Drought Event Analysis and Projection of Future Precipitation Scenario in Abaya Chamo Sub-Basin, Ethiopia

Abstract

Monthly observed and future precipitation magnitudes were subjected to statistical trend analysis to examine possible time series behavior. Future precipitation was downscaled from large-scale output through statistical downscaling. The observed and downscaled future precipitation was analyzed for drought events using the Standardized Precipitation Index (SPI) method. In the Abaya Chamo sub-basin, Ethiopia precipitation is explained by below average magnitudes in most of the low land area, characterized by moderate to extreme drought episodes. Nine drought events were discerned during the period of 1988 to 2015, i.e. once in three years, resulting in harvest failure and subsequent food insecurity. The NCEP-NCAR and CanESM2 model predictors were used to statistically downscale the precipitation data. The monthly observed and downscaled precipitation magnitudes were in good agreement. The RCP-2.6, RCP-4.5 and RCP-8.5 long-term future scenarios were computed to evaluate future drought patterns. The mean annual precipitation scenario decreased by 0.2% to 13.7%, 0.5% to 6.4% and 0.1% to 1.3% for the period from 2016 to 2040, 2050s and 2080s respectively. The increase in mean precipitation was projected to be 0.7% to 12.2%, 0.2% to 11.7% and 0.1% to 17.8% for the period from 2016 to 2040, 2050s and 2080s respectively. The present analysis may provide useful information associated to drought events to decision makers and can be used as a basis for future research in this area.

Implications of changes in land use for ecosystem service values of two highly eroded watersheds in Lake Abaya Chamo sub-basin, Ethiopia

“…Interlinked social, economic, and environmental factors are driving a significant change in LULC in Ethiopia, and these changes are causing considerable losses in ecosystem services (Tolessa et al 2021;Biratu et al 2022). As in other parts of Ethiopia, the current study area, the Lake Abaya-Chamo sub-basin of the Ethiopian Rift Valley is undergoing considerable LULC change (Wolde Yohannes et al 2018;Gebeyehu et al 2019), and these changes could result in reductions in ESVs and adversely affect livelihoods (Markos et al 2018;Temesgen et al 2018).…”

Spatial patterns and temporal dynamics of drought in southern Ethiopia from 1981 to 2100

“…There are few studies that focus mainly on watershed level within Ethiopia (Abrha & Hagos, 2019; Awetu & Kenea, 2023; Gari et al, 2018; Gebeyehu et al, 2019; Orke & Li, 2022; Yisehak et al, 2021). Most subnational research has concentrated on the northern and central regions of the nation except very few studies (e.g., Gebeyehu et al (2019) and Orke and Li (2022)). However, these studies employed fewer climate models, smaller watersheds, or shorter observational data periods.…”

“…Numerous studies have evaluated extreme events at the global and regional scales under the present and predicted future climatic conditions (Abiodun et al, 2020; Dufera et al, 2023; Haile, Tang, Hosseini‐Moghari, et al, 2020; Nguvava et al, 2019; Ogega et al, 2020; Onyutha, 2020; Osima et al, 2018). There are few studies that focus mainly on watershed level within Ethiopia (Abrha & Hagos, 2019; Awetu & Kenea, 2023; Gari et al, 2018; Gebeyehu et al, 2019; Orke & Li, 2022; Yisehak et al, 2021). Most subnational research has concentrated on the northern and central regions of the nation except very few studies (e.g., Gebeyehu et al (2019) and Orke and Li (2022)).…”