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1.
干旱频率分析研究进展   总被引:5,自引:0,他引:5       下载免费PDF全文
从干旱定义与识别、点干旱频率分析和区域干旱频率分析3个方面系统阐述了干旱频率分析研究进展和存在问题,归纳了适用于干旱频率分析的干旱定义,干旱识别存在的主要问题以及区域干旱频率分析研究的3种途径。提出综合利用研究区域水文气象特性、干旱成因、旱情、旱灾,并结合前期的大气环流条件等信息来描述和识别干旱,重点开展对干旱特征变量的理论分布、干旱事件重现期公式和经验频率公式等基本理论的研究,关注区域干旱频率分析,注重对径流、土壤水、地下水和供水系统的干旱特性分析。  相似文献   

2.
Drought risk assessment using remote sensing and GIS techniques   总被引:1,自引:0,他引:1  
Beginning with a discussion of drought definitions, this review paper attempts to provide a review of fundamental concepts of drought, classification of droughts, drought indices, and the role of remote sensing and geographic information systems for drought evaluation. Owing to the rise in water demand and looming climate change, recent years have witnessed much focus on global drought scenarios. As a natural hazard, drought is best characterized by multiple climatological and hydrological parameters. An understanding of the relationships between these two sets of parameters is necessary to develop measures for mitigating the impacts of droughts. Droughts are recognized as an environmental disaster and have attracted the attention of environmentalists, ecologists, hydrologists, meteorologists, geologists, and agricultural scientists. Temperatures; high winds; low relative humidity; and timing and characteristics of rains, including distribution of rainy days during crop growing seasons, intensity, and duration of rain, and onset and termination, play a significant role in the occurrence of droughts. In contrast to aridity, which is a permanent feature of climate and is restricted to low rainfall areas, a drought is a temporary aberration. Often, there is confusion between a heat wave and a drought, and the distinction is emphasized between heat wave and drought, noting that a typical time scale associated with a heat wave is on the order of a week, while a drought may persist for months or even years. The combination of a heat wave and a drought has dire socio-economic consequences. Drought risk is a product of a region’s exposure to the natural hazard and its vulnerability to extended periods of water shortage. If nations and regions are to make progress in reducing the serious consequences of drought, they must improve their understanding of the hazard and the factors that influence vulnerability. It is critical for drought-prone regions to better understand their drought climatology (i.e., the probability of drought at different levels of intensity and duration) and establish comprehensive and integrated drought information system that incorporates climate, soil, and water supply factors such as precipitation, temperature, soil moisture, snow pack, reservoir and lake levels, ground water levels, and stream flow. All drought-prone nations should develop national drought policies and preparedness plans that place emphasis on risk management rather than following the traditional approach of crisis management, where the emphasis is on reactive, emergency response measures. Crisis management decreases self-reliance and increases dependence on government and donors.  相似文献   

3.
Drought is one of the major disasters around the world which cause great social and economic hardship. Recent events of severe droughts have motivated comprehensive research on drought management in China like many other countries of Asia, Europe and Africa. In this paper, the mechanism of drought management has been analyzed in light of water supply and water demand management considering water shortage as an inductor of drought. Catastrophe theory has been proposed to explain transitions through discontinuities and unexpected changes in water system. The study indicates that supply management can increase water supply; however, in long term, it may not be sustainable for drought mitigation. Water demand management, on the other hand, improves water use efficiency with less investment. Therefore, the study emphasizes water demand managements for drought management under future changing scenarios.  相似文献   

4.
East River, one of the major tributaries of Pearl River, is the major source of water supply for mega-cites within and in the vicinity of the Pearl River Delta, China. The availability and variability of water resources of the East River basin are therefore of practical importance. This study aims to investigate the probabilistic behavior of hydrological droughts in the East River basin using the trivariate Plackett copula. Daily streamflow data for the period of 1975–2009 from 3 hydrological stations in the East River basin are analyzed. Defining hydrological droughts by drought severity, duration, and minimum flow, secondary return periods are computed. Results show that the Plackett copula satisfactorily models bivariate and trivariate probability distributions of correlated drought variables. Results of risk evaluation show an increasing drought risk from the upper to the lower East River basin. This result is important for basin-scale water resources management in the East River basin.  相似文献   

5.
Drought is one of the major natural disasters occurring in China and causes severe impacts on agricultural production and food security. Therefore, agricultural drought vulnerability assessment has an important significance for reducing regional agricultural drought losses and drought disaster risks. In view of agricultural drought vulnerability assessment with the characteristics of multiple factors and uncertainty, we applied the fuzzy comprehensive evaluation framework to agricultural drought vulnerability model. The agricultural drought vulnerability assessment model was constructed based on the multi-layer and multi-index fuzzy clustering iterative method, which can better reveal the drought vulnerability (including sensitivity and adaptation capacity). Furthermore, the cycle iterative algorithm was used to obtain the optimal index weight vector of a given accuracy by setting the objective function. It provides a new approach to weight determination of agricultural drought vulnerability assessment. In this study, agricultural drought vulnerability of 65 cities (as well as leagues and states) in the Yellow River basin was investigated using a fuzzy clustering iterative model and visualized by using GIS technique. The results showed clear differences and regularities among the spatial distribution of agricultural drought vulnerability of different regions. A large number of the regions in the basin consisted of those exhibiting high to very high vulnerability and were mainly distributed throughout Qinghai, Gansu, northern Shaanxi, and southern Shanxi, accounting for 46 % of the total assessment units. However, the regions exhibiting very high vulnerability were not significantly affected by droughts. Most of the regions exhibiting moderate vulnerability (21.5 % of the assessment units) were mainly concentrated among agricultural irrigation areas, where agriculture is highly sensitive to droughts, and drought occurrence in these regions will likely cause heavy losses in the future. The regions exhibiting slight to low vulnerability were relatively concentrated, accounting for 32.3 % of the assessment units, and were mainly distributed in the plains of the lower reaches of the Yellow River, where the economy was rather well developed and the agricultural production conditions were relatively stronger.  相似文献   

6.
Severity–duration–frequency (SDF) curves are very useful in the analysis of drought phenomena. Station-level information obtained from SDF curves can be interpolated to obtain severity maps for fixed return period, in order to jointly analyse the spatial variability of drought characteristics (e.g. severity, duration and frequency). This approach is limited because the severity is usually quantified through indices that use hydrological and meteorological data, depending on the type of requirements. Therefore, drought indices can only reflect hydrological conditions, but are unable to quantify economic losses associated with droughts. In other words, SDF curves do not allow effective quantification of the impact expected with a certain return period. This paper proposes the methodology drought economic risk assessment (DERA) as an approach that emphasizes the importance of the relationship between a generic drought index (which quantifies water deficit) and the economic impact of the failure to meet water demand. Using integrated SDF curves, this relationship enables drought severity and corresponding impacts to be mapped. This procedure was applied to agricultural droughts (sunflower crop) in Umbria Region (central Italy). The agricultural drought impact variable was identified by sunflower yield (Y); the economic impact variable by net benefit depletion (EL); and the drought index by Relative Severity Index (RSI), which is quantifiable by a soil–water balance model. The relationships Y = g(RSI) and EL = f(Y) were specifically determined. Using DERA, it was possible to derive curves for SDF, impact–duration–frequency, and economic losses–duration–frequency (ELDF), which were then used to map severity, impact and economic losses for the assigned return period and duration. From the ELDF curves, further information was obtained by mapping critical drought durations for the assigned return period and economic loss threshold. The case study supports the potential of the proposed approach, both in the planning and real-time management of drought effects.  相似文献   

7.
The wet and dry seasons are distinctive in Taiwan as the amount of precipitation in wet seasons accounts for over three-fourth of the total rainfall. And the water-resources management relies pretty much on the rainfall brought in by typhoons as it accounts for a significant portion of the precipitation during wet seasons. Furthermore, as the storage of reservoirs is limited due to topographical factors, the management of typhoon rainfall has always been an important issue in Taiwan. The technique of decision-tree analysis is applied in this article to determine the optimal reservoir release in advance upon the issuance of a typhoon warning by the Central Weather Bureau (CWB), and the proposed methodology may provide solution to the trade-off judgment of reservoir operations between flood control and water supply according to economic efficiency. In this article, the economic loss functions of flooding damage and water-supply shortage are assumed in linear and nonlinear conditions, and the respective expected optimal releases based on the predicted precipitation as issued by CWB are derived. The proposed methodology has been applied to the Shihmen Reservoir System, and the capabilities of the model as an aid to real-time decision-making as well as the evaluation of the economic worth of forecasts is presented.  相似文献   

8.
At present, flash drought occurs globally and regionally and causes a lot of socio-economic loss in a very short time. Therefore, flash drought has been regarded as one of the hottest issues in drought research. However, flash drought monitoring, prediction and decision-making have encountered a lot of challenges due to its multiple driven factors and complex spatio-temporal process. Aiming at this problem, this paper focused on the agricultural land in China, and analyzed the spatio-temporal distribution of three kinds of flash droughts (i.e., precipitation-deficit, high-temperature, and composite flash droughts) from 1983 to 2015. We studied the occurrences, duration, spatial distribution, temporal distribution, and trend of all three kinds of flash droughts. Our results demonstrated that, the occurrences of flash drought agricultural land in China increased year by year, among which high-temperature flash drought increased dramatically; duration of flash droughts had different trends, but the variations were relatively smooth; Northeast China was identified as a vulnerable area of flash drought, indicating more flash drought events and longer duration; flash droughts in China were found to concentrate in spring (high-temperature drought) and summer seasons (precipitation-deficit drought). This study is helpful for building new flash drought monitoring method and system, and it is also valuable for flash drought preparedness on regional scale.  相似文献   

9.
Drought risk assessment in the western part of Bangladesh   总被引:14,自引:8,他引:6  
Though drought is a recurrent phenomenon in Bangladesh, very little attention has been so far paid to the mitigation and preparedness of droughts. This article presents a method for spatial assessment of drought risk in Bangladesh. A conceptual framework, which emphasizes the combined role of hazard and vulnerability in defining risk, is used for the study. Standardized precipitation index method in a GIS environment is used to map the spatial extents of drought hazards in different time steps. The key social and physical factors that define drought vulnerability in the context of Bangladesh are identified and corresponding thematic maps in district level are prepared. Composite drought vulnerability map is developed through the integration of those thematic maps. The risk is computed as the product of the hazard and vulnerability. The result shows that droughts pose highest risk to the northern and northwestern districts of Bangladesh.  相似文献   

10.
区域供水系统干旱历时特性综合分析   总被引:1,自引:0,他引:1       下载免费PDF全文
根据区域供水系统中供水水库(群)的蓄水状态及其运行调度策略在满足区域供水目标方面的重要作用,提出了以水库(群)的时段初始蓄水量与时段内来水量之和,以及时段内供水系统的目标需水量作为主要控制参数,以两者的差值正、负来表达供水系统处于非干旱状态和干旱状态的区域干旱鉴别方法。为了多角度地分析干旱和非干旱历时分布、转移概率以及干旱重现期等干旱历时特性以较全面地掌握区域干旱事件特征,针对一具体区域供水系统,运用模拟统计法和概率解析法两种技术手段来研究区域干旱历时特性,同时针对两种方法的计算结果差异,指出了各种方法的特征以及产生差异的原因。  相似文献   

11.
Drought is one of the most harmful natural hazards in Gansu Province in Northwest China. The changes of precipitation affect the severity of drought. In order to recognize the trend of precipitation and understand the effect of rainfall change on water resources management and drought severity, Mann–Kendall test was used. Standardized Precipitation Index (SPI) was calculated to reconstruct the drought at different time scales and analyze the frequency of drought occurrence in the recent 50 years. The results show that the SPI is applicable in Gansu Province. The number of severe droughts differs among regions: it is more obvious as a 3-month drought in the Yellow River Basin and the Yangtze River Basin than in the Inland River Basin, and other droughts at 6-, 9-, and 12-month time scales have the same effect in the three regions. Mann–Kendall test results show that there is an upward trend in the summer periods and a downward trend in the autumn-winter-spring intervals ranging from 10.5 mm/10 years to −37.4 mm/10 years, which affect the local water resources management, droughts mitigation, and agriculture decision making. This situation poses challenges for future study.  相似文献   

12.
The amount and distribution of precipitation play crucial roles in the occurrence of drought in the Weihe River Basin (WRB), China. Using the precipitation data (1960–2010) of 21 meteorological stations, the spatial and temporal characteristics of short-, medium-, and long-term droughts on 3-, 6-, and 12-month time scales, respectively, were examined using the theory of runs and the Standardized Precipitation Index (SPI). The trends of the drought characteristics were analyzed by a modified Mann-Kendall (MMK) test method. Furthermore, comparative analysis of the SPI at different time scales was conducted. The results showed that (1) the main drought type was moderate drought, which occurred frequently in July and October; (2) the drought intensity and frequency were highest in the 1990s, and the drought severity and drought duration in the northwest was more serious than that in the east; (3) an increasing trend of short droughts appeared mainly in the spring and fall; an increasing trend of medium droughts mainly occurred in the 1990s and that of long-term droughts were mainly presented in the northwest region of the WRB; (4) SPI-3 can better reflect precipitation in the current month, SPI-6 has an advantage in characterizing drought persistence, and SPI-12 performs well in capturing extraordinary droughts; and (5) it was also observed that there is a strong relation between the precipitation distribution and drought zones in the basin, and the drought conditions changed continuously with the seasons depending upon the amount and spatial distribution of precipitation .  相似文献   

13.
全球气候变化影响了气象水文要素的时空分布特性,气象水文干旱事件的转化关系及风险传播特征亟待研究。基于站点、栅格观测资料和CMIP5(Coupled Model Inter-comparison Project Phase5)的19个气候模式输出数据,采用新安江等4个水文模型模拟了中国135个流域历史(1961—2005年)和未来时期(2011—2055年,2056—2100年)的水文过程,计算了SPI(Standard Precipitation Index)和SRI(Standard Runoff Index)干旱指标,通过游程理论识别了气象干旱与水文干旱事件,利用Copula函数与最大可能权函数度量二维干旱风险特征,定量评估了气象干旱至水文干旱的潜在风险传播特性。结果表明:①气象-水文干旱对气候变化响应强烈,华北和东北地区的干旱联合重现期增大,干旱潜在风险减小,华中和华南地区的干旱联合重现期减少60%~80%,干旱潜在风险增加;②气象干旱与水文干旱风险在历史和未来时段均存在显著的正相关关系,相关系数超过0.99;③各流域水文干旱风险变化对气象干旱风险变化的敏感程度不会随气候变暖发生较大变化,但未来北方地区水文干旱同气象干旱同时发生的概率将会小幅度增加。  相似文献   

14.
云南干旱“常态化”的分析   总被引:2,自引:0,他引:2       下载免费PDF全文
付奔  胡关东  杨帆  王龙 《水文》2014,34(4):82-85
近年来云南持续发生严重干旱,云南干旱是否日趋"常态化"成为社会各界关心的一个热点问题,相关报道不断见诸媒体。本文从水文的角度对云南省的历史干旱、水文要素以及趋势预测等方面进行了深入的分析。在历史依据和现代气象水文观测数据的支撑下,考察近100年来全球增暖可能导致部分地区干旱化的可能,从而认为近年来提出的云南干旱"常态化"存在科学依据;但干旱"常态化"仅能局限于近现代时期这一时间范畴,对于今后更长时期云南省干旱发展趋势,依据现有技术手段及研究成果尚难以判断把握。  相似文献   

15.
Drought monitoring is a key topic in environmental monitoring and assessment although there is still a need to determine the correlation between drought monitoring indices and remote sensing products. We analyzed the correlation between the self-calibrating Palmer Drought Severity Index (sc_PDSI), the Standardized Precipitation Index and the Standardized Precipitation Evapotranspiration Index (SPEI) and terrestrial water storage monitored through the Gravity Recovery and Climate Experiment (GRACE) on a monthly timescale from 2002 to 2015 in China. As a consequence of anomalies in the soil water budget, the highly significant correlation between the sc_PDSI and the GRACE satellite-observed terrestrial water storage suggested that these two datasets are the most suitable for use in monitoring droughts. In comparing the three drought indices, the sc_PDSI was introduced as a means of drought monitoring in the Yangtze, Pearl, Huaihe, Southeast and Songhua River Basins, whereas the SPEI was found to be more applicable to other major river basins, such as the Inland River Basin. These diverse spatial behaviors are caused by the differences between the hydrological droughts characterized by these three drought indices.  相似文献   

16.
Many jurisdictions presently utilize, or are now considering the utilization of, high-volume wells as a municipal water supply source. Withdrawal of groundwater in karst regions implicates rights to use groundwater and possible interference with other rights of nearby landowners. Drought conditions and increased population contribute to an increased incidence of legal disputes over the use of groundwater as a municipal water supply source in karst regions. High-volume pumping of groundwater may cause land subsidence, including sinkholes, drying of springs and/or streams and loss in value of nearby land. This paper examines the legal causes of action available to landowners adversely affected by high-volume groundwater pumping: groundwater rights, "loss of lateral and subjacent support", nuisance, and "takings". The author concludes that the law fails to include environmental and geoscience considerations. State legislatures should consider legislative changes to unify legal and scientific principles.  相似文献   

17.
The demand of water is increasing with the socioeconomic development, and the contradictions between supply and demand of water resources in regional scale have become increasingly intensified. Scientifically evaluating the risk caused by the contradictions between supply and demand of water resources has become a useful way to solve the imbalance of water resources effectively. In the current study, the utilization of water resources in Songliao Basin was analyzed based on the water quantity, water quality, and socioeconomic data in 1999?C2006. Accordingly, a risk-evaluation index system of water resources utilization was generated, which included ten indicators, such as the total quantity of regional water resources. Three common factors (i.e., high water-demand, high water-supply, and low-quality water) were identified by factor analysis. These factors were then evaluated with spatial clustering. Thus, the risk distribution of water resources was made in the study area. The results indicate that (1) the pattern of water resources utilization in Songliao Basin was high risk in Songnei Plain and low risk in Changbaishan Mountain, and (2) Nenjiang and Songhua Rivers were high risk; however, Tumen and Wusuli Rivers were low risk.  相似文献   

18.
中国历史极端干旱研究进展   总被引:1,自引:0,他引:1       下载免费PDF全文
中国现有抗旱相关法规、规划、标准和制度等均是按常态干旱考虑的,几乎没有考虑大范围、长历时极端干旱的问题。一旦发生类似崇祯大旱和光绪大旱等极端干旱,将对中国经济社会产生深刻影响。从历史旱涝序列重建、极端干旱事件复原和重演3个方面论述了相关研究进展,发现重建方面缺乏重建方法对比研究、重建序列时空分辨率较低等,复原方面缺乏干旱灾害双重属性的考虑等,重演方面缺乏对抗旱减灾能力以及全球气候变化的考虑等。对未来研究重点和实践需求进行了展望,指出需在不同重建方法交叉检验、高时空分辨率旱涝序列重建、基于自然灾害双重属性的历史极端干旱事件复原、历史极端干旱事件定量化重演和干旱巨灾风险应对战略等方面取得突破性进展。  相似文献   

19.
骤发干旱(简称骤旱)是一种以短历时、高强度、快速度为特征的极端事件,其形成速度已超出现有干旱监测工具的能力范围,监测模拟难度大。基于欧洲中心再分析产品(ERA)土壤含水量数据,构建考虑旱情开始速度的骤旱识别方法,提取中国1979—2018年骤旱事件,剖析旱情初期气象要素异常值的变化规律,探讨利用气象条件模拟骤旱的可行性。结果表明:①开始速度在空间上呈现显著的南北差异,长江以南地区较快,西北地区较慢;②骤旱比缓慢干旱具有更强的气象驱动力,骤旱各气象要素异常值的均值、峰值及变化幅度比缓慢干旱变化更为显著,尤其是峰值,约超过缓慢干旱0.5个标准差;③综合考虑骤旱爆发前后不同时段多个气象要素异常,能够较好地模拟开始速度,可用于监测与模拟骤旱。  相似文献   

20.
The design of the Rovni Lake reservoir in the Kolubara District, western Serbia, is the basis for the regional water-supply system there. The design was promoted as an example of integrative and sustainable water management, with regard to the planned provision for long-term municipal water supply in the Kolubara region, as well as for the regulation of the downstream river flow. Hydrogeological analyses, however, have indicated three key issues that contest this sustainable water-management model: (1) the capability of the available groundwater sources to fully meet the drinking water demands in the region, (2) a pronounced risk of water loss from the reservoir, and (3) a pronounced risk of karst aquifer contamination. The Rovni project ignores the hydrogeological properties of a karst aquifer and thereby needlessly threatens the groundwater resource. Hence, modifications to the project are recommended in order to mitigate or eliminate the most significant construction and ecological risk factors and to improve sustainable exploitation and integrative water-resource management.  相似文献   

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