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针对我国北方地区常见的几种农业气象灾害:干旱、低温冷害、霜冻和干热风,对其各类指标进行了归纳和描述。干旱指标是从监测、防御、经济损失评估、社会经济发展水平和科技进步5个方面来分别描述;冷害指标就目前常见的几类进行了简要介绍;霜冻指标多针对不同作物给出具体判别标准;干热风指标从气象、判别、危害和防御4个方面进行了描述。总结了不同指标的优缺点,同时也对这些灾害指标目前存在的问题和今后改进的方向提出了看法,为形成北方地区农业气象灾害指标体系奠定基础,同时为今后该地区各类农业气象灾害的监测、评估及防灾减灾工作提供参考与支撑。 相似文献
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利用青岛市气象和天然径流资料,借助极端降水指数、气象和水文干旱指数,采用回归分析、相关分析和ARCGIS空间分析等方法对该市气象和水文干旱的变化特征进行分析。主要结论为:(1)青岛市无雨日数明显增多,降水量则呈减少的趋势;最大连续无雨日数(pxcdd)和平均干旱期长度(pdsav)的上升在西部地区大于东部地区,而降水量(prcptot)的下降在东部地区大于西部地区。(2)气象干旱指数SPI和水文干旱指数SSI均表明青岛市干旱呈加剧特征;SSI所反映的旱涝发生频次少于SPI,但持续时间大于SPI,尤以1个月和3个月尺度更明显。(3)干旱指数与历史旱灾面积的相关性较好,其中水文干旱指数与成灾面积的相关性更强,而气象干旱指数与受灾面积的相关性更强。此外,由于干旱的累积效应,在降水并不十分稀缺的年份,造成的局部旱情亦十分严重。 相似文献
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传统地下水动态类型的判别方法存在受人为主观因素影响大、易产生多解性等问题。为提高地下水动态成因类型判断的可靠性,本文提出了基于水文地质条件定性分析与实测数据定量分析相结合的综合判别方法。根据研究区的气象、水文及水文地质条件等,将地下水各补给项及排泄项对地下水动态的影响进行定量化,对动态数据进行相关分析及逻辑判断,辨识出对地下水位动态贡献最大的补给项和排泄项,并依此确定地下水动态的成因类型。基于该方法,以三江平原松花江流域2011年及2015年相同的57个地下水观测点为例,结合地下水位埋深、地下水位、河水位、降水量、观测井距河流的距离、包气带岩性等资料,将研究区地下水动态成因类型共划分为水文型、降水入渗型、降水入渗-蒸发型、降水入渗-径流型、降水入渗-开采型和人工开采型6种类型;对比2011年及2015年研究区地下水动态类型的变化,降水入渗型、降水入渗-径流型等天然地下水动态成因类型占比减少,而受人类活动影响的地下水动态成因类型占比增加,表明人工开采活动对地下水动态的影响日益增强。相比根据地下水动态曲线特征确定动态成因类型的传统定性分析方法,本研究提出的综合判别方法能够在充分考虑水文地质条件的基础上,结合定量化方法识别地下水位动态的驱动因素,提高地下水动态成因类型判别的科学性、可靠性以及工作效率。 相似文献
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为了提高水文与气象工作者动力统计分析及业务预报水平,加强水文与气象之间的交流与合作,促进学科间的渗透和发展,中国气象学会、中国水利学会水文气象学委员会于1988年1月5～18日在广州中山大学举行了现代若干动力统计分析预报方法讲习研讨会。会议邀请陈世训、陈家琦等11位气象、水文方面的教授、专家进行专题报告和讲座,其内容有:优化的非线性预报方法、谱分析方法及其在水文与气象中的应用;水分循环水量平衡模拟、暴雨预报模式、现代系统分析问 相似文献
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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
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K型识别表法是处理定性地质资料而设计的进行二类判别的方法。文中简要介绍了K型识别表的概念,标志分类权的计算方法,对象间海明距离的定义和对未知对象进行判别的准则。为了在该方法中也能利用连续变量的资料,介绍了连续变量离散化的信息度最大的方法。最后,用作者对该方法所设计的源程序对我国南方二十一个未知归属的花岗岩体进行计算试验,确定了六个具有远景的岩体。 相似文献
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采用贝叶斯概率水文预报理论制订水电站水库中长期径流预报模型,以概率分布的形式定量地描述水文预报的不确定度,探索概率水文预报理论及其应用价值。采用气象因子灰关联预报模型处理输入因子的不确定度,将实时气象信息和历史水文资料有效结合,突破传统确定性预报方法在信息利用和样本学习方面的局限性,以提高水文预报的精确度。以丰满水电厂水库为例对所建模型进行检验,模拟计算结果表明,该模型与确定性径流预报方法相比,不仅有利于决策人员定量考虑不确定性,而且在期望意义上提高了径流预报精度,具有较高的应用价值。 相似文献
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干旱通过相互关联的陆气系统与水文循环过程进行传播,在不同的地理时空传播演变成不同的干旱类型,如水文干旱、农业干旱、生态干旱和社会经济干旱等。在全球气候变暖和人类活动加剧的背景下,不同类型干旱之间的传播演变过程呈现出更多的不确定性。近10年来,对干旱传播时空特征、研究方法、演变过程以及驱动因素的理解逐步加深,但明确的科学观点仍相对匮乏。因此,从干旱传播的定义出发,系统分析了该问题的科学内涵,阐明了干旱传播研究的发展阶段。随后综合归纳了当前干旱传播的6类定量研究方法,包括阈值方法与游程理论、相关分析、因果分析、交叉小波、概率模型以及气象水文模型。并进一步从气象—水文和气象—农业两类干旱传播情景以及干旱传播驱动力方面,分析总结了当前形成的主要科学认识,揭示了全球范围内干旱传播研究发现的传播顺序、阶段阈值、时空异质性和人类驱动过程。最后分析指出了未来干旱传播研究面临的一系列挑战,包括进一步挖掘传播过程时空异质性、突破数学与物理知识鸿沟建立可信模型以及融入跨领域知识实现全过程的传播解析。对国内外干旱传播研究的前沿进展和挑战进行了系统分析,可为下一步干旱灾害分析与科学管理提供关键理论与方法支撑。 相似文献
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在钻井油气勘探中，识别油气异常及其属性判别是油气层评价的一项重要工作。为了进行钻井地层中油异常的识别及属性判别，需要一定的手段和方法。通过塔里木盆地北部某井钻井现场轻烃录井工作，应用轻烃分析资料识别该井的油气异常；根据＂轻烃特征成分＂、＂烃组分湿度值＂及＂轻烃流体性质特征＂等判别方法，对油气异常的属性进行判别，其结果与实际钻井地质资料相符。据钻井地质资料与轻烃分析资料综合解释结果表明，在该井所所处地区获得油气突破的关键是寻找该井所属构造的高点。 相似文献
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Drought is a common occurrence in Nebraska and agriculture is the primary economic sector affected. Because of repeated and
widespread severe drought impacts, more emphasis on drought risk management is warranted. This study develops an agricultural
drought risk assessment model using multivariate techniques. The model is specific to corn and soybeans and is able to assess
real-time agricultural drought risk associated with crop yield losses at critical phenological stages prior to and during
the growing season. The assessment results are presented in a Geographic Information System to provide a better visualization.
This model provides information in a timely manner about potential agricultural drought risks on dryland crop yield to decision
makers ranging from agricultural producers to policy makers from local to national levels. 相似文献
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Assessing Vulnerability to Agricultural Drought: A Nebraska Case Study 总被引：14，自引：6，他引：14
Recent drought events in the United States and the magnitude of drought losses indicate the continuing vulnerability of the country to drought. Until recently, drought management in many states, including Nebraska, has been largely response oriented with little or no attention to mitigation and preparedness. In 1998, Nebraska began to revise its drought plan in order to place more emphasis on mitigation. One of the main aspects of drought mitigation and planning is the assessment of who and what is vulnerable and why. This paper presents a method for spatial, Geographic Information Systems-based assessment of agricultural drought vulnerability in Nebraska. It was hypothesized that the key biophysical and social factors that define agricultural drought vulnerability were climate, soils, land use, and access to irrigation. The framework for derivation of an agricultural drought vulnerability map was created through development of a numerical weighting scheme to evaluate the drought potential of the classes within each factor. The results indicate that the most vulnerable areas to agricultural drought were non-irrigatedcropland and rangeland on sandy soils, located in areas with a very high probability of seasonal crop moisture deficiency. The identification of drought vulnerability is an essential step in addressing the issue of drought vulnerability in the state and can lead to mitigation-oriented drought management. 相似文献
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Natural Hazards - Determining the loss mechanism of drought is crucial for the prevention of and adaptation to agricultural drought. This paper proposes a theoretical framework of agricultural... 相似文献
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以鄱阳湖流域为研究区, 基于2011—2020年22个墒情站的逐日地面墒情监测数据、1956—2020年49个雨量站的日降雨数据及2016—2019年墒情站所在灌区的气象数据, 采用考虑植被生理状态的土壤水分亏缺指数(SWDI)表征农业干旱, 分析不同尺度下墒情、包气带缺水量和降水量的时空分布, 评估SWDI在鄱阳湖流域农业干旱监测中的适用性, 揭示该流域农业干旱时空演变特征及其对气象干旱的响应规律, 初步探讨土壤质地与农业干旱强度的相关性。结果表明: ① SWDI对鄱阳湖流域农业干旱诊断具有较好的适用性; ②近10 a该流域农业干旱呈显著加重趋势, 其中2019—2020年发生流域性重度农业干旱, 且夏、秋、冬连旱, 是近10 a的主导季节性农业干旱, 对水稻、油菜等粮食产量影响显著; ③相较于气象干旱, 农业干旱发生、结束时间分别平均约晚2.5周和3周, 历时长10.1周, 频次更低, 干旱等级更小; ④砂土持水性最差, 易发生特大农业干旱, 黏土、黏壤土保水性最好, 轻旱和中旱发生概率较大, 壤土、砂壤土和壤砂土则介于二者之间。 相似文献
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Drought hazard assessment using geoinformatics over parts of Chotanagpur plateau region, Jharkhand, India 总被引：4，自引：3，他引：1
Swati Pandey A. C. Pandey M. S. Nathawat Manoj Kumar N. C. Mahanti 《Natural Hazards》2012,63(2):279-303
Recurrent drought events in the Palamu district of Jharkhand state and the magnitude of drought losses primarily toward agricultural production in this dominantly monocropped region indicate the continuing susceptibility of the society to drought. This paper presents a method for spatial, geoinformatics-based assessment of agricultural, meteorological, and hydrological drought hazard in Palamu district. It was hypothesized that the key climatic, biophysical and social factors that define agricultural drought hazard were soils, geomorphology, drainage density, land use, and relief, whereas for meteorological drought hazard, it is rainfall, coefficient of variation of rainfall and for hydrological drought hazard, it is lithology, depth to water table, aquifer yield, and surface water bodies. The framework for the derivation of an agricultural, meteorological, and hydrological drought hazard map was created through the development of a numerical weighting scheme to evaluate the drought potential of the classes within each factor. A cumulative map created through spatial join of all the three types of drought provided a drought hazard scenario in totality. The area with different severity of drought hazards under cumulative drought hazards scenario (viz. very low (8.9?%), low (24.2?%), moderate (29.2?%), high (20.13), and very high (17.3?%)) revealed high drought proneness of the area and the usefulness of geoinformatics in better spatial prognosis of drought hazards. 相似文献
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Assessment on agricultural drought vulnerability in the Yellow River basin based on a fuzzy clustering iterative model 总被引：3，自引：2，他引：1
Di Wu Deng-Hua Yan Gui-Yu Yang Xiao-Gang Wang Wei-Hua Xiao Hai-Tao Zhang 《Natural Hazards》2013,67(2):919-936
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
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Durowoju Olufemi Sunday Ologunorisa Temi Emmanuel Akinbobola Ademola 《Natural Hazards》2022,111(3):2431-2458
Natural Hazards - Despite measures to mitigate drought, study on the extent of agricultural and hydrological drought vulnerability is still neglected in the savanna ecological zone of Nigeria. This... 相似文献
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Natural Hazards - Carrying out risk assessments of agricultural drought disasters is helpful to understanding agricultural drought quantitatively and scientifically guiding drought prevention and... 相似文献