Water scarcity

About: Water scarcity is a research topic. Over the lifetime, 11579 publications have been published within this topic receiving 228756 citations. The topic is also known as: water shortage.

Global water scarcity including surface water quality and expansions of clean water technologies

Abstract: Water scarcity threatens people in various regions, and has predominantly been studied from a water quantity perspective only. Here we show that global water scarcity is driven by both water quantity and water quality issues, and quantify expansions in clean water technologies (i.e. desalination and treated wastewater reuse) to ‘reduce the number of people suffering from water scarcity’ as urgently required by UN’s Sustainable Development Goal 6. Including water quality (i.e. water temperature, salinity, organic pollution and nutrients) contributes to an increase in percentage of world’s population currently suffering from severe water scarcity from an annual average of 30% (22%–35% monthly range; water quantity only) to 40% (31%–46%; both water quantity and quality). Water quality impacts are in particular high in severe water scarcity regions, such as in eastern China and India. In these regions, excessive sectoral water withdrawals do not only contribute to water scarcity from a water quantity perspective, but polluted return flows degrade water quality, exacerbating water scarcity. We show that expanding desalination (from 2.9 to 13.6 billion m3 month−1) and treated wastewater uses (from 1.6 to 4.0 billion m3 month−1) can strongly reduce water scarcity levels and the number of people affected, especially in Asia, although the side effects (e.g. brine, energy demand, economic costs) must be considered. The presented results have potential for follow-up integrated analyses accounting for technical and economic constraints of expanding desalination and treated wastewater reuse across the world.

Water depletion: An improved metric for incorporating seasonal and dry-year water scarcity into water risk assessments

Abstract: We present an improved water-scarcity metric we call water depletion, calculated as the fraction of renewable water consumptively used for human activities. We employ new data from the WaterGAP3 integrated global water resources model to illustrate water depletion for 15,091 watersheds worldwide, constituting 90% of total land area. Our analysis illustrates that moderate water depletion at an annual time scale is better characterized as high depletion at a monthly time scale and we are thus able to integrate seasonal and dry-year depletion into the water depletion metric, providing a more accurate depiction of water shortage that could affect irrigated agriculture, urban water supply, and freshwater ecosystems. Applying the metric, we find that the 2% of watersheds that are more than 75% depleted on an average annual basis are home to 15% of global irrigated area and 4% of large cities. An additional 30% of watersheds are depleted by more than 75% seasonally or in dry years. In total, 71% of world irrigated area and 47% of large cities are characterized as experiencing at least periodic water shortage.

Toward Prudent management of Water Resources in Iraq

Abstract: In 1977 the Turkish Government started to utilize the water of Tigris and Euphrates Rivers through South-eastern Anatolia Project (GAP). The project includes 22 dams and 19 hydraulic power plants which are to irrigate 17 10 3 km 2 of land with a total storage capacity of 100 km 3 which is three times more than the overall capacity of Iraq and Syrian reservoirs Prior to 1990, Syria used to receive 21 km 3 /year of the Euphrates water which dropped to 12km 3 in 2000 onward and for Iraq it dropped from 29 km 3 before 1990 to 4,4km 3 (90% reduction) now. This reduced agricultural land in both countries from 650 10 3 to 240 10 3 hectares. Iraq used to receive 20.9 km 3 /year of water from the Tigris River and once Ilisu dam is constructed, this is likely to drop to 9.7 km 3 which means that 47% of the river flow will be depleted. This means that 696 10 3 hectares of agricultural land will be abandoned due to water scarcity. The reduction of flow in the Tigris and Euphrates Rivers in Iraq is considered to be national crises and will have severe negative consequences on health and on environmental, industrial and economic development. It is believed that the Iraqi Government should take solid and fast measures to ensure prudent management of its water resources and to secure the life of huge sector of its society and protect the environment.

Prospects of orphan crops in climate change

Abstract: Orphan crops can contribute to building resilience of marginal cropping systems as a climate chnage adaptation strategy. Orphan crops play an important role in global food and nutrition security, and may have potential to contribute to sustainable food systems under climate change. Owing to reports of their potential under water scarcity, there is an argument to promote them to sustainably address challenges such as increasing drought and water scarcity, food and nutrition insecurity, environmental degradation, and employment creation under climate change. We conducted a scoping review using online databases to identify the prospects of orphan crops to contribute to (1) sustainable and healthy food systems, (2) genetic resources for future crop improvement, and (3) improving agricultural sustainability under climate change. The review found that, as a product of generations of landrace agriculture, several orphan crops are nutritious, resilient, and adapted to niche marginal agricultural environments. Including such orphan crops in the existing monocultural cropping systems could support more sustainable, nutritious, and diverse food systems in marginalised agricultural environments. Orphan crops also represent a broad gene pool for future crop improvement. The reduction in arable land due to climate change offers opportunities to expand the area under their production. Their suitability to marginal niche and low-input environments offers opportunities for low greenhouse gas (GHG) emissions from an agro-ecosystems, production, and processing perspective. This, together with their status as a sub-set of agro-biodiversity, offers opportunities to address socio-economic and environmental challenges under climate change. With research and development, and policy to support them, orphan crops could play an important role in climate-change adaptation, especially in the global south.

Optional water development strategies for the Yellow River Basin: Balancing agricultural and ecological water demands

Abstract: [1] The Yellow River Basin is of the utmost importance for China in terms of food production, natural resources management, and socioeconomic development. Water withdrawals for agriculture, industry, and households in the past decade have seriously depleted environmental and ecological water requirements in the basin. This study presents a modeling scenario analysis of some water development strategies to harmonize water withdrawal demand and ecological water demand in the Yellow River Basin through water savings and interbasin water transfers. A global water and food analysis model including the Yellow River Basin as one of the modeling units is applied for the analysis. The model demonstrates that there is little hope of resolving the conflict between agriculture water demand and ecological water demand in the basin if the current water use practices continue. Trade-offs exist between irrigation water use and ecological water use, and these trade-offs will become more intense in future years with population growth, urbanization, and industrial development as well as growing food demand. Scenario analysis in this study concludes that increasing basin water use efficiency to 0.67 first and then supplementary water availability by interbasin water transfer through the South-North Water Transfer Project may provide a solution to water management of the Yellow River Basin in the next 25 years.