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.

Southern California Water Markets: Potential and Limitations

Abstract: This paper explores the potential and limitations for southern California water markets using an economic-engineering network flow optimization model, CALVIN. CALVIN is used to estimate how a market would affect overall southern California water use, to preliminarily assess the economic benefit of more flexible water allocation policies, and to explore the characteristics of an ideal market. Results from CALVIN suggest substantial economic and reliability benefits exist for implementing water market or other transfer mechanisms, and these benefits could be achieved with relatively little reallocation of agricultural water. An ideal water market in southern California would reduce more costly urban water shortages, reducing the demand for increased imports from outside of southern California. Additionally, substantial economic benefits could accrue from expanding some conveyance and storage facilities, particularly the Colorado River Aqueduct and conjunctive use storage capacity.

Assessing Progress on Integrating Disaster Risk Reduction and Climate Change Adaptation in Development Processes

Abstract: Climate change threatens development and the progress needed to achieve the Millennium Development Goals. With shifting seasons, increasing water scarcity, and potentially more frequent and intense extreme events (IPCC 2007), climate change is bringing a series of disaster and livelihood impacts to the poorest and most vulnerable countries and communities, and is placing development assistance at risk. In managing such risks to development, there is a significant overlap of concepts and shared goals between disaster risk reduction (DRR) and climate change adaptation (CCA). In Mitchell and Van Aalst (2008), we reviewed the extent of convergence between the two at a number of scales, finding limited integration and both approaches struggling to be mainstreamed into regular development programming. We suggested that continued separation risked policy incoherence and ineffective use of resources, due to administrative inefficiencies, duplication of efforts and damaging competition between different inter-sectoral coordinating mechanisms. Since 2008, the momentum toward convergence has continued to grow and analysis in this 2010 assessment indicates pockets and trajectories of integration that promise improved development outcomes. However, it also demonstrates continued separation of DRR, CCA and development in some geographic areas and significant structural barriers to convergence in critical institutions at different scales. Assessing progress on integrating DRR and CCA 3

Water for growth and development

Abstract: The immediate goal of this paper is therefore to provoke discussion and strengthen understanding of the importance of water resources management and development in enabling responsible economic growth and poverty alleviation - fully mindful of the fact that this is just one of many aspects that must be weighed and understood in managing water resources. The paper's broader objective is to contribute to a constructive, comprehensive dialogue that will help inform the difficult trade-offs inherent in water management, and assist decision makers in finding the most acceptable balance among human aspirations for growth and poverty alleviation, social and cultural integrity, and environmental sustainability.

Conflicts about water in Lake Chad: Are environmental, vulnerability and security issues linked?

Abstract: This article builds on the growing literature that explores the relationships between environmental change and non-traditional security, defined as non-military threats that challenge the survival ...

Water Deficit and Nitrogen Nutrition of Crops

Abstract: Among the environmental factors that can be modified by farmers, water and nitrogen are the main ones controlling plant growth. Irrigation and fertilizer application overcome this effect, if adequately used. Agriculture thus consumes about 85% of the total fresh water used worldwide. While only 18% of the world’s cultivated areas are devoted to irrigated agriculture, this total surface represents more than 45% of total agricultural production. These data highlight the importance of irrigated agriculture in a framework where the growing population demands greater food production. In addition, tighter water restrictions and competition with other sectors of society is increasing pressure to diminish the share of fresh water for irrigation, thus resulting in the decrease in water diverted for agriculture.The effect of water and nutrient application on yield has led to the overuse of these practices in the last decades. This misuse of irrigation and fertilizers is no longer sustainable, given the economic and environmental costs. Sustainable agriculture requires a correct balance between the agronomic, economic and environmental aspects of nutrient management. The major advances shown in this review are the following: (1) the measurement of the intensity of drought and N deficiency is a prerequisite for quantitative assessment of crop needs and management of both irrigation and fertilizer application. The N concentration of leaves exposed to direct irradiance allows both a reliable and high-resolution measurement of the status and the assessment of N nutrition at the plant level. (2) Two experiments on sunflower and on tall fescue are used to relate the changes in time and irrigation intensity to the crop N status, and to introduce the complex relationships between N demand and supply in crops. (3) Effects of water deficits on N demand are reviewed, pointing out the high sensitivity of N-rich organs versus the relative lesser sensitivity of organs that are poorer in N compounds. (4) The generally equal sensitivities of nitrifying and denitrifying microbes are likely to explain many conflicting results on the impact of water deficits on soil mineral N availability for crops. (5) The transpiration stream largely determines the availability of mineral N in the rhizosphere. This makes our poor estimate of root densities a major obstacle to any precise assessment of N availability in fertilized crops. (6) The mineral N fluxes in the xylem are generally reduced under water deficit and assimilation is generally known to be more sensitive to water scarcity. (7) High osmotic pressures are maintained during grain filling, which enables the plant to recycle large amounts of previously assimilated N. Its part in the total grain N yield is therefore generally higher under water deficits. (8) Most crop models currently used in agronomy use N and water efficiently but exhibit different views on their interaction.