Simulating and Forecasting of Soil Moisture Content Variability Over Ogbomoso Agricultural Watershed Using the SWAT Model

Soil moisture has been recognised as an essential climate and hydrological variable that controls land surface processes. In this study, the soil moisture content within the Ogbomoso watershed, Nigeria was simulated for a 34-year period using the hydrological model, Soil Water Assessment Tool (SWAT). The model was also used to predict soil moisture for a period of 20 years. The SWAT model was calibrated and validated using observed soil moisture. The calibrated SWAT model performed well for the simulation of daily soil moisture. Statistical model performance measures, coefficient of determination (R2) of 0.91, Nash-Sutcliffe efficiency (ENS) of 0.64 and percentage difference of (D) of 13% for calibration and 0.88, 0.84 and 8% respectively for validation indicating good performance of the model simulations. The soil moisture simulated by SWAT showed a generally decreasing trend from 1984 to 2017. The 20 year predicted soil moisture by SWAT also showed a slightly decreasing trend from 2018 to 2037 which may have negative implications for crop yield. The variability in both the simulated and predicted soil moistures generally respond to precipitation decreasing and temperature rising in the region. The results suggest that SWAT model can reasonably simulate and forecast the spatiotemporal variation and trend of the soil moisture in the area. Therefore, the SWAT model may become a good tool to study the regional hydrological variations and the interaction between the land and atmosphere. The result of this study could provide essential resource information for watershed managers.

Author Information
Olukunle Olaonipekun Oladapo, Ladoke Akintola University of Technology, Nigeria
Leonard Kofitse Amekudzi, Kwame Nkrumah University of Science and Technology, Ghana
Olatunde Micheal Oni, Ladoke Akintola University of Technology, Nigeria
Abraham Adewale Aremu, Ladoke Akintola University of Science and Technology, Nigeria
Marian Akwasi Osei, Kwame Nkrumah University of Science and Technology, Ghana

Paper Information
Conference: ECSEE2018
Stream: Environmental Sustainability & Environmental Management: Land Use & Misuse

This paper is part of the ECSEE2018 Conference Proceedings (View)
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