IRRIGATION WATER QUALITY ASSESSMENT OF EXPANDING URBANIZATION IN DISTRICT RAWALPINDI THROUGH GIS MAPPING

Abstract

Pakistan’s irrigation water resources are affected by urbanization. The present study has been conducted for the sake of providing future water policy base which contributes to socio-economic development in country. In most developing countries urbanization is a major trend of 21st century. In recent years, other than urbanization an escalation in population growth has pressurized water resources of world. The present study was undertaken to classify irrigation water suitability for irrigation purposes in tehsil Rawalpindi, Taxila and Gujar khan peri-urban areas of Rawalpindi district. Total 80 water samples were collected through Global positioning System (GPS) to find exact location of samples from three tehsils of Rawalpindi district. Analysis and categorization of samples were conducted based on the suitability criteria of water quality evaluation and Geographic Information System (GIS) are used to record information on to maps. The determinations were cations like Ca+2 + Mg+2 &Na+ and anions such as CO3-2, HCO3- 2 , Cl-. electrical conductivity (EC). Residual sodium carbonates (RSC) and sodium adsorption ratio (SAR). Total 26 samples were collected from tehsil Taxila from which 14 samples were suitable, 8 were marginally suitable and 4 were unsuitable. Whereas 32 samples were collected from tehsil Rawalpindi out of 32 samples 8 were fit 16 were unfit and 8 were marginally fit. While 22 samples were collected from tehsil Gujar Khan from which 4 samples were fit 8 were marginally fit and 18 were found unfit for irrigation purpose. It is concluded that available irrigation water quality is unfit for sustainable soil health and crop production in most of the peri-urban areas.