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1.
Assessment of Water Availability in a Central-European River Basin (Elbe) Under Climate Change 总被引：3，自引：0，他引：3
Fred F. Hattermann Joachim Post Valentina Krysanova Tobias Conradt Frank Wechsung 《气候变化研究进展》2008,4(00):42-50
The Elbe region is representative of humid to semi-humid landscapes in Central Europe, where water availability during the summer season is the limiting factor for plant growth and crop yields, especially in the loess areas with high crop productivity having annual precipitation lower than 500 mm. This paper summarizes the results of the first phase of the GLOWA (GLObal WAter)-Elbe project and tries to assess the reliability of water supply in the German part of the Elbe river basin for the next 50 years, a time scale relevant for the implementation of water and land use management plans. One focus of the study was developing scenarios which are consistent with climate and land use changes considering possible uncertainties. The concluding result of the study is that nature and communities in parts of Central Europe will have to deal with considerably lower water resources under scenario conditions. 相似文献
2.
欧洲中部的易北河流域是典型的湿润半湿润地区。夏季的水资源供给是限制农业生产的因素之一,特别是在具有较高农业生产力水平,而年降水量只有500 mm的黄土地区。通过总结气候变化与水文循环（GLOWA-Elbe）项目第一阶段的成果,根据气候和土地利用变化的各种情景并考虑其不确定性,对未来50 a德国易北河流域水资源供给稳定性作出综合评估。研究表明,欧洲中部必须从自然和社会角度应对未来气候变化情景下产生水资源供给短缺的可能情况。 相似文献
3.
以沩水河流域为例,基于陆面模式CLM4.5,建立了综合考虑作物种植、地下水开采及灌溉等人类活动的流域陆面水文模型。利用所发展模型,针对1981~2012年,取500 m空间分辨率,探讨人为扰动对陆面过程的影响。研究表明:1）地下水侧向流使得中下游地区地下水位有所提高,平原地下水埋深分布在4 m左右,山区埋深可达到几十米;模拟的叶面积指数较静态MODIS叶面积指数偏大1左右,由此使得种植区月蒸腾量提高约10 mm,土壤蒸发和地表产流有所减少;在灌溉作用下,作物叶面积指数略增长,蒸散发稍有提高,而在假设水稻采用漫灌的情况下,水库灌溉补偿了作物生长产生的水消耗,提高了该区域土壤湿度,增加潜热通量;研究区地下水开采存在但其水文效应并不显著。2）土地覆盖变化自1990年有较大变动,1990~2000年以林地为主,2000年后以耕地为主,其中,1990~2000年土地覆盖类型变化不明显,2001~2012年耕地面积呈先减少再增加又减少的趋势,林地面积则先增加再减少又增加,耕地与林地在2012年所占比例基本持平;同一土地类型内,植被类型变化较为明显,导致陆面水文模拟结果差异较大。 相似文献
4.
Urban growth has received little attention in large-scale land change assessments, because the area of built-up land is relatively small on a global scale. However, this area is increasing rapidly, due to population growth, rural-to-urban migration, and wealth increases in many parts of the world. Moreover, the impacts of urban growth on other land uses further amplified by associated land uses, such as recreation and urban green. In this study we analyze urban land take in cropland areas for the years 2000 and 2040, using a land systems approach. As of the year 2000, 213 Mha can be classified as urban land, which is 2.06% of the earth’s surface. However, this urban land is more than proportionally located on land that is suitable and available for crop production. In the year 2040, these figures increase to 621 Mha, or 4.72% of all the earth’s surface. The increase in urban land between 2000 and 2040 is also more than proportionally located on land that is suitable and available for crop production, thus further limiting our food production capacity. The share of urban land take in cropland areas is highest in Europe, the Middle-East and Northern Africa, and China, while it is relatively low in Oceania and Sub-Saharan Africa. Between 2000 and 2040, urban growth caused the displacement of almost 65 Mton of crop production, which could yield an expansion of up to 35 Mha of new cropland. Land-use planning can influence both the location and the form of urbanization, and thus appears as an important measure to minimize further losses in crop production. 相似文献
5.
In this study, the influence of land use change and irrigation in the California Central Valley is quantified using the Pennsylvania State University/National Center for Atmospheric Research fifth generation Mesoscale Model (MM5) coupled with the Community Land Model version 3 (CLM3). The simulations were forced with modern-day and presettlement land use types at 30-km spatial resolution for the period 1 October 1995 to 30 September 1996. This study shows that land use change has significantly altered the structure of the planetary boundary layer (PBL) that affects near-surface temperature. In contrast, many land-use change studies indicate that albedo and evapotranspiration variations are the key processes influencing climate at local-to-regional scales. Our modeling results show that modern-day daily maximum near-surface air temperature (Tmax) has decreased due to agricultural expansion since presettlement. This decrease is caused by weaker sensible heat flux resulting from the lower surface roughness lengths associated with modern-day crops. The lower roughness lengths in the Central Valley also result in stronger winds that lead to a higher PBL. The higher PBL produces stronger sensible heat flux, causing nighttime warming. In addition to land use change, cropland irrigation has also affected hydroclimate processes within the California Central Valley. We generated a 10-member MM5-CLM3 ensemble simulation, where each ensemble member was forced by a fixed volumetric soil water content (SWC) between 3% and 30%, at 3% intervals, over the irrigated areas during a spring?Csummer growing season, 1 March to 31 August 1996. The results show that irrigation lowers the modern-day cropland surface temperature. Daytime cooling is produced by irrigation-related evaporation enhancement. This increased evaporation also dominates the nighttime surface cooling process. Surface cooling and the resulting weaker sensible heat flux further lower the near-surface air temperature. Thus, irrigation strengthens the daytime near-surface air temperature reduction that is caused by land use change, and a similar temperature change is seen for observations over irrigated cropland. Based on our modeling results, the nighttime near-surface warming induced by land use change is alleviated by low-intensity irrigation (17%?<?SWC?<?19%), but such warming completely reverses to a cooling effect under high-intensity irrigation (SWC?>?19%). The land use changes discussed in this study are commonly observed in many regions of the world, and the physical processes identified here can be used to better understand temperature variations over other areas with similar land cover changes. 相似文献
6.
Delineating geographic shifts in crop cultivation under future climate conditions provides information for land use and water management planning, and insights to meeting future demand. A suitability modeling approach was used to map the thermal niche of almond cultivation and phenological development across the Western United States (US) through the mid-21st century. The Central Valley of California remains thermally suitable for almond cultivation through the mid-21st century, and opportunities for expansion appear in the Willamette Valley of western Oregon, which is currently limited by insufficient heat accumulation. Modeled almond phenology shows a compression in reproductive development under future climate. By the mid-21st century, almond phenology in the Central Valley showed ~?2-week delay in chill accumulation and ~?1- and ~?2.5-week advance in the timing of bloom and harvest, respectively. Although other climatic and non-climatic restrictions to almond cultivation may exist, these results highlight opportunities for shifts in the geography of high-value cropping systems, which may influence growers’ long-term land use decisions, and shape regional water and agricultural industry discussions regarding climate change adaptation options. 相似文献
7.
Rapidly increasing populations coupled with increased food demand requires either an expansion of agricultural land or sufficient production gains from current resources. However, in a changing world, reduced water availability might undermine improvements in crop and grass productivity and may disproportionately affect different parts of the world. Using multi-model studies, the potential trends, risks and uncertainties to land use and land availability that may arise from reductions in water availability are examined here. In addition, the impacts of different policy interventions on pressures from emerging risks are examined.Results indicate that globally, approximately 11% and 10% of current crop- and grass-lands could be vulnerable to reduction in water availability and may lose some productive capacity, with Africa and the Middle East, China, Europe and Asia particularly at risk. While uncertainties remain, reduction in agricultural land area associated with dietary changes (reduction of food waste and decreased meat consumption) offers the greatest buffer against land loss and food insecurity. 相似文献
8.
Energy system pathways which are projected to deliver minimum possible deployment cost, combined with low Greenhouse Gas (GHG) emissions, are usually considered as ‘no-regrets’ options. However, the question remains whether such energy pathways present ‘no-regrets’ when also considering the wider environmental resource impacts, in particular those on land and water resources. This paper aims to determine whether the energy pathways of the UK’s Carbon Plan are environmental “no-regrets” options, defined in this study as simultaneously exhibiting low impact on land and water services resulting from resource appropriation for energy provision. This is accomplished by estimating the land area and water abstraction required by 2050 under the four pathways of the Carbon Plan with different scenarios for energy crop composition, yield, and power station locations. The outcomes are compared with defined limits for sustainable land appropriation and water abstraction.The results show that of the four Carbon Plan pathways, only the “Higher Renewables, more energy efficiency” pathway is an environmental “no-regrets” option, and that is only if deployment of power stations inland is limited. The study shows that policies for future low-carbon energy systems should be developed with awareness of wider environmental impacts. Failing to do this could lead to a setback in achieving GHG emission reductions goals, because of unforeseen additional competition between the energy sector and demand for land and water services in other sectors. 相似文献
9.
Summary ?On August the 11th, 1999 Central Europe saw a spectacular astronomical event, a total solar eclipse. We present a model study
concerning the meteorological effects of this eclipse in central Europe using the state-of-the-art limited area forecast model
Deutschland-Modell DM from the German Weather Service DWD. Under typical summer radiation conditions very strong anomalies
in the surface energy flux and temperature in screen height are simulated. The main temperature signal in the lower troposphere
is delayed by about one hour with respect to the surface. Furthermore it is connected with a well defined dynamical signal
which is reminiscent to a large scale land – sea circulation. The event could be used as a test case for mesoscale atmospheric
models.
Received February 19, 1999/Revised May 18, 1999 相似文献
10.
There is an increasing need for transformational changes in the global food system to deliver healthy nutritional outcomes for a growing population while simultaneously ensuring environmental sustainability. However, such changes are subject to political and public constraints that usually allow only gradual, incremental changes to occur. Drawing inspiration from the British cycling team’s concept of marginal gains, we show how transformation might be reconciled with incremental changes. We demonstrate that a set of marginal food system changes acting to increase production efficiency, to reduce losses or to adjust diets could collectively reduce the agricultural land required globally for food production by 21%, or over a third given higher adoption rates. The results show that while all categories of action are important, changes in consumer choices in Europe, North America and Oceania and in the supply-chain in Africa and West and Central Asia have the greatest potential to reduce the land footprint of the food system. 相似文献