Geomatics for Land use / Land cover and Water Quality changes

Abstract

Water is essential to people and the largest available source of fresh water lies underground. Increased demands for water have stimulated exploration of underground water resources. Water resources get polluted due to rapid industrialization, advancement in agricultural techniques, increasing population and other adverse impacts of environments. All these factors may result in changing the hydrological cycle. The urban environmental quality always depends on the usage of land. The quality of the environment is determined by studying the land use features and their impacts are analyzed. In present study an attempt is made to evaluate the impact of landuse / landcover on ground water quality of Zone VII under Greater Hyderabad Municipal Corporation (GHMC) area. Various thematic maps are prepared from the toposheet on 1:50000 scale using ArcGIS Software. The landuse / landcover map of the study area is prepared from the linearly enhanced fused data of IRS-1D PAN and LISS-III satellite imagery by using Visual Interpretation Techniques. Ground water samples were randomly collected at pre-determined sampling locations based on satellite imagery of the study area. All the samples were analyzed for various physico-chemical parameters adopting standard protocols for the generation of attribute data. Based on the results obtained maps showing spatial distribution of selected water quality parameters are prepared for the study area. The variations in the concentrations of water quality parameters indicated high concentrations of Alkalinity, TDS, Fluoride, Hardness, Nitrates are exceeded the permissible limits while other parameters like Sodium, Sulphate and Chloride were within the permissible limits except in few areas like Golnaka, Imlibun, Kamalanagar etc., which may be attributed to seepage of domestic wastes through open nallahs and industrial wastes. The water quality index (WQI) in the study area is calculated to determine the suitability of ground water for drinking purpose. Different ratings of water quality have been observed which indicated deteriorating quality of ground water. Control and remedial measures for the improvement of ground water quality in the study area are suggested.