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基于降水量历史观测数据和气候模式预估数据,采用标准化降水量指数(Standandized Precipitation Index, SPI)识别干旱事件,从干旱发生的频率和强度特征分析其危险性,研究东北地区当前及未来不同气候变化情景下干旱时空变化特征。结果显示:(1)bcc-csm1-1对东北地区降水的模拟效果较好;(2)东北地区年降水量东南多西部少,未来远期较近期降水增幅更为明显,中、西部地区降水增幅略高于其他地区;(3)仅在RCP8.5情景下未来近期研究区中部地区干旱有加重的趋势,主要源于该时段夏季降水的变化,其余时段皆呈干旱危险性减弱。 相似文献
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河西走廊近57年来干旱灾害特征时空演化分析 总被引：1，自引：0，他引：1
根据1960-2016年河西走廊及其周边地区15个气象站点的逐月降水系列数据,采用标准化降水指数表征年、季的干旱等级,分析了河西走廊的15个气象站点的干旱频率、干旱站次比和干旱强度的演化趋势。结果表明:(1)近57年来,河西走廊地区年尺度、春季、夏季和冬季的干旱站次比均呈减小趋势,秋季干旱站次比呈现出不显著的增加趋势,其中春季和秋季全域性干旱发生的频率都高于29. 8%;(2)河西走廊地区年尺度和四季的干旱强度均呈减小趋势,研究区的干旱强度主要以轻度干旱和中度干旱为主;(3)干旱的空间分布具有明显的区域特征,其中酒泉和玉门是干旱频发地区,河西走廊地区有66. 7%的站点在年和季节尺度上都呈干旱减弱的趋势。干旱的减弱有利于当地的农业生产和生态环境,但是在气候变化的背景下,河西走廊地区局地暴雨和山洪灾害发生的可能性变大,要在抗旱的同时加强洪涝灾害的防御。 相似文献
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利用库区水源地(南阳区域)跨越的4个县(市)1974～2003年的气候资料,分析了库区水源地近30年的气候变化特征,结果表明库区水源地近年来年平均气温呈明显递增趋势,特别是近10年来气温增幅明显;降水的年际变化大,季节分布不均,近年来有秋雨增多、春旱频发的趋势,自1996年起,降水气候特点呈连续干旱和持续雨涝的变化特征;库区水源地北部山区降雨量偏多,南部、东南部及丘陵垄岗地区降水偏少,近10年来强降雨日数较前期增幅明显.这种气候变化趋势对水源地的水资源和自然生态环境造成了直接或潜在的影响,并可能继续产生明显影响. 相似文献
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干旱半干旱区气候变化研究综述 总被引：21，自引：0，他引：21
从干旱半干旱区气候的时空变化特征、陆气相互作用的观测试验以及气候变化的动力学机制等几个方面系统总结了近年来国内外干旱半干旱区气候变化的最新研究进展,指出目前干旱半干旱区气候变化研究以特定区域研究为主,缺乏对全球不同区域干旱半干旱区气候变化时空关联的系统性归纳研究,且野外观测试验持续时间较短,这在很大程度上限制了对干旱半干旱区气候变化机理的认识和陆面过程模式的发展。针对这些问题,从资料获取、资料分析及数值模拟3个方面提出未来干旱半干旱区气候变化研究的主要方向。 相似文献
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基于2003—2021年江门市6个国家气象观测站和17个区域自动气象站逐月降水和气温资料，应用标准降水蒸发指数(SPEI)分析该区域干旱时空特征。研究结果表明：(1)近19年来，江门市干旱整体有不明显的湿润趋势，年发生频率为31.6%,平均站次比为38.4%,平均强度值为0.7,发生干旱时，以全域性轻旱为主。空间分布上，干旱发生的频率较高，但强度较低且以轻旱为主。全市存在一致变旱或变涝的特征，易出现全域性的干旱或洪涝。(2)江门市除了夏季有微弱的干旱趋势外，其他季节都呈湿润趋势，冬季最为明显。各个季节干旱发生的频率都较高，发生干旱时覆盖的范围也较大，且多数为全域性或区域性干旱。各个季节的干旱强度也比较接近，都以轻旱为主。年尺度SPEI在江门地区的适用性表现优秀，能准确识别出5个干旱过程，但季节尺度SPEI适用性表现一般，仅识别出3个干旱过程。 相似文献
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渭河上游干旱特征与降水对天水市水资源的影响 总被引：1，自引：0，他引：1
文中利用气象和水文观测资料。分析了渭河上游50a的干旱特征及降水对天水市水资源的影响，分析表明，渭河上游年降水在空间上有量的差异，但在气候变化趋势上基本一致；降水量存在17、13、11和3a的周期；水资源对气候变化有很强的敏感性。岷县降水量的年际变化对渭河水资源变化有很强的指示性；气候阶段性变化比年际变化对水资源所造成的影响严重；未来20a渭河流域降水很可能呈缓慢上升趋势。 相似文献
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干旱已成为全球陆地生态系统面临的普遍问题,其发展具有明显的地域特征,了解区域干旱的时空分布特征是防灾减灾、应对气候变化的基础。基于scPDSI数据集,采用经验正交函数和统计分析方法,分析2002-2017年东北地区气候干湿状况的时空分布和演变特征,探讨了干湿状况的季节变化对年际变化的贡献率,结果表明:东北地区4个季节的干旱面积为52.27%-62.03%,虽然季节和年际尺度的干旱均有减弱趋势,其中冬季干旱程度显著减弱,但干旱仍然是东北地区的主要气候背景;春季和夏季scPDSI的协同作用对年际scPDSI变化的贡献率达88.64%,夏季的贡献率达86.13%;东北地区的西部干旱程度高于东部的,其中呼伦贝尔草原中部和浑善达克沙地东部以严重干旱和中等干旱为主;EOF分析表明,东北地区4个季节和年度的干湿状况呈现一致的正变化趋势,高值中心主要出现在南部地区。 相似文献
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丹江口库区气候变化及对生态环境的影响 总被引：1，自引：0，他引：1
利用库区水源地(南阳区域)跨越的4个县(市)1974~2003年的气候资料,分析了库区水源地近30年的气候变化特征,结果表明:库区水源地近年来年平均气温呈明显递增趋势,特别是近10年来气温增幅明显;降水的年际变化大,季节分布不均,近年来有秋雨增多、春旱频发的趋势,自1996年起,降水气候特点呈连续干旱和持续雨涝的变化特征;库区水源地北部山区降雨量偏多,南部、东南部及丘陵垄岗地区降水偏少,近10年来强降雨日数较前期增幅明显。这种气候变化趋势对水源地的水资源和自然生态环境造成了直接或潜在的影响,并可能继续产生明显影响。 相似文献
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在全球气候变暖的背景下,持续的干旱事件将对生态系统和人类社会产生不利影响。尽管存在多源卫星遥感资料及多种干旱指数,然而区域和全球尺度干旱事件的监测仍具有挑战。采用TRMM（Tropical RainfallMeasuring Mission）数据量化降水异常、MODIS（Moderate Resolution Imaging Spectroradiometer）归一化植被指数（Normalized Difference Vegetation Index,NDVI）和陆表温度（Land Surface Temperature,LST）数据表征植被生长异常,构建了一种兼顾降水异常和植被生长状况异常的多传感器陆表干旱严重程度指数（Multi-sensorsDrought Severity Index,MDSI）。结果表明:MDSI 能够准确检测准全球范围（50°S～50°N,0°～180°～0°）的气象干旱事件,如亚马逊流域2005 和2010 年干旱、中国川渝地区2006 年干旱、中国云南2010 年干旱、非洲东部2011 年干旱、2012 年美国中部干旱等;MDSI 与PDSI（Palmer Drought Severity Index）呈现出大致相同的干湿空间格局,并且MDSI 有助于湿润地区干旱程度的检测。 相似文献
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Australia's vulnerability to climate variability and change has been highlighted by the recent drought (i.e. the Big Dry or Millennium Drought), and also recent flooding across much of eastern Australia during 2011 and 2012. There is also the possibility that the frequency, intensity and duration of droughts may increase due to anthropogenic climate change, stressing the need for robust drought adaptation strategies. This study investigates the socio-economic impacts of drought, past and present drought adaptation measures, and the future adaptation strategies required to deal with projected impacts of climate change. The qualitative analysis presented records the actual experiences of drought and other climatic extremes and helps advance knowledge of how best to respond and adapt to such conditions, and how this might vary between different locations, sectors and communities. It was found that more effort is needed to address the changing environment and climate, by shifting from notions of ‘drought-as-crisis’ towards acknowledging the variable availability of water and that multi-year droughts should not be unexpected, and may even become more frequent. Action should also be taken to revalue the farming enterprise as critical to our environmental, economic and cultural well-being and there was also strong consensus that the value of water should be recognised in a more meaningful way (i.e. not just in economic terms). Finally, across the diverse stakeholders involved in the research, one point was consistently reiterated: that ‘it's not just drought’. Exacerbating the issues of climate impacts on water security and supply is the complexity of the agriculture industry, global economics (in particular global markets and the recent/ongoing global financial crisis), and demographic changes (decreasing and ageing populations) which are currently occurring across most rural communities. The social and economic issues facing rural communities are not just a product of drought or climate change – to understand them as such would underestimate the extent of the problems and inhibit the ability to coordinate the holistic, cross-agency approach needed for successful climate change adaptation in rural communities. 相似文献
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Estimating the Impact of Global Change on Flood and Drought Risks in Europe: A Continental, Integrated Analysis 总被引：11，自引：0，他引：11
Bernhard Lehner Petra Döll Joseph Alcamo Thomas Henrichs Frank Kaspar 《Climatic change》2006,75(3):273-299
Most studies on the impact of climate change on regional water resources focus on long-term average flows or mean water availability,
and they rarely take the effects of altered human water use into account. When analyzing extreme events such as floods and
droughts, the assessments are typically confined to smaller areas and case studies. At the same time it is acknowledged that
climate change may severely alter the risk of hydrological extremes over large regional scales, and that human water use will
put additional pressure on future water resources. In an attempt to bridge these various aspects, this paper presents a first-time
continental, integrated analysis of possible impacts of global change (here defined as climate and water use change) on future
flood and drought frequencies for the selected study area of Europe. The global integrated water model WaterGAP is evaluated
regarding its capability to simulate high and low-flow regimes and is then applied to calculate relative changes in flood
and drought frequencies. The results indicate large ‘critical regions’ for which significant changes in flood or drought risks
are expected under the proposed global change scenarios. The regions most prone to a rise in flood frequencies are northern
to northeastern Europe, while southern and southeastern Europe show significant increases in drought frequencies. In the critical
regions, events with an intensity of today's 100-year floods and droughts may recur every 10–50 years by the 2070s. Though
interim and preliminary, and despite the inherent uncertainties in the presented approach, the results underpin the importance
of developing mitigation and adaptation strategies for global change impacts on a continental scale. 相似文献
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Models that address the impacts of climate change on forests are reviewed at four levels of biological organization: global, regional or landscape, community, and tree. The models are compared for their ability to assess changes in fluxes of biogenic greenhouse gases, land use, patterns of forest type or species composition, forest resource productivity, forest health, biodiversity, and wildlife habitat. No one model can address all of these impacts, but landscape transition models and regional vegetation and land-use models have been used to consider more impacts than the other models. The development of landscape vegetation dynamics models of functional groups is suggested as a means to integrate the theory of both landscape ecology and individual tree responses to climate change. Risk assessment methodologies can be adapted to deal with the impacts of climate change at various spatial and temporal scales. Four areas of research needing additional effort are identified: (1) linking socioeconomic and ecologic models; (2) interfacing forest models at different scales; (3) obtaining data on susceptibility of trees and forest to changes in climate and disturbance regimes; and (4) relating information from different scales.The U.S. Government right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged.Managed by Martin Marietta Energy Systems, Inc., for the U.S. Department of Energy under contract DE-AC05-84OR21400. 相似文献
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利用我国西北地区1960—2003年131个测站降水和小型蒸发皿蒸发量资料, 综合考虑降水和蒸发这两个水分平衡最关键的分量构造了降水蒸发均一化干湿指数, 进而研究了西北地区干湿的时空演变特征。结果表明:一致性异常是西北地区近44年干湿特征的最主要空间分布模态; 西北地区干湿异常特征主要分为西风带气候区型, 高原气候区型和季风气候区型; 整个西北地区及其西风带气候区、高原气候区年干湿特征呈较为显著的变湿趋势, 大约在20世纪70年代中期均发生了由干向湿的突变, 而季风气候区表现为变干趋势, 并且在90年代前期发生了由湿向干的突变; 整个西北地区及各分区近44年来主要以年代际周期振荡为主。 相似文献
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卫星遥感广泛应用于宏观、大范围、动态连续的植被和地表温度监测研究。利用2001—2008年MODIS卫星遥感资料, 分析了安徽省归一化植被指数 (NDVI) 和地表温度 (LST) 的季节、月变化和空间分布特征,探讨了代表城市区域的NDVI和LST时空分布及其相关性。结果表明:安徽省NDVI和LST季节变化显著,具有典型地域特征;受当地气候影响,植被、农作物类型地域差异较大,导致LST季节变化以及空间分布不同;城市中心向郊区过渡时,植被覆盖度在不断增加,伴随着NDVI的增加,LST下降;城市LST明显高于郊区值,呈现热岛效应。研究表明,当地气候和植被分布共同决定了LST的分布状况,这将为安徽省合理进行农业区划、科学监测生态环境以及有效评估土地利用与热岛效应提供重要参考依据。 相似文献
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N. U. Ain M. Latif K. Ullah S. Adnan R. Ahmed M. Umar M. Azam 《Theoretical and Applied Climatology》2020,140(1):69-89
As a result of climate change and unsustainable land use management in the recent past, droughts have become one of the most devastating climatic hazards whose impacts may prolong from months to years. This study presents analysis of droughts for two major cropping seasons, i.e., Kharif (May–September) and Rabi (October–April), over the Potwar Plateau of Pakistan. The analysis is performed using various datasets viz. observational, reanalysis, and Regional Climate Models (RCMs), for the past (1981–2010) and future (2011–2100) time periods. The following two methods for the identification of dry and wet years, also referred to as drought and wetness, are applied: (1) the percentile rank approach and (2) the drought indices, Standardized Precipitation Index (SPI) and Reconnaissance Drought Index (RDI). Future projections of droughts are investigated using RCM (RegCM4.4 and RCA4) outputs from CORDEX South Asia domain under two Representative Concentration Pathway (RCP) scenarios, RCP4.5 and RCP8.5. Generally, the indices show non-significant decreasing trends of drought severity in the recent past for all cases; however, significant increasing trends are observed for annual (0.006) and Kharif (0.007) cases under RCP4.5 scenario. The analysis of large-scale atmospheric dynamics suggests the significant role of low-level geopotential height anomalies over Tibetan Plateau (northwest of Pakistan) during Kharif (Rabi) season in controlling drought occurrence by transporting moisture from the Bay of Bengal (Arabian Sea). Moreover, composites of vertically integrated moisture transport, moisture flux convergence/divergence, and precipitable water anomalies show their marked contribution in maintaining the drought/wetness conditions over the Potwar region. 相似文献
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中国干旱事件成因和变化规律的研究进展与展望 总被引：6，自引：0，他引：6
干旱是世界上危害最广泛、最严重的自然灾害之一。中国地处典型季风气候区,干旱灾害的影响尤为突出。国际上对干旱问题已经进行了大量研究,逐渐由对干旱的定性和表象的认识发展到对干旱客观特征的定量认识和形成机理的深入揭示。自新中国成立以来,中国从以往仅对一些重大干旱事件的零散认识逐步发展到与国际干旱研究的完全接轨,干旱研究取得了长足进展。但是,目前对干旱研究取得的科学进展缺乏客观全面的整体认识,对干旱研究的发展方向尚未能充分洞察。为此,基于国际干旱研究现状,系统回顾了新中国成立以来中国干旱研究的历程,总结了中国干旱研究的重要进展,划分出了干旱事件的现象特征和时空分布、干旱形成机理及变化规律、干旱灾害风险和骤发性干旱研究兴起等中国干旱研究的4个主要发展过程。并从干旱事件特征、干旱时空分布、干旱变化规律、干旱成因、干旱影响机制、干旱风险形成过程以及干旱对气候变暖的响应、骤发性干旱的特殊性等方面归纳凝练了中国干旱研究的主要成果。同时,结合干旱研究的国际前沿、热点问题和发展趋势,科学分析了中国干旱研究的不足和问题,提出了中国未来干旱研究需要在加强典型干旱频发区综合性干旱科学试验研究的基础上,对干旱形成的多因子协同影响、陆-气作用对干旱形成发展的作用、骤发性干旱的判别及监测预测、各类干旱之间转换规律及其非一致性特征、关键影响期对农业干旱发展的作用、干旱对气候变暖响应的复杂性、干旱灾害风险的科学评估等重点科学问题上取得突破。 相似文献
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This study investigates how a large-scale reforestation in Savanna (8–12°N, 20°W–20°E) could affect drought patterns over West Africa in the future (2031–2060) under the RCP4.5 scenario. Simulations from two regional climate models (RegCM4 and WRF) were analyzed for the study. The study first evaluated the performance of both RCMs in simulating the present-day climate and then applied the models to investigate the future impacts of global warming and reforestation on the drought patterns. The simulated and observed droughts were characterized with the Standardized Precipitation and Evapotranspiration Index (SPEI), and the drought patterns were classified using a Self-organizing Map (SOM) technique. The models capture essential features in the seasonal rainfall and temperature fields (including the Saharan Heat Low), but struggle to reproduce the onset and retreat of the West African Monsoon as observed. Both RCMs project a warmer climate (about 1–2 °C) over West Africa in the future. They do not reach a consensus on future change in rainfall, but they agree on a future increase in frequency of severe droughts (by about 2 to 9 events per decade) over the region. They show that reforestation over the Savanna could reduce the future warming by 0.1 to 0.8 °C and increase the precipitation by 0.8 to 1.2 mm per day. However, the impact of reforestation on the frequency of severe droughts is twofold. While reforestation decreases the droughts frequency (by about 1–2 events per decade) over the Savanna and Guinea coast, it increases droughts frequency (by 1 event per decade) over the Sahel, especially in July to September. The results of this study have application in using reforestation to mitigate impacts of climate change in West Africa. 相似文献