Water Crises

Management Creeping Toward A National Drought Policy For The United States

Drought is a normal part of the climate for virtually all portions of the United States it is a recurring, inevitable feature of climate that results in serious economic, environmental, and social impacts. The Federal Emergency Management Agency (FEMA) estimates average annual losses because of drought in the United States to be 6-8 billion, more than for any other natural hazard (FEMA, 1995). Yet the United States is ill prepared to effectively deal with the consequences of drought....

Objectives Of The Drought Plan

As its first official action, the drought task force should state the general purpose for the drought plan. Government officials should consider many questions as they define the purpose of the plan, such as the Purpose and role of government in drought mitigation and response efforts Most drought-prone areas of the state or nation Historical impacts of drought Historical response to drought Most vulnerable economic and social sectors Role of the plan in resolving conflict between water users...

Untapped Water Supply

Water conservation is a powerful yet underutilized drought mitigation tool that can stave off the severe water shortages, financial losses, and public safety risks that historically have been assumed to be an inevitable consequence of drought. Hundreds of hardware technologies and behavior-driven measures are available to boost the efficiency of water use when implemented and put into action, they can drive down short-term as well as long-term water demands (Vickers, 2001). For nearly every...

Conclusions

Water conservation is a powerfully effective short-term drought mitigation tool that is also an equally credible approach to better managing long-term water demands. Conservation-minded water systems have demonstrated that the efficient management of public, industrial, and agricultural water use during drought is critical to controlling and minimizing the adverse effects of reduced precipitation on water supplies. If we understand where and how much water is used and apply appropriate...

Climate Change Componies

Partnerships drive conservation in state government A water efficiency success story for state prisons. Proceedings of the Water Sources Conference & Exposition, Austin, TX, January 11-14, 2004, American Water Works Association, Denver, CO, TUE8, pp. 1-4, 2004. American Water Works Association. Leak Detection and Water Accountability Committee. Committee report Water accountability. Journal of the American Water Works Association 88(7) 108-111, 1996. Amy Vickers...

Optimization of Supplemental Irrigation

Soil Water Deficit Irrigation

Optimal SI in rain-fed areas is based on the following three criteria 1 water is applied to a rain-fed crop that would normally produce some yield without irrigation 2 because rainfall is the principal source of water for rain-fed crops, SI is applied only when rainfall fails to provide essential moisture for improved and stable production and 3 the amount and timing of SI are scheduled not to provide moisture stress-free conditions throughout the growing season, but to ensure a minimum amount...

Water Harvesting Techniques

Classification Rainwater Harvesting

Water harvesting techniques may be classified into two major types, based on the size of the catchment Figure 6 micro-catchment systems and macro-catchment systems Oweis et al., 2001 . Surface runoff in micro-catchment systems is collected from small catchments usually less than 1000 m2 and applied to an adjacent agricultural area, where it is stored in the root zone and used directly by plants. The target area may be planted with trees, bushes, or annual crops. The farmer has control, within...

Poplar and Red Basins

Cookson Reservoir Saskatchewan

The Poplar River Figure 2 rises in Saskatchewan and flows southward, joining the Missouri River at Poplar, Montana. Roughly one-third of the basin is in Canada. The entire surface area of the basin is only 8620 km2. Because annual evapotranspiration usually exceeds precipitation, the climate is considered semiarid. The mean annual flow of the Poplar, where it joins the Missouri, is 3.8 m3 s, about three-quarters of that occurring as spring snowmelt runoff IJC, 1978 . This is equivalent to only...

Great Lakes Basin

Chart Datum

The Great Lakes Superior, Michigan, Huron, Erie, and Ontario contain approximately 18 of the world's freshwater Government of Canada and the U.S. Environmental Protection Agency, 1995 . This leads to a perception of an extraordinary abundance of water. Yet, only 1 of the water in the Great Lakes is renewable on an annual basis the rest is a legacy of deglaciation Gabriel and Kreutzwiser, 1993 . The Great Lakes basin including St. Lawrence River to Trois Rivi res contains the Canadian provinces...

Building a Drought Control and Management System

Developing Irrigation Systems In the early 1950s, efforts concentrated on restoration, expansion, and renovation of old irrigation systems. Storage facilities, including ponds and reservoirs of different sizes, have developed rapidly since the 1960s. In the 1970s, to meet the increasing demand of food supply, irrigation from canals was promoted in the south and well irrigation prevailed in the north China plain. As of 2000, there were more than 85,000 reservoirs of different sizes with a total...

References

Agricultural Council of Australia and New Zealand ACANZ . Record and Resolutions 138th Meeting, Mackay, 24 July 1992 p. 13 . Commonwealth of Australia, 1992. Agriculture and Resource Management Council of Australia and New Zealand ARMCANZ . Record and Resolutions Twenty first Meeting, Darwin, 17 August 2001 p. 33 . Canberra, Commonwealth of Australia, 2001. American Meteorological Society. AMS Statement on Meteorological Drought pp. 847-849 . Boston, MA AMS, 1997. Amery R, the Hon MP. Howard...

Past Efforts

Steinemann et al. (Chapter 4) highlight several of the drought indicators used to monitor drought conditions. The fact that the Palmer Drought Severity Index (PDSI) gained so much attention and acceptance in the years following its development (Palmer, 1965), particularly in the United States, indicated that decision makers needed tools to monitor and respond to drought events. Before the PDSI, most drought monitoring efforts used some representation of precipitation, but these were largely...

Considerations for Drought Indicators and Triggers

Suitability for drought types of concern. An indicator needs to reflect the type of drought of concern, including aspects of water demands, water supplies, drought vulnerabilities, and potential impacts. Because drought depends on numerous factors, no single indicator is likely to cover all types of drought. In choosing indicators, a first consideration is that they should make sense for the context. For instance, the Palmer indices may not be appropriate as sole indicators for managed water...

Globalregionallocal Environmental Change

As discussed in the introduction, many adaptations have been implemented in U.S. water management in recent decades, but the development of institutions that conduct research, assessment, and technology development may be among the most influential. These developments have been neither unqualified successes nor unmitigated disasters. Instead, the results have been mixed. Thus what we need to identify and reduce social vulnerability to the effects of drought is a systematic understanding of...

Introduction

Introduction Droughts

Past attempts to manage drought and its impacts through a reactive, crisis management approach have been ineffective, poorly coordinated, and untimely, as illustrated by the hydro-illogical cycle in Figure 1. The crisis management approach has been followed in both developed and developing countries. Because of the ineffectiveness of this approach, greater interest has evolved in recent years in the adoption of a more proactive risk-based management approach in some countries (see Chapter 6)....

Early Warning Systems

Early warning systems (EWSs) have become increasingly successful at recognizing the development of potential famines and droughts. Saidy (1997) pointed out that in 1992 EWSs were successful in sounding the alarms about the drought emergency. Although some warnings, such as those given in southern Africa during 1997-1998, were not followed by fullblown droughts and famines, such events are not necessarily forecast failures because most, if not all, seasonal forecasts are issued as probabilities...

Water vs Land Productivity

Land Productivity

Land productivity yield and water productivity WP are indicators for assessing the performance of supplemental irrigation. Higher water productivity is linked with higher yields. This parallel increase in yields and water productivity, however, does not continue linearly. At some high level of yield, greater amounts of irrigation water are required to achieve additional incremental yield increase. Water productivity of wheat Figure 3 starts to decline as yield per unit of land increases above...

Water Balance in Spain

Global Water Balance

Spain on average has sufficient water to meet water demands, but these resources are very unevenly distributed. According to the White Paper on Water in Spain (Ministerio de Medio Ambiente, 2000), natural water resources are estimated at 111 billion m3 per year, distributed as shown in Figure 3. The total amount of natural water resources is not available for abstractions.* Two limitations are usually considered (1) a precautionary reserve of 20 of the natural resources for environmental...

Introduction A New Era Of Water Scarcity Or An Old Error Of Water Waste

The discovery from tree rings of ancient drought cycles, the emergence of centuries-old shipwrecks on drying riverbeds, and the forecasts of unruly climate change and variability can easily stir fear for our water future in both scientist and citizen alike. Yet such conditions need not be predictors of our water fate. Exactly how the water demands of the 21st century's growing population will be met is, indeed, a formidable challenge. Half of the world's 6 billion people now live in urban...

Systems Operation

The indicators previously described are mainly based on analysis of precipitation and flows. These two types of indicators Figure 7 Selection of rain gauges for triggering emergency measures. (Example is for 1991.) Figure 7 Selection of rain gauges for triggering emergency measures. (Example is for 1991.) take into account only the water supply, not the demand.* For practical purposes, an indicator for a drought early warning system should indicate if the system is close to a failure, given...

Social And Economic Contexts

Demographic, legal, and environmental changes can and have disrupted existing relationships and current perspectives about the interactions among society, climate, and water. Nowhere is this more apparent than in the many transbound-ary situations that dominate Colorado River management. The Colorado River has been the subject of extensive negotiations and litigation. The federal government accounts for 56 of the land within the basin Indian reservations, 16.5 states, 8.5 and private ownership,...

Final Thoughts

Drought results in widespread and complex impacts on society. Numerous factors influence drought vulnerability. As our population increases and becomes more urbanized, there are growing pressures on water and natural resource managers and policy makers to minimize these impacts. This also places considerable pressure on the science community to provide better tools and credible and timely information to assist decision makers. The adaptive capacity of a community (defined here in the broadest...

Drought Forecasting

Decision makers must have accurate drought monitoring information to respond successfully during drought events. Accurate drought forecast information and tools about future conditions are equally important. The science of drought forecasting, however, is in its infancy. To forecast drought, it is important to know something about the causes of drought. Drought is usually established by persisting high pressure that results in dryness because of subsidence of air, more sunshine and evaporation,...

Risk Assessment Committee

Risk is the product of exposure to the drought hazard (i.e., probability of occurrence) and societal vulnerability, represented by a combination of economic, environmental, and social factors. Therefore, to reduce vulnerability to drought, one must identify the most significant impacts and assess their underlying causes. Drought impacts cut across many sectors and across normal divisions of government authority. These impacts have been classified by Wilhite and Vanyarkho (2000) and are...

Acknowledgments

This work received support from the National Science Foundation under grant CMS 9874391. Any opinions, findings, or conclusions are those of the authors and do not necessarily reflect the views of the National Science Foundation. Alley, WM. The Palmer Drought Severity Index Limitations and assumptions. Journal of Climate and Applied Meteorology 23 1100-1109, 1984. AU-CBM Australia Commonwealth Bureau of Meteorology . Climate Averages for Australian Sites. http www.bom.gov.au climate averages...

Forecasting Drought

Examination of the long-term climate records in some regions around the globe reveals persistent trends and periods of below-average rainfall extending over years to a decade or more, while other regions exhibit episodic, shorter droughts. Hence it is useful to consider the prediction of droughts on seasonal to interannual timescales and, separately, on longer decadal timescales. B. Seasonal to Interannual Prediction Our theoretical ability to make an explicit, reliable prediction of an...

Designing Institutions To Leverage Science And Technology To Achieve Sustainable Development

The research reviewed above provides a springboard for beginning to develop an understanding of the design characteristics of effective drought management institutions. Our research on climate sensitivities and water management in the Great Plains complements this work and suggests several propositions that might tie together a number of the literatures described in Section III. A first proposition is that multiple boundaries characterize the landscape of drought assessment, planning, and...

Okanagan Basin

Cascade Hydrology

The Okanagan basin is located in the southern interior of British Columbia, Canada, situated around Okanagan Lake Figure 1 . The surface area of the basin is 8200 km2 Cohen and Kulkarni, 2001 . The Okanagan has a dry continental climate, because the valley sits in the rain shadow of the Coast and Cascade Mountain ranges. The semiarid climate receives approximately 30 cm of precipitation each year, of which 85 is lost through evapotranspiration from local lakes. The Figure 1 Okanagan and...

Palmer Drought Severity Index PDSI and Palmer Hydrologic Drought Index PHDI

The PDSI, based on the Palmer Drought Model Palmer, 1965 , has been one of the most commonly used drought indicators in the United States. One reason for its popularity is that its development in 1965 preceded other indices and resulted in its widespread use and wide-ranging application. The PDSI is derived from a moisture balance model, using historic records of precipitation, temperature, and the local available water capacity of the soil. The PHDI uses a modification of the PDSI to assess...

Droughtvulnerable Vs Droughtresilient Society

Tecla Que Anomenem Punt Volat

The Drought Discussion Group of the International Strategy for Disaster Reduction (ISDR) has proposed a new paradigm to improve understanding of the drought hazard in the macro and micro contexts with the goal of enhancing drought preparedness and mitigation efforts in all settings ranging from local to national and from developing to developed countries (ISDR Drought Discussion Group, 2003). This new paradigm emphasizes greater understanding and description of both the physical features of the...

Planning For Drought The Process

Drought is a natural hazard that differs from other hazards in that it has a slow onset, evolves over months or even years, affects a large spatial region, and causes little structural damage. Its onset and end are often difficult to determine, as is its severity. Like other hazards, the impacts of drought span economic, environmental, and social sectors and can be reduced through mitigation and preparedness. Because droughts are a normal part of climate variability for virtually all regions,...

Summary And Conclusion

For the most part, previous responses to drought in all parts of the world have been reactive, representing the crisis management approach. This approach has been ineffective (i.e., assistance poorly targeted to specific impacts or population groups), poorly coordinated, and untimely more important, it has done little to reduce the risks associated with drought. In fact, the economic, social, and environmental impacts of drought have increased significantly in recent decades. A similar trend...

Agriculture In The Us Great Plains

Despite the richness of this literature on institutions and environmental affairs, there is room for additional research on the institutional design criteria that lead to effective water management in general and drought management whether anticipatory or reactive in particular. We return to the case of the U.S. Great Plains. Substantial evidence exists about specific water management successes and failures in this region e.g., Glantz, 1994 Riebsame, 1990 Riebsame, 1991 Webb, 1931 . The fact...

The Experience of the Drought

The most severe droughts in Spain in the last century occurred in 1941-45, 1979-83, and 1990-95. These three droughts were extensive and affected most of the country. The map in Figure 2 shows the percentage decrease in average rainfall from October 1990 to September 1995 compared to the average rainfall for the 1940-1996 period. Several river basins suffered decreased rainfall percentages, around 30 . The resulting reduction in runoff in most of the country was more than 40 and amounted to...

Future Threats And Impacts

Vulnerability to drought is influenced by a wide range of factors such as natural resource management policies, water use trends, land use, urbanization, and government policies. The current water management infrastructure has allowed the citizens of both Canada and the United States to make productive use of water and reduce the adverse impacts of droughts and floods. However, population growth and continuing urbanization will affect the long-term availability of water supplies, future levels...

From Australia

Australia is the driest inhabited continent on earth, and it experiences one of the most variable climates. Unlike other continents, its patterns are determined by nonannual cycles (Flannery, 1994), posing challenges for agricultural practices developed in the relatively more reliable climate of Europe. An early report on the prospects for agriculture in the colony of New South Wales noted the uncertain climate and suggested that the future of the colony will be that of pasture rather than...

Development

Major Natural Disaster in the Agricultural Drought is historically one of the major natural disasters affecting China, primarily the agricultural sector. Data for 1949-2000 show that drought affected an average of 21 million ha each year and disastrous droughts affected 8.9 million ha, which accounts for 21 and 8.9 , respectively, of total cultivated land in China (Zhang Shi Fa, 2002). During eight extraordinary dry years (1960, 1961, 1978, 1986, 1988, 1989, 1997, and 2000) in the period...

Water Management Considerations

The preceding discussion has glossed over an extremely important factor in most locations, water systems are highly manipulated. Human decisions can affect water supply and demand, so that drought status can represent a highly nonlinear, and even occasionally counterintuitive or paradoxical, response to the climate drivers and their history (Redmond, 2002). Throughout the United States, but in the western states in particular, the physical facts of climate and its extreme variation in space,...

Opportunities For Technological Interventions And Climate Science Applications

The three major elements of western states' water future are (1) conservation and demand management, (2) municipal-agricultural cooperation, and (3) supply integration. Conservation and demand management approaches range from technology interventions for specific problems to regional water basin planning, including mandatory, voluntary, and incentive-based approaches (Luecke et al., 2003). The innovations described above (the AWBA AWS CAGRD, BECC, the QSA settlement) are based in water...

Planning Framework in Spain

Relleu Espanya

In Spain, water is not just another natural resource. Drought is more than a combination of meteorological factors because it usually produces conflicts between users, deterioration in river ecology, and increased public awareness. During drought, the decreased availability of water results in greater pressure on existing surface and subsurface water supplies, and debates about potential remediation measures usually go beyond the scientific or technical spheres and into the political sphere....

Step Appoint A Drought Task Force

A key political leader initiates the drought planning process through appointment of a drought task force. Depending on the level of government developing the plan, this could be the president or prime minister, a provincial or state governor, or a mayor. The task force has two purposes. First, it supervises and coordinates development of the plan. Second, after the plan is developed and during times of drought when the plan is activated, the task force coordinates actions, implements...

Xstep Publicize The Drought Planbuild Public Awareness And Consensus

If you have communicated well with the public throughout the process of establishing a drought plan, there may already be better-than-normal awareness of drought and drought planning by the time you actually write the plan. Themes to emphasize in writing news stories during and after the drought planning process could include How the drought plan is expected to relieve drought impacts in both the short and long term. Stories can focus on the human dimensions of drought, such as how it affects a...

Step Develop Education Programs

A broad-based education program to raise awareness of short-and long-term water supply issues will help ensure that people know how to respond to drought when it occurs and that drought planning does not lose ground during non-drought years. Try to tailor information to the needs of specific groups (e.g., elementary and secondary education, small business, industry, homeowners, utilities). The drought task force or participating agencies should consider developing presentations and educational...

Drought Policy In South Africa

South Africa has a long history of living with drought. A drought during the early 1930s that coincided with the great depression made a deep impression on many policy makers. Significant droughts also occurred during the 1960s, 1980s, and early 1990s. Despite this familiarity with drought, policy makers still struggle to quantify it and to develop a stable policy framework. Drought policy falls at the interface among the numerous definitions of drought that require some quantification of...

Trends in Water Demands

Lack of water availability can be produced by a lower amount of resources in the system or by an increase in the demand. Higher water demands introduce new uncertainty factors and make some areas particularly vulnerable to drought situations. In many places, overexploitation of resources exacerbates drought impacts. As in other Mediterranean countries, many areas of Spain do not have adequate water resources to meet all demands. In case of water conflicts in Spain, the Water Act of 1995...

Case Study Context

To consider the potential benefits to agricultural production of seasonal forecasts, we investigated their potential impact on farm-level decisions and returns in an irrigated cropping system. We premised that the potential benefit of seasonal forecasts was probably greatest in a farming system subject to significant uncertainty. For this reason, the farming system represented in the decision-making models is that of an irrigated cotton producer operating on an unregulated river system, relying...

Drought Monitoring

As the world moves into the 21st century, the stresses on available water resources will continue to grow. In the United States, increasing growth and development are already straining water supplies not only for the major metropolitan areas of the arid West, but also for areas such as Atlanta, Georgia, in the relatively humid eastern United States. Issues surrounding shared water resources across international boundaries, such as the Colorado and Rio Grande River basins between the United...

International The Border Region

Although international rivers have always been difficult to manage, the Colorado is especially interesting because of its enormously diverse and multiple overlapping jurisdictions, the strong contrast in legal and administrative styles of the two neighboring countries, and the exceptional degree of freedom and influence of the informal, nongovernmental sector in the United States (Varady et al., 2001). In 1964, an international issue erupted when the Mexican government complained that...

Water Harvesting for Supplemental Irrigation

Where groundwater or surface water is not available for supplemental irrigation, water harvesting can be used to provide the required amounts during the rain season. The system includes surface or subsurface storage facilities ranging from an on-farm pond or tank to a small dam constructed across the flow of a wadi with an ephemeral stream. It is highly recommended when inter-seasonal rainfall distribution and or variability are so high that crop water requirements cannot be reasonably met. In...

The Challenge Of Drought Early

Although an understanding of underlying vulnerability is essential to understand the risk of drought in a particular location and for a particular group of people, a drought early warning system (DEWS) is designed to identify negative trends and thus to predict both the occurrence and the impact of a particular drought and to elicit an appropriate response (Buchanan-Smith and Davies, 1995). Numerous natural indicators of drought should be monitored routinely to determine drought onset, end, and...

Time Scales

Improvements in seasonal forecasting have arisen from advances in knowledge made as a result of the careful analysis of data collected over time. The growth in knowledge about the circulation of the oceans and its modes of variability, which was stimulated in large measure during the 1980s with the implementation of the Tropical Ocean Global Atmosphere (TOGA) and World Ocean Circulation Experiment (WOCE) projects of the World Climate Research Program, is beginning to reap rewards in the...

A US Drought Monitor

One of the best examples of a new drought monitoring tool is the U.S. Drought Monitor (http drought.unl.edu dm). The National Drought Mitigation Center (NDMC), U.S. Department of Agriculture (USDA), and National Oceanic and Atmospheric Administration's (NOAA) Climate Prediction Center (CPC) and National Climatic Data Center (NCDC) author the weekly Drought Monitor (DM) map, which was first released in 1999. The DM is not a forecast rather, it was designed as a comprehensive drought assessment...

Precipitation

Precipitation, as a variable, can be transformed into several types of indices 1. Percent of normal can analyze a single region or a single season, yet it is easily misunderstood and gives different values depending on the location and time period. Further, mean precipitation (the average amount) usually differs from median precipitation (the amount exceeded 50 of the time) because precipitation tends to be skewed rather than normally distributed. For a positively skewed precipitation...

Surface Water Supply Index

The SWSI, pronounced swazee, was developed by Shafer and Dezman 1982 to address limitations of the Palmer indices and incorporate water supply data, such as snow accumulation and melt, which are important in the western United States. The index is based on four components snowpack, streamflow, precipitation, and reservoir storage. Monthly data for each component are analyzed according to probabilities of occurrence, combined into an overall index, and weighted according to their relative...

Example The US Drought Monitor

One example of a product developed from multiple indicators is the weekly U.S. Drought Monitor product (see Chapter 3). This product, originally released in August 1999, was developed to provide a weekly assessment of drought conditions across the United States on a general scale. What makes the Drought Monitor unique is that it incorporates a variety of quantitative indicators and is adjusted based on qualitative information from a network of local experts around the country. The quantitative...

Checklist for Indicators and Triggers in a Drought Plan

In addition to the above criteria and considerations, we provide a checklist below. Note that these pertain only to the indicators and triggers portion of a drought plan. Many other drought plan components are important, such as communication and coordination among agencies responsible for monitoring the indicators and implementing the responses if they are triggered see Chapter 5 . Nonetheless, this list offers a straightforward set of metrics to check 1. Indicator specification and...

Participation And Resolve Conflict

Social, economic, and environmental values often clash as competition for scarce water resources intensifies. Therefore, it is essential for task force members to identify all citizen groups (stakeholders) that have a stake in drought planning and understand their interests. These groups must be involved early and continuously for fair representation and effective drought management and planning. Discussing concerns early in the process gives participants a chance to develop an understanding of...

Ixstep Integrate Science And Policy

An essential aspect of the planning process is integrating the science and policy of drought management. The policy maker's understanding of the scientific issues and technical constraints involved in addressing problems associated with drought is often limited. Likewise, scientists generally have a poor understanding of existing policy constraints for responding to the impacts of drought. In many cases, communication and understanding between the science and policy communities must be enhanced...

Post Drought Evaluation

A post-drought evaluation or audit documents and analyzes the assessment and response actions of government, nongovernmental organizations, and others and provides a mechanism to implement recommendations for improving the system. Without post-drought evaluations, it is difficult to learn from past successes and mistakes, as institutional memory fades. Post-drought evaluations should include an analysis of the climatic and environmental aspects of the drought its economic and social...

Pre Drought Policy Period in Australia

Until 1989, drought was considered to be a natural disaster and drought relief was provided in accordance with state disaster relief policy. From the late 1930s, the commonwealth government became progressively more involved in natural disaster relief through a series of ad hoc arrangements with the states and special purpose legislation such as that passed in the mid-1960s to provide drought relief to New South Wales and Queensland. In 1971, disaster relief arrangements were revised by the...

The National Drought Policy

Commonwealth and state ministers, through the Ministerial Council, announced a new National Drought Policy in July 1992. As recommended by the Drought Policy Review Task Force, the policy was based on principles of sustainable development, risk management, productivity growth, and structural adjustment in the farm sector. Support for productivity improvement and improved risk management was to be provided through the commonwealth government's main structural adjustment program for agriculture,...

Current Status and Future Directions

In 2004 a national roundtable was convened to consider drought policy. The roundtable considered a paper produced by an independent panel following consultations with stakeholders, and the roundtable results will be considered by government (Truss, 2003b). A number of issues need to be addressed. First, because the policy is dependent on the declaration of an exceptional circumstances drought, the process of drought declaration has become highly politicized. As is often the case in Australia,...

The Concept and Components of the System

The drier environments, the steppe, or, as they are called in the Arab world, Al Badia, occupy the vast majority of the dry Amount of supplemental irrigation mm Figure 4 SI production functions for wheat in different rainfall zones in Syria. Adapted from Oweis, 1997. Amount of supplemental irrigation mm Figure 4 SI production functions for wheat in different rainfall zones in Syria. Adapted from Oweis, 1997. areas. The disadvantaged people, who depend mainly on livestock grazing, generally live...

Perception of Drought and Water Shortage

Drought is generally viewed as a sustained and regionally extensive occurrence of below-average natural water availability, in the form of precipitation, runoff, or groundwater. Drought should not be confused with aridity, which applies to those persistently dry regions where, even in normal circumstances, water is in short supply. Normally the consequences of droughts are felt most keenly in areas that are in any case arid (UNESCO-WMO, 1985). Furthermore, the adverse effects of drought are...

Impact of Drought on Environment

In arid and semiarid regions (annual precipitation less than 400 mm), local rainfall does not meet agricultural needs. In such cases, too many withdrawals from rivers upstream could directly affect the water environment and ecosystem downstream. Environmental issues due to drought or water shortage (mainly in north China) are discussed below. 1. Drying of Land, Lakes, and Rivers In the north China plain, the annual runoff coefficient dropped from 0.2 in the 1950s to 0.1 in the 1980s because of...

The Changing Rate of Water Use in Different Sectors and Administrative Regions

During the period 1949-2000, total annual water use in China ranged from 103.1 billion m3 to 549.8 billion m3 (Table 2), and the rate of increase was declining. It was high (5.2 ) in 1949-1980, about two times the rate of increase in population growth (2.7 ) for the same time period (Ke Li Dan, 2002). Since the early 1980s, China has maintained rapid economic development and has taken various important measures in water resources management, including initiating a planned water use program and...

Improving Water Use Efficiency

The agricultural sector is the main user of water, but water use efficiency is only 45 for the entire irrigation system. The losses are mainly due to seepage in the irrigation system as well as the use of flood irrigation in many places, especially in southern China, where farmers used to follow traditional technology in applying water to the rice field. Water-saving techniques have been promoted in grain-producing areas, particularly in arid regions. In 1997, China implemented a water-saving...

Drought Definition

As in other Mediterranean countries with large arid or semiarid areas, droughts in Spain are difficult to evaluate and quantify and thus are difficult to define. Many definitions are used, and often it is not clear when a drought situation has started or finished or even if it has existed. In some large river basins, the definition of a drought is based on simple rainfall statistics. For example, for the river Ebro, one of the largest rivers in Spain, a dry period starts according to Spanish...

Response Strategies A Early Identification of Droughts

In Spain and other northern Mediterranean countries, drought forecasting based on climatic indicators is not operational. One of the most suitable indicators is the North Atlantic Oscillation (NAO), which shows the pressure gradient in the region. In the winter, when the NAO is low, westerlies are weaker and do not penetrate as far into Europe, so temperatures are influenced by cold high pressure located over Eurasia and precipitation is reduced (EEA, 2001 Figure 6 Trends in water demand in...

Moving From Crisis To Risk Management Changing The Paradigm

In 1986, an international symposium and workshop was organized at the University of Nebraska that focused on the principal aspects of drought, ranging from prediction, early warning, and impact assessment to response, planning, and policy. The goal of this meeting was to review and assess our current knowledge of drought and determine research and information needs to improve national and international capacity to cope with drought (Wilhite and Easterling, 1987). Reflecting on this meeting...