Browsing by Author "Molden, David"

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Accounting for Water Use and Productivity
(1997) Molden, David
"All science depends on its concepts. These are ideas which receive names. They determine the questions one asks, and the answers one gets. They are more fundamental than the theories which are stated in terms of them."
Adaptive Water Resource Management in the South Indian Lower Bhavani Project Command Area
(2010) Lannerstad, Mats; Molden, David
"This report explores the theory and practice of Adaptive Water Management (AWM) based on a detailed field study in the Lower Bhavani Project (LBP) in the South Indian state of Tamil Nadu. A five-step framework is used to analyze the extent to which AWM is practiced and how it could be improved. The analysis shows that the LBP system has increasingly fulfilled the criteria of a complex adaptive system over the years. The main uncertainty factor, rainfall variability, has been considered in a stepwise way during the system change cycles and has been included in the LBP system design. The study shows that in spite of contending with an imperfect irrigation system design and intense competition for water resources, water resource managers and farmers are able to adapt and continue to reap benefits from a productive agricultural system."
Assessment of Conjunctive Use in Maharashtra Minor Irrigation Systems
(1991) Sawant, M.M.; Barrett, R.E.; Molden, David; Sheng, T.S.
"The objective of this paper is to provide a brief assessment of the status of well irrigation and conjunctive use in Maharashtra. In light of the assessment, we will note areas where assistance could be used to improve the status of conjunctive use. The focus of the paper is on minor irrigation systems. Minor irrigation systems serve less than 2,000 ha and usually consist of a small tank for storing water and a canal distribution system. The development of surface irrigation has led to a rise in wells due to canal seepage in the command areas."
Basin-Level Use and Productivity of Water: Examples from South Asia
(2001) Molden, David; Sakthivadivel, R.; Habib, Zaigham
"Increasing water scarcity poses a threat to food security and safe domestic water supplies. Irrigated agriculture is a major driver in leading to water scarcity because of its high consumption of water resources. Obtaining more benefits from each drop of water consumed, especially from each drop irrigated agriculture consumes, will be key to mitigating problems of scarcity. The means of improving productivity of water are not always immediately apparent due to the complex nature of water diversions and return flows within basins. The purpose of this report is to discuss and illustrate concepts for identifying ways of improving productivity of water within basins. We applied a water accounting procedure to four subbasins in South Asia where there are perceived problems of water scarcity: Bhakra in India, Chishtian in Pakistan, Huruluwewa in northern Sri Lanka and Kirindi Oya in southern Sri Lanka. The accounting procedure identifies the quantities and productivity of various uses of water within a basin. This information is used to identify the water-saving potential, and the means of improving the productivity of the managed supplies. At Bhakra and Chishtian, there is little remaining prospect for water savings, while at Huruluwewa and Kirindi Oya, there is considerable opportunity for water savings and increasing beneficial use. At Chishtian, almost all water is consumed by beneficial uses, but considerable scope remains for improving the productivity of water. In all four of the cases we analyzed, productivity of water that is presently being depleted by agriculture can be improved. The four subbasins are representative of situations that we believe are typical of many other basins worldwide. With the methodology used, we were able to shed light on opportunities to increase water productivity. It appears that the methodology is thorough and robust, and can be applied to other basins."
Combining Urban and Rural Water Use for a Sustainable North China Plain
(2003) Kendy, Eloise; Steenhuis, Tammo S.; Molden, David
"Competing demands on limited water resources have resulted in persistent water shortages for the North China Plain. Despite years of effort to mitigate the problem, ground-water levels continue to decline steadily. A quantitative analysis of hydrologic changes affecting Luancheng County, Hebei Province, from 1949 to 2000 identifies crop evapotranspiration as the root cause of water-table declines beneath this ground-water irrigated area. Potential evapotranspiration greatly exceeds precipitation in the North China Plain. For centuries, farmers raised 2-3 rainfed crops every two years. By not using irrigation, the quantity of water taken up by crops was limited by -- and could not exceed -- precipitation. It was not until the proliferation of mechanized wells in the 1960s that farmers could consistently produce 2 crops every year. From the 1970s to the present, actual evapotranspiration from irrigated cropland in Luancheng County has remained constant at about 66 cm/y, compared to an average of about 46 cm/y of rainfall. Ground-water mining provides the additional 20 cm/y to meet crop water requirements, but also depresses the water table about 1 m/y beneath Luancheng County. Attempts to make water use sustainable have centered on improving irrigation efficiency to reduce ground-water pumping. Indeed, pumping rates have decreased about 50 percent since the 1970s. However, ground-water recharge from excess irrigation has decreased correspondingly. Therefore, water-table declines have continued unabated. Because irrigated areas overlie the shallow aquifer, excess irrigation water always replenishes the water supply. In this physical configuration, irrigation efficiency improvements save no water. The only way to save water is to reduce evapotranspiration, which can be accomplished by reducing the cropped area. Government leaders are currently promoting rapid urbanization of the North China Plain as a means to stimulate economic growth, absorb the rural labor surplus, and reduce the income disparity between rural and urban workers. From a hydrologic standpoint, is urban land use a viable alternative to irrigated cropland? Like agricultural areas, most cities on the North China Plain rely on ground water. However, unlike irrigated fields, water that passes through industrial and domestic users does not necessarily recharge the underlying aquifer. Rather, most wastewater discharges to rural areas outside the cities. Likewise, rainfall that lands on impermeable urban surfaces quickly drains away from cities. Therefore, although evaporation from urban areas is less than from cropland, water-table declines beneath cities are even more severe than beneath cropland. The major hydrologic impacts of urbanization, then, are localized displacement – but not necessarily consumption – and contamination of water. By replacing some cropland with urban areas, regional evapotranspiration would likely decrease. Then the problem would reduce to prudent management and distribution of urban water resources. Municipal wastewater treatment could transform a disposal problem into a water-resource solution, to be utilized by downstream irrigators. There appears to be considerable scope for improving industrial water-use efficiency, which would reduce potential costs of both ground-water pumping and wastewater treatment. Capturing and artificially recharging storm runoff into underlying aquifers could further alleviate ground-water declines beneath urban and nearby areas. Thus, replacing rural with urban land use potentially could benefit the North China Plain hydrologically, provided urban runoff and wastewater quality improve."
Does International Cereal Trade Save Water? The Impact of Virtual Water Trade on Global Water Use
(2004) de Fraiture, Charlotte; Cai, Ximing; Amarasinghe, Upali A.; Rosegrant, Mark; Molden, David
"Virtual water refers to the volume of water used to produce agricultural commodities. When these commodities enter the world market, trade in virtual water takes place. This report argues that the role of virtual water trade in global water use is modest, since most trade takes place, and will continue to take place, between water abundant countries."
From Field to Fork: Wastage of Water in the Food Chain
(2007) Lundqvist, Jan; de Fraiture, Charlotte; Molden, David
"With rising population, urbanisation and higher incomes, food demand may double in the coming 50 years. Given the water scarcity and related environmental problems that are already occurring in many parts of the world, the corresponding increases in the pressure on water and land resources that will accompany these trends is a critical and grossly under-appreciated concern. To date, producer side solutions, like getting more 'crop per drop,' have dominated recent discourse. But this discussion often neglects the tremendous unnecessary resource losses that occur at each stage of the food chain from the farmer’s field to our tables. For real solutions to the food, water and environment nexus, it is essential that we pay attention to the entire production to consumption process, that we understand what happens from 'field to fork.'"
Hydronomic Zones for Developing Basin Water Conservation Strategies
(2001) Molden, David; Sakthivadivel, R.; Keller, Jack
"In this report, the concept and procedures of hydronomic (hydro water + nomus management) zones are introduced. A set of six hydronomic zones are developed and defined based on key differences between reaches or areas of river basins. These are the: Water Source Zone, Natural Recapture Zone, Regulated Recapture Zone, Stagnation Zone, Final Use Zone, and Environmentally Sensitive Zone. The zones are defined based on similar hydrological, geological and topographical conditions and the fate of water outflow from the zone. In addition, two conditions are defined which influence how water is managed: whether or not there is appreciable salinity or pollution loading; and whether or not groundwater that can be used for utilization or storage is present. Generic strategies for irrigation for four water management areas, the Natural Recapture, Regulated Recapture, Final Use, and Stagnation Zones, are presented. The Water Source Zone and Environmentally Sensitive Zone are discussed in terms of their overall significance in basin water use and management. "Hydronomic zones allow us to define, characterize, and develop management strategies for areas with similar characteristics. The concept of zoning is demonstrated in four agricultural areas representing a wide variety of situations: the Kirindi Oya basin in Sri Lanka, Egypts Nile basin, the Bhakra command area in Haryana, India and the Gediz basin in Turkey. We were readily able to apply the zones within each basin and suggest water management strategies for each zone. Hydronomic zones hold potential as a tool to help us better understand complex water interactions within river basins, to isolate similar areas within basins and to help us develop sets of water management strategies better tailored to different conditions within basins."
Implications of Land and Water Degradation for Food Security, with Particular Reference to Asia and Africa
(2002) Penning de Vries, F.W.T.; Molden, David
From Introduction: "It is common fallacy that land is ample and indestructible, and that clean water rains on us every day. Loss and degradation of these natural resources is widespread, particularly in developing countries. The reality is that this degradation threats our future and that of our children. Another common mental image that is that of gradual change: that degradation proceeds slowly and can be reversed, slowly, with adequate inputs. Yet, agroecological systems and societies are reilient only up to a threshold, and collapse when pushed too far. The rates of natural resources degradation may seem slow to some, but this should not lull us into complacency."
Indicators for Comparing Performance of Irrigated Agricultural Systems
(1998) Molden, David; Sakthivadivel, R.; Perry, C.J.; de Fraiture, Charlotte
"A set of comparative performance indicators is defined, which relates outputs from irrigated agriculture to the major inputs of water, land, and finance. Nine indicators are presented with the objective of providing a means of comparing performance across irrigation systems. These indicators require a limited amount of data that are generally available and readily analyzed. Results of application of the indicators at 18 irrigation systems are presented and large differences in performance among systems are shown. In spite of uncertainties in estimation of indicators, the large differences discerned by the indicators justify the approach taken."
Integrated Development and Management of Water Resources for Productive and Equitable Use in the Indrawati River Basin, Nepal
(2002) Bhattarai, Madhusudan; Pant, Dhruba; Mishra, V. S.; Devkota, Hari; Pun, Shuku; Kayastha, R. N.; Molden, David
"This paper on the Melamchi water transfer project which is being carried out in the Indrawati river basin,3 is a summary and synthesis of four detailed case studies conducted earlier, in relation to the project. The case studies were conducted in Nepal by the IWMI and Water and Energy Commission Secretariat (WECS)/Nepal team, funded by the Ford Foundation/India."
Integrated Land and Water Management for Food and Environmental Security
(2003) Penning de Vries, F.W.T.; Acquay, H.; Molden, David; Scherr, Sara J.; Valentin, C.; Cofie, Olufunke O.
"This document focuses on the impact of degradation of land and water on food and environmental security. It aims to provide a basis for priority policy and research actions that will counteract the progression of degradation and will reduce its impact on household food security and the loss of other ecosystem services."
Integrated Management of Water, Forest and Land Resources in Nepal: Opportunities for Improved Livelihood
(2005) Pant, Dhruba; Thapa, Sabita; Singh, Ashok; Bhattarai, Madhusudan; Molden, David
"This paper is aimed at furthering understanding of if and how communities co-manage forest and irrigation activities with a view to gain insights about integrated natural resource management. The main question addressed is whether the management of these two resources can be better integrated for enhanced livelihood opportunities and for reduced vulnerability of the rural poor. It uses case studies from the hills of Nepal, where both water and forest resources are integral to poor people’s lives. The results of the case studies show that water and forest resources are managed separately. The decision-making processes for the management of these two resources are independent from each other. Importantly though, informal interaction between management groups does exist. The reasons for the separation of the two management groups are that the boundaries and people involved in managing forest and irrigation water resources overlap but do not coincide, and problems and issues in management of both resources are distinctly different. Furthermore, government policy and programs support these different groups separately. Programs to support the forest users group and the irrigation users group have met with a degree of success. For forestry, while there are no infrastructure interventions, there are strong policy and legal interventions providing support for the management of forest resources. Community forest programs directly benefit poor users through improved access and use of forest products, and indirectly through investment of forest user funds in community activities that generate income. Benefit sharing was found to be more equitable in the forest users group than in the irrigation users group. However, women’s participation in formal activities of both forestry and irrigation groups was negligible. The supported irrigation systems showed marked gains in yields, income and employment. Support to irrigation systems include physical infrastructure combined with financial and technical assistance, but there is weaker enforcement of policy and legal provisions. Thus there appears to be ample opportunity to learn and share experiences from one another. The study indicates that there are opportunities for the integration of both activities. Because changes in land use impact the water source for irrigation, a starting point could be resolution of conflicts around water and land, and managing forests to protect catchments. The existing informal contacts, especially where there is an overlap of membership, could serve as a platform for future integration. While the two groups do not need to be combined, better interaction can only be constructive. This is an area for future research and action."
Investing in Water for Food, Ecosystems and Livelihoods
(2004) Molden, David; de Fraiture, Charlotte
"Sustainably meeting the food and livelihood needs of a growing population will require some very difficult choices about how water is developed and managed in the next 25 years. More food will be necessary, and more food translates into more water for agriculture. More water for agriculture will in many cases mean less for the environment. So how do you manage water for food and the environment? And how do you do so in a way that also reduces poverty? In the following pages we review several policy and water investment options—along with their livelihood and environmental implications. This paper presents issues being addressed by the Comprehensive Assessment of Water Management in Agriculture, an international research program that brings together scientists, development professionals and stakeholders from around the world. This is the first time science has been focused at this level and intensity on answering questions related to water, agriculture, poverty and environmental conservation. The Assessment is at the mid-way mark and won’t be complete until 2006, but already we have evidence to suggest which approaches are the most promising. Our intention in sharing these preliminary findings is to raise awareness that water in agriculture is a pressing issue, that business as usual is not an option, and that there are potential solutions, but they are not necessarily the ones that have received the most attention."
Land and Water Productivity of Wheat in the Western Indo-Gangetic Plains of India and Pakistan: A Comparative Analysis
(2003) Hussain, Intizar; Sakthivadivel, R.; Amarasinghe, Upali A.; Mudasser, Muhammad; Molden, David
"The purpose of this study is to analyze variations in wheat yields and to assess the range of factors affecting wheat yields and profitability of wheat production in the selected irrigation systems in India and Pakistan. The study attempts to identify constraints and opportunities for closing the existing yield gaps. It is hypothesized that substantial gains in aggregate yields can be obtained by improved water management practices at the farm and irrigation-system levels."
Performance Evaluation of the Bhakra Irrigation System, India, Using Remote Sensing and GIs Techniques
(1999) Sakthivadivel, R.; Thiruvengadachari, S.; Amarasinghe, Upali A.; Bastiaanssen, W.G.M.; Molden, David
"Describes the use of satellite remote sensing and GIs techniques to analyze the agricultural performance and sustainability of the Bhakra Irrigation System in India. Demonstrates the cost-effectiveness of these techniques as diagnostic tools for irrigation system improvement and the advantages of using SRS and GIs in combination."
Policies Drain the North China Plain: Agricultural Policy and Groundwater Depletion in Luancheng County, 1949-2000
(2003) Kendy, Eloise; Molden, David; Steenhuis, Tammo S.; Liu, Changming; Wang, Jinxia
"The North China Plain, 3200,000 km in extent, is China's most important center of agricultural production and home to more than 200 million people. Through extensive irrigation, the region produces more than 50 percent of the nation's wheat and 33 percent of its maize, making it critical to national food self-sufficiency. Yet, on the North China Plain, water is the most vital and limiting resource. Natural streamflow has almost completely ceased because of diversions to urban, industrial and agricultural uses. Groundwater levels are declining steadily, salt water is intruding into previously freshwater aquifers and in some places the land surface is subsiding. Even the largest cities, which receive highest priority for water distribution, endure repeated 'crises' set off by water shortages. "The report examines the relationships between agricultural policies in the North China Plain, the approaches to water management that evolved from them, the quantity of water than was actually used, and the consequent groundwater depletion beneath Luancheng County, Hebei Province, from 1949 to 2000. To systematically address these relationships, we use a comprehensive water-balance approach. Our results indicate that a single, longstanding policy-that of using groundwater to meet the crop-water requirements not supplied by precipitation-is responsible fro the steady rate of groundwater decline. "Attempts to make water use sustainable have centered on improving irrigation efficiency to reduce groundwater pumping. Indeed, pumping rates for irrigation in Luancheng County have decreased more than 50 percent since the 1970s. However, water-table declines have continued unabated. This is because the only significant inflows and outflows to and from this hydrologic system are precipitation and crop evapotranspiration, respectively. As long as the irrigated area remains unchanged, crop evapotranspiration remains constant. In Luancheng County, irrigated areas overlie the shallow aquifer, so any excess irrigation water supplied by groundwater pumping passes through the soil profile and replenishes the water supply. Thus, decreased pumping causes a corresponding decrease in groundwater recharge from excess irrigation, while precipitation and crop evapotranspiration remain unchanged. In this physical configuration, irrigation efficiency improvements save no water. "We explore various proposals to stabilize water levels, including crop changes, water-saving technology, and urbanization. Integrating these proposals, we present a quantitative framework for collaborative land-use planning and long-term, sustainable water management, again using a water-balance approach. The inevitable conclusion of this analysis is that withdrawing some land from irrigation is an essential requisite for achieving sustainable water use in the North China Plain. This finding counters China's longstanding and successfully implemented policy of continually increasing the irrigated area in order to achieve the key societal objective of food self-sufficiency. The report is based on data, maps, reports, and interview obtained in Shijiazhuang City and Luancheng County, Hebei Province, People Republic of China in 2001."
Remote Sensing and Hydrologic Models for Performance Assessment in Sirsa Irrigation Circle, India
(1999) Bastiaanssen, W.G.M.; Molden, David; Thiruvengadachari, S.; Smit, A. A. M. F. R.; Mutuwatte, Lal; Jayasinghe, Gayathri
"Describes the results of an irrigation performance evaluation using remote sensing techniques, GIS procedures, and hydrologic modeling at a regional scale. Demonstrates how advanced information technologies support the analysis of irrigation performance by facilitating an in-depth study of a large irrigated area."
Rice Impact in Henan Irrigation Districts along the Lower Yellow River Reaches
(2003) Bin, Dong; Zhichen, Liang; Loeve, Ronald; Molden, David; Baozhong, Yang
"The Henan Province, located in the lower reaches of the Yellow River Basin, is one of the staple areas of food production in China. There are 26 large and medium-sized irrigation districts along the river and the total area irrigated by Yellow River water is 523.56 thousand hectares, of which 85 thousand hectares are paddy fields, accounting for 16% of the total irrigated area in Henan. Traditionally, the deep flooding irrigation method is used and the field irrigation duty during rice growing season is about 1500 - 1800mm, so a large quantity of water diverted from the river is used for rice production. However, the shortage of water resources in the Yellow River Basin has become very serious, therefore the rice culture in the irrigation districts and its impact on Yellow River water diversion are worthwhile to pay attention and discuss. This paper firstly has an introduction of the Henan irrigation districts along the Yellow River reaches and the current status of rice culture in the irrigation districts. Then, the major impacts of rice cultivation are summarized according to the data collected from some main irrigation districts. Finally, the trend of rice cultivation at the irrigation districts is discussed, and some appropriate management options are suggested."
Saving Water: From Field to Fork: Curbing Losses and Wastage in the Food Chain
(2008) Lundqvist, Jan; de Fraiture, Charlotte; Molden, David
"We need to use our water prudently – no one will argue with this statement. But in fact we are wasteful. This need will become more pronounced, and the cost of bad water management will get higher in the future with increasing water demands from increasing population, cities, agriculture, and the environment. Moreover water management will become more difficult with climate change. New solutions and fast actions are required now. Agriculture is the largest human use of water. Clearly, agricultural practices need to be targeted to reduce wastage of water. This has been the center of attention for water saving practices for years. But there are additional ways to save water. Food consumers and businesses have a key role. Losses of food between the farmers’ field to our dinner table – in food storage, transport, food processing, retail and in our kitchens – are huge. This loss of food is equivalent to a loss in water. Reducing food loss and wastage lessens water needs in agriculture. We need to pay more attention to this fact. Our Key Message: Make the Food Chain More Efficient to Save Water to Facilitate the Achievement of Multiple Development Objectives"
Water and the Millennium Development Goals: Meeting the Needs of People and Ecosystems
(2003) Molden, David; Falkenmark, Malin
"When viewed in terms of water, the Millennium Development Goals (MDGs) targeting poverty and hunger seem to be in direct conflict with the goal on environmental sustainability. It is becoming increasingly clear that ensuring people access to water for growing food and earning a living will be necessary to end extreme poverty and hunger in rural areas."
Water for Food, Water for Life: Influencing What Happens Next
(2007) Rodriguez, Dawn; Molden, David
"Will there be enough water to grow enough food for a growing population over the next 50 years or will we run out of water? It is possible to produce the food, but it is probable that today’s food production and environmental trends will lead to crises in many parts of the world."
World Water Demand and Supply, 1990 to 2025: Scenarios and Issues
(1998) Seckler, David; Amarasinghe, Upali A.; Molden, David; de Silva, Radhika; Barker, Randolph
"Presents two alternative scenarios of water demand and supply for 118 countries over the 1990 to 2025 period and develops indicators of water scarcity for each country and for the world as a whole. This study is the first step in IWMI's long-term research goal: to determine the extent and depth of water scarcity, its consequences for individual countries and what can be done about it."
Yellow River Comprehensive Assessment, Basin Features and Issues
(2003) Zhu, Zhongping; Giordano, Mark; Cai, Ximing; Molden, David; Shangchi, Hong
"A new report assessing the state of China's Yellow River could offer hope in providing much needed answers to the critical water management problems facing the countries 2nd longest river. The assessment carried out by researchers from the International Water Management Institute (IWMI) and the Yellow River Conservancy Commission (YRCC). The report was carried out as part of the Comprehensive Assessment of Water Management in Agriculture, an international research program. The findings are stark. They highlight the four major challenges currently facing the river as being increased water scarcity, degraded environment, massive soil conservation needs and constant flood threats."