This paper introduces and applies iGain4Gains, an Excel-based model, to reveal how changes to water conservation and allocation, and irrigation technology, can produce four nexus gains. These gains are; reduced aggregate water consumption, sustained crop production, lower carbon emissions, and enhanced water availability for nature. We developed the model with limited data and hypothetical future scenarios from the Amman–Zarqa basin in Jordan. Given its significant irrigation and urban water demands and difficult decisions regarding future water allocation and nexus choices, this basin is a highly appropriate case study. The paper’s primary aim is to demonstrate the iGains4Gains nexus model rather than to build an accurate hydrological model of the basin’s water resources. The model addresses two critical questions regarding increased irrigation efficiency. First, can irrigation efficiency and other factors, such as irrigated area, be applied to achieve real water savings while maintaining crop production, ensuring greenhouse gas emission reductions, and ‘freeing’ water for nature? Second, with the insight that water conservation is a distributive/allocative act, we ask who between four paracommoners (the proprietor irrigation system, neighbouring irrigation systems, society, and nature) benefits hydrologically from changes in irrigation efficiency? Recognising nexus gains are not always linear, positive and predictable, the model reveals that achieving all four gains simultaneously is difficult, likely leading to trade-offs such as water consumption rebounds or increased carbon emissions. Demonstrated by its use at a workshop in Jordan in February 2024, iGains4Gains can be used by students, scientists and decision-makers, to explore and understand nexus trade-offs connected to changes in irrigation management. The paper concludes with recommendations for governing water and irrigated agriculture in basins where large volumes of water are withdrawn and depleted by irrigation.

Forty seven percent of the population of Pakistan is food insecure, access to food is uneven and malnutrition is widespread. In addition, food production depends greatly on irrigation, including the use of substantial volumes of water from already stressed aquifers. Our aim in this paper is to examine the implications of continued population growth on the required production of food and the implied water demand.We examine the historical trends of crop production, water use, food availability and population growth in Pakistan, and project them forward to 2050. Food availability has improved over recent decades, mostly as a result of increasing the area and water use of crops and fodder, and partly as a result of importing more pulses and cooking oils. We show that a continuation of current trends leads to nearly a doubling of the (already unsustainable) groundwater use. There is uncertainty in the magnitude of climate change impacts, but climate change may further exacerbate matters. To avoid further increases of groundwater use, some combination would be required of: more dams and other irrigation infrastructure; increasing crop yields (particularly yields per unit volume of water) at a greater rate than in the past; a change in crop mix away from high water use crops like rice and sugarcane, to crops that use less water; and, exporting less and importing more food. The alternatives appear difficult to implement quickly, so it appears likely that in the short to medium term more groundwater will be consumed, with attendant problems of water quality and sustainability. Our analysis provides new perspectives on past trends and future food and water (including groundwater) challenges.

This is the third volume of the proceedings of the national conference on ?Water for Food and Environment?, which was held from June 9 ?11, 2009 at the Bandaranaike Memorial International Conference Hall (BMICH). The volumes 1 and 2 have been produced as separate documents of this report series. In response to a call for abstracts, 81 abstracts were received from government institutes dealing with water resources and agriculture development, universities, other freelance researchers and researchers from the International Water Management Institute (IWMI). Forty seven of the eighty-one abstracts that were submitted were accepted for compiling full papers. | In the past couple of years the sharp increase in food prices worldwide has raised serious concerns about food security, especially in developing countries. To effectively address these concerns a holistic approach is required that encompasses improved agricultural water productivity, adaptation to climate change, targeted and appropriate institutional and financial measures, and a consideration of environmental issues. The main purpose of the conference was to share experiences in these areas and to find opportunities to improve farmers? incomes and food production, and to promote environmentally sustainable practices in Sri Lanka in the face of growing water scarcity and the challenges of climate change.

This is the third volume of the proceedings of the national conference on ‘Water for Food and Environment’, which was held from June 9 –11, 2009 at the Bandaranaike Memorial International Conference Hall (BMICH). The volumes 1 and 2 have been produced as separate documents of this report series. In response to a call for abstracts, 81 abstracts were received from government institutes dealing with water resources and agriculture development, universities, other freelance researchers and researchers from the International Water Management Institute (IWMI). Forty seven of the eighty-one abstracts that were submitted were accepted for compiling full papers. In the past couple of years the sharp increase in food prices worldwide has raised serious concerns about food security, especially in developing countries. To effectively address these concerns a holistic approach is required that encompasses improved agricultural water productivity, adaptation to climate change, targeted and appropriate institutional and financial measures, and a consideration of environmental issues. The main purpose of the conference was to share experiences in these areas and to find opportunities to improve farmers’ incomes and food production, and to promote environmentally sustainable practices in Sri Lanka in the face of growing water scarcity and the challenges of climate change.