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...

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...

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...

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...

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...

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...

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...

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 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...

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...

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...

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...

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...

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...

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...

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...

Summary And Conclusion

Drought is an insidious natural hazard that is a normal part of the climate of virtually all regions. It should not be viewed as merely a physical phenomenon. Rather, drought is the result of the interplay between a natural event and the Risk-based drought policy and plans developed Drought early warning system implemented Drought early warning system implemented Drought mitigation actions implemented Policies to enhance social adaptive capacity, at both local and national scales All groups...

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...

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...

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...

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...

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...

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...