) and phosphorus (P) have been
  identified as having water quality impacts in
  certain regions where concentrations become too
  high for the ecosystems in which they are found.
• The objectives of this study are to estimate the
  relationships between total phosphorus and total
  nitrogen concentrations and the relationships
  between these parameters and the land-use. The
  study area is the Snake River Basin in Idaho.

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Estimation of Runoff and nonpoint source
pollution using GIS techniques
Methodology
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Estimation of Runoff and nonpoint source
pollution using GIS techniques
Counties of Basin
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Estimation of Runoff and nonpoint source
pollution using GIS techniques
Snake River
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Estimation of Runoff and nonpoint source
pollution using GIS techniques
APPROACH ?

• Once the data layers were added to the GIS, some
  tabular manipulation was necessary in order to
  prepare it for use with the ArcGIS, e.g. the
  landuse classification tables, hydrologic soil
  group data.

Map Shows Landuse distribution.
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Estimation of Runoff and nonpoint source
pollution using GIS techniques
curve number distribution.
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Estimation of Runoff and nonpoint source
pollution using GIS techniques
Map shows runoff depth distribution in cm.
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Estimation of Runoff and nonpoint source
pollution using GIS techniques
Runoff volume grids were calculated using the
runoff depth grids, and land use/soil index , and
the curve number using this equation

The estimated average annual runoff depth and
volumes are greatest in the cities. This is
because of the impervious nature of an urban
landscape due to concrete, pavement, and density
of buildings. The areas with lowest runoff depth
are located near the rivers and streams. These
are the lowest elevation areas and are also the
outlets of the watershed.  The runoff depth in
the agricultural areas is medium to low. 
Map shows Runoff Volume in m3.
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Estimation of Runoff and nonpoint source
pollution using GIS techniques
The expected mean concentration (EMC) of nitrogen
and phosphorus which depend on the each land use
are entered to tables.
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Estimation of Runoff and nonpoint source
pollution using GIS techniques
Finally, NPS pollutant loading grids were
generated via the runoff volume grids. Union the
Landuse them and the Runoff Volume theme
multiply Runoff volume times the expected values
of P and N for each land use.

Nitrogen Load (Kg/ha/year)
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Estimation of Runoff and nonpoint source
pollution using GIS techniques
Phosphorus Load (Kg./ha/Year)
It is shown clearly on these maps that lead
pollution potential is greater in the city than
in the agricultural areas. The areas of greatest
risk are the commercial, industrial, and the
high-density residential areas. Phosphorus is
often more problematic in an urban setting.

• The final step was preparation of the data for
  presentation.

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Projection North American Datum of 1927 Clarke
1866 Data Sources Idaho Department of Water
Resources, Version of June 8, 1994
URLhttp//www.idwr.state.id.us/gisdata/
Date November 10,2002 Cartographer Abedalrazq
F. Khalil
Estimation of Runoff and nonpoint source
pollutants loads
The estimated average annual runoff depth and
volumes are greatest in the cities. This is
because of the impervious nature of an urban
landscape due to concrete, pavement, and density
of buildings. The areas with lowest runoff depth
are located near the rivers and streams. These
are the lowest elevation areas and are also the
outlets of the watershed.  The runoff depth in
the agricultural areas is medium to low. 
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Estimation of Runoff and nonpoint source
pollution using GIS techniques
Conclusions
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Cont. Conclusions

• The study confirmed that the presence of
  phosphorus in a stream necessitates the presence
  of nitrate and vise versa.
• The results of the study will be useful in
  developing and calculating the water quality
  indexes, which require information about several
  water quality parameters that may not be
  available for many watersheds.
• These types of results can be very useful to
  raise awareness of the potential long-term
  effects of land use changes within a watershed.

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Estimation of Runoff and nonpoint source
pollution using GIS techniques
RECOMMENDATIONS
THANKS