锡澄运河整治工程双向竖井贯流泵站流道优化及分析

针对锡澄运河整治工程竖井贯流泵站改造的需求,对双向竖井贯流泵装置原型进行了三维定常数值模拟。以泵站竖井流道为研究对象,分析比较了5种不同的竖井流道优化方案,重点分析了正反向运行时竖井流道的内流场特征。结果表明:前移竖井段,将竖井的迎水面的尖角改成圆弧形,并以各个断面的面积作为控制参数改善流态分布较差的断面面积,有助于水流平稳扩散,提高水力性能。优化后,正向运行时,设计流量工况(H=3.81 m,Q=30 m^3/s)下效率为72.40%,当H=2.61 m,Q=33 m^3/s时,效率达到最大值74.53%;反向运行时,当H=3.9 m,Q=30 m^3时,效率达到最大值60.91%,相比原设计方案提高1.04%。     

西宁市林业站抗旱造林综合技术集成与示范项目区

西宁市林业站结合《抗旱造林综合技术集成与示范项目》,将青海云杉、油松、祁连圆柏、青杨雄株、小叶杨、银中杨、山杏、丁香,和引种培育试验区栽植的美国稠李、新疆忍冬、杜梨、文冠果、香茶藨子、海棠,共14种树种种植到海拔 2210～2750米区域,经试验研究：7个树种具有良好的适应性,可以作为西宁高海拔干旱地区林相改造选择树种。就上述14个树种生长情况的初步调查进行了成活率和生长量分析,并提出了相关建议,供参考。     

基于全站仪精准量测树木材积方法初探

笔者根据北京林业大学冯仲科教授提出的精准林业的理念,使用全站仪对树木材积进行量测,并将全站仪量测的材积数据与解析法所得砍伐数据进行比较,结果表明,全站仪量测立木材积的精度在91%以上,平均精度在96%左右,完全能满足高精度量测立木材积的要求,建议推广应用。     

绩溪抽水蓄能电站工程移民安置环境影响

指出了水利工程移民生产安置是关系到移民的生产水平能否恢复或超过安置前的生产水平的问题,但移民安置也会带来诸多环境问题。处理和解决好绩溪抽水蓄能电站移民安置产生的环境问题则是保障工程建设顺利完成及工程综合效益充分发挥的重要工作。对移民安置于环境的作用和影响进行了分析评价。     

新疆水电站项目施工道路水土流失防治探讨

指出了在新疆水电站项目建设中,施工道路的长度平均为十几公里,公路建设扰动地表,破坏地表植被和结皮,加剧了区域的水蚀和风蚀,产生的水土流失危害也比较严重,重点针对施工道路产生的水土流失影响进行了分析,并提出了相应的水土保持措施。希望在水电站项目的建设过程中,能对施工道路引起足够的重视,从而减少施工道路的水土流失。     

宁夏农村信息服务站运行状况评估指标体系研究

根据宁夏农村信息化考核评估工作的需要,运用层次分析法和专家调查法,从硬件配置、系统运行、人员配备、制度建设、服务成效等方面建立农村信息服务站运行状况评估指标体系,并确定评估方法与程序,以促进宁夏农村信息服务站规范化、科学化运行发展,提高宁夏农村信息服务站运行成效。     

Behaviour and growth of juvenile brown trout exposed to fluctuating flow

Abstract –  Parr of brown trout ( Salmo trutta L.) were exposed to constant or fluctuating water level and flow in artificial outdoor stream channels during 21 days in three consecutive runs, and their individual behaviour and social interactions were monitored. Despite the large variation in flow, no clear differences in growth, which was generally poor, and behaviour were found between treatments. The signs of a social structure in the stream channels were very subtle and there were no clear relation between growth rate and aggressive/dominant behaviour in any of the treatments in accordance with findings in studies of growth and dominance in the wild. Thus, in regulated rivers, daily fluctuations in flow and water level (hydropeaking) are not likely to alter the behaviour of juvenile brown trout or affect their energy turnover negatively. Several studies now indicate that if stranding can be avoided, hydropeaking has relatively small direct effects on stream salmonids. Therefore, future research should focus on cascading ecological effects that may influence the productivity of the ecosystems in regulated rivers.     

It is the ambience,not the menu. Prey availability does not drive habitat selection by the endangered Pyrenean desman

1. The Pyrenean desman (Galemys pyrenaicus) is an endangered stream-dwelling insectivore endemic to the Iberian Peninsula and the north of the Pyrenees. It favours riffles over slow habitats such as runs or pools, yet it is still unclear whether habitat preference is based on prey availability or on other factors, such as mechanical constraints on its hunting habits.
2. Desman diet and prey selection were analysed along the pristine Elama Stream and the slightly modified Leitzaran Stream in the Basque Country, Spain.
3. In each stream the prey consumed were identified by metabarcoding 94 desman faeces, and prey availability characterized from 10 Surber samples taken in each habitat type (riffles, runs and pools). Invertebrates were sorted and identified, the biomass of each taxon was calculated, and their DNA was also extracted, amplified using PCR, and sequenced to build a reference database.
4. Prey availability and diet varied between streams. Desmans positively selected shredders and invertebrates that live on the substrate, and selected against taxa that live in fine sediment, taxa with hard shells or those that are highly mobile. The diet of desmans was more selective in the Elama, the stream with better ecological status. Food availability did not differ among habitats, and therefore does not explain the preference of desmans for riffles; rather, mechanical constraints to deal with buoyancy and physical habitat heterogeneity were hypothesized to be the reason behind the habitat preference.
5. The results suggest that promoting the formation of riffles in streams can improve the situation of some desman populations living in degraded habitats.

     

A political tsunami hits Amazon conservation

1. The history of conservation of the Amazon can be viewed as a war involving many battles with interests in agribusiness on one side and in biodiversity conservation and sustainability on the other side. Trends in large-scale deforestation in the 1970s spurred a series of policies, stakeholder alliances and international and grass-roots movements, which decades later led to the establishment of protected areas and interventions in soy and beef supply chains of agribusiness. Together, these advances epitomized a conservation framework for the Amazon, which at one point nearly curbed deforestation in the Brazilian Amazon, although it included very few protections for freshwater ecosystems.
2. While those conservation advances were taking place, however, a series of policy changes started to undermine them through expansions in deforestation, river regulation and mining activities. The election of Brazil's President Jair Bolsonaro in 2019 then hit the Amazon conservation framework much like a tsunami of policy setbacks and the re-establishment of the economic policies that sparked the Amazon war in the past.
3. The current trajectory is one of large-scale degradation of Amazonian ecosystems and biodiversity with consequent impacts on local people. Because freshwater ecosystems are highly sensitive to human activities on water and on land, these growing impacts are particularly large.
4. It is too early to know, but four decades of institutional and policy developments to conserve the Brazilian Amazon may soon be pushed past the point from which they will be able to recover. Four conditions will be pivotal to allowing the Amazon conservation framework to recoup: (a) the end of Bolsonaro’s mandate in 2022 or earlier; (b) remobilization of stakeholders; (c) investments in environmental research, policy and multiple collaborations; and (d) moving conservation beyond terrestrial landscapes to also encompass freshwater ecosystems and their people.

     

抽水蓄能电站建设期水土流失及其次生灾害风险评价

[目的]对抽水蓄能电站建设期水土流失及其次生灾害风险进行评价,对涉及的要素特征进行筛选分析,为提高工程建设期绿色安全施工水平提供科学支持。[方法]采用层次分析法结合模糊综合评价法,从3个维度共选取了8个一级指标和34个二级指标进行分析评价。[结果]构建了抽水蓄能电站建设期水土流失及其次生灾害风险评价模型,并划分为5个风险等级,将模型应用于安徽省绩溪抽水蓄能电站的研究表明该电站在建设期水土流失风险灾害等级为3级,属一般安全等级。结合该工程建设期的实情,验证了模型的可行性。[结论]抽水蓄能电站选址在很大程度上决定着工程建设期水土流失及其次生灾害风险等级。采用该方法评价风险等级为3级及以下的工程,可在确保工程水土保持措施按照要求落实建设的基础上,增强建设期水土保持监测水平。应重点关注建设期弃渣堆置不合规及取弃土过程中的潜在土壤流失量,防微杜渐,避免水土流失及其次生灾害现象的发生。