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.

Sustaining water. Population and the future of renewable water supplies.

Abstract: This report examines the effect of population size growth distribution and consumption patterns on renewable water supplies. Even though more than 66% of this planet is covered with water fresh water makes up only 2.5% of the entire water supply and 69% of that is in the polar ice caps. These figures take on even more meaning as the population increases. The rate at which the global hydrologic cycle renews or replenishes fresh water resources determines the availability of fresh water for human use. Evaporative demand and the timing and location of precipitation contribute greatly to its availability. The greatest drain on water supplies is agriculture (69% of all use) followed by industry and energy (23%) and household use (8%). Desalination of our oceans has been hailed as a technology providing an inexhaustible water supply but extracting salt from seawater is expensive and depends on nonrenewable pollution-causing fossil fuels. Acute water shortages have already plagued some countries regions and municipalities. Europe and North America could not have industrialized had it not been for dependable sources of abundant water. Yet many developing countries do not have such access making economic development more difficult for them to achieve. Countries with less than 1700 cubic meters/person less than 1000 cubic meters/person and less than 500 cubic meters/person face water stress chronic water scarcity and absolute water scarcity respectively. The number of water-scarce countries increased from 7 in 1955 to 20 in 1990 and if population growth projections continue there will be 30-35 water-scarce countries by 2025. Deteriorating water quality caused by raw sewage and industrialized and agricultural wastes further reduces the availability of fresh water and causes numerous diseases (e.g. diarrhea). Access to potable water and sanitation is needed to achieve individual health. Water will eventually overshadow oil as a scarce and precious resource. Population stabilization water conservation and more efficient use of water are the most effective long-term strategies to manage water scarcity.

What is the limit of up-scaling rainwater harvesting in a river basin?

Abstract: The semi-arid savannah environment (SASE) of sub-Saharan Africa are characterized by low erratic rainfall which result to high risk of droughts, intra-seasonal dry spells and frequent food insecurity. The main occupation is subsistence small-scale rainfed agriculture and livestock production, which normally compete for the limited water resources. The main challenges to improving the livelihoods of the small-scale farmers are how to upgrade rainfed agriculture to improve rural livelihoods and conserve nature, and upgrade upstream landuse in balance with water needs for human and ecosystems downstream. There is an increased interest in opportunities of improving rainfed agriculture through adoption of rainwater harvesting (RWH) technologies. However, there is inadequate knowledge on hydrological impacts and limits of up-scaling rainwater harvesting at a river basin scale. Rainwater harvesting has a potential of addressing spatial and temporal water scarcity for domestic, crop production, livestock development, environmental management and overall water resources management is SASE. However, this potential has not been exploited despite the occurrence of persistent low agricultural production and food shortage in sub-Saharan Africa. The need to quantify this perceived potential and related hydrological impacts on a river basin led to the on-going research project titled “hydrological impacts of up-scaling RWH on upper Ewaso Ng’iro river basin water resources management”. It is envisaged that the study will contribute to formulation of sustainable RWH up-scaling strategies to enhance food production and hydro-ecological balance in semi-arid savannahs of Africa. This paper presents the preliminary findings of the study mainly focusing on assessment of the potential of RWH technologies for improving food and water availability especially in semi-arid regions of eastern Africa. This was achieved by evaluating six RWH case studies selected from four countries (Ethiopia, Kenya, Tanzania and Uganda). Despite the success of a number of RWH systems, the rate of adoption is still low, hence making their impacts marginal. Nevertheless, there is a knowledge gap on the limits of up-scaling RWH in a river basin, which the other components of the study will address. The assessment of the hydrological impact of up-scaling RWH technologies is expected to provide answers to the question, what is the limit of up-scaling rainwater harvesting in a river basin ?

Mediterranean coastal lagoons in an ecosystem and aquatic resources management context

Abstract: Aquatic ecosystems, water resources and their management are some of the main problems facing humanity. These problems vary from water scarcity and deteriorating quality for human consumption and use, to floods in areas with torrential rainfall, rising sea levels in coastal zones, the overexploitation of living resources and the loss of ecological quality and biodiversity. Proper water management needs to follow a hierarchical perspective, ranging from the whole planet to individual water bodies. Spatio-temporal scales change at each level, as do driving forces, impacts, and the processes and responses involved. Recently, the European Union adopted the Water Framework Directive (WFD) to establish the basic principles of sustainable water policy in member states, one of the main concerns being the need to consider the vulnerability of coastal aquatic ecosystems and to establish their ecological status. However, from a Mediterranean point of view, the actions of European countries (under the WFD regulations) and non-EU countries need to be coordinated. There are more than 100 coastal lagoons in the Mediterranean. They are habitats with an important ecological role, but also provide essentials goods and services for humans. In the present work, we look at the problems involved in understanding their definition and management. At water body management level, we emphasise that scientific cooperation is necessary to deal with the conceptual and ecological difficulties derived from inter and intra-lagoon variability in hydrology and biological assemblages, inherent factors in the functioning of these complex ecosystems.

Questioning the water wars rationale: a case study of the Indus Waters Treaty.

Abstract: The water wars rationale predicts that countries will wage war to safeguard their access to water resources, especially if there is water scarcity, competitive use and the countries are enemies due to a wider conflict. Following this argument, India and Pakistan should have fought a war over the Indus basin instead of negotiating the 1960 Indus Waters Treaty. In explaining this Indo-Pakistan cooperation which is specifically over water, the critical feature that emerges is that through cooperation the countries were able to safeguard their long-term water supply. In other words, cooperation is water rational. Using the Indus basin experience, the underlying logic of the water wars rationale is questioned, in particular, the use of public statements by key decisionmakers as evidence of future water wars and is shown to be wanting.