共查询到20条相似文献,搜索用时 15 毫秒
1.
数值天气预报和气候预测可预报性研究的若干动力学方法 总被引:2,自引:2,他引:2
简要回顾了数值天气预报和气候预测可预报性研究的若干动力学方法,包括用于研究第一类可预报性问题的线性奇异向量(LSV)和条件非线性最优初始扰动(CNOP-I)方法,以及Lyapunov指数和非线性局部Lyapunov指数方法。前两种方法用于研究预报或预测的预报误差问题,可以用于估计天气预报和气候预测的最大预报误差,而且根据导致最大预报误差的初始误差结构的信息,这两种方法可以用于确定预报或预测的初值敏感区。应该指出的是,LSV是基于线性化模式,对于描述非线性大气和海洋的运动具有局限性。因而,对于非线性模式,应该选择使用CNOP-I估计最大预报误差。Lyapunov指数和非线性局部Lyapunov指数可以用于研究第一类可预报性问题中的预报时限问题,前者是基于线性模式,不能解释非线性对预报时限的影响,而非线性局部Lyapunov指数方法则考虑了非线性的影响,能够较好地估计实际天气和气候的预报时限。第二类可预报性问题的研究方法相对较少,本文仅介绍了由我国科学家提出的关于模式参数扰动的条件非线性最优参数扰动(CNOP-P)方法,该方法可以用于寻找到对预报有最大影响的参数扰动,并可以进一步确定哪些参数最应该利用观测资料进行校准。另一方面,通过对比CNOP-I和CNOP-P对预报误差的影响,可以判断导致预报不确定性的主要误差因子,进而指导人们着力改进模式或者初始场。 相似文献
2.
A 1950–1994 data set of major weather losses developed by the property insurance industry was examined to assess its potential utility in climate change research and use in assessing the relevance of recent extreme losses in the United States. A process for adjusting these historical storm losses to ever-changing factors including dollar values, amount of insurance coverage per area, and the sensitivity of society to damaging storms was developed by the industry. Analysis of the temporal frequency and losses of these adjusted weather catastrophes revealed differences according to the amount of loss. Temporal changes since 1975 in the catastrophes causing $35 to $100 million in loss were strongly related to changes in U.S. population, whereas catastrophes that created insured losses greater than $100 million appear related to both shifting weather conditions and to regional population changes. This evaluation revealed that the industry's catastrophe adjustment technique did not adequately allow for changes in various demographic and social factors affecting damage; however, results suggest use of population values for normalizing the adjusted catastrophe database to allow meaningful studies of their temporal variability. 相似文献
3.
Water managers always have had to cope with climate variability. All water management practices are, to some extent, a response to natural hydrologic variability. Climate change poses a different kind of problem. Adaptation to climate change in water resource management will involve using the kinds of practices and activities currently being used. However, it remains unclear whether or not practices and activities designed with historical climate variability will be able to cope with future variability caused by atmospheric warming. This paper examines the question of adaptation to climate change in the context of Canadian water resources management, emphasizing issues in the context of the Great Lakes, an important binational water resource. 相似文献
4.
《Journal of Meteorological Research》2021,35(1):87-100
The efficiencies and effectiveness of water resource management are inextricably linked to climate services. This study demonstrates a climate information service for Danjiangkou Reservoir, which is the largest artificial lake in Asia, facing mounting challenges for flood control, water storage, and water diversion. Unlike traditional water resource management on the basis of short-term weather forecast and runoff monitoring, subseasonal to seasonal(S2S)and annual climate predictions as well as long-term climate change projections were well used to support the decision makers in Danjiangkou Reservoir. The National Climate Center(NCC) has projected the changes of future climate and extreme events by dynamically downscaling the Coupled Model Intercomparison Project phase 5(CMIP5)projections to 25-km resolution for the long-term planning of water resource management in Danjiangkou Reservoir.Real-time climate predictions based on climate models and downscaling interpretation and application methods at different timescales were also provided to meet the specific needs of earlier predictions and spatial refinement for the short-term diversion of the reservoir. Our results show that such climate services facilitated the Diversion Center of Danjiangkou Reservoir(DCDR) to reasonably control the operational water level, increased the ecological water supply to the northern portion of China by 844 million m~3, and reduced as much as 1.67 billion m~3 of abandoned water in 2019. In the future, it is necessary to develop climate prediction methods to increase spatial and temporal resolutions and prediction skills, and enhance interactions between providers and users. 相似文献
5.
Targeting Climate Forecasts for Agricultural Applications in Sub-Saharan Africa: Situating Farmers in User-Space 总被引:1,自引:0,他引:1
Abigail Amissah-Arthur 《Climatic change》2003,58(1-2):73-92
Several meteorological services in Africa now issue seasonal climate forecasts on an operational basis. However, the failure to develop a comprehensive profile of users has resulted in a considerable gap between the information that is likely to be useful to farmers and that provided and disseminated by these services. The present study develops a methodology to characterize smallholder production systems in order to identify farmer groups who may adopt and benefit from the climate forecast information in sub-Saharan Africa. Through an extensive literature review, data and information was derived from a national household survey of 1540 smallholders in 1995–1997 by the Kenya Agricultural Research Institute and spatial georeferenced data from leading world data centers. The data were analysed and synthesized using the GIS. Considerable opportunities exist for farming communities to improve their profitability using climate forecasts. Although the needs and demand for climate forecasts vary according to the production systems and market forces that determine credit, demand and input availability and, thus, the usability of forecasts depend on the characteristics of the farmers and their place in space. Based on production strategies and options available to farmers, three zones were identified grouping farmers with highly probable, probable and less probable potential of adopting climate forecasts to alter their production practices. Although a climate forecast may be useful to all farmers in the region considered, due to different options available to individual groups of farmers, however, the benefits derived from its use may not be equitable. Some of the options available to farmers in Kenya were considered in this study with a view to highlighting why some may benefit more than others. The methodology demonstrated here could be adopted for other parts of the world for: (1) selecting survey sites to determine the benefits of climate forecasts using farmers participatory rapid rural appraisals and simulation approach, and (2) target climate information where it would be most useful. 相似文献
6.
7.
8.
As part of a long-term effort to both improve access to information on climate change and freshwater resources, and to understand the state of the science, we compiled an electronic bibliography of scientific literature in that area. We analyzed the distribution of information on climatic impacts on freshwater resources, with an emphasis on differences between developed and developing regions as well as differences in the types and focus of research carried out among regions. There has been more research overall in developed countries than in the developing world. Proportionally more of the available research on natural and human systems pertains to developed regions, while most of the analysis done in developing countries is limited to higher-level climatology and hydrology. We argue that scientific information and understanding are important elements of the ability to adapt to potential climatic changes. The distribution of the scientific literature in our database suggests that the types of science most directly relevant to adaptive capacity are skewed towards developed countries, which may exacerbate existing disparities in adaptive capacity, and ultimately worsen the consequences of climatic impacts in developing countries. 相似文献
9.
10.
密云水库近30 a入库水资源量日益减少,严重影响城市供水和可持续发展,其中气候变化对水资源的影响成为最受关注的问题之一。以海河流域密云水库的水资源供应为例,研究了气候变化对入库水资源的影响。结果表明:除SRES A2情景下在2025年入库流量减少外,其他情景均表现为入库流量增加。对入库流量增加的情景,采用"零调整方案",即不采取调整措施是可以的,但由于未来北京水资源压力较大,有必要采取一些综合对策。通过多目标条件分析,为解决北京的饮用水供应问题,建议采用开源(跨河流调水)、节流(水田改旱地)及污水治理三管齐下的方案。 相似文献
11.
12.
华北地区夏季水资源特征分析及其对气候变化的响应(Ⅰ):近40年华北地区夏季水资源特征分析 总被引:8,自引:4,他引:8
近年来 ,淡水资源匮乏问题已经成为全人类普遍关注的严重问题。华北地区是我国的政治、经济和文化中心 ,该区水资源严重不足 ,缺水问题一直困扰着该区经济的发展和人民生活水平的提高。本文利用NCEP/NCAR的 40a(195 8— 1997年 )再分析资料分析发现 ,近 40a来 ,华北地区年平均水资源略有盈余 ,但水资源年内分布很不均匀 ,一年内仅 6 9月份水资源有盈余 ,其它各月均有不同程度亏损。对华北地区水资源最充足的夏季水资源各分量进行EOF分析 ,结果表明 ,华北地区夏季水资源各分量空间分布的最主要特征都表现为全区一致型 ;最主要的时间变化趋势都表现为自 6 0年代至 80年代中期持续下降 ,80年代中期以后略有回升 ,但回升幅度较小 ,降水仍然低于 40a来的平均水平。对各物理量进行M -K突变检验的结果表明 ,各量在 6 0年代中期前后都发生了一次突变过程 ,但发生时间略有差别 相似文献
13.
研究气候变化对雨养冬小麦水分利用效率的影响规律,可为农业适应气候变化提供科学依据。通过构建代表站雨养冬小麦产量和土壤水分变化量的模拟方程,分析水分利用效率的历史变化,并结合两种区域气候模式PRECIS和REGCM4.0输出的4种不同气候变化情景资料,估算未来2021—2050年雨养冬小麦水分利用效率的可能变化。结果表明:1981—2010年甘肃、山西和河南代表站的雨养冬小麦水分利用效率呈二次曲线变化趋势,最大值出现在2003年前后。4种气候变化情景的模拟结果均显示:2021—2050年冬小麦全生育期耗水量明显增加,各代表站不同情景平均增加6.2%;产量有增有减,平均产量变化率为1.4%;水分利用效率平均减小3.8%,且变率减小。区域气候模式PRECIS估算的水分利用效率的减小量A2情景大于B2情景,REGCM4.0模式估算的水分利用效率的减小量RCP8.5情景大于RCP4.5情景。整体来看,RCP气候情景对雨养冬小麦水分利用效率的负面影响更大。 相似文献
14.
15.
为了消除气候模拟数据中气候平均值和气候变率的漂移,发展了一种新的数据订正方案。应用该方案对IPCC提供的B2情景下北京未来100 a气候预估值进行了订正试验,证实了方案的可用性。在此基础上分析了北京未来气候变化特征,结果表明:21世纪北京气温将继续上升,升温速率约为0.31℃/10 a,最低、最高气温的非对称变化仍将持续;未来北京年降水量呈微弱下降趋势,下降速率约为1.03 mm/10 a。 相似文献
16.
17.
Simulations of Water Resource Changes in Eastern and Central China in the Past 130 Years by a Regional Climate Model
下载免费PDF全文
![点击此处可从《Acta Meteorologica Sinica》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Anthropogenic influences on regional climate and water resources over East Asia are simulated by using a regional model nested
to a global model. The changes of land use/land cover (LULC) and CO2 concentration are considered. The results show that variations of LULC and CO2 concentration during the past 130 years caused a warming trend in many regions of East Asia. The most remarkable temperature
increase occurred in Inner Mongolia, Northeast and North China, whereas temperature decreased in Gansu Province and north
of Sichuan Province. LULC and CO2 changes over the past 130 years resulted in a decreasing trend of precipitation in the Huaihe River valley, Shandong Byland,
and Yunnan-Guizhou Plateau, but precipitation increased along the middle reaches of the Yangtze River, the middle reaches
of the Yellow River, and parts of South China. This pattern of precipitation change with changes in surface evapotranspiration
may have caused a more severe drought in the lower reaches of the Yellow River and the Huaihe River valley. The drought trend,
however, weakened in the mid and upper reaches of the Yellow River valley, and the Yangtze River valley floods were increasing.
In addition, changes in LULC and CO2 concentration during the past 130 years led to adjustments in the East Asian monsoon circulation, which further affected
water vapor transport and budget, making North China warm and dry, the Sichuan basin cold and wet, and East China warm and
wet. 相似文献
18.
19.
20.
气候变化将使水利工程的服役环境发生较大改变,水工混凝土作为水利工程建设最主要的建筑材料之一,其对极端气候变化较为敏感与脆弱。本文以水库大坝、大型调水工程等水利工程为对象,系统总结了部分已观测到的低温冻害、寒潮和干旱等气候条件对水利工程影响的事实。结合未来气候变化趋势及其可能的影响,从改善水工材料性能的工程措施角度,分析了在水利工程设计、施工、运行阶段可采取的应对措施,并从规划修订、预案制订、监测预报等非工程措施角度,分析了在防洪安全、水资源安全等领域可采取的减缓适应对策,以提高水工程应对气候变化的能力。 相似文献