Analysis on Schistosomiasis Occurrence And Preventive Measures in Three Gorges Reservoir

Recently, due to more flooding, schistosomiasis is in expanding tendency in some areas. With Three Gorges Engineering progress, schistosomiasis will occurr potentially in Three Gorges reservoir. In order to control the disease, some methods must be applied, e.g. chemicals, biological measures. To some extent every way has its specific effect. However, the vital way is improving the environment and reducing the amount of snails. One of the effective ways is conducting forestry ecological engineering that focuses on snail control and schistosomiasis prevention. The practical ways cover such as pollution controlling, ditches surface hardening. Especially for water-level-fluctuation zone, conducting forestry ecological engineering to improve environment to prevent snails＇ propagation is significant and vital. By operating the project environment could be greatly improved and people＇s living conditions would be bettered.     

官厅水库库滨带生物治理措施初探

官厅水库是北京重要的供水水源地，如何治理库区水土流失，提高水质，改善水库生态环境是当前面临的一个重要课题。文章从库滨带的组成和功能出发，介绍了生物工程措施中植物选取的原则，以此为基础，选取了垂柳、柽柳、酸枣和白榆四种乔灌木；并详细阐述了生物治理措施中植物措施和工程措施的设计模式，以期为官厅水库库岸整治提供理论和实践基础。     

三峡库区坡地梨-旱稻农业模式生态经济分析

运用生态经济学原理对三峡库区坡地新建梨-旱稻复合系统的生态效益和经济效益进行了研究。结果表明:与清耕梨园相比,梨园间作旱稻并秸秆还田后,有良好的水土保持作用和改土培肥效果,同时能有效控制田间杂草,减少梨园病虫害的发生,消减非点源N污染负荷60.19 kg/hm2,非点源P污染负荷8.0kg/hm2。与单一系统相比,复合系统提高土地利用率44%,能量经济系数上升2%。研究结果表明:梨-旱稻复合系统是一种具有良好生态效益的高效种植模式,值得在库区大力推广。     

范厝库区鲂性腺发育周年变化的观测

范厝库区鲂雌性成熟年龄为3龄，雄鱼2龄；性成熟后，鲂性腺发育具有明显周年变化规律，卵巢精巢可分为六个发育时期：冬季，达性成熟的鲂卵巢为Ⅲ期，精巢为Ⅳ期；每年5月份雌鱼成熟系数提高，是该库鲂鱼的主要产卵期；3～5龄鲂绝对生殖力均值为157000粒，相对生殖力均值为218粒。     

颗粒荧光技术可快速判别致密砂岩油层

颗粒荧光技术可快速探测储层颗粒中油包裹体和颗粒表面吸附烃, 能较好地反映储层中油气包裹体丰度及油气性质,可以很好地确认现今油藏和古油藏,有效判别油层、水层、油水过渡带以及古油水界面。用颗粒荧光分析技术,分析了依合2A井志留系柯坪塔格组近20块样品,发现该方法可以较好地识别柯坪塔格组致密砂岩储层中的油层、油水过渡带和水层,为致密砂岩储层油水层判别提供了一种新方法;利用该技术还在志留系柯坪塔格组上段底砂岩中识别出一套含油层,表明该技术具有较好的推广和应用价值。     

Developing co-management in an artisanal gill net fishery of a deep hydro-electric reservoir in Sri Lanka

Abstract Victoria, is a recently (1984) impounded, deep, hydro-electric reservoir in Sri Lanka with an established commercial fishery. Participatory appraisal of the fishing community revealed decreasing reliance on fishing income with many fishermen moving away to supplementary occupations because of declining fish catches. Illegal fishing and theft of fishing gear resulting from open access, difficulties encountered in enforcing fisheries regulations and the need for fishermen to find alternative sources of income during low water levels are the major management problems. The top–down centralized management approach previously practised was ineffective in addressing any of these issues. Therefore, the possibilities and limitations for introducing co-management as an alternative management strategy were discussed. Financial hardship coupled with perceived benefits through state sponsored welfare schemes caused a positive attitude change among fishermen, making them respond favourably to fishery management. Establishing a licensing system for controlled access, ensuring greater user-group participation through equitable distribution of state sponsored benefits among members, attempting to enforce penalties for illegal fishing linked with surprise checks to enforce management regulations, and obtaining stakeholder perceptions regarding management issues are some of the recent steps taken by the Fishermen's Co-operative Society which would positively contribute towards developing effective co-management in this reservoir.     

汤河水库春季浮游生物的群落结构及空间分布

对辽阳市境内的汤河水库春季的浮游生物的群落结构及空间分布进行了调查研究。结果表明,汤河水库春季共有浮游植物42种,平均生物量为14.18 mg/L,以硅藻门最高,占65.85%,隐藻门次之,占17.19%。优势种有硅藻门的针杆藻、桥弯藻等。浮游植物Chl_a含量为4.33μg/L。浮游动物比较贫乏,生物量很低,仅为0.004 mg/L。汤河水库浮游植物生物量的垂直分布无规律性。浮游动物生物量的垂直分布不规律,总的趋势是底层最高。从香农—威纳多样性指数来看,浮游植物多样性指数以上游最大,中游次之,下游最小。浮游动物多样性指数的分布与浮游植物正好相反,下游最大,中游次之,上游最小。根据本次调查结果测得的Carlson营养状态指数判断汤河水库属于中营养型。     

水位变化对蛤蟆通水库浮游植物种群动态影响的研究

1991－1993年蛤蟆通水库水位变化对浮游植物种群的动态影响研究结果表明：1）浮游植种属数随水位下降而减少；2）浮游植物生物量随水位下降而升高，其关系式为y＝299．46－3．37x,r=-0.998;3)浮游植物多样性指数随水位降低而变小，并且与水位呈明显的相关性（r＝0．999，r＝0．983）。     

Impact of stocking on yield in small reservoirs in Andhra Pradesh, India

The relationships between surface area, stocking density and fish yield in 40 small reservoirs in India between 1994 and 1999 were examined. A significant positive correlation (r = 0.6) was found between stocking density and fish yield. Area was negatively correlated with stocking density (r = ?0.57) and fish yield (r = ?0.62), but its correlation with efficiency of stocking was not significant for all the size groups of small reservoirs.