Assessing Public Health Risks by the Use of Deterministic Method for Multivariate Interpolation of Physicochemical Characteristics for Assessing Ground Water Quality Index Using Geo-Spatial-Based AHP Technique and Calculating Saturation Index of Alluvial Aquifer of Bahawalpur City, Pakistan

摘要

Bahawalpur is the twelfth biggest metropolitan of Pakistan situated in South Punjab near to the bank of River Sutluj, Pakistan. This study focuses at the physico-chemical properties of drinking water of Bahawalpur which were assessed experimentally. 13 parameters were tested for 40 ground water samples. These parameters incorporate pH, EC, Total Hardness, TDS, Calcium, Magnesium, Carbonates, Bicarbonates, Chloride, Lead, Chromium, Copper and Arsenic. Testing was done for indiscriminate premises. A GPS device (GARMIN GPS) was utilized to gather samples’ geospatial data. The physio-chemical results were compared with the standard values as suggested by the World Health Organization (WHO) and Pakistan Standards and Quality Control Authority (PSQCA) for drinking. Geographic Information System (GIS) was utilized to speak to the spatial conveyance of the parameters and raster maps were made using Inverse Distance Weighted (IDW) Interpolation to classify water quality in different zones. Water Quality Index (WQI) was ascertained using Analytical Hierarchy Process. The results showed that most of the inspected areas were found unsuitable for the drinking purpose. Maximum value for TDS rose to 1904 which represented elevated amount of EC and pH also. Total hardness reached to a maximum of 602.4 mg/L which is the potential indicator of high carbonate and bicarbonate content which in turn represents high positive metallic content ie., calcium and magnesium. Arsenic was found out to be more than permissible limits in most of the samples which is associated with many diseases such as tooth decay, Knee joint pain, kidney problems, skin pigmentation, stomach ulcer and even different types of cancer etc. among the residents of that area. The data for the diseases associated was collected from Bahawal Victoria Hospital and questionnaires being filled by natives Langelier Saturation Index was calculated to observe the corrosivity and scale forming properties of water. Results showed deterioration of piping system of water supply system from commercial to domestic level. These characteristics have direct effect on the architectural structures and also are esthetically unacceptable. Prior to the initiation of the SCARP project in Pakistan before 1990’s, that area was water logged and saline. Due to this potential reason the ground water quality of that area is highly deteriorated. Hence, the water was found out to be unfit for human consumption.