江西干旱灾害研究

在江西,干旱灾害是仅次于洪涝灾害的第二大农业灾害,本文对江西干旱灾害的面积,频率,分布,危害及其成因等作了较全面的调查和分析,在此基础上提出了减轻江西干旱灾害的若干建议,可供有关部门参考。     

中国的水环境状况及对策

引用翔实的资料,分析了概括了目前中国水环境面临的主要问题是水体污染、水资源短缺和旱涝灾害。指出了解决我国水环境问题的以考仪表 实施水资源管理和污染控制的可持续发展战略。     

遥感在农业旱情监测中的应用现状与展望

文章对我国农业旱情遥感的原理、国内外研究进展情况进行了讨论与分析,认为无人机技术、农业地面传感网与遥感技术相结合及农业专业模型与遥感技术的耦合遥感技术应用是今后旱情定量遥感的发展方向。     

干旱灾害对江西省农业生产的影响及其对策

江西是农业大省,是国家重要的粮食主产区。近10 a来江西省干旱发生频繁,导致农业生产损失严重,威胁到农业的可持续发展。基于历史文献与资料,结合江西省农业厅的农业灾情调查数据和干旱指数最高的星子县、都昌县调研数据,着力分析近10 a来江西省的干旱状况及其对农作物生产的影响,探讨农业干旱灾害的成因。研究结果表明:江西干旱灾害以秋旱为主,近10 a年对江西的粮食和棉花生产造成重大损失,尤其是鄱阳湖区地区;江西农业干旱灾害的主要成因包括降水分布不均匀、红壤持水能力低、水利设施年久失修、植被结构破坏和易改变水文过程的大型水利设施建设。最后针对农业干旱灾害的主要成因,提出了减轻干旱灾害对农业生产不利影响的对策     

长江上游旱涝指标及其变化特征分析

利用长江上游流域51个气象观测站1961～2009年降水资料,计算了各站逐年、四季〖WTBX〗Z〖WTBZ〗指数及区域旱涝指数,在此基础上分析了单站〖WTBX〗Z〖WTBZ〗指数旱涝等级划分的合理性,区域旱涝指数的年代际变化趋势,并对区域典型旱涝年的确定及旱涝成因进行了探讨。结果表明：（1）〖WTBX〗Z〖WTBZ〗指数及以此为基础构建的区域旱涝指数能较好地反映长江上游流域年及四季旱涝变化,作为长江上游流域旱涝指标比较合理;（2）长江上游流域年及四季旱涝有明显的年代际变化特征,年及四季的干旱指数与雨涝指数基本呈反位相特征;（3）长江上游流域四季旱涝与500 hPa高度场分布形势有密切关系,除冬季旱涝与海温场关系较弱外,春、夏、秋季旱涝均与海温场关系密切。研究结论对长江上游流域可持续发展及三峡水库科学运营有一定参考意义     

Adaptive Water Resource Planning in the South Saskatchewan River Basin: Use of Scenarios of Hydroclimatic Variability and Extremes

The South Saskatchewan River Basin is one of Canada's most threatened watersheds, with water supplies in most subbasins over‐allocated. In 2013, stakeholders representing irrigation districts, the environment, and municipalities collaborated with researchers and consultants to explore opportunities to improve the resiliency of the management of the Oldman and South Saskatchewan River subbasins. Streamflow scenarios for 2025‐2054 were constructed by the novel approach of regressing historical river flows against indices of large‐scale ocean‐atmosphere climate oscillations to derive statistical streamflow models, which were then run using projected climate indices from global climate models. The impacts of some of the most extreme scenarios were simulated using the hydrologic mass‐balance model Operational Analysis and Simulation of Integrated Systems (OASIS). Based on stakeholder observations, the project participants proposed and evaluated potential risk management and adaption strategies, e.g., modifying existing infrastructure, building new infrastructure, changing operations to supplement environmental flows, reducing demand, and sharing supply. The OASIS model was applied interactively at live modeling sessions with stakeholders to explore practical adaptation strategies. Our results, which serve as recommendations for policy makers, showed that forecast‐based rationing together with new expanded storage could dramatically reduce water shortages.     

The need for constructing endangered fish habitats that conform to climate-driven flow changes in a western U.S. river

Warmwater fish habitat in the San Juan River of the southwestern United States has been reduced by over 30% as a result of water depletion, reservoir inundation, and cold-water dam releases combined with drought-related changes in hydrology. This reduction and a suite of other factors have contributed to declines in native fish populations including the federally endangered Colorado Pikeminnow (Ptychocheilus lucius) and Razorback Sucker (Xyrauchen texanus). Conservation efforts for these species include determining flow needs; protecting, managing, and augmenting habitats; and stocking hatchery fish. But the young of stocked fish have low survival due largely to a paucity of nursery habitat not being reformed and maintained under current conditions. Flow recommendations for Navajo Dam releases designed to mimic the river's natural hydrograph have not been met due to water shortages, and the desired outcomes of increased channel complexity and enhanced fish habitat have not been observed. Forecasted hydrology that includes ongoing drought shows that achieving the flow targets through further dam reoperations is unlikely. Mechanical construction of early life-stage habitats is a highly recommended complement to flow management for offsetting the effects of flow reduction and habitat loss. Habitats with features that are effective and resilient under a range of flows are important in counterbalancing the effects of climate change.     

湖北省旱涝灾害的基本特征与成因分析

湖北省是我国自然灾害多发省份之一，其中旱涝灾害尤为严重，是社会经济发展的一大制约因素。首先研究了湖北省旱涝灾害的基本特征，认为按出现时段，洪涝可分为梅涝、盛夏涝、春涝和秋涝，干旱可分为伏秋干旱、春夏干旱、秋季干旱和冬季干旱，因而具有季节性；各区灾害严重程度不同，干旱可分为鄂东北干旱严重区、鄂东中部伏秋旱严重区、鄂西北春夏旱严重区和鄂西南干旱不严重区，洪涝可分为鄂东中部和江汉平原梅涝区、鄂东北和鄂东南春梅涝严重区、鄂西南夏秋涝区和鄂西北和三峡河谷少涝区，因而具有区域性；此外，还具有延续性、阶段性、周期性和连发性等特征。分析了湖北省旱涝灾害形成的主要因素，认为旱涝灾害是在天气气候因素、地貌因素、环境资源因素、抗灾能力因素、社会经济因素等自然因素和人为因素的共同作用下产生和发展的；旱涝灾害的形成，自然条件固然很重要，但形成严重灾害，则与人为因素有密切关系，这在20世纪表现得尤为明显。     

ACCEPTING THE STANDARDIZED PRECIPITATION INDEX: A CALCULATION ALGORITHM1

ABSTRACT: The Palmer Drought Severity Index (PDSI) has been calculated for about 30 years as a means of providing a single measure of meteorological drought severity. It was intended to retrospectively look at wet and dry conditions using water balance techniques. The Standardized Precipitation Index (SPI) is a probability index that was developed to give a better representation of abnormal wetness and dryness than the Palmer indices. Before the user community will accept the SPI as an alternative to the Palmer indices, a standard method must be developed for computing the index. Standardization is necessary so that all users of the index will have a common basis for both spatial and temporal comparison of index values. If different probability distributions and models are used to describe an observed series of precipitation, then different SPI values may be obtained. This article describes the effect on the SPI values computed from different probability models as well as the effects on dry event characteristics. It is concluded that the Pearson Type III distribution is the “best” universal model, and that the reliability of the SPI is sample size dependent. It is also concluded that because of data limitations, SPIs with time scales longer than 24 months may be unreliable. An internet link is provided that will allow users to access Fortran 77 source code for calculating the SPI.     

干旱指标及其在新疆阿勒泰地区干旱监测分析中的应用

干旱是限制新疆阿勒泰地区农牧业生产可持续发展最主要的自然灾害之一,研究适合该区的干旱指标,是进行有效干旱监测的基础。采用新疆阿勒泰地区7个气象站1961-2008年4-10月月平均气温、降水量资料,首先通过Thomthwaite方法计算潜在蒸发量确定K干旱指数,然后对R指数、Z指数、K指数3种干旱指标进行了分析,结果表明,在监测诊断干旱轻重程度上,K指数能较客观地反映出干旱程度,R指数和Z指数监测干旱程度较轻。在此基础上,基于K指数建立的阿勒泰地区干旱监测评价的强度指数和面积指数,对该地区近48年来干旱的变化进行了分析,表明该地区干旱灾害主要集中在春夏季节,春夏连旱几率较高,强度较大;该地区干旱灾害具有阶段性特征,近年来干旱发生的频次有增多的趋势,其中秋季干旱相对较为明显。