Assessment of Shallow Groundwater Quality in Zhengzhou Area Using Remote Sensing and GIS

Abstract

The quality of groundwater in Zhengzhou area is important as many individuals depend on groundwater for drinking. A study on shallow groundwater quality assessment in Zhengzhou area, China has been done using Remote Sensing and Geographic Information System (GIS) techniques. The land use/cover classification system and remote image interpretation of characteristics were established in this process. Land types were divided into six categories: water resources, forest land, grass land, barren land, Residential areas, and crop land. Water Quality Index was also calculated for sixty three well samples in the study area to evaluate the suitability of water for human consumption. The results show that the grass land is the greatest proportion of land use/cover in the study area (37.59%), the residential area comprises 13.52%, the area of crop land occupies 22.54%, and the barren land occupies 21.81%. Water Quality Index (WQI) values revealed that the groundwater at twelve locations of the study area are Excellent quality. Twenty wells are V. good quality, and fourteen wells are Good quality, therefore can be exploited safely for human consumption. Six well samples are Fair quality, nine samples are Marginal quality, and two samples are Poor (unfit). The correlation of land use/cover with water quality indicate that the extent of water quality deterioration has a positive linear correlation with the total area of residential and crop land and a negative linear correlation with barren land areas. The analysis of the results revealed that Remote Sensing and GIS are effective tools for assessing and quantifying the impact of land use/cover on groundwater quality. Overlaying the spatial distribution of water quality on Satellite imagery is a very authenticated concept to identify the water quality problems and to correlate them with the land use/cover to interpret the reasons for deterioration of environmental quality.