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1.
湖北省的洪涝灾害受全球尺度和流域尺度的多种因素的影响。全球尺度因素是指全球性的气候异常,流域尺度因素是指不利的自然条件和人类对自然环境与自然资源的不合理开发利用等方面。现阶段所采用的治水对策,即生态措施和工程措施,存在明显的局限性,不能彻底根治水患。通过系统分析湖北省水患原因和治水对策,提出以洪涝灾害承灾区的受因人口和受因财产的总数定量地表示洪涝灾害灾情的指标,该指标与灾情的对应关系明确且简明易得,为治水对策提供了更合理的依据。在此基础上,论述了“提高洪涝灾害承灾区的城市化水平、鼓励抗洪新技术和新机制的开发利用以及加强溃堤后的应对策略研究”等治水对策的必要性、合理性和可行性。  相似文献   

2.
One of the targets of the United Nations ‘Millennium Development Goals’ adopted in 2000 is to cut in half the number of people who are suffering from hunger between 1990 and 2015. However, crop yield growth has slowed down in much of the world because of declining investments in agricultural research, irrigation, and rural infrastructure and increasing water scarcity. New challenges to food security are posed by accelerated climatic change. Considerable uncertainties remain as to when, where and how climate change will affect agricultural production. Even less is known about how climate change might influence other aspects that determine food security, such as accessibility of food for various societal groups and the stability of food supply. This paper presents the likely impacts of thermal and hydrological stresses as a consequence of projected climate change in the future potential agriculture productivity in South Asia based on the crop simulation studies with a view to identify critical climate thresholds for sustained food productivity in the region. The study suggests that, on an aggregate level, there might not be a significant impact of global warming on food production of South Asia in the short term (<2°C; until 2020s), provided water for irrigation is available and agricultural pests could be kept under control. The increasing frequency of droughts and floods would, however, continue to seriously disrupt food supplies on year to year basis. In long term (2050s and beyond), productivity of Kharif crops would decline due to increased climate variability and pest incidence and virulence. Production of Rabi crops is likely to be more seriously threatened in response to 2°C warming. The net cereal production in South Asia is projected to decline at least between 4 and 10% under the most conservative climate change projections (a regional warming of 3°C) by the end of this century. In terms of the reference to UNFCCC Article 2 on dangerous anthropogenic (human-induced) interference with the climate system, the critical threshold for sustained food productivity in South Asia appears to be a rise in surface air temperature of ~2°C and a marginal decline in water availability for irrigation or decrease in rainfall during the cropping season.  相似文献   

3.
Floods in the northern foreland of the Tatra Mountains considerably contribute to the total flood damage in Poland. Therefore, the question whether the magnitude and frequency of floods have changed in this region is of high interest. This study aims at investigating the inter-decadal variability of magnitude, frequency and seasonality of floods since the mid-twentieth century, to better understand regional changes. The analysis was accomplished in a multi-temporal approach whereby trends are fitted to every possible combination of start and end years in a record. Detected trends were explained by estimating correlations between the investigated flood parameters and different large-scale climate indices for the northern hemisphere, and by trends found in intense precipitation indices, number of days with snow cover, cyclonic circulation types, temperature and moisture conditions. Catchment and channel changes that occurred in the region over the past decades were also considered. Results show that rivers in the area exhibit considerable inter-decadal variability of flows. The magnitude and direction of short-term trends are heavily influenced by this inter-decadal variability; however, certain patterns are apparent. More extreme, although perhaps less frequent floods are now likely to occur, with a shift in the seasonality, decreasing flood magnitudes in winter and increasing during autumn and spring. The identification of the factors contributing to the occurrence of flood events and their potential changes is valuable to enhance the flood management in the region and to improve the resilience of the population in this mountainous area.  相似文献   

4.
鄱阳湖生态经济区近60年极端温度事件变化特征研究   总被引:2,自引:0,他引:2  
利用环鄱阳湖生态经济区6站逐日气象数据,建立了该区1952~2011年近60 a极端温度事件演化序列。研究表明:(1) 环鄱阳湖生态经济区极端高、低温事件线性趋势分别为04、-27 d/10 a;冷、热日持续指数线性趋势分别为-04、-24 d/10 a;(2)近60 a间,环鄱阳湖生态经济区内极端温度事件表现出两个明显的高频数(不稳定阶段)和低频数(稳定阶段)。其中极端高温事件和热日持续指数两个阶段分别为:1952~1979年和1980 ~2002年;极端低温事件和冷日持续指数两个阶段分别为:1952~1985年和1986~2007年;(3)近60 a以来,极端高温事件和热日持续指数在1970s晚期至1980s初期发生了较大变化,此前主要表现为叠加在弱准12~13 a周期下的强准7 a周期,之后主要表现为准9 a周期,并有不连续的4~5 a周期;极端低温日数和冷日持续指数周期性在1950s~1990s表现为弱11~12 a周期,1970s晚期至1990s则表现为弱准5 a周期;(4)环鄱阳湖生态经济区内极端低温事件是气候变暖背景下对冬季风强度的敏感响应,极端低温事件的高频数(强烈波动)主要发生在强冬季风背景下,弱冬季风条件下则出现相反情况。而极端高温事件与夏季风强度关系复杂的多,其原因尚待进一步研究  相似文献   

5.
This study investigates future impacts of global warming on climate and extreme climate events in Nigeria, the most populous African country that depends on rain-fed agriculture. Past and future climate simulations from 9 GCMs were downscaled (using a statistical model) and analyzed for the study. The study considers the impacts of two emission scenarios (B1 and A2) on the future climates (2046–2065 and 2081–2100) over ecological zones in Nigeria. The model evaluation shows that the downscaling adds values to the GCMs simulation, and the results capture all the important climatic features over the country. The model projections show that both B1 and A2 scenarios change the future climate over Nigeria. They significantly increase the temperature over all the ecological zones, with greatest warming (between 1 and 4 °C) over the Sudan (short grass) Savanna in March. The warming, which increases the occurrence of extreme temperature and heat wave events over the entire country, enhances the frequency of the extreme rainfall events in the south and southeast and reduces the annual rainfall over the northeast. Since heavy rains and floods are major problems in the south and southeast, and drought is major problem in the northeast, the global warming may further aggravate these environmental problems in future. These could have negative impacts on agriculture and further threaten livelihood and food security in the rapidly growing country. Hence, there is need for further studies on adaptation and mitigation strategies to address the impacts of global warming in Nigeria.  相似文献   

6.
利用云南省40个气象站逐日降水量和蒸发量数据,采用RDI指数研究云南旱涝灾害的时空分布特征。结果表明:云南年际、季节旱涝与历史记录十分一致,1960~2013年云南年RDI指数呈下降趋势,表现为变干趋势,但不显著;2001年以前发生雨涝年的强度和站次比较干旱年明显,在此之后,发生干旱年的强度和站次比较雨涝年明显。季节尺度上,春季呈显著的变湿趋势,夏、秋、冬季呈不显著的变干趋势;春、夏季分别突变于1980年和1965年。从空间分布上来看,年、夏、秋、冬季整体以滇南和滇东北呈变干趋势,而滇西北呈变湿趋势;春季除滇东北外,其余区域均呈变湿趋势;年际、季节干旱频率以滇西北、滇西南、滇东南较高;年、春、夏、秋季重旱频率以滇中和滇东十分突出;年、夏、秋季特旱频率均以滇东北十分突出,春季滇中和滇东北极易发生特旱;冬季以滇中重旱频率较高,特旱极易发生在滇西北、滇西南、滇东北。年际、季节雨涝频率以滇西、滇东南较突出。年重、特涝频率以滇西南十分突出;春季重涝频率以滇西南和滇中较突出,特涝频率以滇中和滇东南较突出;夏季重、特涝频率均以滇西北较高;秋季重涝频率以滇西北较高,特涝频率以滇东南较高;冬季重涝频率以滇东南较突出,特涝频率以滇西北较高。 关键词: 云南省;RDI指数;旱涝变化趋势;时空特征  相似文献   

7.
为分析洪泽湖流域洪涝灾害在千年尺度序列上的演变趋势,采用统计历史洪涝记录的方法,分析了气候变化背景下洪涝灾害的响应过程,探讨了洪泽湖流域洪涝灾害同El Ni(n)o事件的关系.结果表明:近1 000 a来洪泽湖流域洪涝灾害的频度总体是趋于上升的,这种变化趋势同气候变化的趋势是一致的.研究结果显示:公元1000~1400年洪涝记录偏少,同我国东部地区尤其是中世纪暖期出现的一次200 a以上的干旱化过程有较好的对应性.1400~1800年是洪泽湖流域洪涝的多发期,这一事实同我国东部1550~1850年小冰期期间总体偏湿的环境特征相一致.分析洪涝灾害变化同El Ni(n)o事件对应性关系表明:在El Ni(n)o事件年及其次年是洪泽湖流域洪涝的多发年份.这可能是由于El Ni(n)o事件通过改变西太平洋副高的强度与位置,以及大气环流形势而引起的降水异常所致.了解洪泽湖流域洪涝的演变趋势及其同El Ni(n)o的关系对于长期防灾减灾策略具有重要的参考意义.  相似文献   

8.
With a changing climate and increased urbanisation, the occurrence and the impact of flooding is expected to increase significantly. Floods can bring pathogens into homes and cause lingering damp and microbial growth in buildings, with the level of growth and persistence dependent on the volume and chemical and biological content of the flood water, the properties of the contaminating microbes, and the surrounding environmental conditions, including the restoration time and methods, the heat and moisture transport properties of the envelope design, and the ability of the construction material to sustain the microbial growth. The public health risk will depend on the interaction of these complex processes and the vulnerability and susceptibility of occupants in the affected areas. After the 2007 floods in the UK, the Pitt review noted that there is lack of relevant scientific evidence and consistency with regard to the management and treatment of flooded homes, which not only put the local population at risk but also caused unnecessary delays in the restoration effort. Understanding the drying behaviour of flooded buildings in the UK building stock under different scenarios, and the ability of microbial contaminants to grow, persist, and produce toxins within these buildings can help inform recovery efforts. To contribute to future flood management, this paper proposes the use of building simulations and biological models to predict the risk of microbial contamination in typical UK buildings. We review the state of the art with regard to biological contamination following flooding, relevant building simulation, simulation-linked microbial modelling, and current practical considerations in flood remediation. Using the city of London as an example, a methodology is proposed that uses GIS as a platform to integrate drying models and microbial risk models with the local building stock and flood models. The integrated tool will help local governments, health authorities, insurance companies and residents to better understand, prepare for and manage a large-scale flood in urban environments.  相似文献   

9.
1998年长江大洪水与大气环流和海温异常分析   总被引:7,自引:2,他引:5  
概述了引起1998年长江大洪水的雨情,从天气气候角度分析了1998年长江流域降水异常偏多的原因。指出了最直接的原因是副高移动的反常,特别7月15日以后副高突然南撤南海季风爆发晚,南亚和东亚季风强度偏弱、夏季赤道辐合带偏弱热带地区台风生成少、生成时间晚,  相似文献   

10.
利用江浙沪地区1644~1949年洪涝灾害数据库,基于年受灾县次,对该地区历史重大洪涝灾害年进行了辨识,并以历史重大洪涝灾害为情景,对其重现于2010年的人口和GDP物理暴露量进行分析,得到以下结论:(1)按受灾县次划分,1644~1949年江浙沪地区重大洪涝灾害频率在50~100年一遇的为1670年、1683年、1804年;100~300年一遇的为1823年、1849年;300年一遇的为1931年;(2)重大洪涝灾害暴露区主要集中于长江三角洲地区;(3)6次重大洪涝灾害情景下,人口物理暴露量基本超过2010年该区人口总量的40%,而GDP物理暴露量则几乎超过了其总量的50%;(4)江苏受灾最为明显,上海受灾幅度波动最大,尤其是在100年一遇洪涝灾害前后受灾影响差距很大,浙江受灾影响相对稳定;(5)该区人口、GDP物理暴露量并不一定与受灾县次呈典型的正相关关系,可能与其人口、经济分布格局等因素有关  相似文献   

11.
为分析洪泽湖流域洪涝灾害在千年尺度序列上的演变趋势,采用统计历史洪涝记录的方法,分析了气候变化背景下洪涝灾害的响应过程,探讨了洪泽湖流域洪涝灾害同El Nio事件的关系。结果表明:近1 000 a来洪泽湖流域洪涝灾害的频度总体是趋于上升的,这种变化趋势同气候变化的趋势是一致的。研究结果显示:公元1000~1400年洪涝记录偏少,同我国东部地区尤其是中世纪暖期出现的一次200 a以上的干旱化过程有较好的对应性。1400~1800年是洪泽湖流域洪涝的多发期,这一事实同我国东部1550~1850年小冰期期间总体偏湿的环境特征相一致。分析洪涝灾害变化同El Nio事件对应性关系表明:在El Nio事件年及其次年是洪泽湖流域洪涝的多发年份。这可能是由于El Nio事件通过改变西太平洋副高的强度与位置,以及大气环流形势而引起的降水异常所致。了解洪泽湖流域洪涝的演变趋势及其同El Nio的关系对于长期防灾减灾策略具有重要的参考意义。  相似文献   

12.

Even if climate change mitigation is successful, sea levels will keep rising. With subsidence, relative sea-level rise represents a long-term threat to low-lying deltas. A large part of coastal Bangladesh was analysed using the Delta Dynamic Integrated Emulator Model to determine changes in flood depth, area and population affected given sea-level rise equivalent to global mean temperature rises of 1.5, 2.0 and 3.0 °C with respect to pre-industrial for three ensemble members of a modified A1B scenario. Annual climate variability today (with approximately 1.0 °C of warming) is potentially more important, in terms of coastal impacts, than an additional 0.5 °C warming. In coastal Bangladesh, the average depth of flooding in protected areas is projected to double to between 0.07 and 0.09 m when temperatures are projected at 3.0 °C compared with 1.5 °C. In unprotected areas, the depth of flooding is projected to increase by approximately 50% to 0.21–0.27 m, whilst the average area inundated increases 2.5 times (from 5 to 13% of the region) in the same temperature frame. The greatest area of land flooded is projected in the central and north-east regions. In contrast, lower flood depths, less land area flooded and fewer people are projected in the poldered west of the region. Over multi-centennial timescales, climate change mitigation and controlled sedimentation to maintain relative delta height are key to a delta’s survival. With slow rates of sea-level rise, adaptation remains possible, but further support is required. Monitoring of sea-level rise and subsidence in deltas is recommended, together with improved datasets of elevation.

  相似文献   

13.
In the wake of the flood that affected Brisbane, Australia, in January 2011, public attention turned to the causes of the event and lessons for minimizing the impacts of future floods. The news media was an important vehicle for understanding and internalizing the 2011 Brisbane flood. Examining how the flood was framed in the media is, therefore, useful to understand broad public perception of floods. We undertook a systematic newspaper analysis during a one-year period to explore media framings of the flood, focused on learning as an aspect of resilience in relation to two themes: (1) perceived links between the flood and climate change and (2) perceived roles of government in managing the flood. We show that media coverage of the flood reinforces aspects of resilience by acknowledging community spirit, self-reliance and the importance of sharing experiences for learning; articulating the risk of extreme events in a changing climate; and highlighting regional management trade-offs. Much of the discourse is likely to inhibit resilience, however, by casting the flood in terms of blame and political opportunity and paying inadequate attention to longer-term aspects of regional resilience. The limited learning observed to date may highlight a need for other mechanisms and actors to lead learning processes. As policy related to the 2011 Brisbane flood, and extreme events more generally, is influenced by the public discourse, it is important to understand the nuances of communication around these events and the media’s role in reinforcing or changing perceptions.  相似文献   

14.
Climate change in Nepal and its impact on Himalayan glaciers   总被引:2,自引:0,他引:2  
Climate change can be particularly hard-hitting for small underdeveloped countries, relying heavily on natural resources for the economy and livelihoods. Nepal is one among these countries, being landlocked, with diverse physiographical characteristics within a relatively small territory and with rugged terrain. Poverty is widespread and the capacity of people and the country to cope with climate change impact is low. The country is dominated by the Asian monsoon system. The main occupation is agriculture, largely based on rain-fed farming practices. Tourism based on high altitude adventures is one of the major sources of income for the country. Nepal has a large hydropower potential. While only 0.75% of the theoretical hydropower potential has been tapped, Nepal can greatly benefit from this natural resource in the future. Climate change can adversely impact upon water resources and other sectors of Nepal. The source of water is mainly summer monsoon precipitation and the melting of the large reserve of snow and glaciers in the Himalayan highlands. Observations show clear evidences of significant warming. The average trend in the country is 0.06°C per year. The warming rates are progressively higher for high elevation locations. The warming climate has resulted in rapid shrinking of majority of glaciers in Nepal. This paper presents state-of-knowledge on the glacial dynamics in the country based on studies conducted in the past in Shorong, Khumbu, Langtang, Dhaulagiri and Kanchenjunga regions of Nepal. We present recent trends in river flow and an overview of studies on expected changes in the hydrological regime due to climate change. Formation, growth and likely outburst of glacial lake are phenomena directly related to climate change and deglaciation. This paper provides a synopsis of past glacial lake outburst floods impacting Nepal. Further, likely impacts of climate change on other sectors such as agriculture, biodiversity, human health and livelihoods are discussed.  相似文献   

15.
Problems with extreme floods have been aggravatedin Germany mainly due to loss of flood retainingareas caused by river regulation measures in former centuries,and byintensified use of the former naturalflood plains.The situation may have been worsenedin t…  相似文献   

16.
The Ganges–Brahmaputra delta enables Bangladesh to sustain a dense population, but it also exposes people to natural hazards. This article presents findings from the Gibika project, which researches livelihood resilience in seven study sites across Bangladesh. This study aims to understand how people in the study sites build resilience against environmental stresses, such as cyclones, floods, riverbank erosion, and drought, and in what ways their strategies sometimes fail. The article applies a new methodology for studying people’s decision making in risk-prone environments: the personal Livelihood History interviews (N = 28). The findings show how environmental stress, shocks, and disturbances affect people’s livelihood resilience and why adaptation measures can be unsuccessful. Floods, riverbank erosion, and droughts cause damage to agricultural lands, crops, houses, and properties. People manage to adapt by modifying their agricultural practices, switching to alternative livelihoods, or using migration as an adaptive strategy. In the coastal study sites, cyclones are a severe hazard. The study reveals that when a cyclone approaches, people sometimes choose not to evacuate: they put their lives at risk to protect their livelihoods and properties. Future policy and adaptation planning must use lessons learned from people currently facing environmental stress and shocks.  相似文献   

17.
在气候变化背景下,区域降水变化波动较大。湖北地处亚热带,位于典型的季风区内,旱涝灾害比较突出,特别是水患,历来是威胁湖北的一大灾害,因此对降水时空变化进行分析研究,有很现实的意义。利用1961年以来全省65站逐日降水观测资料为基础,根据气候特征和行政区划将湖北省进行区域划分,利用多种统计分析方法,以揭示在全球气候变暖背景下湖北省各区域的降水变化事实。结果表明:湖北省平均年降水量鄂西北最少,鄂东南最多,秋季降水量的减少和冬季降水量的增加最为显著;极端降水事件的变化中,鄂西北发生站次最多,江汉平原其次,鄂西南和鄂东南最少。该结论为湖北各区域的旱涝变化趋势预估、为水资源管理和防汛抗旱工作提供科学的参考  相似文献   

18.
ENSO事件对汉江上游暴雨洪水影响的研究   总被引:1,自引:0,他引:1  
对汉江上游1951~2010年降水量、洪水与ENSO事件进行χ2检验和对照分析。结果表明:在El Nino事件年,汉江上游年降水量显著减少;与非La Nina年相比,La Nina年降水量略有增多,但没有达到显著变化水平;汉江上游洪水与ENSO事件关系密切:在上一年年底或本年年初有较强El Nino,且当年为El Nino向La Nina转换的年份,发生洪水的概率最大,相关性超过极显著水平,且洪峰大,成灾重,可能会发生最大流量20 000 m3/s以上的大洪水甚至超过30 000 m3/s(安康站)的特大洪水;在非El Nino也非La Nina事件发生的年份,大洪水的发生概率较低;发生El Nino事件或La Nina事件的当年,发生大洪水的频次也不高,相对于El Nino事件年,La Nina事件年,尤其是连续发生La Nina事件的年份,发生洪水的概率略大。这些结果对于指导汉江上游农业生产、水资源开发和防洪减灾具有重要的意义  相似文献   

19.
我国洪灾发展特点及成灾机制分析   总被引:9,自引:0,他引:9  
洪涝灾害是一种严重的自然灾害,无论是它发生的普遍性和破坏性,还是它发生的经常性,都居各种自然灾害之首,本文利用大量数据对我国洪灾发展的特点进行了分析,并指出:与历史相比,近年来我国洪涝灾害呈“频发,灾重”的趋势。对洪水的成灾机制进行了介绍,并将诱发洪涝灾害的原因分自然和人为两个方面进行了比较全面的论述。  相似文献   

20.
了解和认识百年来中国气候发生的变化、引起其变化的驱动因素以及未来的可能变化,可以更好地适应和减缓气候变化。本文综合评估了观测到的中国气候变化事实、中国气候变化的驱动力、中国未来气候变化预估三大方面,分析了气候变暖的趋势、水循环以及降水和冰川变化、极端天气气候事件变化、生物化学循环、海洋和土地覆盖变化及其气候效应以及未来气候变化的特点和趋势等最新科学进展。在中国百年温度趋势、气候系统多气候指标变化特征、极端天气气候事件中的人类活动作用以及气候系统模拟能力等方面的研究有了新的进展。可以看到中国气候变暖趋势持续、大气二氧化碳等长寿命温室气体浓度继续增长、人为强迫影响了多种气候要素在强度和频率的变化,中国陆地生态系统的固碳量增加。本文最后提出未来中国气候变化研究需要进一步加强的问题,包括:中国气候变化中的城市化效应、气候系统内部变率在年代际变化中的作用、气溶胶-云-降雨相互作用的机理、大范围土地利用变化(如大规模生态恢复工程)的气候效应,以及云辐射反馈、海洋环流对气候变化的响应与反馈、气候-碳循环反馈等过程对气候模拟不确定的影响等。  相似文献   

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