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1.
Interventions to reduce farmers’ vulnerability to crises rarely build on existing coping strategies. Emergency seed aid offers a unique opportunity to examine links between different types of interventions and local coping mechanisms, as such relief has been abundant and long-term. This study focuses on farmers’ use and assessment of crisis assistance within Ethiopia, where seed aid delivery dates back at least 34 years. Farmers’ abilities to strategize and negotiate inter-/intra-seasonal variability are not being addressed by current supply-driven approaches. Lessons derived from seed aid give insights toward more effective practice for programs aiming to bolster farmers’ resilience in high-stress and uncertain contexts. 相似文献
2.
In much of sub-Saharan Africa, considerable research exists on the impacts of climate change on social-ecological systems. Recent adaptation studies emphasize sectoral vulnerability and largely physical adaptation strategies that mirror anti-desertification plans. The adaptive role of subsistence farmers, the vulnerable ‘target’ population, is largely overlooked. This article aims to fill this gap by putting the views from the vulnerable in the center of the analysis. Drawing from participatory risk ranking and scoring among smallholders in central Senegal, data on multiple hazards indicate that farmers’ adaptive capacity to climate change is undermined by poor health, rural unemployment, and inadequate village infrastructure. Results from conceptual mapping reveal incomplete understanding of causes and consequences of climate change. Yet, shared knowledge and lessons learned from previous climatic stresses provide vital entry points for social learning and enhanced adaptive capacity to both wetter and drier periods now and in the future. 相似文献
3.
枯季是水旱、水生态和水资源问题的重要时期,枯季径流的变化直接影响着河流生态和流域水资源管理。基于中国网格气象数据和主要江河枯季径流资料,初步分析了1961—2018年中国气候变化趋势和主要江河枯季径流演变特征与成因。结果表明,全国枯季平均气温显著上升,北方地区升温较早,南方地区2001—2018年升温明显。全国约84%的地区枯季降水有增加趋势,其中约42.2%的地区增加显著;全国枯季降水呈现西北、东北和东南显著增加,中部变化不显著格局。黄河中游和海河枯季径流下降显著,2001—2018年黄河中游枯季径流较1961—1980年减少了34%,同时期海河流域枯季径流量减少幅度均超过80%;松花江上游和长江流域枯季径流增加显著,2001—2018年松花江上游枯季径流量增加了约67%,长江流域枯季径流量增加了约16%。枯季降水增加主导了松花江上游、辽河、淮河、长江以及珠江枯季径流的增加;气温的显著上升对黄河中游和海河等地枯季径流有显著负向作用;人类活动是松花江中游、黄河和海河枯季径流下降的主要影响因素。尽管全国枯季降水的增加对于缓解流域生态和水资源问题有积极作用,但人类活动和气温显著上升加速了水资源的消耗,加大了流域水资源脆弱性。 相似文献
4.
Multiple exposures and dynamic vulnerability: Evidence from the grape industry in the Okanagan Valley, Canada 总被引：7，自引：1，他引：7
This paper assesses the vulnerability of grape growers and winery operators in the Okanagan Valley, British Columbia to climate variability and change, in the context of other sources of risk. Through interviews and focus groups, producers identified the climatic and non-climatic risks relevant to them and the strategies employed to manage these risks. The results show that the presence of multiple exposures affects the way in which producers are vulnerable to climate change. Producers are vulnerable to conditions that not only affect crop yield, but also affect their ability to compete in or sell to the market. Their sensitivity to these conditions is influenced in part by institutional factors such as trade liberalization and a “markup-free delivery” policy. Producers’ ability to adapt or cope with these risks varies depending on such factors as the availability of resources and technology, and access to government programmes. Producers will likely face challenges associated with the supply of water for irrigation due to a combination of climatic changes and changing demographics in the Okanagan Valley, which in turn affect their ability to adapt to climatic conditions. Finally, adaptations made by producers can change the nature of the operation and its vulnerability, demonstrating the dynamic nature of vulnerability. 相似文献
5.
影响黄河下游断流的气象因素分析 总被引：1，自引：0，他引：1
分析了影响黄河下游断流的气象因素 ,结果表明 :降雨量减少造成产流量减少是影响黄河下游断流的重要原因 ;气温升高 ,蒸发量增大 ,造成农业灌溉等用水增加 ,加剧了黄河水资源的供需矛盾 ;而各区间耗水量的增加 ,使进入下游河道的水量减少是断流的主要原因 相似文献
6.
While it is generally asserted that those countries who have contributed least to anthropogenic climate change are most vulnerable to its adverse impacts some recently developed indices of vulnerability to climate change come to a different conclusion. Confirmation or rejection of this assertion is complicated by the lack of an agreed metric for measuring countries’ vulnerability to climate change and by conflicting interpretations of vulnerability. This paper presents a comprehensive semi-quantitative analysis of the disparity between countries’ responsibility for climate change, their capability to act and assist, and their vulnerability to climate change for four climate-sensitive sectors based on a broad range of disaggregated vulnerability indicators. This analysis finds a double inequity between responsibility and capability on the one hand and the vulnerability of food security, human health, and coastal populations on the other. This double inequity is robust across alternative indicator choices and interpretations of vulnerability. The main cause for the higher vulnerability of poor nations who have generally contributed little to climate change is their lower adaptive capacity. In addition, the biophysical sensitivity and socio-economic exposure of poor nations to climate impacts on food security and human health generally exceeds that of wealthier nations. No definite statement can be made on the inequity associated with climate impacts on water supply due to large uncertainties about future changes in regional water availability and to conflicting indicators of current water scarcity. The robust double inequity between responsibility and vulnerability for most climate-sensitive sectors strengthens the moral case for financial and technical assistance from those countries most responsible for climate change to those countries most vulnerable to its adverse impacts. However, the complex and geographically heterogeneous patterns of vulnerability factors for different climate-sensitive sectors suggest that the allocation of international adaptation funds to developing countries should be guided by sector-specific or hazard-specific criteria despite repeated requests from participants in international climate negotiations to develop a generic index of countries’ vulnerability to climate change. 相似文献
7.
黄河上游和源区气候、水文的年代际变化及其对华北水资源的影响 总被引：12，自引：1，他引：11
利用我国气象观测站1951~2000年降水、气温资料以及黄河上游有关水文测站1960~2003年的径流资料,分析了黄河上游和源区气候的年代际变化及其对径流变化的影响,并分析了黄河上游径流变化对华北水资源的影响。分析结果表明:黄河上游和源区降水从20世纪90年代有所减少,气温明显上升,导致了黄河源区和上游径流量锐减。黄河上游径流的减少是90年代黄河下游流量锐减、黄河断流天数增多的重要原因,并表明了黄河上游来水量的多少是影响华北地区水资源的重要原因。 相似文献
8.
Vulnerability of and risk to water resources in arid and semi-arid regions of West China under a scenario of climate change 总被引：3，自引：0，他引：3
This paper quantifies the vulnerability of and risk to water resources (VRWR) under a scenario of climate change in the arid and semi-arid region of West China. A new approach integrating hazard, sensitivity, resilience, exposure and risk is developed to assess the VRWR from climate change. Drought is regarded as the key hazard, with its frequency and severity defined using a surface humidity index. Exposure is quantitatively linked with indicators of population and social and economic characteristics using statistical and Geographical Information System (GIS) methodologies. Risk is defined as the product of hazard, exposure and vulnerability, while vulnerability is treated as a function of sensitivity and adaptation. Vulnerability and risk in the water resources system in the coming 20 years are assessed for the RCP 4.5 scenario. The results reveal that both hazard and exposure of water resources display strong spatial variation in the study area. High hazard and exposure are found in the northern Tianshan Mountain as well as the eastern part of Hexi Corridor. Water resources are particularly sensitive to variation in precipitation and potential evapotranspiration in the upstream areas of Hexi Corridor, rivers in Central Asia, headwater streams of Tarim River and most of Chang Tang Plateau. Our assessment shows that there is high vulnerability of and risk to water resources in the study area, especially in the areas of Hexi Corridor, northern Tianshan Mountain and Tarim River. Under the RCP 4.5 climate change scenario, the vulnerability and risk decline over the entire area but remain at a serious level in inland rivers in Hexi Corridor, northern Tianshan Mountain and headwater streams of Tarim River. Thus, these areas are the highest priority for strengthening policy measures to adapt to climate change and reduce exposure and vulnerability and their risk to water resources. 相似文献
9.
受气候增暖和人类活动的双重影响,黄河流域的水循环正在发生显著变化,水资源供需矛盾突出。陆地水循环是一个复杂的非线性系统,为清晰认识水循环变化的全貌,并合理高效利用有限的水资源量,需要综合考虑水循环各个要素之间的协同变化机制。同时,在“人类世”背景下,黄河流域水循环研究必须考虑人类活动的影响,主要包括植被变化和人类用水,其中人类用水主体为农业灌溉。自从实施生态恢复工程以来,黄土高原植被覆盖明显改善的同时也引发了对径流、蒸散发、降水、土壤湿度以及地下水的一系列影响,且研究结论还存在一些争议,但黄土高原植被覆盖改善使得该地区蒸散发量增加基本达成共识,大多数研究支持植被改善减少径流的结论。黄河流域的农业灌溉方式主要为大水漫灌,其对地表蒸散发、地表水及地下水多个过程具有重要影响。本文主要针对黄河流域的水循环研究,讨论相关研究进展以及发展方向。 相似文献
10.
Based on the variations of geographical locations, the summer rain belts over eastern China were classified in this study into eight types: Inner Mongolia, North China, the Yellow River, the Huaihe River, the Yangtze River, the northern and southern parts of Jiangnan ( to the south of the lower Yangtze River valley), and South China. The file of 8-type rain belts was compiled from 1470 to 2005, and in order to extend the file of rain belts, it was further merged into a file of 4-type rain belts and also completed during the last millennium from 1000 to 1999. At last, the two files show that summer rain belts frequently occur in the Yangtze River valley in warm climate periods, but in the Yellow River or the Huaihe River valley in cold periods. 相似文献
11.
结合考古资料,对气候异变与中国上古农业转型的关系进行了论述,认为在全新世时期中国发生过几次较大的降温事件,气候异变一方面给原始农业文化造成严重的损害,另一方面又激发了人们应对这种挑战的勇气和智慧,成为原始农业文化进化和转型的契机;中国上古农业发展中的两次重大转型——农业"边缘"地区游牧经济的形成和黄河中下游地区"沟洫农业"的出现,均与气候异变有关;人类科学地应对和适应气候异变,使中华文明的进程出现了新格局。历史经验表明,自然环境虽然能够对历史过程产生重大影响,但关键是人类如何去应对,人类自身才是历史发展更为重要的决定性因素。 相似文献
12.
冬季北太平洋涛动和我国夏季降水 总被引：9，自引：0，他引：9
本文分析了冬季北太平洋涛动与我国夏季降水的关系。结果表明,当冬季北太平洋涛动偏强时,我国夏季主要多雨带位于黄河流域及其以北地区(即1类雨型);当冬季北太平洋涛动偏弱时,夏季主要多雨带位于黄河与长江之间,中心在淮河流域一带(即2类雨型)。据此建立了我国夏季1、2类雨型的预报判据。并进一步分析了北太平洋涛动遥相关型从冬到夏的演变过程及其对北太平洋地区海温异常的响应。 相似文献
13.
利用1960—2019年黄淮海地区186个气象站逐日气象数据,结合春花生发育期数据,采用标准化降水作物需水指数将旱涝灾害分为7个等级,分析春花生旱涝灾害的时空分布特征;并以旱涝灾害发生的强度和频率构建春花生旱涝灾害危险性指数,开展黄淮海地区春花生旱涝灾害危险性评价。结果表明:黄河流域西北部和中部、淮河流域东北部以及海河流域北部是干旱灾害高发区;涝害高发区主要集中在黄河流域的大部分地区、淮河流域北部和南部地区以及海河流域东部,以中度涝害为主。春花生干旱灾害高危险性地区零散分布,主要集中在黄河流域西北部;而涝害中、高危险性地区多分布于黄河流域。 相似文献
14.
使用NASA/NCAR有限区域大气环流模型FvGCM结果驱动高分辨率区域气候模式RegCM3 (20 km),进行1961～1990年当代气候模拟(控制试验)和2071～2100年IPCC A2排放情景下未来气候模拟(A2情景模拟试验)。将RegCM3径流模拟结果同大尺度汇流模型LRM [分辨率0.25°(纬度)×0.25°(经度)]相连接,模拟预估未来气候变化对我国黄河流域水文过程的影响。结果表明:相对于当代气候,未来黄河流域呈现气温升高、降水增加(夏季7～8月降水减少)和蒸发增大的趋势,且空间分布极不均匀,造成河川径流在5～10月减少,加剧流域夏季的水资源短缺;未来气温升高使得融雪径流增加,可能导致更早和更大的春季径流,使径流过程发生季节性迁移,引起黄河流域水资源年内分配发生变化。 相似文献
15.
夏季中国中东部不同历时降水时空分布特征 总被引：7，自引：2，他引：5
利用1961~2012年台站逐时降水资料,分析了夏季中国中东部不同历时降水的主要气候分布和长期变化特征,为深入认识其时空变化规律和形成机理奠定基础。分析结果表明,降水事件的平均历时由南向北呈"短—长—短"分布型,华南和北方地区以6 h以下的短历时降水为主;而中部地区(28°N~37°N)6 h以上长历时降水占总降水量60%以上。随着降水历时的增加,小雨事件(0.1~1.0 mm/h)的发生概率降低,中雨事件(1.1~10.0 mm/h)的发生概率升高;大雨、暴雨事件(10.0 mm/h)更易出现在35°N以南历时偏短的降水事件中。1961~2012年,中国中东部总降水量呈"南升北降"的趋势分布,夏季南方大部分地区降水强度、时数和事件数均呈上升趋势;而北方地区降水时数和事件数显著减少,不过降水强度呈增强趋势。中东部降水历时总体呈上升趋势,尤其以我国长江与黄河之间的中部地区变化最为显著。同时,该地区短历时(1~6 h)降水无显著的年代际转折,长历时(6 h)降水的年代际增加是20世纪70年代末至20世纪90年代初降水增多的主要原因。20世纪90年代初期以来,南方地区降水的年代际增多则是长、短降水共同作用的结果,但超过6 h降水的影响范围更广,且影响中心较短历时降水偏北。 相似文献
16.
The spatiotemporal variations of the site and regional droughts in China during 1960–2009 were analyzed by applying a daily composite-drought index (CDI) to 722 stations in mainland China. Droughts frequently happened in a zone extended from Southwest China to the Yellow River, North China, and the southwestern part of Northeast China, with two centers of high frequency in North China and Southwest China. In Southwest and South China, droughts tend to happen during the winter. In North China and along the Yellow River, droughts mainly occur during the winter and during May–June. During the past 50 years, the geographical distribution of site drought events showed high frequencies (0.9–1.3 times per year) in the upper Yellow River basin and North China, comparing with moderate frequencies (0.6–0.9 times per year) in Southwest China and the southwestern part of Northeast China and with lower frequencies over the middle and lower Yangtze River basin. And the frequencies increased over mainland China except for the upper reaches of the Yangtze River. A regional drought (RD) event is a widespread and persistent event that covers at least five adjacent sites and lasts for at least 10 days. There were 252 RD events in the past 50 years—five times per year. Most RD events lasted for <100 days and covered <100 stations, but the longest and largest RD event lasted for 307 days from 6 September 1998 to 9 July 1999 and covered 327 stations from North to Southwest China. 相似文献
17.
Veena Srinivasan Karen C. Seto Ruth Emerson Steven M. Gorelick 《Global Environmental Change》2013,23(1):229-239
While there is consensus that urbanization is one of the major trends of the 21st century in developing countries, there is debate as to whether urbanization will increase or decrease vulnerability to droughts. Here we examine the relationship between urbanization and water vulnerability for a fast-growing city, Chennai, India, using a coupled human–environment systems (CHES) modeling approach. Although the link between urbanization and water vulnerability is highly site-specific, our results show some generalizable factors exist. First, the urban transformation of the water system is decentralized as irrigation wells are converted to domestic wells by private individuals, and not by the municipal authority. Second, urban vulnerability to water shortages depends on a combination of several factors: the formal water infrastructure, the rate and spatial pattern of land use change, adaptation by households and the characteristics of the ground and surface water system. Third, vulnerability is dynamic, spatially variable and scale dependent. Even as household investments in private wells make individual households less vulnerable, over time and cumulatively, they make the entire region more vulnerable. Taken together, the results suggest that in order to reduce vulnerability to water shortages, there is a need for new forms of urban governance and planning institutions that are capable of managing both centralized actions by utilities and decentralized actions by millions of households. 相似文献
18.
Building comparable global change vulnerability assessments: The vulnerability scoping diagram 总被引：29，自引：1，他引：29
Advancing vulnerability science depends in part on identifying common themes from multiple, independent vulnerability assessments. Such insights are difficult to produce when the assessments use dissimilar, often qualitative, measures. The Vulnerability Scoping Diagram is presented to facilitate the comparison of assessments with dissimilar measures. The diagram is illustrated with recent research on drought vulnerabilities, showing that common insights into vulnerability may emerge if independent research teams use a common structure for organizing information about exposure, sensitivity and adaptive capacity—even if the underlying measures differ between assessments. Broadly adopting this technique, which is grounded in the “Eight Steps” methodological protocol [Schröter, D., Polsky, C., Patt, A., 2005. Assessing vulnerabilities to the effects of global change: an eight step approach. Mitigation and Adaptation Strategies for Global Change 10(4), 573–595], will enable a vulnerability meta-analysis, the lessons from which may permit places to identify helpful adaptation or mitigation options without first having to conduct their own vulnerability assessments. 相似文献
19.
Climatic regime shift and decadal anomalous events in China 总被引：15，自引：0，他引：15
Climatic time series from historical documents and instrumental records from China showed temporal and regional patterns in
the last two to three centuries, including two multidecadal oscillations at quasi-20-year and quasi-70-year timescales revealed
by signal analysis from wavelet transform. Climatic anomalous events on the decadal timescale were identified based on the
two oscillations when their positive (or negative) phases coincide with each other to amplify amplitude. The coldest event
occurred in the decade of 1965–1975 in eastern China, while the periods of 1920–1930, 1940–1950, and 1988–2000 appeared to
be warmer in most parts of China. For the precipitation series in northern China, the dry anomalous event was found in the
late 1920s, while the wet anomalous event occurred in the 1950s. A severe drought in 1927–1929 in northern China coincided
with the anomalous warm and dry decade, caused large-scale famine in nine provinces over northern China. Climatic anomalous
events with a warm-dry or cold-wet association in the physical climate system would potentially cause severe negative impacts
on natural ecosystem in the key vulnerable region over northern China. The spatial pattern of summer rainfall anomalies in
the eastern China monsoon region showed an opposite variations in phase between the Yellow River Valley (North China) and
the mid-low Yangtze River Valley as well as accompanied the shift of the northernmost monsoon boundary. Climatic regime shifts
for different time points in the last 200 years were identified. In North China, transitions from dry to wet periods occurred
around 1800, 1875, and 1940 while the transitions from wet to dry periods appeared around 1840, 1910, and the late 1970s.
The reversal transition in these time points can also be found in the lower Yangtze River. Climatic regime shifts in China
were linked to the interaction of mid- and low latitude atmospheric circulations (the westerly flow and the monsoon flow)
when they cross the Tibetan Plateau in East Asia. 相似文献
20.
Beyond the circle of poison: Significant shifts in the global pesticide complex, 1976–2008 总被引：1，自引：0，他引：1
Almost 30 years after its introduction, the “circle of poison” remains a common conceptualization of the global pesticide complex among scholars and especially in popular understanding. The circle of poison describes a situation in which, pesticides banned in industrialized countries continue to be manufactured there and exported to developing countries, are then used in developing countries almost entirely on export crops, and return to industrialized countries as pesticide residues on food. Using secondary data and a case study of pesticide use in Costa Rica, I review the applicability of the circle of poison conceptualization to the current global pesticide complex. I argue that (1) the circle of poison is no longer accurate due to important global changes in pesticide regulation, production, trade, sales, and use driven by a number of dynamic economic, social, and ecological processes; (2) using industrialized countries’ pesticide regulations as proxies for safety should be replaced by multi-characteristic risk assessments; and (3) revisions of the circle of poison conceptualization should be updated because of export farmers’ adoption of newer classes of pesticides. The paper concludes by offering a new characterization of the global pesticide complex vis-à-vis pesticide use in developing countries: pesticide divergence by market orientation. 相似文献