Trend Analysis of Climate Change-Induced Extreme Events in DroughtProne Areas: A Case of Legambo District in South Wollo Zone of Amhara National Regional State, North Central Ethiopia

Abstract

Ethiopia is among the most vulnerable countries to the adverse effects of climate change, which are manifested in recurrent droughts, extreme temperatures, and erratic rainfall,affecting agriculture and food security.This study examinesthe trend of climate change-induced extreme eventsover Legambodistrict using indices from Expert Team on Climate Change Detection and Indices (ETCCDI) for the period 1979-2019. Trend analysis was based on daily records of precipitationand temperature data obtained from KoninklijkNederlandsMeteorologishInstituut(KNMI) climate explorer, mainly from Climate Hazard Groups Infrared Precipitation with Stations (CHIRPS 2.0 Africa) at 0.05 by 0.05-degree resolution and Climate Research Unit (CRU TS 4.07) at 0.5⁰ resolutions respectively. Data analysis was done using R-Studio (RClimDex) software. We employed Mann-Kendall's trend tests and a nonparametric Sen's slope estimator to detect the statistical significance and magnitude of changes in extreme climate, respectively. The findingsfounda statistically significant (P<0.05) positive trend in temperature-related indices such asmonthly maximum of daily maximum temperature (TXx) (0.08⁰C per year);monthly maximum of daily minimum temperature (TNx) (0.065⁰C per year), warm days (TX90p) (5.4 per century), warm nights (TN90p) (5 days per century), warm spell duration indicator (WSDI) (2.81days per decade) and hot days (SU) (14.92days per decade).A negative trend was observed in temperature extremes of the number of cool nights (TN10p) (-3.05C per decade), cool days (TX10p), and cold spell duration indicator (CSDI) (-2.2days per decade). A statistically significant (P<0.05) decreasing trend was observed in most precipitation-related indices like total precipitation (10.305mm/year), simple daily intensity index (-0.024 mm/day), maximum one-day precipitation (-0.5mm/year), maximum five-day precipitation (-0.56mm/year), very heavy precipitation with greater than 20mm per day (-1.89 days/decade), very wet days (-5.537mm/year) and extremely wet days (-1.534mm/year). With the high variability of indices and the fact that farmers live in a business-as-usualscenario,the vulnerability of smallholder farmers will be further exacerbated.Therefore, it is highly recommended that the government design appropriate adaptation strategies forfarmers to cope with these variability.