The impact of land use and land cover changes on the water balance components of Big Creek Lake Watershed South Alabama

Keywords: LULC, DEM, SWAT, SUFI-2
Session Type: Virtual Paper Abstract
Day: Monday
Session Start / End Time: 2/28/2022 03:40 PM (Eastern Time (US & Canada)) - 2/28/2022 05:00 PM (Eastern Time (US & Canada))
Room: Virtual 46

Abstract

The hydrological processes to the changing environment have become a research interest area in the past few decades. The goal of this research is to quantify the changing streamflow and other components with the changes in the land use and land cover (LULC) by applying the Soil and Water Assessment Tool (SWAT) to the Big Creek Lake watershed located in Mobile County, South Alabama. To run the SWAT model, Digital elevation model (DEM), LULC data, weather data, soil data, observed streamflow data were applied. These data were used as inputs to calibrate and validate the SWAT model of the watershed to determine the effects of LULC on streamflow, evaporation, percolation, surface runoff, lateral flow, groundwater, and water yields in the watershed. The Sequential Uncertainty Fitting (SUFI-2) algorithm incorporated in the SWAT Calibration Uncertainties Program (SWAT-CUP) software was applied to calibrate and validate the model. From 1991 and 2020, about 11,045 acres of agricultural land and 3,350 acres of the urban area have been increased and on the other hand, forest area has been decreased by approximately 11,482 acres in the past three decades. The total streamflow has been higher at about 38 m3/s in the LU_2020 scenario than in the LU_1990 scenario. Evaporation and percolation have a growing trend in all the seasons. However, surface runoff and groundwater flow had a decreasing trend and both had a positive relationship with the total streamflow. Higher evaporation and percolation and lower groundwater can be characterized by the increasing agricultural lands over time.