You are here: Home Knowledge Base Environment Water Scarcity and Virtual Water Trade Proposals by Yacov Tsur
Symposium 2011

Proposal - by Yacov Tsur

The Challenge

Two fifths of the world’s population faces water shortages. During the coming decades, water scarcity is expected to rise as a result of a rapid increase in the demand for water due to population gr ...

Two fifths of the world’s population faces water shortages. During the coming decades, water scarcity is expected to rise as a result of a rapid increase in the demand for water due to population growth, urbanization and increasing consumption of water per capita. In addition, climate change is expected to influence the supply of water, modifying the regional distribution of freshwater resources.

Water reuse

Rapid technological development has increased the efficiency and reduced the cost of recycled water. We now know that about 60 percent of residential water consumption can be treated (to secondary or tertiary level) and reused in crop production and environmental (stream flows, ecosystems) restoration. Moreover, in more and more countries, environmental standards require treatment of sewage water. As a result, the residential sector, which has been competing fiercely with Agriculture for the limited amount of renewable fresh water, becomes an important source of irrigation water supply. And the potential of this source will continue to increase in the foreseeable future. The use of recycled water requires substantial infrastructure investment in treatment, conveyance and distribution facility as well as strict control of how recycled water of different quality is used. The role of governments in advancing water reuse and in setting and enforcing quality standards is therefore crucial.

Conjunctive ground-and-surface water management

It is important to distinguish between spatial and temporal water scarcity. Spatial scarcity can be alleviated by conveying water from where it is abundant to where it is scarce or, alternatively, by trading the product of water (crop yield) between water abundant and water scarce regions (i.e., virtual water trade). Temporal scarcity results from temporal fluctuations in water supplies and can be alleviated by conveyance from water abundant periods (e.g., a rainy year) to water scarce periods (e.g., a dry year). This requires water storage (natural or constructed, surface or subsurface) that accumulates surplus water during wet periods and from which water can be extracted during dry periods. Groundwater (aquifers) is a ubiquitous storage medium and often water supplies are derived conjunctively from surface and ground sources. In such cases water should be managed as a conjunctive system. The benefit from water storage is twofold. First, it increases the (long-run) average annual supply of water. Second, it mitigates inter- and intra-temporal fluctuations in water supply. The economic value associated with the second role is called the buffer value of water storage. Empirical studies show that the buffer value can be substantial with important implications regarding sustainable management of conjunctive ground and surface water systems. It is worth noting that recycled water, by nature, includes storage to coordinate the constant water input with the periodic water demand and thus entails also a buffer value.

    Related Proposals

    Proposal
    Symposium 2011

    Water Scarcity and Virtual Water Trade

    1) Analyzing the source of the problem Compared to industry and residential water use the agricultural sector is the largest consumer of water. Today, many water-short regions and countries still use ...

    1) Analyzing the source of the problem Compared to industry and residential water use the agricultural sector is the largest consumer of water. Today, many water-short regions and countries still use the little water they have for growing crops. However, before water-scarce countries implement policy measures dealing with the problem, they should carefully analyze the causes of water scarcity. Measures will need to differ between countries characterized by absolute water scarcity and those where institutional inadequacies are the main causes. 2)   Institutional failures Water shortage is often caused by inadequate management of water resources. Production decisions in agriculture are so

    Polity, Business
    Proposal
    Symposium 2011

    by John W. McDonald

    I would like to propose the following two ideas to my panel on water issues: 1. To create an International Water Commission to develop and manage water usage agreements in order to prevent conflict wi ...

    I would like to propose the following two ideas to my panel on water issues: 1. To create an International Water Commission to develop and manage water usage agreements in order to prevent conflict with the waters of the Tigris, Euphrates, and Jordan rivers. This proposal has never been presented before, but once completed will be a major step forward in reducing conflict and building peace in the Middle East. I have been involved in drinking water and sanitation issues at the global and local levels since 1978, and have lived as a US diplomat in the region for

    Polity, Academia, Business, Civil Society
    Proposal
    Symposium 2011

    Four key messages

    Take away messages and solutions In conditions where 90% of the water in the economy is managed by farmers at the beginning of the food supply value chain. They manage all the green water used from th ...

    Take away messages and solutions In conditions where 90% of the water in the economy is managed by farmers at the beginning of the food supply value chain. They manage all the green water used from the root zone and 70% of all blue water. That is 90% of society’s total use. They have increased water productivity four times in the past half century. We need to help them further intensify BUT the intensification must be sustainable.   1. We must enable farmers to intensify their productivity sustainably Increased returns to water and water resource stewardship   2.

    Polity, Academia, Business, Civil Society
    Proposal
    Symposium 2011

    by Richard Evans

    In many societies water is considered a right rather than a commodity with economic value. This is not surprising when water is abundant and demand is low relative to supply. That condition no longer ...

    In many societies water is considered a right rather than a commodity with economic value. This is not surprising when water is abundant and demand is low relative to supply. That condition no longer exists in many – and perhaps most – societies. In some cases water is being seen as either a commodity or a right depending upon its use – i.e. a commodity in industrial use but a right in personal use. The single largest use of water, however, is for agriculture which arguably encompasses both personal use (subsistence farming) and industrial use (large scale corporate farms) –

    Polity, Business