Analysis of seasonal variations in the quality of water in a reservoir using GIS techniques

Abstract

This paper analyzes the seasonal behavior of water quality in the reservoir of Rio Hondo (Sali-Dulce river basin, Argentina) using Geographic Information Systems (GIS) interpolation techniques. Due to its geographical location, the water of this lake is influenced by human activities from the upper basin, such as agricultural development, urban and industrial wastewater discharges which vary in intensity depending on the season. In this study the techniques of interpolation IDW (Inverse Distance Weight) and Kriging were applied to values of a water quality index named ICA2. The integrated tool Geostatistics Analyst in ArcGIS 9.2 software was used to check if it is possible to get a proper ICA2 spatial interpolation with the employed methods and which of them would be the best technique to estimate the quality of water. With the observed and interpolated values of ICA2 index, a series of maps were obtained that allow us to conclude that both methods are valid for estimating trends in water quality. However, slightly better results have been obtained with the Kriging method.

Keywords:

• Interpolation
• Water quality index
• Seasonal analysis
• Environmental impact

CE Database subject headings:

• Argentina
• Spatial analysis
• Water quality
• Reservoirs
• Geographic Information Systems