Showing papers on "Water scarcity published in 2004"

Balancing Water for Humans and Nature: The New Approach in Ecohydrology

Abstract: Balancing Water for Humans and Nature, authored by two of the world's leading experts on water management, examines water flows - the 'blood stream' of both nature and society - in terms of the crucial links, balances, conflicts and trade-offs between human and environmental needs. The authors argue that a sustainable future depends fundamentally on our ability to manage these trade-offs and encourage long-term resilience. They advocate an ecohydrological approach to land/water/environmental problems and advance a strong, reasoned argument for viewing precipitation as the gross fresh water resource, ultimately responsible for sustaining all terrestrial and aquatic ecosystem services. This book makes the most coherent and holistic argument to date for a new ecological approach to understanding and managing water resources for the benefit of all. Basing their analysis on per capita needs for an acceptable nutritional diet, the authors analyse predictions of the amounts of water needed for global food production by 2050 and identify potential sources. Drawing on small-scale experiences in Africa and Asia, they also cover the vulnerability of the semi-arid tropics through a simplified model of green and blue water scarcity components.

A Pilot Global Assessment of Environmental Water Requirements and Scarcity

Abstract: This paper presents a first attempt to estimate the volume of water required for the maintenance of freshwater-dependent ecosystems at the global scale This total environmental water requirement consists of ecologically relevant low-flow and high-flow components and depends upon the objective of environmental water management Both components are related to river flow variability and estimated by conceptual rules from discharge time series simulated by the global hydrology model A water stress indicator is further defined, which shows what proportion of the utilizable water in world river basins is currently withdrawn for direct human use and where this use is in conflict with environmental water requirements The paper presents an estimate of environmental water requirements for 128 major river basins and drainage regions of the world It is shown that approximately 20 to 50 percent of the mean annual river flow in different basins needs to be allocated to freshwater-dependent ecosystems to ma

The Institutional Economics of Water: A Cross-Country Analysis of Institutions and Performance

Abstract: This book provides a detailed and comprehensive evaluation of water reform and water sector performance from the perspectives of institutional economics and political economy. It integrates institutional theory with resource economics, and set against an exhaustive review of the theoretical and empirical literature, the authors develop an alternative methodology to quantitatively assess the performance of institutions in the context of water. This methodology is built on the principle of 'institutional ecology', the 'institutional decomposition and analysis' framework, and the 'subjective theory' of institutional change. Using this new methodology, plus information collected through an international survey of 127 water experts, the authors present a detailed empirical analysis of the process of institution-performance interaction in the water sector. Relying on the institutional transaction cost approach and an extensive cross-country review of recent water sector reforms, they also provide evidence on the relative role of various factors that influence the extent and depth of water institutional reforms in 43 countries and regions around the world. The book concludes with far reaching implications for the theory and policy of water sector reform in particular and institutional reform in general.

Optimization of California's Water Supply System: Results and Insights

Abstract: This paper presents results of a large-scale economic-engineering optimization model of California's water supply system. The results of this 4-year effort illustrate the value of optimization modeling for providing integrated information needed to manage a complex multipurpose water system. This information includes economic benefits of flexible operations, economic valuation of capacity expansion opportunities, estimating user willingness to pay for additional water, economic opportunity costs of environmental flows, and identification of promising conjunctive use and water transfer opportunities. The limitations of such modeling also are discussed. Overall, the results suggest improvements to system operation and water allocations with a statewide expected value potentially as high as $1.3 billion/year. Significant improvements in performance appear possible through water transfers and exchanges, conjunctive use, and various operational changes to increase flexibility. These changes also greatly reduce costs to agricultural and urban users of accommo- dating environmental requirements. Model results also suggest benefits for expanding selected conveyance and storage facilities.

Mountains of the world: vulnerable water towers for the 21st century.

Abstract: Mountains as "Water Towers" play an important role for the surrounding lowlands. This is particularly true of the world's semiarid and arid zones, where the contributions of mountains to total discharge are 50-90%. Taking into account the increasing water scarcity in these regions, especially for irrigation and food production, then today's state of knowledge in mountain hydrology makes sustainable water management and an assessment of vulnerability quite difficult. Following the IPCC report, the zone of maximum temperature increase in a 2 x CO2 state extends from low elevation in the arctic and sub-arctic to high elevation in the tropics and subtropics. The planned GCOS climate stations do not reach this elevation of high temperature change, although there are many high mountain peaks with the necessary sensitive and vulnerable ecosystems. Worldwide, more than 700 million people live in mountain areas, of these, 625 million are in developing countries. Probably more than half of these 625 million people are vulnerable to food insecurity. Consequences of this insecurity can be emigration or overuse of mountain ecosystems. Overuse of the ecosystems will, ultimately, have negative effects on the environment and especially on water resources. New research initiatives and new high mountain observatories are needed in order to understand the ongoing natural and human processes and their impacts on the adjacent lowlands.

Siren Song: Chilean Water Law As a Model for International Reform

Abstract: Increasing scarcity, conflict, and environmental damage are critical features of the global water crisis. As governments, international organizations, NGOs, and corporations have tried to respond, Chilean water law has seemed an attractive alternative to older legislative and regulatory approaches. Boldly introduced in 1981, the Chilean model is the worlds leading example of a free market approach to water law, water rights, and water resource management. Despite more than a decade of international debate, however, a comprehensive, balanced account of the Chilean experience has been unavailable. Siren Song is an interdisciplinary analysis combining law, political economy, and geography. Carl Bauer places the Chilean model of water law in international context by reviewing the contemporary debate about water economics and policy reform. He follows with an account of the Chilean experience, drawing on primary and secondary sources in Spanish and English, including interviews with key people in Chile. He presents the debate about reforming the law after Chile‘s 1990 return to democratic government, as well as emerging views about how water markets have worked in practice. The resulting book provides insights about law, economics, and public policy within Chile and lessons for the countries around the world that are wrestling with the challenges of water policy reform.

The problems of sustainable water use in the Mediterranean and research requirements for agriculture.

Abstract: This study addresses the sustainable use of water resources in the Mediterranean basin, particularly in the Southern and Eastern parts of the region, and the many problems generated by water scarcity and misuse. Water economy in the region is beset by two specific problems: high irrigation needs and changes in consumer demands (especially after population shifts from rural to urban areas and because of increasing tourism and industrialisation). The challenges presented by the water crisis are even greater because of growing populations and estimated future climatic changes in the region. The integrated management of limited water resources in the Southern and Eastern parts of the Mediterranean involves several areas of research. Those most directly related with agriculture concern improving water (and nutrient) use in agriculture through the management and breeding of irrigated and rain-fed crops. However, these fields of research address only one face of a multi-factorial equation that affects water sustainability in the region. Thus, other research fields include the design of comprehensive water policies and integrated planning, and technologies for advanced water treatment and re-use. Moreover, local problems and socio-economic aspects must be considered when addressing research issues.

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.

Water and Economic Growth

Abstract: Several hydrological studies forecast a global problem of water scarcity. This raises the question as to whether increasing water scarcity may impose constraints on the growth of countries. The influence of water utilisation on economic growth is depicted through a growth model that includes this congestible nonexcludable good as a productive input for private producers. Growth is negatively affected by the government's appropriation of output to supply water but positively influenced by the contribution of increased water use to capital productivity, leading to an inverted-U relationship between economic growth and the rate of water utilisation. Cross-country estimations confirm this relationship and suggest that for most economies current rates of fresh water utilisation are not yet constraining growth. However, for a handful of countries, moderate or extreme water scarcity may adversely affect economic growth. Nevertheless, even for water-scarce countries, there appears to be little evidence that there are severe diminishing returns to allocating more output to provide water, thus resulting in falling income per capita. These results suggest caution over the claims of some hydrological-based studies of a widespread global ‘water crisis’.

Spatial variation in water supply and demand across river basins of India

Abstract: India is a large country with regional differences in per-capita water supply and demand. Attempts to describe the water situation in India at a national level are often misleading due to the tremendous diversity in the water situation across the country. This Report analyzes the spatial variation of water supply and demand across river basins in India. The study identifies basins that are water-scarce because of inadequate water availability to meet the effective demand. It also identifies issues that are important for estimating the future water demand and for the formation of policy for future water-resources development and management.

The impacts of human activities on the water–land environment of the Shiyang River basin, an arid region in northwest China / Les impacts des activités humaines sur l’environnement pédo-hydrologique du bassin de la Rivière Shiyang, une région aride du nord-ouest de la Chine

Abstract: The Shiyang River basin is a typical interior river basin that faces water shortage and environmental deterioration in the arid northwest of China. Due to its arid climate, limited water resources and some inappropriate water-related human activities, the area has developed serious loss of vegetation, and gradual soil salinization and desertification, which have greatly impeded the sustainable development of agriculture and life in this region. In this paper, the impacts of human activities on the water–soil environment in Shiyang River basin are analysed in terms of precipitation, runoff in branches of the river, inflow into lower reaches, water conveyance efficiency of the canal system and irrigation water use efficiency in the field, replenishment and exploitation of groundwater resources, soil salinization, vegetation cover and the speed of desertification. The results show that human activities and global climate change have no significant influence on the precipitation, but the tot...

Economic growth and water use

Abstract: In recent years the issue of global water scarcity has attracted increasing attention within academia, non-governmental organizations and the media. The aim of this short note is to ascertain whether there is a systematic relationship between water use and income, and particularly whether an inverted U-shaped relationship exists, as has been found for other resources and pollutants. Using a new data set of water use, evidence of such a relationship is provided, suggesting that water use may benefit from composition and technique effects. While this finding appears optimistic, regional forecasts are made that suggest that levels of water use in developing regions will continue to increase for many years to come. The implications of these findings are discussed.

Geographic Information System and groundwater quality mapping in Panvel Basin, Maharashtra, India

Abstract: Panvel Basin of Raigarh district, Maharashtra, India is the study area for groundwater quality mapping using the Geographic Information System (GIS). The study area is typically covered by Deccan basaltic rock types of Cretaceous to Eocene age. Though the basin receives heavy rainfall, it frequently faces water scarcity problems as well as water quality problems in some specific areas. Hence, a GIS based groundwater quality mapping has been carried out in the region with the help of data generated from chemical analysis of water samples collected from the basin. Groundwater samples show quality exceedence in terms of chloride, hardness, TDS and salinity. These parameters indicate the level of quality of groundwater for drinking and irrigation purposes. Idrisi 32 GIS software was used for generation of various thematic maps and for spatial analysis and integration to produce the final groundwater quality map. The groundwater quality map shows fragments pictorially representing groundwater zones that are desirable and undesirable for drinking and irrigation purposes.

Climatic change and U.S. water resources: From modeled watershed impacts to national estimates

Abstract: Water is potentially one of the most affected resources as climate changes. Though knowledge and understanding has steadily evolved about the nature and extent of many of the physi- cal effects of possible climate change on water resources, much less is known about the economic responses and impacts that may emerge. Methods and results are presented that examine and quan- tify many of the important economic consequences of possible cli- mate change on U.S. water resources. At the core of the assessment is the simulation of multiple climate change scenarios in economic models of four watersheds. These Water Allocation and Impact Models (Water-AIM) simulate the effects of modeled runoff changes under various climate change scenarios on the spatial and temporal dimensions of water use, supply, and storage and on the magnitude and distribution of economic consequences. One of the key aspects and contributions of this approach is the capability of capturing economic response and adaptation behavior of water users to changes in water scarcity. By reflecting changes in the relative scarcity (and value) of water, users respond by changing their pat- terns of water use, intertemporal storage in reservoirs, and changes in the pricing of water. The estimates of economic welfare change that emerge from the Water-AIM models are considered lower- bound estimates owing to the conservative nature of the model for- mulation and key assumptions. The results from the Water-AIM models form the basis for extrapolating impacts to the national level. Differences in the impacts across the regional models are car- ried through to the national assessment by matching the modeled basins with basins with similar geographical, climatic, and water use characteristics that have not been modeled and by using hydro- logic data across all U.S. water resources regions. The results from the national analysis show that impacts are borne to a great extent by nonconsumptive users that depend on river flows, which rise and fall with precipitation, and by agricultural users, primarily in the western United States, that use a large share of available water in relatively low-valued uses. Water used for municipal and indus- trial purposes is largely spared from reduced availability because of its relatively high marginal value. In some cases water quality concerns rise, and additional investments may be required to con- tinue to meet established guidelines. (KEY TERMS: climate change; economics; modeling; impacts; watershed; management.)

The dynamics of water scarcity on irrigated landscapes: Mazarrón and Aguilas in south‐eastern Spain

Abstract: The new irrigated lands of Mazarron and Aguilas, south-east Spain, have led to the overexploitation of local aquifers and to seawater intrusion, water salinization and to declining water tables. This paper discusses a dynamic model developed to analyse the key socio-economic and environmental factors driving the whole system. The New Irrigated Lands dynamic model includes five sectors: Irrigated Lands, Profitability, Available Space, Water Resources and Pollution. The dynamic model simulates the environmental effects regarding water consumption by reference to aquifer levels, natural outflows through springs, piezometric levels and aquifer water salinity. The exploration of scenarios shows that current policies based on the increase in water resources do not eliminate the water deficit problem because the feedback loops of the system lead to a further increase in irrigated land and continuation of the water deficit. This demonstrates highly counter-intuitive behaviour. This article constitutes a contribution to the analysis of intensive irrigated lands and water management in Spain, which is mostly lacking a systemic and dynamic approach. Copyright © 2004 John Wiley & Sons, Ltd.

Roof water harvesting for domestic water security: who gains and who loses?

Abstract: Roof water harvesting is being widely promoted as a panacea for the growing drinking water crisis in India and many underdeveloped and developing countries. This article analyzes the scope, physical feasibility, and economic viability of roof water harvesting systems across classes and under different physical and socioeconomic situations. This article argues that roof water harvesting systems (RWHS) are not alternative to public systems in urban and rural areas of regions receiving low rainfall. Hydrological opportunities for RWHS are very poor in urban and rural areas. The systems offer very little scope in ensuring domestic water security for urban housing stocks of low- and middle-income groups. At the same time, they offer tremendous potential for independent bungalows having large roof area. However, their physical feasibility is very poor in urban areas. Their economic viability as a supplementary source of domestic water supply seems to be poor in urban areas, when compared to augmenting ...

Plumbing the depths of D.C.'s drinking water crisis.

Abstract: High levels of lead in the U.S. capital's water have exposed weak regulations and raised the specter of undiscovered problems elsewhere.

Common Waters, Diverging Streams: Linking Institutions and Water Management in Arizona, California, and Colorado

Abstract: Preface PART 1 Common Waters: Managing Surface Water and Groundwater Resources Together 1. Water Scarcity, Management, and Institutions 2. The Promise of Conjunctive Water Management 3. Opportunities and Obstacles for Conjunctive Management PART 2 How Institutions Matter: Institutions and Conjunctive Management in California, Arizona, and Colorado 4. California 5. Arizona 6. Colorado PART 3 Institutions and Policy Change: Analysis and Recommendations 7. Tracing and Comparing Institutional Effects 8. Future Directions of the Diverging Streams 9. Shaping the Future: Institutional Changes to Improve Water Management Appendix. The Three States: Why We Chose Them, and What We Did Notes Bibliography Index

Matching of crop and environment for optimal water use: the case of Ethiopia

Abstract: Water is the major limiting factor for crop production in the semi-arid regions of the world, particularly in sub-Saharan Africa where farming is predominantly subsistence In such a system, the shortage of water for crop production results from not only scarcity of water but also mismatches between resource availability and demand A study was conducted in Ethiopia to investigate the agroclimatic resource (particularly rainfall) of 10 stations, which are in the different ecoregions of the country, and the crop water use of three grain legume species which are traditionally grown in many parts of the country The results showed the existence of mismatches between resource (agro-climate) and demand (crop water use) in many areas In some areas, the crops could not utilize all the available water (eg Bahir Dar and Bako) whereas in others the water supply did not satisfy the water requirements of the crops (eg Dire Dawa and Jijiga) Bako, Awassa, Bole and Debre Zeit have high water supply suitable for long maturity crops (>150 days) Alemaya, Melkassa and Mekele have intermediate water supply which can support crops maturing within 90–120 days Dire Dawa and Jijiga have low water supply with a growing season of less than 60 days A crop, which best fits in a given region, does not perform well in another because of differences in rainfall distribution and amount It was concluded that knowledge of both the growing environment and the crops inherent behaviour is crucial for efficient use of water Therefore, recommendations for adjustment to management practices can be based on this type of crop-environment matching and thus reduce the impact of crop failure due to water shortage