对洪水分级的浅见

洪水的等级划分应考虑流量、水位、防洪能力及灾害等因素,综合这些因素把洪水分成5个等级。1、2级洪水,洪水流量小,水位低,基本无灾;3级洪水,洪水流量较大或水位较高,有一定灾害;4级洪水,为大洪水或高水位,有较大灾害;5级洪水,为特大洪水或高水位,灾情严重。     

Coupling GIS with Hydrologic and Hydraulic Flood Modelling

Geographic Information Systems (GIS) have been recognised as a powerful means to integrate and analyse data from various sources in the context of comprehensive floodplain management. As part of this comprehensive approach to floodplain management, it is very important to be able to predict the consequences of different scenarios in terms of flooded areas and associated risk. Hydrologic and hydraulic modelling plays a crucial role and there is much to gain in incorporating these modelling capabilities in GIS. This is still a rather complex task and research is being done on the full integration of these models. Interfacing between these models and GIS may be a very efficient way of overcoming the difficulties and getting very good results in terms of engineering practice. This paper presents results based on the use of Intergraph GIS coupled with Idrisi GIS. Using these two systems substantially increased the flexibility of using GIS as a tool for flood studies. A lumped (XSRAIN) and a distributed (OMEGA) hydrologic models were used to simulate flood hydrographs. The well known HEC-2 Hydraulic model was used to compute flooded areas. These models were applied in the Livramento catchment with very good results. The computation of flooded areas for different flood scenarios, and its representation in GIS, can be used in the assessment of affected property and associated damages. This is a very useful GIS-based approach to floodplain management.     

鄱阳湖流域水土保持与防洪治涝

鄱阳湖流域水土流失加剧了洪涝灾害。治理水土流失能增强山丘地涵养水源的能力,削洪减沙,减少库容损失,降低河床,具有明显的防洪效益。进行流域防洪规划时,应将防治水土流失与防洪治涝结合起来,因地制宣,综合治理。     

黄河中游多沙粗沙区水沙控制途径的探讨

根据黄河中游多沙粗区暴雨洪水及产流产沙特点，提出了为控制水沙危害，黄河中游治理应分两步走的战略。第一步解决近期水沙控制和耕地问题，主要措施是建设淤地坝和骨干坝。研究表明，在现状坝地，梯田条件下，为满足粮食生产需要，每平方公里需新增坝地３．１８ｈａ，且能港口控制水沙的要求。第二步是进行坡面治理，改善生态环境，以达到根治水沙的目的。     

Flood hazard maps in the European context

The implementation of the EU Floods Directive by water authorities across Europe has generated a lack of consistency in the present situation, especially regarding the scales adopted, the hydrological scenarios and the elements represented on flood hazard and risk maps. From the EU-funded project HYTECH, this article presents a general overview of Floods Directive implementation in eight European countries, highlighting the differences between them, with particular attention to flood hazard maps. For the implementation cycle that started at the beginning of 2016, a minimization of such differences is necessary in order to manage flood risk in a better and more integrated way.     

A customised approach to determining the geomorphic effectiveness of small flood events in a regulated river

The construction of dams significantly alters flow and sediment regimes with subsequent deleterious effects on the morphological and ecological character of rivers. Effective experimental floods can ameliorate the downstream geomorphic impacts of dams. The traditional view is that large floods are required to perform effective geomorphic work, and the geomorphic outcomes of small floods are often overlooked. Many river restoration frameworks do not consider small floods. Yet, there is evidence that the hydrological characteristics that ameliorate specific geomorphic impacts in a river are unique to each river, and a customised approach to setting the right mix of floods (including small experimental floods) is needed. In this study, we modify an existing flood effectiveness model developed for large floods, for determining the geomorphic effectiveness of small floods in a highly regulated Australian river. Two flood classes were added to the model (medium peak stream power and moderate total energy expenditure), and the flood power characteristics were rescaled to reflect the relative difference in the magnitude of the small floods and the magnitude of the geomorphic work performed. Using a step‐wise approach, this customised model determined the geomorphic effectiveness of small floods. The best flood for ameliorating the geomorphic impacts of flow regulation had medium to long duration (10 to 51 days), high peak unit stream power (77 to 123 Wm^?2) and moderate to large total energy expenditure (78,600 to 342,320 × 10³ J). This approach to determining flood effectiveness for small floods is applicable to other geomorphically impacted river channels downstream of dams and can be used to inform experimental flood releases for geomorphic outcomes.     

长江中游根治洪灾策略与措施的探讨

长江中游是长江自然—经济—社会复合生态系统的重要组成部分,当前洪涝灾害频繁而严重。按照长江洪水发生的自然规律调整好人与自然的关系,改变长期以来舍南保北、以堵为主、重蓄轻泄的做法,实施疏泄为主的防洪策略,并采取相应的工程和非工程措施(如下荆江裁弯、开辟分流洪道、四口建闸、洞庭湖水系南北分流、疏浚河道、南水北调及平垸行洪等),同时配合进行水源生态工程及江河库湖调蓄工程建设,才能根治长江中游洪涝灾害。     

桃汛试验对万家寨水库冲淤影响分析

通过对桃汛试验前后两个时段对比分析,认为桃汛试验没有增加万家寨库区淤积;库区淤积形态有所调整,淤积三角洲向坝前推进,库尾段平均河底高程没有抬升.     

2010年长江流域暴雨洪水初步分析

分析2010年长江流域暴雨洪水,有利于更全面认识长江流域暴雨洪水特性,可为今后更好开展长江流域防汛水情保障工程。从主汛期长江流域暴雨及气候特征、干支流主要洪水过程及洪水特性等方面,进行了初步的总结和分析。2010年长江主汛期洪水发生范围广、持续时间长且局部地区洪水量级大,通过与三峡水库蓄水前后几次大的历史洪水分析对比,初步认为,2010年长江流域主汛期出现的洪水为长江上中游区域性较大洪水。     

基于用“动态汛限水位”来利用雨洪资源

雨洪资源的依法利用,早已在国外广泛展开。国内的雨洪资源利用,还面临着重新计算汛限水位高度,然后再依法予以重新确认的难题。唯有如此,才能缓解各级行政部门为了多产粮而＂压＂水库管理部门不顾风险的超汛限蓄水。因此,现阶段用＂动态汛限水位＂来化解矛盾,使水库管理部门从被迫接受潜规则的超汛限蓄水,转变为可以摆上台面的依法科学合理...