scholarly journals Effect of Climate Change on Drinking Water Utilities in Nzoia River Basin, Kenya

Author(s):  
Ernest Othieno Odwori

Climate change is already having noticeable effects on water utilities in Nzoia River Basin. Extreme weather and climate-related occurrences are becoming more common and intense, as predicted by the Intergovernmental Panel on Climate Change (IPCC), Third Assessment Report. Because most water utilities are unprepared, the repercussions might be severe. The water supply infrastructure is built for resiliency and sustainability of operations during weather events or other circumstances that could potentially interrupt services; but when events that were historically considered to be “100-year” events happen more and more frequently, utilities must prepare for a new normal. These extreme events are occurring or being exceeded more regularly, and as a result, the past may no longer be a reliable predictor of the future. In Nzoia River Basin, the water supply infrastructure currently designed for historical climate conditions is more vulnerable to future weather extremes and climate change. This study assessed the effect of climate change on drinking water utilities in Nzoia River Basin. A cross-sectional survey design was used. Three counties were randomly selected from the basin for study with Busia representing the lower catchment, Kakamega middle catchment and Trans Nzoia upper catchment. The study was carried out from May, 2017 to September, 2017. In-depth expert interviews and brainstorming sessions were used to identify the climate change impacts affecting drinking water utilities experienced in the last ten years in the basin. A carefully selected team of water and climate change experts consisting of decision makers, practitioners, managers, scientists and technology adopters were used to rank the severity of the climate change impacts. Climate change occurring in Nzoia River Basin is expected to have a wide range of consequences for drinking water utilities. By assessing its potential impacts on water utilities, we become better positioned to make improvements today to decrease the future risks. The results of this study provide valuable insights for the national and county governments in preparing to effectively anticipate and respond to the relevant issues that they can expect to face in the coming century.

Author(s):  
Ernest Othieno Odwori

Nzoia River Basin is one of the regions in Kenya that is highly vulnerable to climate change. An understanding of community knowledge and perception on climate change and drinking water supply will provide strategic directions for national and county government policy, adaptation strategies and development of community-based guidelines on climate change. This study assessed community knowledge and perception on climate change and drinking water supply in Nzoia River Basin. A cross-sectional survey design was used. Three counties were randomly selected from the basin for study with Busia representing the lower catchment, Kakamega middle catchment and Trans Nzoia upper catchment. The study was carried out from May, 2017 to September, 2017. Multistage random sampling technique was used to select the 403 households administered with questionnaires. An observation checklist was used by the interviewers to collect household- and community-related information. The study results revealed that the community largely comes from low socio-economic background: only 24 % had post secondary education or higher, the majority were small scale farmers, housewives, casual workers and househelps (58 %), and only 25 % earned a monthly income above Ksh. 20,000 (equivalent to US $200). The majority of the participants 81 % had some knowledge about climate change but 19 % did not. On level of knowledge about climate change, 70% know a little/something about climate change, 21% know nothing about climate change and 9% know a lot about climate change. Majority of respondents, 76% receive climate change news from mass media (radio, newspaper and magazines, television); and 81 % point out that climate change will have public health risks in the community. The knowledge level about climate change in the basin was average. National and county governments should work with the sector stakeholders in the basin to improve community knowledge and perception regarding climate change, drinking water supply and health needs with proper content. The results of this study will go a long way in bridging the gap between policy formulation and building adaptive capacity to climate change in the basin.


Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2462
Author(s):  
Tharo Touch ◽  
Chantha Oeurng ◽  
Yanan Jiang ◽  
Ali Mokhtar

An integrated modeling approach analyzing water demand and supply balances under management options in a river basin is essential for the management and adaptive measures of water resources in the future. This study evaluated the impacts of climate change on the hydrological regime by predicting the change in both monthly and seasonal streamflow, and identified water supply and demand relations under supply management options and environmental flow maintenance. To reach a better understanding of the consequences of possible climate change scenarios and adaptive management options on water supply, an integrated modeling approach was conducted by using the soil and water assessment tool (SWAT) and water evaluation and planning model (WEAP). Future scenarios were developed for the future period: 2060s (2051–2070), using an ensemble of three general circulation model (GCM) simulations: GFDL-CM3, GISS-E2-R-CC, and IPSL-CM5A-MR, driven by the climate projection for representative concentration pathways (RCPs): 6.0 (medium emission scenario). The results indicated that, firstly, the future streamflow will decrease, resulting in a decline of future water availability. Secondly, water supply under natural flow conditions would support 46,167 ha of irrigation schemes and the water shortages will be more noticeable when environmental flow maintenance was considered. The study concludes that reservoir construction would be necessary for agriculture mitigation and adaptation to climate change. Furthermore, the water resources management options considering both supply and demand management are more effective and useful than supply management only, particularly in dealing with climate change impacts.


Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1218
Author(s):  
Hemakanth Selvarajah ◽  
Toshio Koike ◽  
Mohamed Rasmy ◽  
Katsunori Tamakawa ◽  
Akio Yamamoto ◽  
...  

Climate change is increasingly sensed by nations vulnerable to water-related disasters, and governments are acting to mitigate disasters and achieve sustainable development. Uncertainties in General Circulation Models’ (GCM) rainfall projections and seamless long-term hydrological simulations incorporating warming effects are major scientific challenges in assessing climate change impacts at the basin scale. Therefore, the Data Integration and Analysis System (DIAS) of Japan and the Water Energy Budget-based Rainfall-Runoff-Inundation model (WEB-RRI) were utilized to develop an integrated approach, which was then applied to the Mahaweli River Basin (MRB) in Sri Lanka to investigate climate change impacts on its hydro-meteorological characteristics. The results for the Representative Concentration Pathway (RCP8.5) scenario from four selected GCMs showed that, with an average temperature increase of 1.1 °C over the 20 years in future (2026 to 2045), the basin will experience more extreme rainfall (increase ranging 204 to 476 mm/year) and intense flood disasters and receive sufficient water in the future climate (inflow increases will range between 11 m3/s to 57 m3/s). The socio-economic damage due to flood inundation will also increase in the future climate. However, qualitatively, the overall trend of model responses showed an increasing pattern in future meteorological droughts whereas there is uncertainty in hydrological droughts. Policymakers can utilize these results and react to implementing soft or hard countermeasures for future policymaking. The approach can be implemented for climate change impact assessment of hydro-meteorology in any other river basin worldwide.


2020 ◽  
Vol 186 ◽  
pp. 109544 ◽  
Author(s):  
Thundorn Okwala ◽  
Sangam Shrestha ◽  
Suwas Ghimire ◽  
S. Mohanasundaram ◽  
Avishek Datta

Author(s):  
X. Costoya ◽  
M. deCastro ◽  
D. Carvalho ◽  
Z. Feng ◽  
M. Gómez-Gesteira

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1548
Author(s):  
Suresh Marahatta ◽  
Deepak Aryal ◽  
Laxmi Prasad Devkota ◽  
Utsav Bhattarai ◽  
Dibesh Shrestha

This study aims at analysing the impact of climate change (CC) on the river hydrology of a complex mountainous river basin—the Budhigandaki River Basin (BRB)—using the Soil and Water Assessment Tool (SWAT) hydrological model that was calibrated and validated in Part I of this research. A relatively new approach of selecting global climate models (GCMs) for each of the two selected RCPs, 4.5 (stabilization scenario) and 8.5 (high emission scenario), representing four extreme cases (warm-wet, cold-wet, warm-dry, and cold-dry conditions), was applied. Future climate data was bias corrected using a quantile mapping method. The bias-corrected GCM data were forced into the SWAT model one at a time to simulate the future flows of BRB for three 30-year time windows: Immediate Future (2021–2050), Mid Future (2046–2075), and Far Future (2070–2099). The projected flows were compared with the corresponding monthly, seasonal, annual, and fractional differences of extreme flows of the simulated baseline period (1983–2012). The results showed that future long-term average annual flows are expected to increase in all climatic conditions for both RCPs compared to the baseline. The range of predicted changes in future monthly, seasonal, and annual flows shows high uncertainty. The comparative frequency analysis of the annual one-day-maximum and -minimum flows shows increased high flows and decreased low flows in the future. These results imply the necessity for design modifications in hydraulic structures as well as the preference of storage over run-of-river water resources development projects in the study basin from the perspective of climate resilience.


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