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谌柯 《水资源与水工程学报》2007,18(1):19-23
世界城市的发展已构成了对湿地的严重威胁,处于内陆地区的四川省南充市滨江湿地在城市化进程中已经损失60%以上。本文通过清查滨江湿地面积、湿地资源,分析当前湿地存在的主要问题,探讨在保护和利用嘉陵江水资源的同时,加强污染控制工程的建设,恢复和重建滨江湿地,构建“嘉陵江湿地保护小区”及建设人工湿地系统的“活水公园”。 相似文献
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基于LandsatMSS／TM／ETM＋、HJ-1A等多源多期卫星遥感数据,采用归一化水指数（NDWI）模型、监督分类结合人机交互式解译的方式,对呼伦湖湿地1975—2011年的湿地面积变化特征进行了动态监测,并从自然和社会经济两个方面进行了驱动力分析。结果表明：呼伦湖湿地近36年来呈现出萎缩和退化的趋势。该区域水体面积较1975年减少了22．7％,非水体湿地面积较1975年减少了25．9％,自然因素是造成呼伦湖湿地面积减少的最主要原因,社会经济因素也在一定程度上加速了呼伦湖湿地的退化。 相似文献
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There is growing concern in the United States over the ‘residual’ flood risk behind leveed floodplains, which is commonly assessed based on one‐dimensional (1D) river flow models. These models fail to capture the complex flow dynamics that typically characterise floodplain inundation. Here, we demonstrate methodologies for mechanistically simulating a levee breach and flow into a levee district along the Middle Mississippi River using a hybrid 1D/two‐dimensional (1D2D) flow model that combines a 1D model of the river channel with a two‐dimensional (2D) overland‐flow model for the leveed floodplain. This 2D modelling documents the complexity of flow over a large and topographically diverse leveed floodplain, including distribution and timing of inundation as well as the resulting public‐safety threats. In relation to safety threats, three distinct flood phases can be recognised: (1) a flash flood phase, (2) a flow redistribution phase and (3) an equilibrium phase. The flash flood phase presents imminent threats to human life and safety, whereas subsequent phases determine inundation areas and depths, and therefore infrastructure damages. 2D modelling of levee‐breach flooding provides input data necessary for: (1) specific local evacuation and mitigation planning in the Metro East area, and (2) methodologies for analyses of residual risk facing other levee‐protected floodplain areas. 相似文献
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湿地是地球生态系统中的重要组成部分,具有巨大的经济、社会和环境价值,在抵御洪水、调节径流、蓄洪防旱、降解污染、调节气候等方面 有着其他生态系统不可替代的作用,是河流健康不可或缺的指标因子。根据长江流域湿地状况的调查和湿地分布特征对长江流域湿地进行分区,并对各个分区的湿地现状进行评价,对健康长江湿地保留率的涵义进行了探讨,初步分析了长江湿地的现状以及湿地保留率健康评价的分级方法。 相似文献
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In large river ecosystems, the timing, extent, duration and frequency of floodplain inundation greatly affect the quality of fish and wildlife habitat and the supply of important ecosystem goods and services. Seasonal high flows provide connectivity from the river to the floodplain, and seasonal inundation of the floodplain governs ecosystem structure and function. River regulation and other forms of hydrologic alteration have altered the connectivity of many rivers with their adjacent floodplain – impacting the function of wetlands on the floodplain and in turn, impacting the mainstem river function. Conservation and management of remaining floodplain resources can be improved through a better understanding of the spatial extent and frequency of inundation at scales that are relevant to the species and/or ecological processes of interest. Spatial data products describing dynamic aspects floodplain inundation are, however, not widely available. This study used Landsat imagery to generate multiple observations of inundation extent under varying hydrologic conditions to estimate inundation frequency. Inundation extent was estimated for 50 Landsat scenes and 1334 total images within the Gulf Coastal Plains and Ozarks Landscape Conservation Cooperative (GCPO LCC), a conservation science partnership working in a 730 000‐km2 region in the south central USA. These data were composited into a landscape mosaic to depict relative inundation frequency over the entire GCPO LCC. An analytical methodology is presented for linking the observed inundation extent and frequency with long‐term gage measurements so that the outcomes may be useful in defining meaningful critical thresholds for a variety of floodplain dependent organisms as well as important ecological processes. Published 2015. This article is a U.S. Government work and is in the public domain in the USA 相似文献
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黄河河口生态需水研究进展与展望 总被引：1，自引：0，他引：1
黄河河口生态需水包括河流生态需水、湿地生态需水和近海生态需水。系统梳理了近20年来黄河河口生态需水目标、需水类别和需水量计算结果;结合黄河河口演变特点,提出生态需水研究的重点和主要方向。河流生态需水以满足重要渔业物种生境为主,重点研究指示物种对天然径流量节律的响应特征,量化水文-生态响应关系,在某种程度上恢复自然水文情势的生态功能。湿地生态需水应深入研究植被、土壤、水体的水盐平衡和蒸散发规律,从植被和鸟类生态位的合理设计以及生物多样性维持出发构建生态系统结构,确定湿地合理规模。近海生态需水应研究入海冲淡水对渔业物种低盐产卵育幼场的塑造和维持机制,以及重要渔业物种习性、适宜营养盐水平与磷酸盐输送扩散机制。小浪底水库运用以来,利津断面径流量满足已有生态需水径流量各项研究成果要求的年份比例为37%～58%,春季经流过程经常缺乏流量脉冲。初步分析以湿地、河道鱼类和近海鱼类为主要目标的全年生态需水量为86亿m3,径流过程需要阶段性场次洪水。建议对小浪底水库调度方案进行多年优化调整,兼顾春季流量脉冲的塑造,在更大程度上满足河口生态需求。 相似文献
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新疆塔里木河湿地是我国最长的内陆河流湿地，是多种鸟类栖息与多种候鸟迁徙中转、繁殖的重要区域。对塔里木河湿地的基本特征、生态功能、近代变化和其保护与建设的现实意义进行了研究，指出应该重视科学研究，拯救珍稀濒危物种，并提出了相应对策。 相似文献
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采用复合型人工湿地模型对支漳河流域滏阳河中城市污水进行处理,对水中pH值、浊度、CODmn、TN、TP、NH+4-N、NO-3-N、NO-2-N等水质指标进行了检测,实验表明,该人工湿地模型稳定运行后净化效果良好,湿地对浊度、CODmn、TN、TP、NO-3-N、NO-2-N的平均去除率达到91%、50%、36%、91%、35%和89%。出水水质均可达到GB 18918—2002的二级排放标准,有的可达到一级A排放标准。该模型可以在岳城水库水源地水生态环境综合治理中采用,应用中建议给模型安装曝气充氧装置,以降低基质中胞外聚合物累积而造成的堵塞作用。 相似文献
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人工湿地对滏阳河河水净化的试验研究 总被引：1，自引：0，他引：1
为了研究表面流人工湿地系统中不同植物对滏阳河受污染水体的净化作用,以表面流人工湿地系统为研究对象,分析研究系统中各植物对受污染滏阳河河水的处理效果。结果表明:湿地对亚硝酸盐氮、硝酸盐氮、TN、TP、CODMn、凯氏氮的平均去除率分别达到37.1%、26.3%、45.39%、57.8%、64.7%、43.9%,对受污染河水的净化效果显著。出水均达到GB 18918—2002Ⅲ类水排放标准,部分指标已达到一级A类标准。该成果可以应用到永年洼高效净污人工湿地系统示范工程中。通过分析发现部分指标的去除率较低,如硝酸盐氮的平均去除率仅为26.3%,故建议修建湿地系统示范性工程时使水流以S型向前推流,以增加水力停留时间,为各污染因子的吸收提供足够的反应时间,进而提高这些指标的去除率。 相似文献
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Akanksha Bhardwaj Gh Nabi Najar Puneeta Pandey 《Lakes & Reservoirs: Research and Management》2017,22(4):349-363
The Harike Wetland situated in Punjab is a Ramsar site and a wetland of national importance. The present study was undertaken to assess the spatiotemporal dynamics of the wetland on the basis of geospatial technology and ground‐based studies. Landsat images for the years 2002 and 2014 were acquired from the United States Geological Survey and classified digitally to generate landuse/land cover maps involving four classes (water, grassland (including water hyacinth), agriculture, built‐up (settlement), barren land). The total area of the Harike Wetland was found to be 8023.68 ha. Water sampling at eleven sites was carried out and evaluated for physicochemical parameters. The water quality at several sampling points was found to be severely degraded. Change detection analysis revealed the submerged area (area under water) and grassland (including water hyacinth) had decreased over the past 12 years, whereas that area under agriculture and built‐up land has increased, indicating a shrinkage in the total wetland area. The present study also indicated that the near‐infrared band is a good indicator of water quality parameters, as indicated by the significant positive correlation between the near‐infrared band and relevant water parameters. Because the wetland is important from both an ecological perspective and economic perspective, regular monitoring is recommended, for which geospatial technology has proven to be very useful. 相似文献
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基于LandsatTM/ETM+、CBERS-02B CCD遥感影像数据,运用RS和GIS技术对二滩库区1995年以来的土地利用/覆盖进行分类研究,对二滩库区13年来的土地利用/覆盖变化情况及驱动力进行了分析。结果表明:1995~2008年间,二滩库区耕地面积明显减少,林地、草地和水域面积明显增加,建设用地面积变化不大;其中林地和草地面积的增加与1998年、1999年两大林业生态工程——天然林资源保护工程、退耕还林(草)工程的相继实施以及二滩水库蓄水后对库区局地气候的调节作用有关。 相似文献
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洪水风险管理需要将工程和非工程措施结合起来,编制洪水风险图是非工程措施中降低洪水风险的重要手段之一.我国洪水风险图编制已经进入全国试点阶段,但至今还没有建立一套指导和规范洪水风险图编制的技术标准.本文结合我国的国情和流域特征,对我国洪水风险图编制中的基础资料、洪水泛滥模拟模型、洪灾损失评价模型以及风险图的表现内容等基本技术和方法的标准化进行了探讨,并提出了我国洪水风险图编制技术标准化和规范化过程中急需解决的问题. 相似文献
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A remotely operated underwater vehicle (ROV) is a tethered underwater mobile device that can conduct a bathymetric survey cost-efficiently. Assessment of the utility of ROV-based bathymetric surveys in flood inundation mapping remains limited. This study aims to examine the utility of ROV-based bathymetric surveys in high-resolution flood inundation mapping for a hypothetical case study of the Lake Tuscaloosa Dam breach in the state of Alabama, USA. This study conducted the sensitivity test of flood inundation mapping to the river channel depth (ROV-based vs. digital elevation model [DEM]-based) and initial flow condition (e.g., wet vs. dry), via six different simulations of the parallelized diffusion hydrodynamic model (pDHM). This study found that the ROV-based pDHM runs had higher maximum water depths over the flood-inundated areas, ranging from +73% to +166% of the simulated depths of the DEM-based pDHM runs. However, the impact of initial streamflow condition on the maximum depths was limited. This study also found that the pDHM runs with a dry initial flow condition delayed the time to reach the maximum depth after the dam breach by 2 h relative to the pDHM runs with a wet initial streamflow condition. This study suggests that ROV-based bathymetry surveys improve flood inundation mapping by emphasizing the influence of river channel depth, initial streamflow conditions, and bathymetry, thereby bolstering community resilience to a potential human-made hazard such as dam failure. 相似文献
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应用ERDAS遥感影像解译软件,在ArcGIS软件支持下建立了豫东黄河故道湿地景观要素数据库,采用景观多样性指数、斑块特征指数和分离度等指标,分析了豫东黄河故道湿地的景观格局多样性变化规律,以及影响其格局变化的驱动力。结果表明:从各景观多样性指数的变化看,丰富度、景观最大多样性指数和景观优势度均为低洼湿地带最大,说明该地带景观类型多样化;从斑块变化特征看,由低洼带到背脊带,斑块边界趋向复杂化,性状呈现不规则变化,且斑块面积有效性逐渐减弱,不利于物种保护和湿地生态价值、生态功能的提升。豫东黄河故道湿地演化的过程中,受到自然和人为两方面演化驱动力的共同作用,其中自然因素有黄河断流、促淤造陆和湿地自身演替变化等,人为驱动力主要有农田开垦、滩涂开发及人工建筑等。 相似文献
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《Journal of Flood Risk Management》2018,11(Z1):S98-S109
The trend of using volunteered and collaborative data in the context of natural disasters has been increasing. This fact, together with floods and inundations, which occur in the city of Sao Paulo, makes it possible to explore the volunteered and collaborative way of generating and transmitting geographic data dynamically. This can be done by using technologies affordable to the population, such as the Internet, the global positioning system and other monitoring systems embedded in mobiles. This article aims to present the proposal of a conceptual scheme for a dynamic and collaborative mapping system of flooding points, whose data source comes from people equipped with mobile devices that allow identify their locations. The results correspond to the conceptual scheme of the system as well as the prototype ‘Flooding Points’ – a map available on the web showing the flooding points in the city, which were provided at the time of the event by ordinary people. The prototype was developed by using the free and open source Crowdmap/Ushahidi platform. The system was assessed by a questionnaire answered by the users, who gave their opinion about its feasibility, as well as the adjustments which must be made for the population's effective use. It was found that the application of system for subjects of inundation and flooding is complex in relation for other types of events due to its temporal dynamics characteristics. The results of the questionnaire, applied to evaluate the system, demonstrated the public utility of the application and the interest of the population for a dynamic system that enables the exchange of information on the problem of inundation and flooding in near real time in the city of Sao Paulo. 相似文献
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Flood management activities require development of flood maps that depict the spatial and temporal extent of floods with the help of hydrodynamic models. Two-dimensional (2-D) hydrodynamic models are frequently employed for flood inundation modeling and mapping with the help of high-end computational resources and high-resolution terrain information such as LiDAR (light detection and ranging) data. However, LiDAR data are either unavailable or not freely accessible in many parts of the world, especially in nations belonging to Global South. Hence, one-dimensional (1-D) models are still in practice owing to their lesser computational cost and data requirement. Nonetheless, the successful application of a 1-D model depends mainly on the representation of the natural river and floodplain geometry, which is the primary input in the form of discrete cross-sections. The assumed flow directions on floodplains while orienting the cross-sections in 1-D models induce some uncertainty in the model simulations. This study aims to evaluate the variability in the model simulations caused by the cross-sectional orientations. Flood simulations were performed using a 1-D hydrodynamic model for six different cross-sectional realizations for three river reaches, having distinct morphological and topographical characteristics, and were compared with the simulations of a 2-D hydrodynamic model and available reference inundation maps. The study suggests that the simulations of flood inundation extent and maximum flow depth variation are influenced by the cross-sectional orientation on flood plains in river reaches characterized by broad flood plains with complex local topographical variations. In contrast, for reaches with relatively less wide and complex terrains, 1-D models can generate robust simulations of flood inundation extent and spatial variation in maximum flood depth (R2 and NSE greater than 0.89) for high flood events. 相似文献
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河流生命危机与河流伦理构建 总被引：4，自引：1，他引：4
从哲学的观点看,河流具有生命.人类与河流关系的发展经历了原始文明、农耕文明、工业文明、生态文明四个时期.在当前河流生命危机时期,需要构建河流伦理观.河流作为道德主体,具有完整性权利、连续性权利、清洁性权利、用水权利、造物权利.人类对河流的道德义务应通过尊重性、整体性、保护性、评价性、补偿性等原则来实现.河流立法有助于促进人们河流伦理水平的提高.构建河流伦理是"维持黄河健康生命"治河新理念的组成部分,其创新意义在于扩大了道德共同体的边界,改变了人在自然中的地位,确定了新的价值尺度. 相似文献