Abstract:
This study assessed the hydrological impacts of LULC changes on water resources in the
Ouriyori basin, Benin. Two LULC data (1988 and 2016) and Soil and Water Assessment Tool
(SWAT) model was used for the hydrological modelling. Sequential uncertainty fitting (SUFI-2)
algorithm in SWAT-CUP has been applied for the model calibration and uncertainty analysis.
Also, daily climate data and streamflow including digital elevation model, soil characteristics
were considered in the model. Climate data for the entire simulation period and the soil datasets
being kept constant, the model was run using the land use maps separately. LULC analysis
showed that cropland and settlement areas have increased, while savanna areas have decreased
from 1988 to 2016. Calibration (2014-2015) and validation (2016-2017) of the simulated
streamflow at the basin outlet were achieved with good performance statistics ranging from 0.67
to 0.89 for the R
2
, NSE, KGE and PBIAS ranged between 8% to 18%. Results also indicated a
decrease in LULC corresponding to an increase in surface runoff followed by a decrease in
evapotranspiration (ET). Thus, identifying appropriate strategies in terms of soil and water
conservation techniques and effort in improving land management practices are recommended.
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