Population Growth–Land Use/Land Cover Transformations–Water Quality Nexus in Upper Ganga River Basin

Abstract. For sustainable development in a river basin it is crucial to understand population growth–Land Use/Land Cover (LULC) transformations–water quality nexus. This study investigates effects of demographic changes and LULC transformations on surface water quality of Upper Ganga River basin. River gets polluted in both rural and urban area. In rural area, pollution is because of agricultural practices mainly fertilizers, whereas in urban area it is mainly because of domestic and industrial wastes. First, population data was analyzed statistically to study demographic changes in the river basin. LULC change detection was done over the period of February/March 2001 to 2012 [Landsat 7 Enhanced Thematic Mapper (ETM+) data] using remote sensing and Geographical Information System (GIS) techniques. Further, water quality parameters viz. Biological Oxygen Demand (BOD), Dissolve Oxygen (DO) %, Flouride (F), Hardness CaCO 3 , pH, Total Coliform bacteria and Turbidity were studied in basin for pre-monsoon (May), monsoon (July) and Post-monsoon (November) seasons. Non-parametric Mann–Kendall rank test was done on monthly water quality data to study existing trends. Further, Overall Index of Pollution (OIP) developed specifically for Upper Ganga River basin was used for spatio-temporal water quality assessment. From the results, it was observed that population has increased in the river basin. Therefore, significant and characteristic LULC changes are observed in the study area. Water quality degradation has occurred in the river basin consequently the health status of the rivers have also changed from range of acceptable to slightly polluted in urban areas.