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1.
Is irrigated agriculture in the Murray Darling Basin well prepared to deal with reductions in water availability? 总被引：1，自引：0，他引：1
Yongping WeiJohn Langford Ian R. WillettSnow Barlow Clive Lyle 《Global Environmental Change》2011,21(3):906-916
The “Big Dry”, a prolonged dry period in Australia from 1997 to 2009, dried out much of the Murray-Darling Basin (MDB) and resulted in large agricultural losses and degraded river ecosystems. Climate projections are that dry conditions in the MDB are likely to be more regular and severe than ever before, and recent policy initiatives are likely to reduce consumptive water use and redirect water to ecosystem management. This paper aims to develop an understanding of the interactions between water policy and irrigation practices by deriving lessons from drought management in irrigated agriculture of the MDB during the Big Dry, and furthermore, to draw out lessons to enhance the preparedness of irrigated agriculture for a future drier climate and reduced water availability. Reviews of irrigation farmers’ practices, attitudes and capacity to manage during prolonged droughts in the MDB, and the evolution of agricultural water policy in Australia since 1990 were made. It is clear that farmers could be better prepared to deal with a drier climate if their water management practices, e.g. irrigation methods and soil moisture measuring tools are improved, if the impediments to the uncertainty of water allocation and low water availability could be overcome, and if well-targeted research and extension could assist farmers to use water more wisely. It is also clear that Australian water policy could be better prepared in terms of assisting irrigated agriculture to deal with a drier climate. Key areas are reduction of barriers and distortions to water trading, optimizing the environmental water allocation, and seeking mutual benefits between environmental water allocation and irrigated agriculture, improvement of the cost-effectiveness of investments in water supply infrastructure, facilitating carryover and capacity sharing at larger scales, and provision of accurate, accessible and useful water information at different scales. An approach to irrigation practice and water policy is proposed based on past experience and potential opportunities. The approach is a set of linked strategies for more robust agricultural production and a more sustainable environment under a drier climate and reduced water availability. 相似文献
2.
近年来，我国政府和科技界十分关注气候王馥棠变暖对我国经济发展可能影响的评估, 开展了许多重大项目和课题的研究。该文仅就气候变暖对我国自然植被、农业、森林、水资源、能源利用和区域海平面上升等领域影响评估研究的若干有意义的初步结果简要归纳和评述如下:取自不同GCM模型的未来气候变化情景下的影响评估模拟表明，我国的特征性自然植被类型将会发生明显的变化。同当前气候（1951~1980年）下的模拟分布相比，到2050年我国几乎所有地方的农业种植制度均将发生较大变化；气候变暖将导致复种指数增加和种植方式多样化，但降水与蒸散之间可能出现的负平衡和土壤水分胁迫的增加以及生育期的可能缩短，最终将导致我国主要作物的产量下降。气候变暖对我国水资源最明显的影响将会发生在黄淮海流域，这个区域的水资源供需短缺将大大提高。同时，气候变暖将改变我国室内取暖和降温的能源需求关系:北方冬季取暖的能源消耗将减少, 而南方夏季降温的能源消耗将会增加。海平面的上升将使我国三个主要沿海低洼脆弱区，即珠江三角洲、长江三角洲和黄河三角洲，面临部分遭受海水淹没的威胁。 相似文献
3.
The high uncertainty associated with the effect of global change on water resource systems calls for a better combination of conventional top–down and bottom–up approaches, in order to design robust adaptation plans at the local scale. The methodological framework presented in this article introduces “bottom–up meets top–down” integrated approach to support the selection of adaptation measures at the river basin level by comprehensively integrating the goals of economic efficiency, social acceptability, environmental sustainability and adaptation robustness. The top–down approach relies on the use of a chain of models to assess the impact of global change on water resources and its adaptive management over a range of climate projections. Future demand scenarios and locally prioritised adaptation measures are identified following a bottom–up approach through a participatory process with the relevant stakeholders and experts. The optimal combinations of adaptation measures are then selected using a hydro-economic model at basin scale for each climate projection. The resulting adaptation portfolios are, finally, climate checked to define a robust least-regret programme of measures based on trade-offs between adaptation costs and the reliability of supply for agricultural demands.This innovative approach has been applied to a Mediterranean basin, the Orb river basin (France). Mid-term climate projections, downscaled from 9 General Climate Models, are used to assess the uncertainty associated with climate projections. Demand evolution scenarios are developed to project agricultural and urban water demands on the 2030 time horizon. The results derived from the integration of the bottom–up and top–down approaches illustrate the sensitivity of the adaptation strategies to the climate projections, and provide an assessment of the trade-offs between the performance of the water resource system and the cost of the adaptation plan to inform local decision-making. The article contributes new methodological elements for the development of an integrated framework for decision-making under climate change uncertainty, advocating an interdisciplinary approach that bridges the gap between bottom–up and top–down approaches. 相似文献
4.
Andrew Wiltshire Jemma Gornall Ben Booth Emily Dennis Pete Falloon Gillian Kay Doug McNeall Carol McSweeney Richard Betts 《Global Environmental Change》2013,23(5):1083-1097
Future levels of water stress depend on changes in several key factors including population, climate-change driven water availability, and a carbon dioxide physiological-forcing effect on evaporation and run-off. In this study we use an ensemble of the HadCM3 climate model forced with a range of future emissions scenarios combined with a simple water scarcity index to assess the contribution of each of these factors to the projected population living in water stress over the 21st century.Population change only scenarios increase the number of people living in water stress such that at peak global population 65% of people experience some level of water stress. Globally, the climate model ensemble projects an increase in water availability which partially offsets some of the impacts of population growth. The result is 1 billion fewer people living in water stress by the 2080s under the high end emissions scenarios than if population increased in the absence of climate change.This study highlights the important role plant-physiological forcing has on future water resources. The effect of rising CO2 is to increase available water and to reduce the number of people living in high water stress by around 200 million compared to climate only projections. This effect is of a similar order of magnitude to climate change. 相似文献
5.
Future cereal production in China: The interaction of climate change,water availability and socio-economic scenarios 总被引：4，自引：0，他引：4
Xiong Wei Conway Declan Lin Erda Xu Yinlong Ju Hui Jiang Jinhe Holman Ian Li Yan 《Global Environmental Change》2009,19(1):34-44
Food production in China is a fundamental component of the national economy and driver of agricultural policy. Sustaining and increasing output to meet growing demand faces significant challenges including climate change, increasing population, agricultural land loss and competing demands for water. Recent warming in China is projected to accelerate by climate models with associated changes in precipitation and frequency of extreme events. How changes in cereal production and water availability due to climate change will interact with other socio-economic pressures is poorly understood. By linking crop and water simulation models and two scenarios of climate (derived from the Regional Climate Model PRECIS) and socio-economic change (downscaled from IPCC SRES A2 and B2) we demonstrate that by the 2040s the absolute effects of climate change are relatively modest. The interactive effects of other drivers are negative, leading to decreases in total production of ?18% (A2) and ?9% (B2). Outcomes are highly dependent on climate scenario, socio-economic development pathway and the effects of CO2 fertilization on crop yields which may almost totally offset the decreases in production. We find that water availability plays a significant limiting role on future cereal production, due to the combined effects of higher crop water requirements (due to climate change) and increasing demand for non-agricultural use of water (due to socio-economic development). Without adaptation, per capita cereal production falls in all cases, by up to 40% of the current baseline.By simulating the effects of three adaptation scenarios we show that for these future scenarios China is able to maintain per capita cereal production, given reasonable assumptions about policies on land and water management and progress in agricultural technology. Our results are optimistic because PRECIS simulates much wetter conditions than a multi-model average, the CO2 crop yield response function is highly uncertain and the effects of extreme events on crop growth and water availability are likely to be underestimated. 相似文献
6.
Richard M. Adams Ronald A. Fleming Ching-Chang Chang Bruce A. McCarl Cynthia Rosenzweig 《Climatic change》1995,30(2):147-167
This study uses recent GCM forecasts, improved plant science and water supply data and refined economic modeling capabilities to reassess the economic consequences of long-term climate change on U.S. agriculture. Changes in crop yields, crop water demand and irrigation water arising from climate change result in changes in economic welfare. Economic consequences of the three GCM scenarios are mixed; GISS and GFDL-QFlux result in aggregate economic gains, UKMO implies losses. As in previous studies, the yield enhancing effects of atmospheric CO2 are an important determinant of potential economic consequences. Inclusion of changes in world food production and associated export changes generally have a positive affect on U.S. agriculture. As with previous studies, the magnitude of economic effects estimated here are a small percentage of U.S. agricultural value. 相似文献
7.
This paper evaluates the role of trade as a mechanism of economic adjustment to the impacts of climate change on agriculture.
The study uses a model of the world economy able to reflect changes in comparative advantage; the model is used to test the
hypotheses that trade can assure that, first, satisfying global agricultural demand will not be jeopardized, and, second,
general access to food will not decrease. The hypotheses are tested for three alternative scenarios of climate change; under
each scenario, regions adjust to the climatic assumptions by changing the land areas devoted to agriculture and the mix of
agricultural goods produced, two of the major mechanisms of agricultural adaptation. We find that trade makes it possible
to satisfy the world demand for agricultural goods under the changed physical conditions. However, access to food decreases
in some regions of the world. Other patterns also emerge that indicate areas of concern in relying on trade as a mechanism
for the adjustment of agriculture to likely future changes in climate. 相似文献
8.
Improving the adaptive capacity of small-scale irrigation systems to the impacts of climate change is crucial for food security in Asia. This study analyzes the capacity of small-scale irrigation systems dependent on the Asian monsoon to adapt to variability in river discharge caused by climate change. Our study is motivated by the Pumpa irrigation system, a small-scale irrigation system located in Nepal that is a model for this type of system. We developed an agent-based model in which we simulated the decisions farmers make about the irrigation strategy to use according to available water flow. Given the uncertainty associated with how climate change may affect the Asian monsoon, we simulated the performance of the system under different projections of climate change in the region (increase and decrease in rainfall, reduction and expansion of the monsoon season, and changes in the timing of the onset of the monsoon). Accordingly to our simulations, farmers might need to adapt to rainfall intensification and a late onset in the monsoon season. The demands for collective action among farmers (e.g. infrastructure repair, meetings, decisions, etc.) might increase considerably due to climate change. Although our model suggests that investment in new infrastructure might increase the performance of the system under some climate change scenarios, the high inequality among farmers when water availability is reduced might hinder the efficiency of these measures due to a reduction of farmers’ willingness to cooperate. Our modeling exercise helps to hypothesize about the most sensitive climate change scenarios for smallscale irrigation farming in Nepal and helps to frame a discussion of some possible solutions and fundamental trade-offs in the process of adaptation to improve for food and water security under climate change. 相似文献
9.
Climate change is expected to produce reductions in water availability in England, potentially necessitating adaptive action by the water industry to maintain supplies. As part of Ofwat's fifth Periodic Review (PR09), water companies recently released their draft Water Resources Management Plans, setting out how each company intends to maintain the balance between the supply and demand for water over the next 25 years, following Environment Agency guidelines. This paper reviews these plans to determine company estimates of the impact of climate change on water supply relative to other resource pressures. The approaches adopted for incorporating the impact in the plans and the proposed management solutions are also identified.Climate change impacts for individual resource zones range from no reductions in deployable output to greater than 50% over the planning period. The estimated national aggregated loss of deployable output under a “core” climate scenario is ∼520 Ml/d (3% of deployable output) by 2034/2035, the equivalent of the supply of one entire water company (South West Water). Climate change is the largest single driver of change in water supplies over the planning period. Over half of the climate change impact is concentrated in southern England. In extreme cases, climate change uncertainty is of the same magnitude as the change under the core scenario (up to a loss of ∼475 Ml/d). 44 of the 68 resource zones with available data are estimated to have a climate change impact. In 35 of these climate change has the greatest impact although in 10 zones sustainability reductions have a greater impact. Of the overall change in downward pressure on the supply-demand balance over the planning period, ∼56% is accounted for by increased demand (620 Ml/d) and supply side climate change accounts for ∼37% (407 Ml/d). Climate change impacts have a cumulative impact in concert with other changing supply side reducing components increasing the national pressure on the supply-demand balance. Whilst the magnitude of climate change appears to justify its explicit consideration, it is rare that adaptation options are planned solely in response to climate change but as a suite of options to provide a resilient supply to a range of pressures (including significant demand side pressures). Supply-side measures still tend to be considered by water companies to be more reliable than demand-side measures. 相似文献
10.
11.
Impacts of Present and Future Climate Change and Climate Variability on Agriculture in the Temperate Regions: North America 总被引：2，自引：0，他引：2
The potential impact of climate variability and climate change on agricultural production in the United States and Canada
varies generally by latitude. Largest reductions are projected in southern crop areas due to increased temperatures and reduced
water availability. A longer growing season and projected increases in CO2 may enhance crop yields in northern growing areas. Major factors in these scenarios analyzes are increased drought tendencies
and more extreme weather events, both of which are detrimental to agriculture. Increasing competition for water between agriculture
and non-agricultural users also focuses attention on water management issues. Agriculture also has impact on the greenhouse
gas balance. Forests and soils are natural sinks for CO2. Removal of forests and changes in land use, associated with the conversion from rural to urban domains, alters these natural
sinks. Agricultural livestock and rice cultivation are leading contributors to methane emission into the atmosphere. The application
of fertilizers is also a significant contributor to nitrous oxide emission into the atmosphere. Thus, efficient management
strategies in agriculture can play an important role in managing the sources and sinks of greenhouse gases. Forest and land
management can be effective tools in mitigating the greenhouse effect. 相似文献
12.
In the Arkansas River Basin in southeastern Colorado, surface irrigation provides most of the water required for agriculture.
Consequently, the region’s future could be significantly affected if climate change impacts the amount of water available
for irrigation. A methodology to model the expected impacts of climate change on irrigation water demand in the region is
described. The Integrated Decision Support Consumptive Use model, which accounts for spatial and temporal variability in evapotranspiration
and precipitation, is used in conjunction with two climate scenarios from the Vegetation-Ecosystem Modeling and Analysis Project.
The two scenarios were extracted and scaled down from two general circulation models (GCMs), the HAD from the Hadley Centre
for Climate Prediction and Research and the CCC from the Canadian Climate Centre. The results show significant changes in
the water demands of crops due to climate change. The HAD and CCC climate change scenarios both predict an increase in water
demand. However, the projections of the two GCMs concerning the water available for irrigation differ significantly, reflecting
the large degree of uncertainty concerning what the future impacts of climate change might be in the study region. As new
or updated predictions become available, the methodology described here can be used to estimate the impacts of climate change. 相似文献
13.
Impact of climate change on irrigation water demand of dry season Boro rice in northwest Bangladesh 总被引：4，自引：1，他引：3
Shamsuddin Shahid 《Climatic change》2011,105(3-4):433-453
Climate change will affect irrigation water demand of rice via changes in rice physiology and phenology, soil water balances, evapotranspiration and effective precipitation. As agriculture is the main sector of water use in Bangladesh, estimation of the agricultural water demand in the changing environment is essential for long-term water resources development and planning. In the present paper, a study has been carried out to estimate the change of irrigation water demand in dry-season Boro rice field in northwest Bangladesh in the context of global climate change. The study shows that there will be no appreciable changes in total irrigation water requirement due to climate change. However, there will be an increase in daily use of water for irrigation. As groundwater is the main source of irrigation in northwest Bangladesh, higher daily pumping rate in dry season may aggravate the situation of groundwater scarcity in the region. 相似文献
14.
政府间气候变化专门委员会（IPCC）于2008年4月8日正式通过了"气候变化和水"技术报告。该报告建立在IPCC 3个工作组第四次评估报告的基础上,客观、全面而审慎地评估了与水有关的气候变化以及对水的过去、现在和未来的认知。最重要的进展是：过去几十年观测到全球变暖已经与大尺度水文循环的大规模变化联系在一起;气候模型对21世纪的模拟结果一致显示出降水在高纬和部分热带地区将增加,而在部分亚热带和中低纬地区将减少的结果;预计到21世纪中期,河流年平均径流和水量可能会因为高纬和部分湿润热带地区的气候变化而增加,而在中低纬和干旱热带将可能减少;许多地方降水强度和变率的增加将使洪旱危险性上升;预计冰雪储藏的水的补给将在本世纪减少;预计较高的水温和极端变化,包括洪旱等,将影响水质并加剧水污染;对全球而言,气候变化对淡水系统负面影响将超过收益;预计由于气候变化导致的水量-水质变化将影响食物的产量、稳定性、流通和利用;气候变化影响现有水的基础设施的功能和运行,包括水电、防洪、排水、灌溉系统,同时影响到水的管理;目前的水管理措施不足以应对气候变化的影响;气候变化挑战"过去水文上的经验能得到未来的情况"的传统说法;为保障平水和干旱情况所设计的适应选择,必须综合需水和供水双方的战略;减缓措施可以降低升温对全球水资源的影响程度,进而减低适应的需求;水资源管理明显地影响到很多其他政策领域。 相似文献
15.
A multi-scale approach has linked farm level decisions with regional water availability assessments that allow for environmental water needs and the competing demands for water. This is incorporated within a user-interactive software tool, enabling the impact of a range of variables to be easily examined. Climate change leads to increased potential irrigation demand in East Anglia and North West England. Under baseline socio-economic conditions, results suggest that such increased future water demands can be met in the North West, but in the drier East Anglian region are counter to the decreasing water availability under all climate scenarios. The decreasing availability is moderated or exacerbated according to the environmental priorities of the future socio-economic scenarios. Under economically focussed regional futures, water supply availability increases at the expense of the environment, despite high water demands. Under environmentally focussed futures, demand restrictions are needed due to the further decreased water availability as a consequence of the high environmental priority. Results show that the effectiveness of water pricing for reducing irrigation demand is also scenario-dependent. Where regional food production is important, irrigation demand is relatively price-insensitive and abstraction controls will be most effective, whereas in a global market-drive future, irrigation demand is shown to be price-sensitive. 相似文献
16.
Vulnerability of water supply from the Oregon Cascades to changing climate: Linking science to users and policy 总被引：1，自引：0，他引：1
Despite improvements in understanding biophysical response to climate change, a better understanding of how such changes will affect societies is still needed. We evaluated effects of climate change on the coupled human-environmental system of the McKenzie River watershed in the Oregon Cascades in order to assess its vulnerability. Published empirical and modeling results indicate that climate change will alter both the timing and quantity of streamflow, but understanding how these changes will impact different water users is essential to facilitate adaptation to changing conditions. In order to better understand the vulnerability of four water use sectors to changing streamflow, we conducted a series of semi-structured interviews with representatives of each sector, in which we presented projected changes in streamflow and asked respondents to assess how changing water availability would impact their activities. In the McKenzie River watershed, there are distinct spatial and temporal patterns associated with sensitivity of water resources to climate change. This research illustrates that the implications of changing streamflow vary substantially among different water users, with vulnerabilities being determined in part by the spatial scale and timing of water use and the flexibility of those uses in time and space. Furthermore, institutions within some sectors were found to be better positioned to effectively respond to changes in water resources associated with climate change, while others have substantial barriers to the flexibility needed to manage for new conditions. A clearer understanding of these opportunities and constraints across water use sectors can provide a basis for improving response capacity and potentially reducing vulnerability to changing water resources in the region. 相似文献
17.
During this century global warming will lead to changes in global weather and climate, affecting many aspects of our environment. Agriculture is the sector of the United States economy most likely to be directly impacted by climatic changes. We have examined potential changes in dryland agriculture (Part 3) and in water resources necessary for crop production (Part 4) in response to a set of climate change scenarios. In this paper we assess to what extent, under these same scenarios, water supplies will be sufficient to meet the irrigation requirement of major grain crops in the US. In addition, we assess the overall impacts of changes in water supply on national grain production. We apply the 12 climate change scenarios described in Part 1 to the water resources and crop growth simulation models described in Part 2 for the conterminous United States. Drawing on data from Parts 3 and 4 we calculate what the aggregate national production would be in those regions in which grain crops are currently produced by applying irrigation where needed and water supplies allow. The total amount of irrigation water applied to crops declines under all climate change scenarios employed in this study. Under certain of the scenarios and in particular regions, precipitation decreases so much that water supplies are too limited; in other regions precipitation becomes so plentiful that little value is derived from irrigation. Nationwide grain crop production is greater when irrigation is applied as needed. Under irrigation, less corn and soybeans are produced under most of the climate change scenarios than is produced under baseline climate conditions. Winter wheat production under irrigation responds significantly to elevated atmospheric carbon dioxide concentrations [CO2] and appears likely to increase under climate change. 相似文献
18.
The climate change research community’s shared socioeconomic pathways (SSPs) are a set of alternative global development scenarios focused on mitigation of and adaptation to climate change. To use these scenarios as a global context that is relevant for policy guidance at regional and national levels, they have to be connected to an exploration of drivers and challenges informed by regional expertise.In this paper, we present scenarios for West Africa developed by regional stakeholders and quantified using two global economic models, GLOBIOM and IMPACT, in interaction with stakeholder-generated narratives and scenario trends and SSP assumptions. We present this process as an example of linking comparable scenarios across levels to increase coherence with global contexts, while presenting insights about the future of agriculture and food security under a range of future drivers including climate change.In these scenarios, strong economic development increases food security and agricultural development. The latter increases crop and livestock productivity leading to an expansion of agricultural area within the region while reducing the land expansion burden elsewhere. In the context of a global economy, West Africa remains a large consumer and producer of a selection of commodities. However, the growth in population coupled with rising incomes leads to increases in the region’s imports. For West Africa, climate change is projected to have negative effects on both crop yields and grassland productivity, and a lack of investment may exacerbate these effects. Linking multi-stakeholder regional scenarios to the global SSPs ensures scenarios that are regionally appropriate and useful for policy development as evidenced in the case study, while allowing for a critical link to global contexts. 相似文献
19.
Zamani Reza Akhond-Ali Ali-Mohammad Roozbahani Abbas Fattahi Rouhollah 《Theoretical and Applied Climatology》2017,129(3-4):1109-1121
Water shortage and climate change are the most important issues of sustainable agricultural and water resources development. Given the importance of water availability in crop production, the present study focused on risk assessment of climate change impact on agricultural water requirement in southwest of Iran, under two emission scenarios (A2 and B1) for the future period (2025–2054). A multi-model ensemble framework based on mean observed temperature-precipitation (MOTP) method and a combined probabilistic approach Long Ashton Research Station-Weather Generator (LARS-WG) and change factor (CF) have been used for downscaling to manage the uncertainty of outputs of 14 general circulation models (GCMs). The results showed an increasing temperature in all months and irregular changes of precipitation (either increasing or decreasing) in the future period. In addition, the results of the calculated annual net water requirement for all crops affected by climate change indicated an increase between 4 and 10 %. Furthermore, an increasing process is also expected regarding to the required water demand volume. The most and the least expected increase in the water demand volume is about 13 and 5 % for A2 and B1 scenarios, respectively. Considering the results and the limited water resources in the study area, it is crucial to provide water resources planning in order to reduce the negative effects of climate change. Therefore, the adaptation scenarios with the climate change related to crop pattern and water consumption should be taken into account.
相似文献20.
What information do policy makers need to develop climate adaptation plans for smallholder farmers? The case of Central America and Mexico 总被引：1，自引：1，他引：0
Camila I. Donatti Celia A. Harvey M. Ruth Martinez-Rodriguez Raffaele Vignola Carlos Manuel Rodriguez 《Climatic change》2017,141(1):107-121
Scientific and technical information can increase the ability of policy makers to make strategic decisions. However, climate change policy is often formulated without significant input from science. We examine whether the availability and accessibility of information related to climate change is a major barrier for policy action on climate change adaptation for smallholder farmers. We also investigate whether scientific information related to climate change is available and used in policy making in Central America and Mexico. Our online survey of 105 decision makers indicated that a lack of scientific and technical information hinders policy makers from developing policies to help smallholder farmers adapt to climate change. Specific needs include information on the impacts of climate change on water availability for agriculture and the areas that are or will be prone to flooding, droughts or landslides. Information about the location of the farmers who are most vulnerable to climate change, the projected temperature and precipitation in agricultural areas and the expected impacts of climate change on crop yields or animal productivity, is also needed. Despite high interest in having scientific information guide policy making, many respondents indicated that policy makers rarely use this information in adaptation planning. In addition to ensuring that relevant information is available to inform policy making, technical and scientific information must be published in venues that are readily accessible for policy makers, easy to understand, and written in a format that is policy-relevant. It is also critical that scientific articles provide specific recommendations for achieving desired policy outcomes. 相似文献