河流生态修复的国际经验及对长江大保护的启示

为推进长江大保护,针对长江流域河流生态修复的需求,梳理了美国杜瓦米什河、欧洲莱茵河和德国德莱萨姆河等河流生态修复的实践做法:重视立法和标准化建设,严格制度管理,健全工作机制,强化科技支撑,鼓励全民参与等;分析了长江大保护现状与面临的挑战:政策法规和行业标准不完善,顶层设计与整体谋划不足,工作机制和监管体系不完善,修复工作难点较多且科研能力薄弱,社会力量参与长江生态修复的主体意识不强;提出了长江流域开展河流生态修复工作的建议:健全法规、完善制度、强化机制、创新技术、立体宣传。     

南方季节性缺水河流逐月保证率设定法的改进

改进计算生态基流的逐月保证率设定法以适用于南方季节性缺水河流。构建逐月保证率设定模型,综合分析各类影响设定保证率因素,构建模型评价指标体系及评价标准,耦合AHP与熵值法求解指标组合权重,运用模糊综合评价法求评价值,并通过对比Tennant法、年内展布法等耦合最终适宜生态基流过程。以秦淮河流域为例,将计算结果与传统逐月保证率设定法计算结果对比,验证了改进方法的可靠性与优越性。     

老挝南欧江梯级水电站二期厂房生活给水系统设计

水电站厂房生活给水系统应能够可靠、高效地为厂内工作人员提供满足要求的生活用水。老挝南欧江梯级水电站二期厂区附近均无可用的市政供水管,无法依靠市政供水系统为厂区提供生活用水。以老挝南欧江梯级水电站二期厂房生活给水系统设计为例,提出了针对远离城镇,无市政供水情况下,水电站厂房生活给水系统的设计思路、设计方案、设计的要点及难点。     

感潮河道桥梁和码头工程群对行洪累积影响

以宁波甬江流域感潮河段所建工程群为研究对象,基于Delft3D数学模型开展了典型洪潮条件下桥梁和码头群对河道行洪的累积影响研究,对比分析单类工程群和两类工程群对河道洪水位和流速的影响。结果表明:桥梁和码头群对河道行洪存在累积影响,位置集中在宁波大学上游的甬江、奉化江和姚江河段;在两类工程群单独作用下均存在水位(流速)增加或减小的区域,桥梁和码头群的联合作用使得水位(流速)变化幅度更大,但不是两类工程群影响幅度的简单叠加;在两类工程群单独作用下水位(流速)变化相反的区域,桥梁和码头群的联合作用下水位(流速)的变化幅度减小。     

妫水河入官厅水库水污染成因及减排措施评估

为保障妫水河入官厅水库入流水质达标,分析水质成因,分步制订水质改善措施。采用MIKE21耦合植物作用的Ecolab生态水质模型,对妫水河下游入官厅水库断面至东大桥断面、支流三里河水域进行模拟。通过对丰水期和枯水期监测数据及模拟结果进行分析,流域上游来流水量及水质、区间污染源及河流湿地等自净作用是影响官厅水库入流水质的主要原因,其中:妫水河入流污染负荷对水库入流水质贡献率最大,丰枯水期氨氮、总磷和总氮的贡献率分别为18.32%～45.76%、9.31%～31.17%和29.34%～67.56%;区间入河污染源氨氮、总磷和总氮削减率分别为19.41%、31.31%和24.94%;丰枯水期河道自净对氨氮、总磷和总氮削减率分别为44.85%～61.29%、51.40%～77.92%和8.40%～23.06%。为改善官厅水库入流水质,在流经城市区的妫水河下游及三里河修建了河流湿地公园,对区域污染源进行截污,使得入库水质可达到Ⅲ类水。为长远确保官厅水库的水质,控制来流水质和加强流域治理是关键,同时营造岸带湿地,对水质改善有积极的作用。研究结果及方法可为水库污染防治及负荷量削减提供理论依据。     

一种自适应运动目标检测算法及其应用

针对ViBe算法在动态背景下存在鬼影消除时间长、算法适应性差、前景检测噪声多的问题,本文提出一种基于ViBe算法框架的改进算法.该算法采用鬼影检测法标记第1帧中的鬼影区域,并向位于鬼影区域的背景模型中强制引入背景样本,从而快速抑制鬼影;在像素分类过程中,引入自适应分类阈值,解决全局阈值易受动态噪声干扰的问题;在背景模型更新中,根据像素分类的匹配值来动态决定更新因子,提高算法适应场景变化的能力.定性与定量的对比实验结果表明,本文算法相较于ViBe算法能够有效地检测动态背景下的运动目标,应用于河流漂浮物检测场景中也有较好的效果.     

Screening model for assessing ‘cost’ of minimum flow requirements in the Svartå River,Sweden

The minimum flow requirements in the Svartå River in Sweden are directed at maintaining fishlife and providing suitable dilution for waste flows. The implications of varying the minimum flow requirements in the river are examined using a mixed integer optimisation model. The model is formulated as a modified method-of-weights technique with the economic issues of hydro-electricity generation, irrigation and urban water supply placed in the objective function and the minimum flows specified within the constraint set. The integer component of the model is required to model the operating policy at the major flow regulation facility in the system and the restricted validity of the irrigation permits. Application of the model shows that in dry years where competition between minimum flow levels and the other economic uses, is most intense, the levels achieved by the various economic objectives are only slightly reduced even with significant increases in the minimum flow requirements. Variations in minimum flow requirements of up to 45% only produce changes of 10% or less in the economic objectives. The lack of sensitivity of the objective levels is due primarily to the level of control exerted indirectly on the whole system in dry years by the release regulation policy and the restricted validity of the irrigation permits. In normal to wet years these policies are not as restrictive and more choice is available. In such years, however, there is generally sufficient water to satisfy all requirements and allocation is not a critical issue. The model itself is formulated generally so that a range of scenarios beyond those examined specifically in the paper can be considered.     

Planning for the Subernarekha river system in eastern India

The study describes the systems studies carried out to plan a river basin in order to determine the nature and size of water storage facilities and releases for irrigation and industrial uses, and the associated cropping pattern. The model has been formulated in the framework of a linear programming model for a specific target year. This model is developed in the context of planning the Subernarekha river basin. The results are discussed and these provide information and insight suggesting the need for more disaggregated analysis of interaction between irrigation and related agroeconomic parameters.     

黄浦江上游感潮水文条件对金泽水源地原水水质影响

对黄浦江上游饮用水水源取水口太浦河金泽段在感潮水文条件下的主要水质指标差异进行统计分析,结果显示:大潮整体上利于金泽水源地取水口总氮、总磷、总有机碳、溶解氧、高锰酸盐指数的指标改善,而对浑浊度和锑无显著影响;涨落潮对水质无显著影响。     

基于水质模拟的水质在线监测站点布设研究

随着水质监测连续化的需求增加,河流水质在线监测站布设成为不可忽视的问题。本文采用水文模拟模型HSPF对台湾淡水河流域进行水量水质联合模拟。水文模拟以9个测站比对,纳什效率系数多数大于0.7;相关系数r皆大于0.7。水质模拟以27个测站比对,生化需氧量、氨氮、悬浮固体、溶氧的修正平均百分误差多数小于25%。基于水质变化率和水质超标率提出水质敏感河段概念,并以此确定为补充布设水质在线监测站点的优先河段。研究指出,淡水河流域水质在线监测站目前仍缺乏且位置不尽合理,应优先补充三峡河的三峡大桥、景美溪的宝桥、基隆河的江北桥水质在线监测站。