Your search found 9 records
(Location: IWMI HQ Call no: e-copy only Record No: H042476)
(1.28 MB)
Globally, most food is produced using soil moisture that comes from precipitation (i.e., “green” water). Moreover, most of the water that reaches plants in irrigated systems also stems from precipitation. Despite this, irrigation (or “blue”) water has typically been the focus for policy analysis, largely because it is possible for humans to manipulate blue water. This paper analyzes alternative water futures using a combined green and blue water accounting framework embedded within the water simulation components of IFPRI’s International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT). Future scenarios recently developed for the International Assessment of Agricultural Knowledge, Science and Technology for Development (IAASTD) and other studies are assessed with respect to this adjusted green/blue water accounting framework. The results reveal that accounting explicitly for green water resources broadens the scope of options for decision-makers who are seeking to improve agricultural production in the face of rising food and energy prices, a degrading water and land resource base, and increasing demands. This analysis highlight the importance of green/blue water accounting and presents a wider range of agricultural science and technology policy options for increasing global crop productivity across a span of potential futures.
2 Nelson, G. C.; Rosegrant, M. W.; Palazzo, A.; Gray, I.; Ingersoll, C.; Robertson, R.; Tokgoz, S.; Zhu, T.; Sulser, T. B.; Ringler, C.; Msangi, S.; You, L. 2010. Food security, farming, and climate change to 2050: scenarios, results, policy options. Washington, DC, USA: International Food Policy Research Institute (IFPRI). 131p. (IFPRI Research Monograph)
(Location: IWMI HQ Call no: 338.19 G0000 NEL Record No: H044082)
(13.17 MB) (13.14MB)
3 Ringler, C.; Cai, X.; Wang, J.; Ahmed, A.; Xue, Y.; Xu, Z.; Yang, E.; Jianshi, Z.; Zhu, T.; Cheng, L.; Yongfeng, F.; Xinfeng, F.; Xiaowei, G.; You, L. 2012. Yellow River Basin: living with scarcity. In Fisher, M.; Cook, Simon (Eds.). Water, food and poverty in river basins: defining the limits. London, UK: Routledge. pp.192-217.
(Location: IWMI HQ Call no: IWMI Record No: H044845)
4 Xie, H.; Ringler, C.; Zhu, T.; Waqas, A. 2015. Droughts in Pakistan: a spatiotemporal variability analysis using the Standardized Precipitation Index. In Ringler, C.; Anwar, Arif (Eds.). Water for food security: challenges for Pakistan. Oxon, UK: Routledge. pp.116-127.
(Location: IWMI HQ Call no: IWMI Record No: H046854)
5 Zhu, T.; Ringler, C.; Iqbal, M. M.; Sulser, T. B.; Goheer, M. F. 2015. Climate change impacts and adaptation options for water and food in Pakistan: scenario analysis using an integrated global water and food projections model. In Ringler, C.; Anwar, Arif (Eds.). Water for food security: challenges for Pakistan. Oxon, UK: Routledge. pp.147-165.
(Location: IWMI HQ Call no: IWMI Record No: H046856)
(Location: IWMI HQ Call no: e-copy only Record No: H047545)
(0.94 MB) (956 KB)
Agricultural water use includes a continuum from purely rainfed to fully irrigated systems. Growing pressures on limited water supplies from domestic, industrial, and environmental uses will likely lead to a decline in water availability for food production. Similarly, income growth and urbanization lead to dietary shift s that require more water resources per calorie consumed, putting further pressures on water supplies. As a result, semiarid and arid countries continue to increase net imports of food. Crop water use for sugarcane (Saccharum officinarum L.), maize (Zea mays L.), soybean [Glycine max (L.) Merr.], and fruits are expected to grow over time, whereas water use for wheat (Triticum aestivum L.) and rice (Oryza sativa L.) are expected to decline after 2030. These projections include substantial improvements in water use efficiency at the field, farm, and river basin scale over the coming decades in response to growing water scarcity. If these efficiency improvements are not achieved, future crop water demands would be even larger. Although water resources are a key limiting factor for future food security, policy and investment options to reduce agricultural water use exist on both the water supply and demand side; but political will and ingenuity are needed for their implementation.
(Location: IWMI HQ Call no: e-copy only Record No: H047546)
(1.38 MB)
Efficient reallocation and conjunctive operation of existing water supplies is gaining importance as demands grow, competitions among users intensify, and new supplies become more costly. This paper analyzes the roles and benefits of conjunctive use of surface water and groundwater and market-based water transfers in an integrated regional water system where agricultural and urban water users coordinate supply and demand management based on supply reliability and economic values of water. Agricultural users optimize land and water use for annual and perennial crops to maximize farm income, while urban users choose short-term and long-term water conservation actions to maintain reliability and minimize costs. The temporal order of these decisions is represented in a two-stage optimization that maximizes the net expected benefits of crop production, urban conservation and water management including conjunctive use and water transfers. Long-term decisions are in the first stage and short-term decisions are in a second stage based on probabilities of water availability events. Analytical and numerical analyses are made. Results show that conjunctive use and water transfers can substantially stabilize farmer’s income and reduce system costs by reducing expensive urban water conservation or construction. Water transfers can equalize marginal values of water across users, while conjunctive use minimizes water marginal value differences in time. Model results are useful for exploring the integration of different water demands and supplies through water transfers, conjunctive use, and conservation, providing valuable insights for improving system management.
(Location: IWMI HQ Call no: e-copy only Record No: H047781)
(1.38 MB)
The resolution adopted by the General Assembly of the United Nations on 25 September 2015 is symptomatic of the water-energy-food (WEF) nexus. It postulates goals and related targets for 2030 that include (1) End hunger, achieve food security and improved nutrition, and promote sustainable agriculture (SDG2); (2) Ensure availability and sustainable management of water and sanitation for all (SDG6); and (3) Ensure access to affordable, reliable, sustainable, and modern energy for all (SDG7). There will be tradeoffs between achieving these goals particularly in the wake of changing consumption patterns and rising demands from a growing population expected to reach more than nine billion by 2050. This paper uses global economic analysis tools to assess the impacts of long-term changes in fossil fuel prices, for example, as a result of a carbon tax under the UNFCCC or in response to new, large findings of fossil energy sources, on water and food outcomes. We find that a fossil fuel tax would not adversely affect food security and could be a boon to global food security if it reduces adverse climate change impacts.
(Location: IWMI HQ Call no: e-copy only Record No: H047966)
(4.16 MB)
Following the debate on whether drought has become more severe under climate change, this paper assesses drought frequency in northern and eastern India using two datasets of Palmer Drought Severity Index (PDSI) (generated by Dai, 2013 and Sheffield et al., 2012). The univariate return period for three drought characteristics (duration, severity and peak intensity) is examined regarding whether drought has occurred with longer duration, higher severity and/or larger peak intensity. The spatial variation of those changes is analyzed through eight areas in the study region. The temporal and spatial comparisons based on the univariate return period show different change patterns of duration, severity and peak intensity in different areas. Generally, in the areas which plant wheat more than rice (areas 1 and 2), drought has been alleviated in duration and intensity after 1955; while in the areas which plant more rice than wheat (areas 3–8), drought have been aggravated in duration, severity and intensity (except for area 8, a coastal area). This spatial change pattern may imply potential crop pattern change, for example, switching from rice to wheat in areas 3–7. Furthermore, the bivariate return period for pairs of drought characteristics based on the copulas and considering correlation between the drought characteristics is examined to understand how bivariate return periods change over time and space. Finally, it is also found that one data set (Sheffield et al.) results in more severe, longer and more intense drought in most of the areas, especially for the drought events with long-return-periods than the other (Dai).
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