Groundwater investigation of district Mianwali (Thal Doab) using electrical resistivity method (T-1460) (MFN 3329)

Abstract

Thal Doab of Pakistan is facing the problem of increase in population at alarming rate, which needs more water and food. Therefore, irrigation needs to be expanded in this area to meet all the basic requirements. For this purpose exploitation of groundwater is required in upper Thal doab, particularly in Mianwali. Investigations of geology, ydrology and soil were carried out in Punjab Plains of Pakistan. These investigations became necessary due to present demand of water for irrigation. District Mianwali is facing water logging and salinity problems. To acquire water quality data of Mianwal five wells were drilled (TH-01, TH-02, TH-06, TH-08, and TH-11) based on 86 electrical resistivity probes. The study is carried out to find the quality of groundwater of District Mianwali. Water in most of area is saline and not usable for drinking and irrigation purpose. However; some patches and lenses of freshwater are available in project area. For groundwater assessment potential electrical resistivity is carried out in Mianwali district at regular gird of 5 x 5Km. The electrical resistivity survey is supported by well drilling at 20 x 20Km grid. Soil and water samples are collected at vertical interval of 3 meters and analyzed in laboratory. Correlation of electrical resistivity models with well drilling were carried out for record accuracy. Water quality mapping (based on electrical resistivity and well data) was carried out at different horizons of 50m depth by using GIS techniques. The water quality samples were nalyzed using Aqua-Chem Software. Four water quality zones up to the depth of 300 meters were mapped groundwater at six vertical horizons with interval of 50m. Specific yield and retention was calculated for future utilization of groundwater.