Assessment of groundwater resource utilization in wet and dry zone aquifers in Sri Lanka and quantifying recharge losses due to urbanization and land-use change

Abstract

In Sri Lanka, almost all people have either direct or indirect connection to the groundwater resources. Rapid urbanization, deforestation and land use changes have recently incurred adverse impacts on groundwater recharge, leading to groundwater table decline and drying up of wells. A quantitative analysis of groundwater utilization and recharge loss due to urbanization and subsequent land use change was carried out in this research. Attanagaluoya (Dunamale catchment) and Kirindioyabasin (Thanamalwila catchment) were the study areas selected in wet and dry zones, respectively. The 4-parameter “abcd” monthly water balance model was developed to be compatible with the research objectives based on the gathered and simulated stream flow, groundwater and recharge data and the calibrated and validated model was then used in further analyses and quantitative assessment of recharge loss. The results indicate severe impact on groundwater recharge in dry zone in the future. Further, sustainable groundwater management and proper land use policies to overcome groundwater recharge loss in both wet and dry zones were proposed based on scenario analyses.