scholarly journals Climate Change Impact on Water Resources in the Awash Basin, Ethiopia

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1560 ◽  
Author(s):  
Meron Taye ◽  
Ellen Dyer ◽  
Feyera Hirpa ◽  
Katrina Charles

Rapid growth of agriculture, industries and urbanization within the Awash basin, Ethiopia, as well as population growth is placing increasing demands on the basin’s water resources. In a basin known for high climate variability involving droughts and floods, climate change will likely intensify the existing challenges. To quantify the potential impact of climate change on water availability of the Awash basin in different seasons we have used three climate models from Coupled Models Inter-comparison Project phase 5 (CMIP5) and for three future periods (2006–2030, 2031–2055, and 2056–2080). The models were selected based on their performance in capturing historical precipitation characteristics. The baseline period used for comparison is 1981–2005. The future water availability was estimated as the difference between precipitation and potential evapotranspiration projections using the representative concentration pathway (RCP8.5) emission scenarios after the climate change signals from the climate models are transferred to the observed data. The projections for the future three periods show an increase in water deficiency in all seasons and for parts of the basin, due to a projected increase in temperature and decrease in precipitation. This decrease in water availability will increase water stress in the basin, further threatening water security for different sectors, which are currently increasing their investments in the basin such as irrigation. This calls for an enhanced water management strategy that is inclusive of all sectors that considers the equity for different users.

2012 ◽  
Vol 9 (11) ◽  
pp. 12395-12433 ◽  
Author(s):  
T. C. Yang ◽  
C. Chen ◽  
C. M. Kuo ◽  
H. W. Tseng ◽  
P. S. Yu

Abstract. This study aims at assessing the impact of climate change on drought risk in a water resources system in Southern Taiwan by integrating the weather generator, hydrological model and simulation model of reservoir operation. Three composite indices with multi-aspect measurements of reservoir performance (i.e. reliability, resilience and vulnerability) were compared by their monotonic behaviors to find a suitable one for the study area. The suitable performance index was then validated by the historical drought events and proven to have the capability of being a drought risk index in the study area. The downscaling results under A1B emission scenario from seven general circulation models were used in this work. The projected results show that the average monthly mean inflows during the dry season tend to decrease from the baseline period (1980–1999) to the future period (2020–2039); the average monthly mean inflows during the wet season may increase/decrease in the future. Based on the drought risk index, the analysis results for public and agricultural water uses show that the occurrence frequency of drought may increase and the severity of drought may be more serious during the future period than during the baseline period, which makes a big challenge on water supply and allocation for the authorities of reservoir in Southern Taiwan.


Elem Sci Anth ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Pilar Barría ◽  
Ignacio Barría Sandoval ◽  
Carlos Guzman ◽  
Cristián Chadwick ◽  
Camila Alvarez-Garreton ◽  
...  

Chile is positioned in the 20th rank of water availability per capita. Nonetheless, water security levels vary across the territory. Around 70% of the national population lives in arid and semiarid regions, where a persistent drought has been experienced over the last decade. This has led to water security problems including water shortages. The water allocation and trading system in Chile is based on a water use rights (WURs) market, with limited regulatory and supervisory mechanisms, where the volume to be granted as permanent and eventual WURs is calculated from statistical analyses of historical streamflow records if available, or from empirical estimations if they are not. This computation of WURs does not consider the nonstationarity of hydrological processes nor climatic projections. This study presents the first large sample diagnosis of water allocation system in Chile under climate change scenarios. This is based on novel anthropic intervention indices (IAI), which were computed as the ratio between the total granted water volume to the water availability within 87 basins in north-central and southern Chile (30°S–42°S). The IAI were evaluated for the historical period (1979–2019) and under modeled-based climatic projections (2055–2080). According to these IAI levels, to date, there are 20 out of 87 overallocated basins, which under the assumption that no further WURs will be granted in the future, increases up to 25 basins for the 2055–2080 period. The results show that, to date most of north-central Chilean catchments already have a large anthropic intervention degree, and the increases for the future period occurs mostly in the southern region of the country (approximately 38°S), which has been considered as possible source of water for large water transfer projects (i.e., water roads). These indices and diagnosis are proposed as a tool to help policy makers to address water scarcity under climate change.


Author(s):  
Sunil Londhe

Climate is the primary determinant of agricultural productivity and evidence shows possibility of shifts in earth's climate. Concern over the potential effects of long-term climatic change on agriculture has been raised over the past decade. Change in the climatic conditions on the globe created threat to the availability water for agriculture production. The present chapter is an attempt to distil what is known about the likely effects of climate change on water availability to agriculture for food security and nutrition in coming decades. Apart from few exceptions, the likely impacts of climate change on agriculture water resources in the future are not understood in any great depth. There are many uncertainties as to how changes in various environmental parameters will interact with the availability of water and further agriculture production. The future consequences of water resources on agriculture are discussed and summarized. Possible mitigation and adaptations to changing water availability for agriculture are also discusses.


2020 ◽  
Author(s):  
Kai Sonntag ◽  
Matthias Gassmann

<p>Due to climate change, meteorological extremes affect the environment and our society in the past decades. But not only the extremes are piling up, the average temperatures and the precipitation regimes have changed in recent decades. The change in meteorological conditions also affects the water balance and thus also the generation processes of runoff. The aim of this work is to estimate this future change for a small low-mountain catchment in central Germany using climate projections and hydrological modelling.</p><p>As input to the hydrological model HBV Light, climate data from seven different combinations of global and regional climate models are used. However, due to their substantial bias it is necessary to apply bias correction. For each of the three climate input time series used by HBV Light, different bias correction methods are tested: Precipitation (Linear Scaling Multiplication, Quantile Mapping, Power Transformation, Distribution Mapping Gamma), Temperature (Linear Scaling Addition, Quantile Mapping, Variance Scaling, Distribution Mapping Normal) and Potential Evapotranspiration (Linear Scaling Multiplication, Linear Scaling Addition, Quantile Mapping). The corrected climate model outputs are compared to the observed timeseries and rated based on three different efficiency criteria. Overall, the combination of different climate models and bias correction methods generates 63 future hydrological projections. Based on this ensemble, the future water balance of the catchment is assessed. The results show that (1) the biggest uncertainties in the hydrological simulation were generated by uncorrected climate model outputs; (2) the uncertainties in hydrological simulations increase till the end of the century; (3) Power Transformation and Quantile Mapping perform best for precipitation, Linear Scaling Addition and Quantile Mapping for temperature, Linear Scaling Addition and Quantile Mapping for potential evapotranspiration; (4) the total annual outflow increases till 2070 because of an increase of the outflow in winter and spring; (5) in the future, interflow will increase in spring and winter and reduce in summer and autumn; (6) till the end of the century the baseflow will rise in spring and in the rest of year the baseflow will decrease. This study shows that even if changes in the annual total discharge for small catchments have no significant trend, the generation processes and the seasonal values may change in the future.</p>


2021 ◽  
Author(s):  
Loris Compagno ◽  
Sarah Eggs ◽  
Matthias Huss ◽  
Harry Zekollari ◽  
Daniel Farinotti

Abstract. With the Paris Agreement, the urgency of limiting ongoing anthropogenic climate change has been recognized. More recent discussions have focused on the difference of limiting the increase in global average temperatures below 1.0, 1.5, or 2.0 °C compared to pre-industrial levels. Here, we assess the impacts that such different scenarios would have on both the future evolution of glaciers in the European Alps and the water resources they provide. Our results show that the different temperature targets 5 have important implications for the changes predicted until 2100, and that glaciers might start recovering after the end of the 21st century.


Author(s):  
Andre Schardong ◽  
Slobodan P. Simonovic

Global Climate Models (GCMs) are currently the most powerful tools for accessing changes in the hydrological regime at the watershed scale due to climate change and variability. GCMs, however, have limitations due to their coarse spatial and temporal resolutions.  Regional Climate Models (RCMs) are often referred to as suitable alternatives due to their higher resolution of the long-term climate projections. It is expected that RCMs are better for simulating extreme conditions than the GCMs. This  present work, investigate the difference in updated IDF (Intensity-Duration-Frequency) relationships developed using GCMs and RCMs. The IDF updating method implemented with the IDF_CC tool for Canada has been used for comparison. The analyses are conducted using 369 selected Environment and Climate Change Canada hydro-meteorological stations from the IDF_CC tool database with record length longer than 20 years. Results for the future period (2020-2100), are based on multi-model ensembles of (i) the RCMs from the NA-CORDEX (North-American Coordinated Regional Climate Downscaling Experiment) project (ensemble 1) (ii) a sub-set of six GCMs from the GCMs available in the IDF_CC tool used as drivers for the RCMs (ensemble 2) and (iii) all 24 GCMs from the IDF_CC tool database (ensemble 3). One representative concentration pathway (RCP), RCP 8.5, is used in the analysis. The RCMs from the NA-CORDEX project selected for this study use six GCMs as drivers to produce the future predictions for the North American continent, including Canada. Two metrics are applied for the comparison of results: (i) the difference in projected precipitation using the multi-model ensemble median; and (ii) the difference in uncertainty range. The uncertainty range is defined in this study as the percentage projected change in future, 25 to 75 quantiles obtained using the RCMs a GCMs ensembles. The regional models from the NA-CORDEX project generated lower extreme precipitation projections than the GCMs for the stations located in the Canadian prairies (provinces of Alberta, Saskatchewan, Manitoba). Stations located at the East and West coasts of Canada show a smaller difference in the projected extremes obtained using GCMs and RCMs. The use of RCMs shows increase in uncertainty when compared to GCMs. This result indicates that even when using regional climate models, it’s advisable to extend the analyses and include as many as possible models from different climate centers.


2021 ◽  
Author(s):  
Pragya Pradhan ◽  
Trang Thi Huyen Pham ◽  
Sangam Shrestha ◽  
Loc Ho ◽  
Edward Park

Abstract This study aims to project the compound impacts of climate change and human activities, including agriculture expansion and hydropower generation, on the future water availability in the Sre Pok River Basin. The five regional climate models (RCMs): ACESS, REMO2009, MPI, NorESM, CNRM were selected for the future climate projection under two scenarios i.e., RCP 4.5 and RCP 8.5. Our results reveal that the future annual rainfall is expected to decrease by 200 mm whereas the average temperature is expected to increase by 0.69°C to 4.16°C under future scenarios. The future water availability of Sre Pok River Basin was projected using soil and water assessment tool (SWAT). Next, the CROPWAT model was used to examine the irrigation water requirement and the HEC-ResSim model to simulate the hydropower generation of Buon Tuar Sarh reservoir. The future simulation indicates the decrease in future water availability, increasing demand for irrigation water and decreases in hydropower generation for the future periods. The irrigated areas are increases from 700 ha to 1500 ha as per the provincial development plan. This study also examines the present and future drought conditions of Sre Pok River via streamflow drought index (SDI). Our results expect to contribute toward supporting the planning and management of water resources for agriculture and to efficiently cope with drought conditions in the studied basin and beyond.


2021 ◽  
Vol 15 (6) ◽  
pp. 2593-2599
Author(s):  
Loris Compagno ◽  
Sarah Eggs ◽  
Matthias Huss ◽  
Harry Zekollari ◽  
Daniel Farinotti

Abstract. With the Paris Agreement, the urgency of limiting ongoing anthropogenic climate change has been recognised. More recent discussions have focused on the difference of limiting the increase in global average temperatures below 1.0, 1.5, or 2.0 ∘C compared to preindustrial levels. Here, we assess the impacts that such different scenarios would have on both the future evolution of glaciers in the European Alps and the water resources they provide. Our results show that even half-degree differences in global temperature targets have important implications for the changes predicted until 2100, and that – for the most optimistic scenarios – glaciers might start to partially recover, owing to possibly decreasing temperatures after the end of the 21st century.


Author(s):  
Sunil Londhe

Climate is the primary determinant of agricultural productivity and evidence shows possibility of shifts in earth's climate. Concern over the potential effects of long-term climatic change on agriculture has been raised over the past decade. Change in the climatic conditions on the globe created threat to the availability water for agriculture production. The present chapter is an attempt to distil what is known about the likely effects of climate change on water availability to agriculture for food security and nutrition in coming decades. Apart from few exceptions, the likely impacts of climate change on agriculture water resources in the future are not understood in any great depth. There are many uncertainties as to how changes in various environmental parameters will interact with the availability of water and further agriculture production. The future consequences of water resources on agriculture are discussed and summarized. Possible mitigation and adaptations to changing water availability for agriculture are also discusses.


Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1560
Author(s):  
Carlos R. Mello ◽  
Nayara P. A. Vieira ◽  
Jorge A. Guzman ◽  
Marcelo R. Viola ◽  
Samuel Beskow ◽  
...  

Approximately 70% of all the electric energy produced in Brazil comes from hydropower plants. In this context, the Grande River Basin (GRB) stands out in Brazil. Some studies have been carried out to investigate the impacts of climate change in tropical regions to support water resources’ management and planning. This study aims to project the changes in the runoff that feed the Furnas Hydropower Plant (FHP) reservoir (GRB-Furnas basin), the largest and most important facility in Southeast Brazil. The lavras simulation of hydrology model (LASH) was used to project the impacts on runoff and hydrological droughts over the century in GRB-Furnas. The regional climate models (RCMs) Eta-HadGEM-ES, Eta-MIROC5, and Eta-CanESM2 forced the LASH model from 2007 to 2099, taking the representative concentration pathways (RCPs) 4.5 and 8.5. LASH simulated the runoff adequately for the baseline period (1961–2005) using the RCMs’ outputs. A noticeable reduction in precipitation was identified in the wet season, especially in the 2007–2040 period for RCP4.5 and in the 2071–2099 period for RCP8.5. As a result, a significant reduction in the runoff, mainly in the baseflow, and an increase in droughts’ severity were projected throughout the XXI Century, which may compromise the water security to the FHP reservoir.


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