Lake Corangamite, Australia, a permanent saline lake: Conservation and management issues

Lake Corangamite in western Victoria, Australia, is the largest permanent lake on the Australian mainland. Its levels and salinities fluctuated naturally until recently. Since about 1960, its major inflow creek has been diverted for management purposes and lake levels have fallen and salinities risen. The changes have been most profound since 1980. Since 1980, salinity has risen from ～35g/L to >50g/L, water levels have fallen by nearly 2m, and many islands have become peninsulas or have disappeared. The major effect has been a change in the composition of the biota from one that is characteristic of lakes in the region of moderate salinity (>35g/L) to one that is characteristic of more saline lakes (50-100 g/L). In particular, Austrochiltonia subtenuis (Amphipoda), Coxiella (Gastropoda), Galaxias maculatus (Pisces) and Ruppia (macrophyte) have almost disappeared. The loss of these species has greatly decreased the value of the lake to the avifauna in particular and as a natural resource in general. The changes to Lake Corangamite resulted largely from the diversion of the inflowing waters from the Woady Yaloak Creek, the major influent stream, into the Barwon River. The diversion scheme, undertaken by the Rural Water Commission of Victoria, was implemented mainly to minimize the possibility of flooding of land adjacent to the lake. The environmental consequences of such diversion were not fully considered. The paper documents the physico-chemical and biological changes that occurred up to 1992, and discusses issues of conservation and management interest associated with the changes. Changes in the level of Lake Corangamite and associated limnological features accord with the pattern observed in many salt lakes worldwide.     

东江—深圳供水三期扩建工程东江抽水站引水口防淤工程措施研究

东深供水三期扩建工程，是为了增加向香港和深圳市提供工业和生活用水的重要工程。本文对第一梯级抽水站即东江抽水站的水文泥沙特性、河床演变、引水口位置的选择．引水口布置型式和防淤工程措施，做了系统地分析研究和模型试验。工程建成后，试验研究成果与工程实际吻合，取得了巨大的经济效益。     

黄土高原主要造林树种应为灌木

纵观黄土高原３０多年来造林工作中存在的问题，主要是造林成活率低、保存率低、生长差。造成这种问题的原因固然很多，但主要原因是造林树种选择不当。对灌木在森林演替中的地位、灌木适应严酷自然条件的林学特性、灌木具有的经济价值和开发前景及灌木林的水土保持效益等方面进行研究的结果表明，在干旱瘠薄的黄土高原，选择以灌木为主，营造灌、草、乔相结合的水土保持林，对加快绿化荒山荒沟速度，保持水土，减少入黄泥沙具有重大     

直立摇板简谐摇荡造二维波时所受水动力矩的频域二阶解和时域线性解

本文给出直立摇板简谐摇荡造二维波时所受水动力矩的频域二阶解和时域线性解的解析表达式,可供估算摇板式造波机设计功率时使用,也可为摇板所受水动力矩时域非线性数值计算提供比较的依据。     

长江流域水能资源开发的新举措：从三峡建设到金沙江开发

中国水资源十分丰富，但目前仅开发13％～14％。国家已明确了梯级滚动开发的方针。进一步开发长江流域，以此作为中国东、中、西部相互促进、协调发展的一个重要措施。同时明确中国三峡总公司为金沙江浪洛渡和向家坝两水电站的业主单位。长江上游金沙江段是可开发水能资源最集中的地区，总装机容量接近5000万kw，是“西电东送”北、中、南三条线中，中线的主要基地。争取在“十五”计划期间，溪洛渡和向家坝两电站其中有一个开工建设。     

SBR型防水剂性能的研究

本文分别研究了添加ＳＢＲ型防水剂的砂浆及混凝土的强度、抗渗性和孔结构等性能，发现ＳＢＲ型防水剂不仅能显著提高砂浆、混凝土的抗渗性，提高其抗压强度，还能改善孔结构，从而可在不改变原材料和生产工艺条件下，配制出防水补强砂浆和抗渗防水混凝土，并对防水剂作用机理作初步的探讨。     

高水头弧形闸门伸缩式水封切片试验研究

试验表明：橡胶材质水封在一定背上可封间隙１５ｍｍ、水头１２０ｍ的漏水，其封水背压与间隙大小、压板型式、水封形式、水封材质有关，其中Ⅱ２型００５橡胶水封采用（２）型压板时封水背压最小。     

Water-table variation in a sloping aquifer due to random recharge

Variation in the level of the water table is closely linked with recharge. Therefore, any uncertainty associated with the recharge rate is bound to affect the nature of the water-table fluctuation. In this note, a ditch-drainage problem of a sloping aquifer is considered to investigate the effect of uncertainty in the recharge rate on water-table fluctuation. The rate of recharge is taken as an exponentially decaying function with its decay constant as a Gaussian random variable. Expressions for the first two moments of the water-table height, i.e. mean and standard deviation, are presented. By using these expressions, the effect of uncertainty in the recharge rate on the water-table fluctuation has been analyzed with the help of a numerical example.     

因地制宜探索“长治”工程不同类型小流域治理模式

１９８９年开展实施的长江上游水土流失重点防治工程到“八五”期末，已水土流失面积３．９万ｋｍ＾２，而且根据因地制宜的原则，不断优化土地利用结构，形成了各具特色的经济型、粮食型、基础型、兼顾型、生态型等水土资源利用模式；同时，发挥“长治”工程的龙头作用，吸引各方资金和力量投入水土保持工作之中，开创了股份制、协作制、承包制、全民制等形式多样的水土流失治理模式，从而使“长治”工程最显著治理效益。