Effect of dynamically varying zone-based hedging policies on the operational performance of surface water reservoirs during climate change

2018 ◽  
Vol 488 (1) ◽  
pp. 277-289 ◽  
Author(s):  
Adebayo J. Adeloye ◽  
Bankaru-Swamy Soundharajan
Keyword(s):  
Climate Change ◽  
Surface Water ◽  
Operational Performance ◽  
Dynamic Hedging ◽  
Water Reservoirs ◽  
Complex Dynamic ◽  
Water Shortages ◽  
Operational Conditions ◽  
Static Hedging ◽  
The Impact

AbstractHedging is universally recognized as a useful operational practice in surface water reservoirs to temporally redistribute water supplies and thereby avoid large, crippling water shortages. When based on the zones of available water in storage, hedging has traditionally involved a static rationing (i.e. supply to demand) ratio. However, given the usual seasonality of reservoir inflows, it is also possible that hedging could be dynamic with seasonally varying rationing ratios. This study examined the effect of static and dynamic hedging policies on the performance of the Pong reservoir in India during a period of climate change. The results show that the reservoir vulnerability was unacceptably high (≥60%) without hedging and that this vulnerability further deteriorated as the catchment became drier due to projected climate change. The time- and volume-based reliabilities were acceptable. The introduction of static hedging drastically reduced the vulnerability to <25%, although the hedging reduction in the water supplied during normal operational conditions was only 17%. Further analyses with dynamic hedging provided only modest improvements in vulnerability. The significance of this study is its demonstration of the effectiveness of hedging in offsetting the impact of water shortages caused by climate change and the fact that static hedging can match more complex dynamic hedging policies.

scholarly journals Impact of climate change on groundwater point discharge: backflooding of karstic springs (Loiret, France)

2011 ◽  
Vol 8 (2) ◽  
pp. 2235-2262
Author(s):  
E. Joigneaux ◽  
P. Albéric ◽  
H. Pauwels ◽  
C. Pagé ◽  
L. Terray ◽  
...  
Keyword(s):  
Climate Change ◽  
Surface Water ◽  
Groundwater Quality ◽  
Atmospheric Circulation ◽  
Large Scale ◽  
Weather Type ◽  
Future Climate Change ◽  
Impact Of Climate Change ◽  
The Impact ◽  
Large Scale Atmospheric Circulation

Abstract. Under certain hydrological conditions it is possible for spring flow in karst systems to be reversed. When this occurs, the resulting invasion by surface water, i.e. the backflooding, represents a serious threat to groundwater quality because the surface water could well be contaminated. Here we examine the possible impact of future climate change on the occurrences of backflooding in a specific karst system, having first established the occurrence of such events in the selected study area over the past 40 yr. It would appear that backflooding has been more frequent since the 1980s, and that it is apparently linked to river flow variability on the pluri-annual scale. The avenue that we adopt here for studying recent and future variations of these events is based on a downscaling algorithm relating large-scale atmospheric circulation to local precipitation spatial patterns. The large-scale atmospheric circulation is viewed as a set of quasi-stationary and recurrent states, called weather types, and its variability as the transition between them. Based on a set of climate model projections, simulated changes in weather-type occurrence for the end of the century suggests that backflooding events can be expected to decrease in 2075–2099. If such is the case, then the potential risk for groundwater quality in the area will be greatly reduced compared to the current situation. Finally, our results also show the potential interest of the weather-type based downscaling approach for examining the impact of climate change on hydrological systems.

scholarly journals Water Security in Africa in the Age of Global Climate Change

Daedalus ◽  
2021 ◽  
Vol 150 (4) ◽  
pp. 7-26
Author(s):  
Allen Isaacman ◽  
Muchaparara Musemwa
Keyword(s):  
Climate Change ◽  
Global Climate ◽  
Water Governance ◽  
Water Security ◽  
Well Being ◽  
African Continent ◽  
Urban Centers ◽  
Water Shortages ◽  
Critical Dimensions ◽  
The Impact

Abstract This essay explores the multiple ways in which the nexuses between water scarcity and climate change are socially and historically grounded in ordinary people's lived experiences and are embedded in specific fields of power. Here we specifically delineate four critical dimensions in which the water crises confronting the African continent in an age of climate change are clearly expressed: the increasing scarcity, privatization, and commodification of water in urban centers; the impact of large dams on the countryside; the health consequences of water shortages and how they, in turn, affect other aspects of people's experiences, sociopolitical dynamics, and well-being, broadly conceived; and water governance and the politics of water at the local, national, and transnational levels. These overarching themes form the collective basis for the host of essays in this volume that provide rich accounts of conflicts and struggles over water use and how these tensions have been mitigated.

scholarly journals A plea for a novel kind of ecohydrology: the interaction between hydrological processes and - endangered or not - wildlife

2020 ◽  
Author(s):  
Jasper Griffioen ◽  
Martin Wassen ◽  
Joris Cromsigt
Keyword(s):  
Climate Change ◽  
Surface Water ◽  
Ecosystem Engineer ◽  
Sewage Water ◽  
Water Systems ◽  
Nature Reserves ◽  
Hydrological Processes ◽  
Groundwater Levels ◽  
Nature Restoration ◽  
The Impact

&lt;p&gt;Ecohydrology usually refers to the effects of hydrological processes on the occurrence, distribution and patterns of plants. Here, we emphasize a new kind of ecohydrology in which the effects of hydrological processes on the occurrence of &amp;#8211; endangered or not - wildlife become addressed via the threat of its habitat or, oppositely, where the occurrence of wildlife leads to a threat of endangered fauna. We present three examples to illustrate this.&lt;/p&gt;&lt;p&gt;First, the habitat of the tiger in the Terai Arc Landscape (TAL) at the foot of the Himalayas seems to increasingly become threatened by changes in the hydrological conditions. Grasslands in floodplains are an important part of the tiger habitat as these are the grounds where the tiger preferably hunts for deer as his prey. Disturbances of the water systems such as gravel and sand extraction from the river beds, intake of water for irrigation and hydropower production are increasingly happening and climate change may further alter the Himalayan water systems. This seems to disturb the grasslands in their hydrological and hydromorphological dynamics, which may negatively impact the density of deer, which may put additional pressure on the tiger populations in the nature reserves of the TAL.&lt;/p&gt;&lt;p&gt;Second, ungulates are important mammals in the grasslands and savannah of southern Africa. The water availability for these animals may alter upon climate change, including higher frequencies of droughts. Research suggests that the community composition of ungulates may alter by this. Here, the larger water-dependent grazers may be replaced by smaller, less water-dependent species.&lt;/p&gt;&lt;p&gt;Third, the beaver is well-known as hydrological ecosystem engineer. The beaver, therefore, has obtained some attention within the context of ecohydrology. The impact of the beaver as ecosystem engineer is, however, peculiar for nature reserves at the Belgian-Dutch border. Surface water with poor quality due to lack of appropriate sewage water treatment is running along nature reserves. The reintroduction of the beaver causes a rise in the surface and groundwater levels due to its dam-building activities. This induces an introduction of polluted surface water into the Dutch wetlands which contain a less eutrofied ecosystem than the Belgian ones that were fed by the polluted surface water. Nature restoration may thus go on the expense of nature degradation.&lt;/p&gt;&lt;p&gt;These examples show that the ecohydrology of wildlife is as fascinating and diverse as classical ecohydrology is.&lt;/p&gt;

scholarly journals Quantifying Focused Groundwater Recharge Induced by Irrigation Surface Water Reservoirs in Crystalline Basement Areas for Complementary Irrigation

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2880
Author(s):  
Apolline Bambara ◽  
Philippe Orban ◽  
Issoufou Ouedraogo ◽  
Eric Hallot ◽  
Francis Guyon ◽  
...  
Keyword(s):  
Surface Water ◽  
Groundwater Recharge ◽  
Large Diameter ◽  
Spatiotemporal Analysis ◽  
Sub Saharan Africa ◽  
Water Reservoirs ◽  
Water Shortages ◽  
Physico Chemical ◽  
Drying Up ◽  
Sub Saharan

Through the practice of irrigation, surface water reservoirs (SWRs) contribute to the socio-economic development and food production activities of populations in Sub-Saharan Africa (SSA). However, they tend to dry up prematurely. One solution to circumvent these irrigation water shortages is to ensure their conjunctive use with groundwater. The objective of this study is to better understand the contribution of SWRs to groundwater recharge and to determine if groundwater may be considered as a complementary local resource for irrigation. The study was carried out on two watersheds in Burkina Faso, Kierma and Mogtedo. The spatiotemporal analysis of piezometric and SWRs level records coupled with physico-chemical analyses of water was used to characterize exchanges between SWRs and groundwater. The regional groundwater recharge at the scale of the watersheds was assessed. At the SWRs scale, a water balance methodology was developed and used to estimate focused recharge. The results show that SWRs interact almost continuously with groundwater and contribute focused recharge. The magnitude of this recharge is a function of the geological context and the sediment texture of the SWRs. It is estimated at 5 mm/day in Kierma and 4 mm/day in Mogtédo. These values are higher than the natural recharge estimated at 0.2 mm/day in Kierma and 0.1 mm/day in Mogtédo. Additionally, the values of hydraulic conductivity are between 0.01 and 2 m/day in Kierma and between 1 × 10−4 and 0.2 m/day in Mogtédo. These conductivities could allow pumping in large-diameter hand-dug wells with a significant yield between 0.5 and 120 m3/day in Kierma and between 0 and 10 m3/day in Mogtédo to palliate the early drying up of the SWRs.

scholarly journals Climate change and sectors of the surface water cycle in CMIP5 projections

2014 ◽  
Vol 11 (7) ◽  
pp. 8537-8569 ◽  
Author(s):  
P. A. Dirmeyer ◽  
G. Fang ◽  
Z. Wang ◽  
P. Yadav ◽  
A. D. Milton
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Surface Water ◽  
Interannual Variability ◽  
Water Cycle ◽  
Global Climate ◽  
Water Shortages ◽  
Change Models ◽  
River Flooding ◽  
Increased Risk

Abstract. Results from ten global climate change models are synthesized to investigate changes in extremes, defined as wettest and driest deciles in precipitation, soil moisture and runoff based on each model's historical twentieth century simulated climatology. Under a moderate warming scenario, regional increases in drought frequency are found with little increase in floods. For more severe warming, both drought and flood become much more prevalent, with nearly the entire globe significantly affected. Soil moisture changes tend toward drying while runoff trends toward flood. To determine how different sectors of society dependent the on various components of the surface water cycle may be affected, changes in monthly means and interannual variability are compared to data sets of crop distribution and river basin boundaries. For precipitation, changes in interannual variability can be important even when there is little change in the long-term mean. Over 20% of the globe is projected to experience a combination of reduced precipitation and increased variability under severe warming. There are large differences in the vulnerability of different types of crops, depending on their spatial distributions. Increases in soil moisture variability are again found to be a threat even where soil moisture is not projected to decrease. The combination of increased variability and greater annual discharge over many basins portends increased risk of river flooding, although a number of basins are projected to suffer surface water shortages.

scholarly journals How might climate change affect river flows across West Africa?

2021 ◽  
Vol 169 (3-4) ◽  
Author(s):  
Ponnambalam Rameshwaran ◽  
Victoria A. Bell ◽  
Helen N. Davies ◽  
Alison L. Kay
Keyword(s):  
Climate Change ◽  
West Africa ◽  
Regional Scale ◽  
Weather Data ◽  
Eastern Region ◽  
Water Shortages ◽  
River Flows ◽  
Considerable Uncertainty ◽  
Modelling Framework ◽  
The Impact

AbstractWest Africa and its semi-arid Sahelian region are one of the world’s most vulnerable regions to climate change with a history of extreme climate variability. There is still considerable uncertainty as to how projected climate change will affect precipitation at local and regional scales and the consequent impact on river flows and water resources across West Africa. Here, we aim to address this uncertainty by configuring a regional-scale hydrological model to West Africa. The model (hydrological modelling framework for West Africa—HMF-WA) simulates spatially consistent river flows on a 0.1° × 0.1° grid (approximately 10 km × 10 km) continuously across the whole domain and includes estimates of anthropogenic water use, wetland inundation, and local hydrological features such as endorheic regions. Regional-scale hydrological simulations driven by observed weather data are assessed against observed flows before undertaking an analysis of the impact of projected future climate scenarios from the CMIP5 on river flows up to the end of the twenty-first century. The results indicate that projected future changes in river flows are highly spatially variable across West Africa, particularly across the Sahelian region where the predicted changes are more pronounced. The study shows that median peak flows are projected to decrease by 23% in the west (e.g. Senegal) and increase by 80% in the eastern region (e.g. Chad) by the 2050s. The projected reductions in river flows in western Sahel lead to future droughts and water shortages more likely, while in the eastern Sahel, projected increases lead to future frequent floods.

scholarly journals Climate Change, Water Scarcity, and the Potential for Interstate Conflict in South Asia

2020 ◽  
Vol 13 (4) ◽  
pp. 109-122
Author(s):  
Michael Klare
Keyword(s):  
Climate Change ◽  
South Asia ◽  
Critical Factor ◽  
Interstate Conflict ◽  
Security Analysts ◽  
River Systems ◽  
Water Shortages ◽  
Himalayan Glaciers ◽  
The Subject ◽  
The Impact

Ever since American security analysts began to consider the impact of global warming on international security, water has been viewed as an especially critical factor. In many parts of the developing world, water supplies are already insufficient to meet societal requirements, and, by shrinking these supplies further, climate change will cause widespread hardship, unrest, and conflict. But exactly what role water plays in this equation has been the subject of considerable reassessment over time. When analysts first examined warming’s impacts, they largely assumed that climate-related water scarcities would most likely provoke conflict within nations; only later did analysts look closely at the possibility of conflicts arising between states, typically in the context of shared river systems. This risk appears particularly acute in South Asia, where several highly-populated countries, including China, India, and Pakistan, rely on river systems which depend for part of their flow on meltwater from the Himalayan glaciers, which are contracting as a result of climate change. In the absence of greater efforts by these countries to address this peril in a collaborative, equitable manner, looming water shortages could combine with other antagonisms to trigger armed conflict, possibly entailing the use of nuclear weapons.

scholarly journals Assessment of impacts of climate change on surface water availability using coupled SWAT and WEAP models: case of upper Pangani River Basin, Tanzania

2018 ◽  
Vol 378 ◽  
pp. 23-27 ◽  
Author(s):  
Peter Kishiwa ◽  
Joel Nobert ◽  
Victor Kongo ◽  
Preksedis Ndomba
Keyword(s):  
Climate Change ◽  
Surface Water ◽  
River Basin ◽  
Water Use ◽  
Water Availability ◽  
Swat Model ◽  
Economic Activities ◽  
Peak Flows ◽  
Global Circulation Models ◽  
The Impact

Abstract. This study was designed to investigate the dynamics of current and future surface water availability for different water users in the upper Pangani River Basin under changing climate. A multi-tier modeling technique was used in the study, by coupling the Soil and Water Assessment Tool (SWAT) and Water Evaluation And Planning (WEAP) models, to simulate streamflows under climate change and assess scenarios of future water availability to different socio-economic activities by year 2060. Six common Global Circulation Models (GCMs) from WCRP-CMIP3 with emissions Scenario A2 were selected. These are HadCM3, HadGEM1, ECHAM5, MIROC3.2MED, GFDLCM2.1 and CSIROMK3. They were downscaled by using LARS-WG to station scale. The SWAT model was calibrated with observed data and utilized the LARS-WG outputs to generate future streamflows before being used as input to WEAP model to assess future water availability to different socio-economic activities. GCMs results show future rainfall increase in upper Pangani River Basin between 16–18 % in 2050s relative to 1980–1999 periods. Temperature is projected to increase by an average of 2 ∘C in 2050s, relative to baseline period. Long-term mean streamflows is expected to increase by approximately 10 %. However, future peak flows are estimated to be lower than the prevailing average peak flows. Nevertheless, the overall annual water demand in Pangani basin will increase from 1879.73 Mm3 at present (2011) to 3249.69 Mm3 in the future (2060s), resulting to unmet demand of 1673.8 Mm3 (51.5 %). The impact of future shortage will be more severe in irrigation where 71.12 % of its future demand will be unmet. Future water demands of Hydropower and Livestock will be unmet by 27.47 and 1.41 % respectively. However, future domestic water use will have no shortage. This calls for planning of current and future surface water use in the upper Pangani River Basin.

Climate change vs. human impact. A look into Austrian groundwater

2020 ◽  
Author(s):  
Johannes Christoph Haas ◽  
Steffen Birk
Keyword(s):  
Climate Change ◽  
Surface Water ◽  
Water Supply ◽  
Human Impact ◽  
Water Use ◽  
Special Role ◽  
European Alps ◽  
Groundwater Levels ◽  
Human Use ◽  
The Impact

&lt;p&gt;Climate change is mostly associated with the term of &amp;#8220;global warming&amp;#8221; and thus conjures images of a hotter and dryer future. Indeed, the Alpine region already has seen much higher warming compared to the average of the northern hemisphere [1]. However, because of the impact of other climate variables (e.g. precipitation) and vegetation responses, warming does not necessarily have to mean higher evapotranspiration and dryer conditions [2]. This matter is further complicated as groundwater is closely interlinked with surface water. While surface water is of course related to precipitation, it is also one of the major pathways for humans to have a large and direct impact on the water cycle, e.g. by the construction of run-of-river powerplants. A further direct human impact is the abstraction of groundwater. For this factor, it is generally understood that water use increased with economic activity until the rise of environmentalism in the 1980s and more efficient water use stopped this trend and turned it into a decrease in many industrialized countries.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Assessing impacts of climate change on groundwater resources therefore is a challenging task. In order to assess these, as well as direct human impacts on groundwater, we analyzed a large dataset (1017 groundwater level-, 426 stream stage- and 646 precipitation time series) covering Austria from earlier than 1930 until 2015, with the majority of the data from the 1970s on.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;It is shown that groundwater shows a strong falling trend, followed by a rise, fitting the human water use, whereas precipitation shows a more moderate trend. River stages show a completely deviating behavior before the 1980s but also follow the rising trend afterwards [3]. While this does not yet prove a causal link, it does highlight the possibility that human use could affect groundwater levels more than the climate, especially since Austria almost exclusively uses groundwater for human use and the wells in the dataset are all located in the populated lowlands.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Going beyond [3], we take a closer look at the history and future of the human factor, namely water abstraction for public water supply and the effects of humans on rivers. We show that Austria has a very particular form of water supply, mainly due to the special role of the capital, Vienna, whose history could see a repeat in the near future. Under a changing climate, there is also a possibility for further changes in Austria&amp;#8217;s rivers. In addition to effects of such changes on groundwater levels, we try to address potential impacts on the chemical quality and ecological status of groundwater.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;References:&lt;/p&gt;&lt;p&gt;[1] Gobiet et al., 2014, 21&lt;sup&gt;st&lt;/sup&gt; century climate change in the European alps-a review. Sci. Total. Environ. 493, 1138 &amp;#8211; 1151.&lt;/p&gt;&lt;p&gt;[2] Pangle et al., 2014, Rainfall seasonality and an ecohydrological feedback offset the potential impact of climate warming on evapotranspiration and groundwater recharge, Water Resour. Res., 50, 1308&amp;#8211;1321&lt;/p&gt;&lt;p&gt;[3] Haas &amp; Birk, 2019, Trends in Austrian groundwater &amp;#8211; climate or human impact? J. Hydrol.: Reg. Stud. 22, 100597&lt;/p&gt;

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