DEVELOPMENT OF WATER MANAGEMENT STRATEGIES IN ARID REGION OF PUNJAB PAKISTAN

Development of different strategies for sustainable water management is very important in arid region of Punjab - Pakistan having 280km2 area. In this researeh, water budget is estimated using the hydrologie water balanee equation in Bahawalpur district in Punjab. Initially, landcover of the study area is determined using the Geographic Information System (GIS) and remote sensing. Due to excess rainfall and mostly grown crop in the study area, 4 scenarios were made, (1) 70% of sugarcane area is changed into wheat (2) 70% of sugarcane area is changed into wheat and cotton (3) 50% of sugarcane is changed into orchard (citrus) and 30% of sugarcane is changed into wheat (4) Construction of artificial ponds for storage of excess rainfall. Observed evapotranspiration is estimated using the Cropwat model, which is changed into the potential evapotranspiration for all the scenarios. Average annual rainfall in 2015 was 511.3mm in 51 events, with evapotranspiration of 4.29mm/day resulting in 366.34mm excess water. For estimation of precipitation recharge, runoff is estimated using the Hydrological Engineering Center - Hydrologieal Modelling System (HEC -HMS). The model was ealibrated and validated for year 1996 and 1997 respectively, and runoff was estimated from 1998 to 2015. Strcamflow (3L and 4L distributaries) rceharge is estimated by using the average hydraulic conductivity value and interpolated on total length of distributaries. Groundwater recharge is estimated by adding precipitation recharge and stream flow recharge. Data of total number of pumping wells is taken from Agricultural Department, Punjab. Total groundwater pumpage is estimated for pumping rate of each well. Water budget for all 3 scenarios is estimated by subtracting groundwater recharge to groundwater pumpage. Actual groundwater levels were measured in the study area. Water budget is compared with the actual groundwater levels which show that our calculations are correct. Result shows that 102,575,200m3 of water can be saved annually for an area of 280km2. This study also concluded that annual average water deficit is -2.138m, -2.117m, -2.128m and -2.064m for actual condition, scenario 1, scenario 2 and scenario 3 respectively. For rainwater storage, about 7,000 artificial ponds can be constructed having capacity of 15,000m3. This water will not only cover the irrigation requirement but also decrease the threat to groundwater depletion. If these ponds are not constructed, then scenario 3 has t