Water Availability--The Connection Between Water Use and Quality

Fact Sheet ◽  
2008 ◽  
Author(s):  
Robert M. Hirsch ◽  
Pixie A. Hamilton ◽  
Timothy L. Miller ◽  
Donna N. Myers
Keyword(s):  
2018 ◽  
Vol 22 (5) ◽  
pp. 2795-2809 ◽  
Author(s):  
Hafsa Ahmed Munia ◽  
Joseph H. A. Guillaume ◽  
Naho Mirumachi ◽  
Yoshihide Wada ◽  
Matti Kummu

Abstract. Countries sharing river basins are often dependent upon water originating outside their boundaries; meaning that without that upstream water, water scarcity may occur with flow-on implications for water use and management. We develop a formalisation of this concept drawing on ideas about the transition between regimes from resilience literature, using water stress and water shortage as indicators of water scarcity. In our analytical framework, dependency occurs if water from upstream is needed to avoid scarcity. This can be diagnosed by comparing different types of water availability on which a sub-basin relies, in particular local runoff and upstream inflows. At the same time, possible upstream water withdrawals reduce available water downstream, influencing the latter water availability. By developing a framework of scarcity and dependency, we contribute to the understanding of transitions between system regimes. We apply our analytical framework to global transboundary river basins at the scale of sub-basin areas (SBAs). Our results show that 1175 million people live under water stress (42 % of the total transboundary population). Surprisingly, the majority (1150 million) of these currently suffer from stress only due to their own excessive water use and possible water from upstream does not have impact on the stress status – i.e. they are not yet dependent on upstream water to avoid stress – but could still impact on the intensity of the stress. At the same time, 386 million people (14 %) live in SBAs that can avoid stress owing to available water from upstream and have thus upstream dependency. In the case of water shortage, 306 million people (11 %) live in SBAs dependent on upstream water to avoid possible shortage. The identification of transitions between system regimes sheds light on how SBAs may be affected in the future, potentially contributing to further refined analysis of inter- and intrabasin hydro-political power relations and strategic planning of management practices in transboundary basins.


2011 ◽  
Vol 15 (12) ◽  
pp. 3785-3808 ◽  
Author(s):  
Y. Wada ◽  
L. P. H. van Beek ◽  
M. F. P. Bierkens

Abstract. During the past decades, human water use has more than doubled, yet available freshwater resources are finite. As a result, water scarcity has been prevalent in various regions of the world. Here, we present the first global assessment of past development of water stress considering not only climate variability but also growing water demand, desalinated water use and non-renewable groundwater abstraction over the period 1960–2001 at a spatial resolution of 0.5°. Agricultural water demand is estimated based on past extents of irrigated areas and livestock densities. We approximate past economic development based on GDP, energy and household consumption and electricity production, which are subsequently used together with population numbers to estimate industrial and domestic water demand. Climate variability is expressed by simulated blue water availability defined by freshwater in rivers, lakes, wetlands and reservoirs by means of the global hydrological model PCR-GLOBWB. We thus define blue water stress by comparing blue water availability with corresponding net total blue water demand by means of the commonly used, Water Scarcity Index. The results show a drastic increase in the global population living under water-stressed conditions (i.e. moderate to high water stress) due to growing water demand, primarily for irrigation, which has more than doubled from 1708/818 to 3708/1832 km3 yr−1 (gross/net) over the period 1960–2000. We estimate that 800 million people or 27% of the global population were living under water-stressed conditions for 1960. This number is eventually increased to 2.6 billion or 43% for 2000. Our results indicate that increased water demand is a decisive factor for heightened water stress in various regions such as India and North China, enhancing the intensity of water stress up to 200%, while climate variability is often a main determinant of extreme events. However, our results also suggest that in several emerging and developing economies (e.g. India, Turkey, Romania and Cuba) some of past extreme events were anthropogenically driven due to increased water demand rather than being climate-induced.


2018 ◽  
Vol 36 (1) ◽  
pp. 7-13
Author(s):  
Melissa C. Smith ◽  
Richard N. Mack

Abstract Suitable plant water dynamics and the ability to withstand periods of low moisture input facilitate plant establishment in seasonally arid regions. Temperate bamboos are a major constituent of mixed evergreen and deciduous forests throughout temperate East Asia but play only an incidental role in North American forests and are altogether absent in the Pacific Northwest forest. Many bamboo species are classified as mesic or riparian, but none are considered drought tolerant. To assess their ability to withstand low water, we subjected five Asian temperate and one North American temperate bamboo species to three irrigation treatments: 100%, 50%, and 10% replacement of water lost through evapotranspiration. Plants were irrigated every four days over a 31-day period. Plant response to treatments was measured with stomatal conductance, leaf xylem water potentials, and intrinsic water use efficiency (iWUE). Pleioblastus distichus and Pseudosasa japonica showed significant reductions in conductance between high and low irrigation treatments. Sasa palmata had significantly lower stomatal conductance in all treatments. Pleioblastus chino displayed significantly higher iWUE in the mid irrigation treatment and Arunindaria gigantea displayed significantly lower iWUE than P. chino and S. palmata in the low irrigation treatment. The Asian bamboo species examined here tolerate low water availability and readily acclimate to different soil moisture conditions. Index words: Temperate bamboos, irrigation response, stomatal conductance, intrinsic water use efficiency. Species used in this study: Giant Cane [Arundinaria gigantea (Walt.) Muhl.]; Pleioblastus chino (Franchet & Savatier) Makino; Pleioblastus distichus (Mitford) Nakai; Pseudosasa japonica (Makino); Sasa palmata (Bean) Nakai.


Author(s):  
V.B. Zhezmer

Водообеспеченность объектов мелиоративного комплекса имеет решающее значение при обеспечении высоких и устойчивых урожаев сельскохозяйственных культур в аридных регионах страны. В статье рассмотрены способы устранения негативного влияния основных факторов, способствующих созданию дефицита воды для орошения. Проведен анализ схемы, в которой целью мероприятий является эффективное вложение средств при восстановлении элементов гидромелиоративных систем и обеспечение рационализации водопользования. Установлено, что алгоритмы и конечные выводы, подученные в ходе анализа, могут различаться в зависимости от поставленных задач и объема информации.Water availability of the reclamation complex facilities is crucial in ensuring high and sustainable crop yields in the arid regions of the country. The article discusses ways to eliminate the negative impact of the main factors contributing to the creation of a shortage of water for irrigation. The analysis of the scheme in which the purpose of the measures is an effective investment in the restoration of elements of irrigation and drainage systems and ensuring the rationalization of water use is carried out. It is established that the algorithms and final conclusions obtained during the analysis may vary depending on the tasks and the amount of information.


2020 ◽  
Vol 462 ◽  
pp. 117999 ◽  
Author(s):  
Yansen Xu ◽  
Zhaozhong Feng ◽  
Bo Shang ◽  
Xiangyang Yuan ◽  
Lasse Tarvainen

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1538 ◽  
Author(s):  
V. A. Tzanakakis ◽  
A. N. Angelakis ◽  
N. V. Paranychianakis ◽  
Y. G. Dialynas ◽  
G. Tchobanoglous

Crete, located in the South Mediterranean Sea, is characterized by long coastal areas, varied terrain relief and geology, and great spatial and inter-annual variations in precipitation. Under average meteorological conditions, the island is water-sufficient (969 mm precipitation; theoretical water potential 3284 hm3; and total water use 610 hm3). Agriculture is by far the greatest user of water (78% of total water use), followed by domestic use (21%). Despite the high average water availability, water scarcity events commonly occur, particularly in the eastern-south part of the island, driven by local climatic conditions and seasonal or geographical mismatches between water availability and demand. Other critical issues in water management include the over-exploitation of groundwater, accounting for 93% of the water used in agriculture; low water use efficiencies in the farms; limited use of non-conventional water sources (effluent reuse); lack of modern frameworks of control and monitoring; and inadequate cooperation among stakeholders. These deficiencies impact adversely water use efficiency, deteriorate quality of water resources, increase competition for water and water pricing, and impair agriculture and environment. Moreover, the water-limited areas may display low adaptation potential to climate variability and face increased risks for the human-managed and natural ecosystems. The development of appropriate water governance frameworks that promote the development of integrated water management plans and allow concurrently flexibility to account for local differentiations in social-economic favors is urgently needed to achieve efficient water management and to improve the adaptation to the changing climatic conditions. Specific corrective actions may include use of alternative water sources (e.g., treated effluent and brackish water), implementation of efficient water use practices, re-formation of pricing policy, efficient control and monitoring, and investment in research and innovation to support the above actions. It is necessary to strengthen the links across stakeholders (e.g., farmers, enterprises, corporations, institutes, universities, agencies, and public authorities), along with an effective and updated governance framework to address the critical issues in water management, facilitate knowledge transfer, and promote the efficient use of non-conventional water resources.


Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1078 ◽  
Author(s):  
Alvaro Sordo-Ward ◽  
Alfredo Granados ◽  
Ana Iglesias ◽  
Luis Garrote ◽  
María Bejarano

We evaluated different management alternatives to enhance potential water availability for agriculture under climate change scenarios. The management goal involved maximizing potential water availability, understood as the maximum volume of water supplied at a certain point of the river network that satisfies a defined demand, and taking into account specified reliability requirements. We focused on potential water availability for agriculture and assumed two types of demands: urban supply and irrigation. If potential water availability was not enough to satisfy all irrigation demands, management measures were applied aiming at achieving a compromise solution between resources and demands. The methodological approach consisted of estimation and comparison of runoff for current and future period under climate change effects, calculation of water availability changes due to changes in runoff, and evaluation of the adaptation choices that can modify the distribution of water availability, under climate change. Adaptation choices include modifying water allocation to agriculture, increasing the reservoir storage capacity, improving the efficiency of urban water use, and modifying water allocation to environmental flows. These management measures were evaluated at the desired points of the river network by applying the Water Availability and Adaptation Policy Analysis (WAAPA) model. We simulated the behavior of a set of reservoirs that supply water for a set of prioritized demands, complying with specified ecological flows and accounting for evaporation losses. We applied the methodology in six representative basins of southern Europe: Duero-Douro, Ebro, Guadalquivir, Po, Maritsa-Evros, and Struma-Strymon. While in some basins, such as the Ebro or Struma-Strymon, measures can significantly increase water availability and compensate for a fraction of water scarcity due to climate change, in other basins, like the Guadalquivir, water availability cannot be enhanced by applying the management measures analyzed, and irrigation water use will have to be reduced.


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