问与答

问什么是警戒水位、保证水位?答警戒水位:汛期江河水位达到某一高程,防洪工程已有可能出现险情时的水位。警戒水位是制定防汛方案的重要依据。当汛期洪水位达到警戒水位时,防洪工程就有可能随时发生各种险情。此时防汛部门就要密切注视水情和工情变化,进一步检查落实各项防守准备工作,有关防汛人员要迅速到达工地,做好岗     

洞庭湖地区地球化学土壤质量分区及评价

该文根据营养元素的含量，对洞庭湖地区的土壤质量进行了优、劣分区。在优势区可以少施或免施钙镁磷肥，在劣势区应少施有机肥和磷肥，多施氮、钾肥及多元素复合肥。     

基于层次分析法与Arcgis的榆阳区地质灾害易发性与危险性分区评价

在了解地质环境和灾害特征的基础上,选择影响灾害发育的三级因子,建立评价体系。依据层次分析法,确定因子权重,通过Arcgis空间分析软件对各因子分别进行指标分析和归一化处理。最后,运用栅格计算工具将各评价因子与评价权重进行叠加,按自然间距分类法,确定分区界限值。将区域的险情与易发性进行叠加计算,得出各个区域的危险性等级,最后结合地质灾害易发性分区得出危险性分区。分区结果反应出野外调查实际情况。     

伊犁河伊宁城区段防洪工程存在问题及解决对策探析

洪水灾害是影响地区经济健康发展的重要因素。新疆伊犁河伊宁城区段防洪工程存在规划系统性欠缺、已建防洪工程缺乏维护等一系列问题,使得防洪工程的防洪效果不足,不能有效发挥洪水防护价值。基于此,本次研究选择伊宁市城市规划区段防洪工程作为研究对象,深入分析该防洪工程存在的问题以及解决方案,提出应在洪水灾害常发区域加强防洪工程的规划建设,更加注重防洪工程的建设与完善,以此有效防止洪水灾害侵袭,提升城市规划区段实际防洪能力。     

杜诗记载的唐代荆湘地区寒冬及其古气候意义

中国唐代诗人杜甫(公元712—770年)的诗中,有15首记载了公元768和769年唐代荆湘地区连续2年冬季出现的寒冷气候。公元768和769年冬季,洞庭湖及以南的潭州(今湖南长沙)地区出现降雪,公元769年早春甚至出现洞庭湖局部结冰的现象。杜诗记载的冷冬及洞庭湖结冰事件,在其他史料中未曾发现,是对史料中唐代洞庭湖地区寒冷和结冰记录的补充。公元768和769年气候寒冷事件发生在8世纪中叶以后,是公元750年之后唐代气候变冷过程中的一次重要事件。     

沽源——多伦地区航空磁场特征研究

本文以区内岩矿石物性及地质资料为基础，对沽源—多伦地区航空磁场进行了分析和研究，依据磁场的分布特征及幅值大小将其划分为８个磁场分区，并对各分区磁场进行了地质解释，为在该地区应用航磁资料预测铀矿远景区提供了基础材料。     

新疆盖孜河塔什米里克渠首下游段防洪工程设计洪水分析计算

从防洪工程的实际情况出发,分析防洪工程防洪堤设计气象、水文,防洪设计,防洪堤堤基高程的确定等。通过塔什米里克防洪工程的实施,基本保证该河段及下游居民、耕地及基础设施不受洪水危害,为疏附县社会经济的可持续发展提供坚实的基础保障。     

浅谈城镇地质灾害危险性评价与防治对策 ——以甘肃省天水市麦积区三岔乡为例

甘肃省天水市麦积区三岔乡不稳定斜坡、崩塌、泥石流等地质灾害十分发育,灾情、险情严重。本文拟以甘肃省天水市麦积区三岔乡为例,研讨地质灾害在不同工况条件下的稳定状态及形成机制,确定地质灾害的发生概率,评价地质灾害危险性,并预测地质灾害威胁范围。结合地质灾害易发程度分区评价,进行地质灾害危险性分区评价、工程建设适宜区划分,并提出科学有效的地质灾害防治对策。     

和静县乌浪巴依沟防洪工程洪水分析

和静县乌浪巴依沟位于新疆巴音郭楞蒙古自治州和静县,是和静县城较大的山洪沟。根据乌浪巴依沟3处拟建防洪工程,将乌浪巴依沟分成3个计算节点进行洪水分析。通过分析乌浪巴依沟概况、防洪工程存在问题和洪水的成因、类型以及特征,采用洪峰流量模比系数地区综合频率曲线法对4条沟的洪水和3处工程点不同频率的设计洪峰流量,以及河床演变进行探讨,为乌浪巴依沟防洪工程建设设计提供参考。     

论三峡工程对洞庭湖区土壤潜育化和沼泽化的影响

三峡工程完工后，在坝下长江水位抬高的季节里，顶托洞庭湖的排泄，使东、西洞庭湖地段地表、地下水位相应抬高，对这些地区土壤的潜育化和沼泽化有明显影响，农业部门应引起重视。     

Early warning system using tilt sensors in Chibo,Kalimpong, Darjeeling Himalayas,India

The National Flash Flood Prevention Project, which mainly consists of non-structural and supplementary structural measures, has been conducted for 6 years in China. Some preliminary achievements have contributed to the prevention of flash flood in China. Based on the latest information, this article introduces China’s flash flood prevention system, primarily from the perspective of its development process, components, investment, and characteristics. To date, the system has incorporated many distinguished large-scale features such as the largest rain gauge network (approximately 0.5 million stations) in the world, massive disaster observation and preparedness networks, people-and-expert combined monitoring and forecasting data integration system, and a vast implementation area. Based on its early achievements and some typical case investigations of such flash flood prevention system, the article also discusses China’s prospects for preventing flash flood disasters in the future.     

渭河中游洪水影响因素分析

近几年来渭河中游多次发生较大洪水,给渭河防汛带来了巨大影响.其洪水来源有渭河上游、中游的北岸和秦岭北麓,受多种因素影响,每种影响因素产生的作用方式和产生的结果不同.本文认真分析了雨水情特点,找出了渭河中游洪水主要影响因素,对如何提高洪水预报的精度提出了建议.     

Linking past flood frequencies in Norway to regional atmospheric circulation anomalies

Analysis of two continuous, high‐resolution palaeo‐flood records from southern Norway reveals that the frequency of extreme flood events has changed significantly during the Holocene. During the early and middle Holocene, flood frequency was low; by contrast, it was high over the last 2300 years when the mean flood frequency was about 2.5–3.0 per century. The present regional discharge regime is dominated by spring/summer snowmelt, and our results indicate that the changing flood frequency cannot be explained by local conditions associated with the respective catchments of the two lakes, but rather long‐term variations of solid winter precipitation and related snowmelt. Applying available instrumental winter precipitation data and associated sea‐level pressure re‐analysis data as a modern analogue, we document that atmospheric circulation anomalies, significantly different from the North Atlantic Oscillation (NAO), have some potential in explaining the variability of the two different palaeo‐flood records. Centennial‐scale patterns in shifting flood frequency might be indicative of shifts in atmospheric circulation and shed light on palaeo‐pressure variations in the North Atlantic region, in areas not influenced by the NAO. Major shifts are found at about 2300, 1200 and 200 years ago (cal. a BP). Copyright © 2011 John Wiley & Sons, Ltd.     

七大流域设计洪水修订成果分析

在全国各大流域防洪规划和综合规划设计洪水成果的基础上,整理设计洪水相关资料,延长洪水系列,进行还原计算和频率适线分析。经过数年工作,完成了七大流域设计洪水成果的修订和审查工作。设计洪水修订的项目主要包括设计洪峰和不同时段的洪量,修订后的设计洪水成果代表性更好。介绍了七大流域设计洪水修订成果及变化情况,并对不同流域影响设计洪水成果的因素进行了分析,通过与原审批成果的对比分析,推荐了设计洪水成果修订的采用成果,以此作为各站点修订后的成果以及以后工程设计的依据。     

Contribution de l'hydrogéomorphologie à l'évaluation du risque d'inondation : le cas du Midi méditerranéen français

The hydrogeomorphological method for delimiting flood risk zones in France was developed some twenty years ago. It is based on a simple principle: the outer limits of a stream's flood plain constitute the outer envelope of past floods. These limits are determined with the use of aerial photographs and field surveys of micro-topography as well as analyses of deposit granulometry and colour. Indications of present or past land use (fields, location and distribution of archaeological sites, houses and farm buildings, roads) are also useful. This field-based method long remained ignored, but being reliable, easy to use and inexpensive, it has now been incorporated into the package of methods recommended by French risk-prevention plans (PPRI). The many recent catastrophes that have occurred over the past fifteen years in the Mediterranean regions of southern France demonstrated both the inadequacy of the hydrological–hydraulic method and the reliability of the hydrogeomorphological method, which can, however, be improved by setting observations for the present period against information on the more ancient Holocene evolution of flood plains. To cite this article: J.-L. Ballais et al., C. R. Geoscience 337 (2005).     

Influence of hydrate exploitation on stability of submarine slopes

Urban pluvial flash floods have become a matter of widespread concern, as they severely impact people’s lives in urban areas. Hydrological and hydraulic models have been widely used for urban flood management and urban planning. Traditionally, to reduce the complexity of urban flood modelling and simulations, simplification or generalization methods have been used; for example, some models focus on the simulation of overland water flow, and some models focus on the simulation of the water flow in sewer systems. However, the water flow of urban floods includes both overland flow and sewer system flow. The overland flow processes are impacted by many different geographical features in what is an extremely spatially heterogeneous environment. Therefore, this article is based on two widely used models (SWMM and ANUGA) that are coupled to develop a bi-directional method of simulating water flow processes in urban areas. The open source overland flow model uses the unstructured triangular as the spatial discretization scheme. The unstructured triangular-based hydraulic model can be better used to capture the spatial heterogeneity of the urban surfaces. So, the unstructured triangular-based model is an essential condition for heterogeneous feature-based urban flood simulation. The experiments indicate that the proposed coupled model in this article can accurately depict surface waterlogged areas and that the heterogeneous feature-based urban flood model can be used to determine different types of urban flow processes.

     

长江中、下游特大暴雨洪水的成功预报和科学依据

进入 2 0世纪 90年代以来 ,中国七大江河流域旱涝频繁 ,旱涝灾害和由旱涝引起的次生地质灾害十分严重 ,特别是长江中、下游地区的洪涝几率高达 5 0 % (5 /10 )。 195 1— 2 0 0 0年长江中、下游地区发生了 9个大水年 ,几率为 18% (9/5 0 ) ,90年代洪涝的频繁程度属 2 0世纪之最 ,1998年特大暴雨洪水的时空集中强度也属 2 0世纪之最。长江的大暴雨洪水在近 10a来很频繁 ,但从气候分布几率来看 ,它毕竟是小概率事件 ,对小概率事件的长期预报具有很大的难度 ,而且暴雨洪水的长期影响因子也错综复杂 ,这就给预报带来了艰巨性。通过对降水的各种影响因子的分析研究和多因子集成预报模型的研制 ,对 1998年长江流域的特大暴雨洪水从时间、地区和量级三要素的长、中期预报都取得了成功 ,对其他 5个洪涝年也从趋势和分级两方面做出了成功的长期预报。文中重点剖析了预报取得成功的科学依据。     

温德河流域“2010·07”暴雨洪水分析

2010年7月27～28日,第二松花江支流温德河流域普降特大暴雨,致使温德河干流发生了350年一遇超历史纪录的特大洪水。依据实测资料和暴雨洪水调查成果,分析了此次暴雨洪水的特性,以及水利工程在抵御洪水中的作用,并与历史最大暴雨、最大洪水进行了对比分析,为该流域暴雨洪水灾害及防治对策研究积累了经验。     

Impact of climate change on extreme rainfall events and flood risk in India

The occurrence of exceptionally heavy rainfall events and associated flash floods in many areas during recent years motivate us to study long-term changes in extreme rainfall over India. The analysis of the frequency of rainy days, rain days and heavy rainfall days as well as one-day extreme rainfall and return period has been carried out in this study to observe the impact of climate change on extreme rainfall events and flood risk in India. The frequency of heavy rainfall events are decreasing in major parts of central and north India while they are increasing in peninsular, east and north east India. The study tries to bring out some of the interesting findings which are very useful for hydrological planning and disaster managements. Extreme rainfall and flood risk are increasing significantly in the country except some parts of central India.     

1849年长江中下游大水灾的时空分布及天气气候特征

清道光二十九年（1849年）长江中下游地区的大水灾,对民生造成了严重的影响。作者系统收集了档案、方志、日记和文集资料中关于该年份水灾的记载,以县级成灾分数资料为基础,重建了此次水灾的时空分布,并分析了形成这次水灾的天气气候特征。研究认为,该年度水灾基本在N28°～N33°间呈条状东西向分布,而以N31°一线的灾情最为严重;连续性的降水开始于5月18日左右,到7月18日才结束,中间还有3次持续各达10余天的强降雨过程;这次大水灾是全流域性的,涝灾大于洪灾,降水最集中区域为东部的太湖流域,这和有器测记录的几次长江全流域大洪水并不一致;本次大水灾的直接天气成因是梅雨期提前并超长,雨量明显偏大,持续时间长达62天左右,比有器测记录的更早、更长;当年夏季风应偏弱,副热带高压脊线位置异常偏南,且西风分支明显,经向环流发展,西风南支位置应该也异常偏南;夏季冷空气异常活跃可能是雨带长期在长江沿岸徘徊的真正原因。