Your search found 8 records
1 Fischer, G.; Van Velthuizen, H.; Hizsnyik, E.; Wiberg, D.. 2009. Potentially obtainable yields in the semi-arid tropics. Patancheru, Andhra Pradesh, India: International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) 63p. (Global Theme on Agroecosystems Report 54)
(Location: IWMI HQ Call no: e-copy only Record No: H042776)
http://dspace.icrisat.ac.in/dspace/bitstream/123456789/935/1/Potentially-obtainable-yields.pdf
https://vlibrary.iwmi.org/pdf/H042776.pdf
https://vlibrary.iwmi.org/pdf/H042776.pdf
(1.33 MB)
Close to one billion people in the world are undernourished and world population is expected to increase by 30% to approximately 9 billion by 2050 while food demand is expected to double. There is increasing competition for land and water resources from other sectors and increasing competitive demand for agricultural products for biofuel production. The UN’s Millenium Development Goal of reducing the number of undernourished to less than 420 million by 2015 has placed additional emphasis on the question of how we can secure food for the current and future populations and where the additional food requirement can be produced. One world region that possesses significant potential for improvements in agricultural output is the Semi-Arid Tropics (SAT), which lie primarily in developing countries where agriculture is almost entirely rainfed and largely comprises poor, smallholder farms. Due to a variety of factors including high climatic variability in time and space, poverty and poor education, poor policy and institutional support, and political instability, many areas within the SAT are far from reaching their potential agricultural production. Developing their full agricultural potential would help these areas feed their often rapidly growing populations as well as reduce poverty, boost their economies and provide more food for world markets. In this report, IIASA’s Agro-Ecological Zones (AEZ) methodology is applied to assess the agricultural potential of the semi-arid tropics and compare it to currently reported yields. Yield potentials are calculated for rain-fed conditions under high inputs and advanced management to show how much yields can be improved. Furthermore, the AEZ methodology is adjusted to model the impacts on yield potentials of water management techniques such as rainwater harvesting and soil moisture management. Bio-physical constraints to agriculture and the impacts of climate change are also analyzed with AEZ. Results indicate that modeled potential yields under high inputs and advanced management are on average 3.6 times more than the current average yields in countries under the SAT. Soil moisture management and rainwater harvesting practices could add an additional 10% on average to these high input potentials while further reducing the variability in yields and number of failure years. Climate change impacts are slightly positive for the SAT as a whole, but all results in the study vary considerably depending on the crop and the region.
2 Wada, Y.; Florke, M.; Hanasaki, N.; Eisner, S.; Fischer, G.; Tramberend, S.; Satoh, Y.; van Vliet, M. T. H.; Yillia, P.; Ringler, C.; Burek, P.; Wiberg, D.. 2016. Modeling global water use for the 21st century: the Water Futures and Solutions (WFaS) initiative and its approaches. Geoscientific Model Development, 9:175-222.
Water use ; Water demand ; Water availability ; Water scarcity ; Food production ; Models ; Socioeconomic environment ; Agriculture ; Livestock ; Irrigation water ; Domestic water ; Irrigated land ; Energy generation ; Electricity generation ; Environmental flows ; Secondary sector
(Location: IWMI HQ Call no: e-copy only Record No: H047861)
http://www.geosci-model-dev.net/9/175/2016/gmd-9-175-2016.pdf
https://vlibrary.iwmi.org/pdf/H047861.pdf
https://vlibrary.iwmi.org/pdf/H047861.pdf
To sustain growing food demand and increasing standard of living, global water use increased by nearly 6 times during the last 100 years, and continues to grow. As water demands get closer and closer to the water availability in many regions, each drop of water becomes increasingly valuable and water must be managed more efficiently and intensively. However, soaring water use worsens water scarcity conditions already prevalent in semi-arid and arid regions, increasing uncertainty for sustainable food production and economic development. Planning for future development and investments requires that we prepare water projections for the future. However, estimations are complicated because the future of the world's waters will be influenced by a combination of environmental, social, economic, and political factors, and there is only limited knowledge and data available about freshwater resources and how they are being used. The Water Futures and Solutions (WFaS) initiative coordinates its work with other ongoing scenario efforts for the sake of establishing a consistent set of new global water scenarios based on the shared socio-economic pathways (SSPs) and the representative concentration pathways (RCPs). The WFaS "fast-track" assessment uses three global water models, namely H08, PCR-GLOBWB, and WaterGAP. This study assesses the state of the art for estimating and projecting water use regionally and globally in a consistent manner. It provides an overview of different approaches, the uncertainty, strengths and weaknesses of the various estimation methods, types of management and policy decisions for which the current estimation methods are useful. We also discuss additional information most needed to be able to improve water use estimates and be able to assess a greater range of management options across the water–energy–climate nexus.
3 Burek, P.; Satoh, Y.; Fischer, G.; Kahil, M. T.; Scherzer, A.; Tramberend, S.; Nava, L. F.; Wada, Y.; Eisner, S.; Florke, M.; Hanasaki, N.; Magnuszewski, P.; Cosgrove, B.; Wiberg, D.. 2016. Water futures and solution - fast track initiative. Final Report. Laxenburg, Austria: International Institute for Applied Systems Analysis (IIASA). 115p. (IIASA Working Paper WP 16-006)
Water supply ; Water demand ; Water use ; Water security ; Water scarcity ; Water availability ; Surface water ; Groundwater extraction ; Irrigation water ; Domestic water ; Sociocultural environment ; Economic growth ; Income ; Energy demand ; Climate change ; Agricultural development ; Food supply ; Food production ; Cultivated land ; Land use ; Population growth ; Deforestation ; Assessment / Africa / Asia / Europe / India / China / Pakistan / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H047862)
4 van Vliet, M. T. H.; Wiberg, D.; Leduc, S.; Riahi, K. 2016. Power-generation system vulnerability and adaptation to changes in climate and water resources. Nature Climate Change, 6(1):375-381. [doi: https://doi.org/10.1038/nclimate2903]
Energy generation ; Energy demand ; Electricity generation ; Climate change adaptation ; Water resources ; Water power ; Water security ; Thermal energy ; Refrigeration equipment
(Location: IWMI HQ Call no: e-copy only Record No: H047927)
Hydropower and thermoelectric power together contribute 98% of the world’s electricity generation at present. These power-generating technologies both strongly depend on water availability, and water temperature for cooling also plays a critical role for thermoelectric power generation. Climate change and resulting changes in water resources will therefore affect power generation while energy demands continue to increase with economic development and a growing world population. Here we present a global assessment of the vulnerability of the world’s current hydropower and thermoelectric power-generation system to changing climate and water resources, and test adaptation options for sustainable water–energy security during the twenty-first century. Using a coupled hydrological–electricity modelling framework with data on 24,515 hydropower and 1,427 thermoelectric power plants, we show reductions in usable capacity for 61–74% of the hydropower plants and 81–86% of the thermoelectric power plants worldwide for 2040–2069. However, adaptation options such as increased plant efficiencies, replacement of cooling system types and fuel switches are effective alternatives to reduce the assessed vulnerability to changing climate and freshwater resources. Transitions in the electricity sector with a stronger focus on adaptation, in addition to mitigation, are thus highly recommended to sustain water–energy security in the coming decades.
5 Dile, Y. T.; Karlberg, L.; Daggupati, P.; Srinivasan, R.; Wiberg, D.; Rockstrom, J. 2016. Assessing the implications of water harvesting intensification on upstream–downstream ecosystem services: a case study in the Lake Tana basin. Science of The Total Environment, 542:22-35. [doi: https://doi.org/10.1016/j.scitotenv.2015.10.065]
Water harvesting ; Water requirements ; Water quality ; Water use ; Intensification ; Stream flow ; Upstream ; Downstream ; Ecosystem services ; Crop yield ; Supplemental irrigation ; Irrigation water ; Sediment ; Sustainable agriculture ; Intensification ; Ecology ; Decision support systems ; Ponds ; Watersheds ; Soils ; Assessment ; Nutrient availability ; Onions ; Food security ; Food production ; Economic aspects ; Case studies / Ethiopia / Africa South of Sahara / Lake Tana Basin
(Location: IWMI HQ Call no: e-copy only Record No: H047928)
Water harvesting systems have improved productivity in various regions in sub-Saharan Africa. Similarly, they can help retain water in landscapes, build resilience against droughts and dry spells, and thereby contribute to sustainable agricultural intensification. However, there is no strong empirical evidence that shows the effects of intensification of water harvesting on upstream–downstream social–ecological systems at a landscape scale. In this paper we develop a decision support system (DSS) for locating and sizing water harvesting ponds in a hydrological model, which enables assessments of water harvesting intensification on upstream–downstream ecosystem services in meso-scale watersheds. The DSS was used with the Soil and Water Assessment Tool (SWAT) for a case-study area located in the Lake Tana basin, Ethiopia. We found that supplementary irrigation in combination with nutrient application increased simulated teff (Eragrostis tef, staple crop in Ethiopia) production up to three times, compared to the current practice. Moreover, after supplemental irrigation of teff, the excess water was used for dry season onion production of 7.66 t/ha (median). Water harvesting, therefore, can play an important role in increasing local- to regional-scale food security through increased and more stable food production and generation of extra income from the sale of cash crops. The annual total irrigation water consumption was ~ 4%–30% of the annual water yield from the entire watershed. In general, water harvesting resulted in a reduction in peak flows and an increase in low flows. Water harvesting substantially reduced sediment yield leaving the watershed. The beneficiaries of water harvesting ponds may benefit from increases in agricultural production. The downstream social–ecological systems may benefit from reduced food prices, reduced flooding damages, and reduced sediment influxes, as well as enhancements in low flows and water quality. The benefits of water harvesting warrant economic feasibility studies and detailed analyses of its ecological impacts.
6 Khan, A.; Richards, K. S.; McRobie, A.; Fischer, G.; Wiberg, D.; Burek, P.; Satoh, Y. 2016. Accuracy assessment of ISI-MIP modelled ows in the Hidukush-Karakoram-Himalayan basins [Abstract only] Paper presented at the European Geosciences Union (EGU) General Assembly, Vienna, Austria, 17-22 April 2016. 1p.
Mountain ranges ; Glaciers ; Meltwater ; Climate change ; Stream flow ; Energy generation ; Hydrology ; Models ; River basins ; Precipitation / Afghanistan / Pakistan / China / India / Tajikistan / Hindu Kush / Karakoram / Himalayan Region / Upper Indus Basin
(Location: IWMI HQ Call no: e-copy only Record No: H047865)
7 van Vliet, M. T. H.; Sheffield, J.; Wiberg, D.; Wood, E. F. 2016. Impacts of recent drought and warm years on water resources and electricity supply worldwide. Environmental Research Letters, 11:1-10. [doi: https://doi.org/10.1088/1748-9326/11/12/124021]
Water resources ; Drought ; Electricity generation ; Electricity supplies ; Thermal energy ; Water power ; Drought ; Temperature ; Water temperature ; Stream flow
(Location: IWMI HQ Call no: e-copy only Record No: H048083)
http://iopscience.iop.org/article/10.1088/1748-9326/11/12/124021/pdf
https://vlibrary.iwmi.org/pdf/H048083.pdf
https://vlibrary.iwmi.org/pdf/H048083.pdf
(4.00 MB) (4.00 MB)
Recent droughts and heatwaves showed the vulnerability of the electricity sector to surface water constraints with reduced potentials for thermoelectric power and hydropower generation in different regions. Here we use a global hydrological-electricity modelling framework to quantify the impacts of recent drought and warm years on hydropower and thermoelectric power usable capacity worldwide. Our coupled modelling framework consists of a hydrological model, stream temperature model, hydropower and thermoelectric power models, and was applied with data of a large selection of hydropower and thermoelectric power plants worldwide. Our results show that hydropower utilisation rates were on average reduced by 5.2% and thermoelectric power by 3.8% during the drought years compared to the long-term average for 1981–2010. Statistically significant (p < 0.01) impacts on both hydropower and thermoelectric power usable capacity were found during major drought years, e.g. 2003 in Europe (-6.6% in hydropower and -4.7% in thermoelectric power) and 2007 in Eastern North America (-6.1% in hydropower and -9.0% in thermoelectric power). Our hydrological-electricity modelling framework has potential for studying the linkages between water and electricity supply under climate variability and change, contributing to the quantification of the 'water-energy nexus'.
8 Sadoff, C. W.; Hall, J. W.; Grey, D.; Aerts, J. C. J. H.; Ait-Kadi, M.; Brown, C.; Cox, A.; Dadson, S.; Garrick, D.; Kelman, J.; McCornick, Peter; Ringler, C.; Rosegrant, M.; Whittington, D.; Wiberg, D.. 2015. Securing water, sustaining growth. Report of the GWP/OECD Task Force on Water Security and Sustainable Growth. Oxford, UK: University of Oxford. 171p.
Water security ; Water scarcity ; Water supply ; Sustainable development ; Economic growth ; Investment ; Energy conservation ; Sanitation ; River basins ; Aquifers ; Urban areas ; Hydrological factors
(Location: IWMI HQ Call no: e-copy only Record No: H047036)
http://www.water.ox.ac.uk/wp-content/uploads/2015/04/SCHOOL-OF-GEOGRAPHY-SECURING-WATER-SUSTAINING-GROWTH-DOWNLOADABLE.pdf
https://vlibrary.iwmi.org/pdf/H047036.pdf
https://vlibrary.iwmi.org/pdf/H047036.pdf
(11.03 MB)
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