Spatiotemporal analysis of drought and flood hazards in the teff-growing areas, East Shewa Zone, Central Ethiopia
摘要
Climate change is intensifying extreme weather events, posing major threats to rainfed agriculture in Ethiopia. This study aimed to analyze the spatiotemporal pattern of drought and flood susceptibility in the teff-growing districts of the East Shewa zone, Ethiopia. Drought was quantified using the Standard Precipitation Index (SPI) for temporal scales of 1, 3, and 6 months from 1990 to 2024, while drought trends were examined using the Mann-Kendall test and Sen’s slope estimator. Temporal flood data from 2014 to 2024 were mapped using Sentinel-1 Synthetic Aperture Radar within the Google Earth Engine platform, and spatial flood was assessed using a GIS-based Analytic Hierarchy Process (AHP). The results revealed drought variability, with Bora experiencing more frequent and severe drought events than Adea. Trend analysis indicated a significant increase in drought in Bora, particularly at the 3-month scale, whereas Adea showed a decreasing drought trend at the 6-month scale. In Adea, the highest recorded flood extent was 117.8 km2 in 2016. Bora’s flood extent was 199.4 km2 in 2016, followed by 193.5 km2 in 2018 and 173.9 km2 in 2017. Spatial flood hazard shows that Adea had moderate flood hazards (58.99%), while Bora had high flood hazards (64.58%). The study contributes to meteorological drought intervention in Adea during the Belg and early Kiremt, and Bora during the Belg and Thedey seasons. It also addresses floods risk management, through improved drainage and early warning in both districts. Additionally, for climate-resilient agriculture, we recommend optimizing planting schedules, irrigation, and improved crop varieties for farmers.