Climate Change Impact on the Water Resources of the Limpopo Basin

2018 ◽  
pp. 177-200
Author(s):  
Berhanu F. Alemaw ◽  
Thebeyame Ronald Chaoka
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Water Resources ◽  
Potential Evapotranspiration ◽  
Annual Runoff ◽  
Climate Change Scenarios ◽  
Atmospheric Processes ◽  
Hydrologic Regimes ◽  
Change Impact ◽  
High Runoff

This chapter aims to evaluate the impacts of climate change on both hydrologic regimes and water resources of the Limpopo River Basin in southern Africa. Water resources availability in the basin, in terms of, seasonal and annual runoff (R), soil moisture (S) and actual evapotranspiration (Ea) is simulated and evaluated using the hydrological model, HATWAB. These water balances were computed from precipitation (P), potential evapotranspiration (Ep) and other variables that govern the soil-water-vegetation-atmospheric processes at 9.2km latitude/ longitude gird cells covering the basin. The 1961-90 simulated mean annual runoff reveals mixed patterns of high and low runoff across the region. Although relatively small changes in runoff simulations are prevalent among the three climate change scenarios, generally the OSU simulated relatively high runoff compared to the UKTR and HADCM2 GCMs.

Climate Change Impact on the Water Resources of the Limpopo Basin

2018 ◽  
pp. 656-680
Author(s):  
Berhanu F. Alemaw ◽  
Thebeyame Ronald Chaoka
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Water Resources ◽  
Potential Evapotranspiration ◽  
Annual Runoff ◽  
Climate Change Scenarios ◽  
Atmospheric Processes ◽  
Hydrologic Regimes ◽  
Change Impact ◽  
High Runoff

This chapter aims to evaluate the impacts of climate change on both hydrologic regimes and water resources of the Limpopo River Basin in southern Africa. Water resources availability in the basin, in terms of, seasonal and annual runoff (R), soil moisture (S) and actual evapotranspiration (Ea) is simulated and evaluated using the hydrological model, HATWAB. These water balances were computed from precipitation (P), potential evapotranspiration (Ep) and other variables that govern the soil-water-vegetation-atmospheric processes at 9.2km latitude/ longitude gird cells covering the basin. The 1961-90 simulated mean annual runoff reveals mixed patterns of high and low runoff across the region. Although relatively small changes in runoff simulations are prevalent among the three climate change scenarios, generally the OSU simulated relatively high runoff compared to the UKTR and HADCM2 GCMs.

scholarly journals Contrasting climate change impact on river flows from high-altitude catchments in the Himalayan and Andes Mountains

2016 ◽  
Vol 113 (33) ◽  
pp. 9222-9227 ◽  
Author(s):  
Silvan Ragettli ◽  
Walter W. Immerzeel ◽  
Francesca Pellicciotti
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
High Altitude ◽  
Water Availability ◽  
Climate Change Impact ◽  
River Flow ◽  
Climate Change Scenarios ◽  
Glacier Area ◽  
Spatiotemporal Resolution ◽  
Change Impact

Mountain ranges are the world’s natural water towers and provide water resources for millions of people. However, their hydrological balance and possible future changes in river flow remain poorly understood because of high meteorological variability, physical inaccessibility, and the complex interplay between climate, cryosphere, and hydrological processes. Here, we use a state-of-the art glacio-hydrological model informed by data from high-altitude observations and the latest climate change scenarios to quantify the climate change impact on water resources of two contrasting catchments vulnerable to changes in the cryosphere. The two study catchments are located in the Central Andes of Chile and in the Nepalese Himalaya in close vicinity of densely populated areas. Although both sites reveal a strong decrease in glacier area, they show a remarkably different hydrological response to projected climate change. In the Juncal catchment in Chile, runoff is likely to sharply decrease in the future and the runoff seasonality is sensitive to projected climatic changes. In the Langtang catchment in Nepal, future water availability is on the rise for decades to come with limited shifts between seasons. Owing to the high spatiotemporal resolution of the simulations and process complexity included in the modeling, the response times and the mechanisms underlying the variations in glacier area and river flow can be well constrained. The projections indicate that climate change adaptation in Central Chile should focus on dealing with a reduction in water availability, whereas in Nepal preparedness for flood extremes should be the policy priority.

scholarly journals Modelling flow changes in potential climate change conditions – an example of the Kaczawa basin

2012 ◽  
Vol 34 (2) ◽  
pp. 51-61
Author(s):  
Leszek Kuchar ◽  
IWAŃSKI SŁAWOMIR ◽  
Leszek Jelonek ◽  
Wiwiana Szalińska
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Social Impact ◽  
Meteorological Data ◽  
Annual Runoff ◽  
Climate Change Scenarios ◽  
Rainfall Runoff ◽  
Data Generator ◽  
Flow Changes ◽  
Potential Climate Change

Abstract Climate change, regardless of the causes shaping its rate and direction, can have far-reaching environmental, economic and social impact. A major aspect that might be transformed as a result of climate change are water resources of a catchment. The article presents a possible method of predicting water resource changes by using a meteorological data generator and classical hydrological models. The assessment of water resources in a catchment for a time horizon of 30-50 years is based on an analysis of changes in annual runoff that might occur in changing meteorological conditions. The model used for runoff analysis was the hydrological rainfall-runoff NAM model. Daily meteorological data essential for running the hydrological model were generated by means of SWGEN model. Meteorological data generated for selected climate change scenarios (GISS, CCCM and GFDL) for the years 2030 and 2050 enabled analysing different variants of climate change and their potential effects. The presented results refer to potential changes in water resources of the Kaczawa catchment. It should be emphasized that the obtained results do not say which of the climate change scenarios is more likely, but they present the consequences of climate change described by these scenarios.

Evaluation of methods for calculating potential evapotranspiration in climate change scenarios

2021 ◽  
Author(s):  
Maria-Carmen Vicente-Torres ◽  
Miguel Angel Perez Martin
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Moisture Content ◽  
Temperature Increase ◽  
Soil Moisture Content ◽  
Potential Evapotranspiration ◽  
Climate Change Scenarios ◽  
Future Scenarios ◽  
Mitigation And Adaptation ◽  
The Mediterranean

<p>Despite uncertainties involved by future scenarios, the acknowledgement of climate change problem (WMO 2019/1248 reinforces the past five years as the warmest in industrial records, part of the warmest decade on record 2010-2019, and the need for urgent mitigation and adaptation actions have only grown in recent years. In the European Territory (EEA 1/2017), a significant decrease in summer soil moisture content in the Mediterranean region, while increases in north-eastern countries are projected for the coming decades. The current temperature increase derived from the emission of gases to the atmosphere, in the range of 0.1-0.3 ºC per decade by the IPCC experts Special Report 2018, obliges a deep review of the agricultural productivity factors, according to the FAO-56 /2006.</p><p>Soil moisture content is thus approached as a dynamic variable, with changes in temperature as well as precipitation constantly affecting evapotranspiration and infiltration rates. In this paper, five computing methods for crop water evapotranspiration (Penman-Monteith proposed by FAO-56, Thornwaite, and three temperature-based methods: Hargreaves 1975, Hargreaves-Samani 1985, Samani 2000) are not only scientifically compared but also applied to a Spanish Study Case at Valencian Community in the Mediterranean Basin. Results are affected by local single crops coefficient (also proposed by FAO-56) for citrus trees in upper Palancia River catchment, representative of intensive agriculture in the area, and calculated under four future scenarios (from +1ºC to 4ºC of unitary temperature increase).</p><p>Analysed results by percentual comparison with Penman-Monteith estimation, demonstrate a similar application range (from -1% of variation in +1ºC scenario to -4% of variation in 4ºC scenario) for scarcer data-based methods (Hargreaves 1975, Hargreaves-Samani 1985 and Samani 2000) except Thornthwaite. Allowing to conclude that Thornthwaite projections in the Mediterranean Climate overestimate up to 3% (+1ºC scenario), 6% (+2ºC scenario), 11% (+3ºC scenario) and 16% (+4ºC scenario) the monthly values of crop evapotranspiration.</p>

scholarly journals Land-use change may exacerbate climate change impacts on water resources in the Ganges basin

2017 ◽  
pp. 1-33
Author(s):  
Gina Tsarouchi ◽  
Wouter Buytaert
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Soil Moisture ◽  
Water Resources ◽  
Land Use Change ◽  
River Basin ◽  
Land Surface ◽  
Surface Model ◽  
Climate Change Scenarios ◽  
Northern India

Quantifying how land-use change and climate change affect water resources is a challenge in hydrological science. The Upper Ganges (UG) river basin in northern India experiences monsoon flooding almost every year. Studies have shown evidence of strong coupling between the land surface (soil moisture) and atmosphere (precipitation) in northern India, which means that regional climate variations and changes in land use/cover could influence the temporal dynamics of land-atmosphere interactions. <br><br> This work aims to quantify how future projections of land-use and climate change are affecting the hydrological response of the UG river basin. Two different sets of modelling experiments were run using the JULES Land Surface Model and covering the period 2000&amp;ndash;2035: In the first set, climate change is taken into account, as JULES was driven by the CMIP5 (Coupled Model Intercomparison Project Phase 5) outputs of 21 models, under two Representative Concentration Pathways (RCP4.5 &amp; RCP8.5), whilst land use was kept constant at year 2010. In the second set, both climate change and land-use change were taken into consideration, as apart from the CMIP5 model outputs, JULES was also forced with a time-series of 15 future land-use scenarios, based on Landsat satellite imagery and Markov chain simulation. Variations in hydrological variables (stream flow, evapotranspiration and soil moisture) are calculated during the simulation period. <br><br> Significant changes in the near-future (years 2030&amp;ndash;2035) hydrologic fluxes arise under future land cover and climate change scenarios pointing towards a severe increase in high extremes of flow: the multi-model mean of the 95th percentile of streamflow [Q<sub>5</sub>] is projected to increase by 63&amp;thinsp;% under the combined land-use and climate change high emissions scenario [RCP8.5]. The changes in all examined hydrological components are greater in the combined land-use and climate change experiment. <br><br> Results are further presented in a water resources context, aiming to address potential implications of climate change from a water-demand perspective, highlighting that that demand thresholds in the UG region are projected to be exceeded in the future winter months (Dec&amp;ndash;Feb).

scholarly journals A high-resolution assessment of climate change impact on water footprints of cereal production in India

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Santosh S. Mali ◽  
Paresh B. Shirsath ◽  
Adlul Islam
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Water Resources ◽  
Climate Change Impact ◽  
Water Resource Management ◽  
Water Footprint ◽  
National Level ◽  
Winter Season ◽  
Climate Change Scenarios ◽  
Change Impact

AbstractWater footprint (WF), a comprehensive indicator of water resources appropriation, has evolved as an efficient tool to improve the management and sustainability of water resources. This study quantifies the blue and green WF of major cereals crops in India using high resolution soil and climatic datasets. A comprehensive modelling framework, consisting of Evapotranspiration based Irrigation Requirement (ETIR) tool, was developed for WF assessment. For assessing climate change impact on WF, multi-model ensemble climate change scenarios were generated using the hybrid-delta ensemble method for RCP4.5 and RCP6.0 and future period of 2030s and 2050s. The total WF of the cereal crops are projected to change in the range of − 3.2 to 6.3% under different RCPs in future periods. Although, the national level green and blue WF is projected to change marginally, distinct trends were observed for Kharif (rainy season—June to September) and rabi (winter season—October to February) crops. The blue WF of paddy is likely to decrease by 9.6%, while for wheat it may increase by 4.4% under RCP4.5 during 2050s. The green WF of rabi crops viz. wheat and maize is likely to increase in the range of 20.0 to 24.1% and 9.9 to 16.2%, respectively. This study provides insights into the influences of climate change on future water footprints of crop production and puts forth regional strategies for future water resource management. In view of future variability in the WFs, a water footprint-based optimization for relocation of crop cultivation areas with the aim of minimising the blue water use would be possible management alternative.

Assess 21st century Flash Drought in the United States using high resolution regional climate models

2021 ◽  
Author(s):  
Brandi Gamelin ◽  
Jiali Wang ◽  
V. Rao Kotamarthi
Keyword(s):  
Climate Change ◽  
United States ◽  
Soil Moisture ◽  
Climate Models ◽  
Wrf Model ◽  
The United States ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Regional Variability ◽  
Groundwater Levels

&lt;p&gt;Flash droughts are the rapid intensification of drought conditions generally associated with increased temperatures and decreased precipitation on short time scales.&amp;#160; Consequently, flash droughts are responsible for reduced soil moisture which contributes to diminished agricultural yields and lower groundwater levels. Drought management, especially flash drought in the United States is vital to address the human and economic impact of crop loss, diminished water resources and increased wildfire risk. In previous research, climate change scenarios show increased growing season (i.e. frost-free days) and drying in soil moisture over most of the United States by 2100. Understanding projected flash drought is important to assess regional variability, frequency and intensity of flash droughts under future climate change scenarios. Data for this work was produced with the Weather Research and Forecasting (WRF) model. Initial and boundary conditions for the model were supplied by CCSM4, GFDL-ESM2G, and HadGEM2-ES and based on the 8.5 Representative Concentration Pathway (RCP8.5). The WRF model was downscaled to a 12 km spatial resolution for three climate time frames: 1995-2004 (Historical), 2045-2054 (Mid), and 2085-2094 (Late). &amp;#160;A key characteristic of flash drought is the rapid onset and intensification of dry conditions. For this, we identify onset with vapor pressure deficit during each time frame. Known flash drought cases during the Historical run are identified and compared to flash droughts in the Mid and Late 21&lt;sup&gt;st&lt;/sup&gt; century.&lt;/p&gt;

Climate and land use change impacts on water resources in Sardinia (Italy)

2021 ◽  
Author(s):  
Dario Ruggiu ◽  
Salvatore Urru ◽  
Roberto Deidda ◽  
Francesco Viola
Keyword(s):  
Land Use ◽  
Water Resources ◽  
Land Use Change ◽  
Hydrological Cycle ◽  
Potential Evapotranspiration ◽  
Regional Scale ◽  
Annual Runoff ◽  
Annual Rainfall ◽  
Land Use Scenarios ◽  
Near Future

&lt;p&gt;The assessment of climate change and land use modifications effects on hydrological cycle is challenging. We propose an approach based on Budyko theory to investigate the relative importance of natural and anthropogenic drivers on water resources availability. As an example of application, the proposed approach is implemented in the island of Sardinia (Italy), which is affected by important processes of both climate and land use modifications. In details, the proposed methodology assumes the Fu&amp;#8217;s equation to describe the mechanisms of water partitioning at regional scale and uses the probability distributions of annual runoff (Q) in a closed form. The latter is parametrized by considering simple long-term climatic info (namely first orders statistics of annual rainfall and potential evapotranspiration) and land use properties of basins.&lt;/p&gt;&lt;p&gt;In order to investigate the possible near future water availability of Sardinia, several climate and land use scenarios have been considered, referring to 2006-2050 and 2051-2100 periods. Climate scenarios have been generated considering fourteen bias corrected outputs of climatic models from EUROCORDEX&amp;#8217;s project (RCP 8.5), while three land use scenarios have been created following the last century tendencies.&lt;/p&gt;&lt;p&gt;Results show that the distribution of annual runoff in Sardinia could be significantly affected by both climate and land use change. The near future distribution of Q generally displayed a decrease in mean and variance compared to the baseline. &amp;#160;&amp;#160;&lt;/p&gt;&lt;p&gt;The reduction of&amp;#160; Q is more critical moving from 2006-2050 to 2051-2100 period, according with climatic trends, namely due to the reduction of annual rainfall and the increase of potential evapotranspiration. The effect of LU change on Q distribution is weaker than the climatic one, but not negligible.&lt;/p&gt;

scholarly journals Climate change impact on water resource extremes in a headwater region of the Tarim basin in China

2011 ◽  
Vol 15 (11) ◽  
pp. 3511-3527 ◽  
Author(s):  
T. Liu ◽  
P. Willems ◽  
X. L. Pan ◽  
An. M. Bao ◽  
X. Chen ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Ground Water ◽  
Climate Change Impact ◽  
Snow Accumulation ◽  
Tarim River Basin ◽  
Hydrological Models ◽  
Snow Melting ◽  
Change Impact ◽  
Ipcc Sres

Abstract. The Tarim river basin in China is a huge inland arid basin, which is expected to be highly vulnerable to climatic changes, given that most water resources originate from the upper mountainous headwater regions. This paper focuses on one of these headwaters: the Kaidu river subbasin. The climate change impact on the surface and ground water resources of that basin and more specifically on the hydrological extremes were studied by using both lumped and spatially distributed hydrological models, after simulation of the IPCC SRES greenhouse gas scenarios till the 2050s. The models include processes of snow and glacier melting. The climate change signals were extracted from the grid-based results of general circulation models (GCMs) and applied on the station-based, observed historical data using a perturbation approach. For precipitation, the time series perturbation involves both a wet-day frequency perturbation and a quantile perturbation to the wet-day rainfall intensities. For temperature and potential evapotranspiration, the climate change signals only involve quantile based changes. The perturbed series were input into the hydrological models and the impacts on the surface and ground water resources studied. The range of impact results (after considering 36 GCM runs) were summarized in high, mean, and low results. It was found that due to increasing precipitation in winter, snow accumulation increases in the upper mountainous areas. Due to temperature rise, snow melting rates increase and the snow melting periods are pushed forward in time. Although the qualitive impact results are highly consistent among the different GCM runs considered, the precise quantitative impact results varied significantly depending on the GCM run and the hydrological model.

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