| Global temperatures continue to rise unabated,intensified episodes of heat-related catastrophes and serious extreme precipitations have surpassed all the past records.Mainstreaming climate change adaptation measures in development agenda has recently gained increasing attention of policy decisionmakers around the globe.Mega infrastructure projects as well as a wide range of auxiliary development programs are planned in form of development corridors by Kenya Government to reach it development vision called "Kenya Vision 2030".Considering that both human and natural systems have greatly suffered from severe weather-related disasters as result of climate change,there is a crucial need of reliable information about current and future extreme weather events to ensure a climate resilient society across the country.This study on one hand investigated future changes in extreme precipitation events and their implication for floodrisk,and the spatiotemporal evidence of heatwave events over Kenya on another hand.As a case study,the study also attempted to develop effective and practical adaptation pathways for flood risk and heatwaves stresses within the SGR corridor.To conduct a detailed analysis on future changes in extreme precipitation events,this study calculated weighted ensemble mean from a comprehensive range of CORDEX-Africa RCMs which were firstly bias corrected.The projection covered near-future(2021-2045),mid-future(2046-2075)and farfuture(2076-2095)periods.Extreme precipitation indices such as CDD,CWD,R50mm,ECA_R95p,R95p,R99p,SDII,Rx1D,and Rx5D were analyzed on annual basis using CHIRPS daily precipitation.About heatwaves,the study used Heatwave Magnitude Index daily(HWMId)as heatwave detection and measurement metrics based on satellite remotely sensed and station blended temperature dataset(CHIRTS).To address the adaptation challenges related to flood and heatwave risks in the SGR corridor,the study,based on extensive literature review,departed from the fact of weakness of adaptation actions in general due to non-existence of scientific based on how to adapt to climate change.Then,develop new climate change adaptation pathways using a system approach,and suggested an appropriate adaptation pathway for flood and heatwave risks within the SGR corridor.Extreme precipitation results indicated that more than half of the years in each future time periods will experience significant increase up to at least about 30%,65%and 150%under RCP2.6,RCP4.5 and RCP8.5,respectively,across the whole country.Meanwhile,negative changes were also observed for some years in each period,especially for R95p,SDII,ECA_R95p,and R99p indices.Magnitude and variability under RCP4.5 and RCP8.5 were more remarkable compared to RCP2.6.At spatial level,most part of Kenya is subject to substantial longer duration,more frequent and more intense precipitation.Specifically,southern and western parts were shown to experience severe precipitation,while wetness conditions were seen over eastern part.In overall,the country is subject to flood hazards,particularly over the southern and western parts(zonel and zone 2)where R50mm event,classified as severe and destructive flood disaster in the country could nearly happen twice per year on average by mid and farfuture under RCP 4.5 and RCP8.5.However,drought and dry spells events were shown to reduce over the eastern part.These suggest that the southern and western part of the country where most of the existing critical infrastructures and ongoing SGR development corridor of the country are located may experience sever flood hazard events throughout the remaining years of the current century.Heatwaves analysis showed that contrary to the absence of heatwave records in official national and international disaster database about Kenya,the country experienced heatwaves ranging from less severe to deadly between 1987 and 2016.The most affected areas were located in the eastern parts of the country,especially in Garissa and Tana River,and in the northernwest side around the upper side of Turkana county.It was also found that the recent years' heatwaves were more severe in magnitude,duration and spatial extent.The highest magnitude of the heatwaves was recorded in 2015(HWMId=22.64)while the average over the reference period is around 6.This sharp rise observed lately might be attributed to climate change.CHIRTS and HWMId were able to reveal and capture most critical heatwave events over the study period.Therefore,they could be used respectively as data source and detection metrics,for heatwaves disaster emergency warning over short period as well as for long-term projection to provide insight for adaptation strategies.This study gives new insight to adaptation pathways by developing four pathways based on the core properties of the system at risk.Basically,there are self-adaptability,self-adaptability inspired by outside intervention,outside intervention combined with self-adaptability and pure outside intervention which correspond to transformational adaptation while the others belong to incremental.Self-adaptability inspired by outside intervention was suggested as the most suitable and sustainable adaptation pathways for the SGR corridor in face of flood and heatwave risks.It accommodates locally improved response measures such as nature-based solutions.Therefore,the study taking insight from China ecological civilization concept,especially the sponge city initiative,recommended the construction of adaptation technology system by using and restoring existing and potential biodiversity and ecosystem services within the SGR corridor.A package of both natural and artificial green and blue infrastructure such as wetlands,vegetation covers,bio-swales,water-tanks,water-ponds,and other nature based-solutions which have huge flood and heatwave risks mitigation potential.The main highlights of this study could be summarized in the following four main points:1)This study made use of high resolution gridded dataset as observational data for precipitation and temperature.2)Severe flood events are very likely to happen for the remaining years of the current century over the coastal and western regions of Kenya while drought events may decrease in eastern parts of the country.3)Contrary to the absence of official heatwave records in Kenya,this study gives evidence of experienced heatwave facts ranging from less severe to deadly.4)New insight to climate change adaptation pathways consisting in four pathways(self-adaptability,self-adaptability inspired from outside intervention,self-adaptability combined with outside intervention,and pure outside intervention)based on the core properties of the system at risk were developed.Following the outcomes of this study,recommendations are made for practical application as well as for further research directions.The key findings of this work strengthen and expand the existing scientific boundaries on climate risks and adaptation understanding in general and in Kenya in particular.However,future research work should focus on the construction of adaptation technology system which will help the implementation on the ground. |
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