Modeling the Effect of Climate Change on Water Stored above a Micro-Dam in an Inland Valley Swamp in Sierra Leone, Using SWAT

Abstract

Many societies have experienced water scarcity resulting from population growth, increased urbanization and industrialization, increased irrigation associated with advances in agriculture productivity, desertification, global warming, or poor water quality. Climate change, and soil heterogeneity has a direct impact on the discharges of many rivers in and around the world. Various hydrological models have been used to characterize the impact of climate and soil properties on hydrology and water resources. The SWAT (Soil and Water Assessment Tool) water balance model, one such model, has been used at a variety of scales. In this instance it was used to model the impact of climate change on water storage in a reservoir at the downstream end of a small (75 ha) watershed. The watershed is the major component of an inland valley swamp, with a valley bottom that receives runoff from the watershed. The SWAT model was calibrated using storage data from 2014/15 and validated with data from 2015/16. Using future ensemble values derived from GCMs, the model predicted a reduction in the storage volume at the beginning of December of every dry season, with the 100-year storage volume down from 10,000 to 6900 cubic meters.