Leveraging Earth Observation and Geomatics for Flood Adaptation and Best Management Practices in a Data Scarce West African Basin
- Paper number
IAC-20,B5,2,13,x55588
- Author
Dr. Olabanji Aladejana, Nigeria
- Year
2020
- Abstract
Availability of information is essential for adequate adaptation and adoption of best management practices for flood disasters. However, a large portion of West Africa basins, such as the North West Benin Owena River Basin (NWBORB) in Nigeria experiences paucity of in-situ data, resulting from inadequate hydrometric infrastructure. Open access, satellite-based gridded precipitation, and temperature data at defined spatiotemporal resolutions provides complementary data required to substitute for substantial spatiotemporal gaps in ground measurements. This paper adopts the use of two open-access precipitation and temperature datasets respectively - TRMM (Tropical Rainfall Measuring Mission), and ECMWF (European Centre for Medium-Range Weather Forecasts). These datasets were employed to drive the Soil and Water Assessment Tool (SWAT) model of the basin, simulate the daily runoff per sub-basin for the flooded the year 2015, and the hydrologic response of each of its five sub-basin towards precipitation events. Furthermore, three Best Management Practices (contour farming, terracing and check dams were selected to test their effectiveness in reducing excess runoff and floods after precipitation events. R2, ENS, and PBIAS values of 0.86, 0.82, 1.6; and 0.89, 0.84, 0.9 were obtained for model calibration and validation respectively. The rainfall-runoff hydrograph for the five sub-basins of the NWBORB showed that runoff peaks closely follows rainfall peaks over the river basin. Contour farming, terraces, and check dams presented a runoff decrease of 12.06%, 21.06% and 10.05%, showing their ability to reduce excess runoff and floods after precipitation within the basin significantly. The results suggests that open-access earth observation data is a promising and complementary alternative to aid in-depth flood investigation and mitigation in in-situ data scarce West African basins.
- Abstract document
- Manuscript document
(absent)