桥渡壅水对河道水位流场影响二维数值模拟

采用Simple算法建立了一套河道平面二维水流数学模型.针对桥渡壅水问题,提出了两项措施来进行桥墩的概化:①局部地形修正,主要通过增加桥墩所在节点的河底高程来反映桥墩对河道过水面积的压缩效果;②局部糙率修正,主要通过加糙来反映桥墩的阻水作用.通过对工程问题的计算验证其效果,选取赣江神岗山-井冈山拟建的阳明大桥长约7.5 km的河段作为计算河段.地形采用2000年实测河道地形图.计算网格采用边界层坐标系下河道拟贴体正交网格.网格节点数为73×70个,计算结果较好地反映了建桥前后桥墩附近水位流场的变化情况,说明桥墩概化较为合理.     

River regulation in Southern China: Ecological implications,conservation and environmental management

Southern China—i.e. China south of the Chang Jiang (Yangtze River)—has a monsoon climate with pronounced wet and dry seasons and consequent effects on river discharge. There is considerable inter-year variation in the duration and intensity of the monsoon, and the region experiences frequent floods and droughts which cause considerable human misery. The importance of floods as an incentive for river regulation is apparent from the fact that 10% of China's area, inhabited by 65% of the population and responsible for 70% of the agricultural and industrial output, is below the flood level of major rivers. Irrigation and hydroelectric power are additional benefits to be derived from river regulation. China has a 4000 year history of river regulation, but most of the changes that have been made to riverine environments have not taken account of the ecological consequences. This review considers the ecological implications of planned or existing schemes for the regulation of southern Chinese rivers. Particular attention is paid to the Chang Jiang and Zhujiang (Pearl River) which, by volume of discharge, are the two largest rivers in China. Large-scale water-transfer projects and the planned construction of the biggest dam in the world (the Three Gorges High Dam) on the Chang Jiang have the potential to affect fisheries stocks and endangered fish species, to alter inundation patterns in wetlands of international conservation significance and may contribute to the extinction of the endemic and highly endangered Chinese alligator (Alligator sinensis) and Chinese river dolphin (Lipotes vexillifer). In addition, deforestation and soil erosion in the Chang Jiang basin have given rise to siltation and degradation of floodplain habitats. In the Zhujiang, dam construction has caused reductions in fisheries stocks but here, as elsewhere in China, the ecologically damaging consequences of river regulation are exacerbated by overfishing and increasing pollution of rivers by sewage, pesticides and industrial wastes.     

长江镇扬河段近期河床演变趋势分析

 通过了解对镇扬河段近百年的演变过程及演变规律，采用原型观测资料分析法，分析了仪征水道、世业洲汊道、六圩弯道和畅洲汊道以及大港水道近期河床演变的特征及演变趋势，并提出了进一步治理的建议。     

河道过水能力降低的原因分析及解决措施

根据沧州市防洪排沥河道现场考查以及“96·8”洪水和2000年、2002年“引黄济津”实测资料,从几个方面分析河道过水能力明显降低的原因,提出恢复河道行洪标准的措施建议。     

汉江中下游河流生态需水量探讨

在借鉴国内外河流生态需水量研究的基础上,对汉江中下游河流生态需水量计算进行了分析,重点分析了维护汉江中下游河流生态所需要的最小水量,探讨了河流自净需水量和防止水华发生的生态需水量,并初步探讨了三峡工程和南水北调中线工程建成后对汉江中下游生态需水量的影响。     

黄河干流水体污染时空变化特征

黄河水体污染加剧黄河水资源的短缺情势。本文根据1992年～1999年监测资料对黄河干流水质级别以及溶解氧、氨氮、高锰酸盐指数和BOD。等4种典型污染物的时空变化进行评价，分析产生这些变化的原因，揭示了黄河干流多年来水体污染的时空变化规律。最后以1998年2月和8月为例，对干流各站点的水质水量进行联合评价。     

对淮河下游治理形势和任务的几点认识

洪泽湖是黄河南下夺淮的产物。新中国成立后通过兴建一系列的控制工程，使其成为真正意义上的一座巨型平原水库，并对淮河下游地区防洪安全和水资源供给产生了巨大影响。深入研究淮河与洪泽湖的关系．对促进淮河下游治理具有现实的意义。     

滦河下游灌区信息化建设的实践

滦河下游灌区为适应近些年华北地区的水资源短缺矛盾,经科学设计和规划,分步建设了灌区信息化系统.该系统分为数据采集层、执行操作层、运行管理层和指挥决策层,为灌区实现信息化管理打下了良好的基础.     

黄河下游人工扰沙措施探讨

2004年黄河调水调沙期间进行了首次人工扰沙试验,以促进河床土启动,降低河床土启动流速,实现河床以下切为主和向水流中加沙、高效率输沙入海.理论和实践证实,实验采用的利用外力松动或冲搅河床土和利用机械摄取河床土再均匀喷洒加回到河水中的两种扰沙方式,后者更有利于增加水流紊动动能和悬移质数量及其均匀分布,利于泥沙远距离输送,扰沙效果明显优于前者,且后者还具有一船多用的特点.     

洮儿河、霍林河流域湿地保护探讨

洮儿河、霍林河是松嫩平原西部嫩江相邻的两个主要支流,分布着大片的湿地、盐碱地。本着流域管理一体化的理念,通过工程措施、生物措施以及蓄滞洪区的建立,实现该流域的水资源优化配置,使流域生态环境向良性发展。