Evaluation of Meteorological Drought and Flood Scenarios over Kenya, East Africa

Abstract

This work examines drought and flood events over Kenya from 1981 to 2016 using the Standardized Precipitation–Evapotranspiration Index (SPEI). The spatiotemporal analysis of dry and wet events was conducted for 3 and 12 months. Extreme drought incidences were observed in the years 1987, 2000, 2006, and 2009 for SPEI-3, whilst the SPEI-12 demonstrated the manifestation of drought during the years 2000 and 2006. The SPEI showed that the wettest periods, 1997 and 1998, coincided with the El Nino event for both time steps. SPEI-3 showed a reduction in moderate drought events, while severe and extreme cases were on the increase tendencies towards the end of the twentieth century. Conversely, SPEI-12 depicted an overall increase in severe drought occurrence over the study location with ab observed intensity of −1.54 and a cumulative frequency of 64 months during the study period. Wet events showed an upward trend in the western and central highlands, while the rest of the regions showed an increase in dry events during the study period. Moreover, moderate dry/wet events predominated, whilst extreme events occurred least frequently across all grid cells. It is apparent that the study area experienced mild extreme dry events in both categories, although moderately severe dry events dominated most parts of the study area. A high intensity and frequency of drought was noted in SPEI-3, while the least occurrences of extreme events were recorded in SPEI-12. Though drought event prevailed across the study area, there was evidence of extreme flood conditions over the recent decades. These findings form a good basis for next step of research that will look at the projection of droughts over the study area based on regional climate models.

Evaluation and projection of mean surface temperature using CMIP6 models over East Africa

“…However, future projection studies of T2m and precipitation climate have been conducted using the available GCMs from CMIP3/5 (Shongwe et al, 2011;Otieno and Anyah, 2013a, b;Ongoma et al, 2018aOngoma et al, , 2018b or dynamically downscaled regional datasets (RCMs) (Osima et al, 2018;Ayugi et al, 2020;Onyutha, 2020;Ogega et al, 2020). Undoubtedly, these "studies' overall conclusion shows a varying change trend, mainly attributed to the datasets employed or period analyzed.…”

“…For instance, temperature changes have resulted in an increase in malaria infestations (Omumbo et al, 2011), lowered food production (Lyon, 2014;Adhakari et al, 2015;Mumo et al, 2018;Ayugi et al, 2020a), and recurring pest and diseases outbreak (Walther et al, 2012;Rosenzweig et al, 2014).…”

Quantifying the impacts of waterlogging on cotton at different growth stages: A case study in Hubei Province, China

“…According to the common threshold for identifying wet soil events in the SPEI (Ayugi et al., 2020; Liu & Liu, 2019; Polong et al., 2019), when SPEI >1.00, wet soil events were identified and counted. Accordingly, wet months occurring during the entire cotton growth period (from May to Oct.) were determined.…”

Assessment of Drought Event, its Trend and Teleconnected Factors Over Burundi, Central East Africa

“…The Greater Horn of Africa (GHA) is among the most threatened by drought events (Lyon 2014;Nicholson, 2014;Mpelasoka et al 2018;Gebremeskel Haile et al 2020). According to the World Health Organization, the Greater Horn of Africa region registers many deaths due to drought hazards, and the most affected countries are Somalia, Ethiopia and Kenya (Bayissa et al 2017;Zeleke et al 2017;Abro et al 2019;Gebremeskel et al 2019;Nguvava et al 2019;Polong et al 2019;Ayugi et al 2020). Gebremeskel et al (2019) established that apart from the great horn of Africa, the drought is extending toward other countries of the East and Central East Africa.…”