Agricultural Lakes in Finland: Current Water Quality and Trends

Agriculture is the largest source of nutrients into surface waters in Finland, and yet relatively little is known about the actual impact of the agricultural load on the state of lakes. We analysed the water quality data of 20 Finnish agricultural lakes and found that they had higher levels of nutrients, chlorophyll a and turbidity than did the other types of lakes (e.g. those receiving point-source load) in the national monitoring network (the Finnish Eurowaternet). Currently, six of the agricultural lakes can be classified as eutrophic and 14 as hypertrophic. Trend analysis (based on Kendall's tau-b) indicated that during 1976–2002 the water quality of the lakes either remained constant or showed signs of increasing eutrophication and elevated turbidity. Decreasing nutrient concentrations were found only in one intensively restored lake. In none of the lakes had the chlorophyll a concentration decreased. The results of the trend analysis are compatible with the recent finding that, despite vigorous efforts, the nutrient load from agriculture has not declined in Finland. Recovery of the most eutrophied agricultural lakes would call for a drastic reduction in the external nutrient load, possibly supplemented with in-lake restoration.     

西北干旱区发展节水农业保障体系研究

水资源短缺已成为西北干旱区严重的制约因素之一.实施节水型农业模式,成为促进西北干旱区农业持续发展、生态环境保护乃至整个社会经济发展的必要选择.结合西北干旱区水资源开发利用的现状和节水农业发展中存在的主要问题,构建了西北干旱区节水型农业发展的保障体系:加强宣传培训,提高节水农业意识;制定科学规划,促进农业持续发展;构建完整体系,支持节水农业发展;健全法律制度,保障节水农业发展.     

四川阿坝州特色水果产业现状及其发展方向

高山峡谷区是阿坝州生态环境脆弱和人口密度大的区域,特色水果是与该区域环境、资源与气候特点相适应的传统优势产业。近年来,在特色水果新品种引进、基地建设和产业体系建设方面取得了较大的进展,特色水果产业快速发展,已成为该区域生态农业发展、农民增收和产业结构调整的重要支柱产业。对阿坝州特色水果产业发展的现状与目前存在的问题进行了全面的分析,为该产业今后的发展指出了方向。     

Sedimentation retention basin utilization for best management practice

Approaches to the artificial impoundment and theoretical design of sedimentation retention basin are reviewed with particular attention to best management practice(BMP) to control agriculture and surface runoff. Sediments retention basins are the small version of farm pond usedwhere a criteria of farm pond is not met. Such basin traps the pollutants and suspended solids prior to entry into streams and lakes. The study is focused with special reference to the assessment and control of non-point source pollution(NPSP) from the sub-basin area of Tai Lake in the Xishan County of Wuxi City of China, The author suggested two different approaches to conduct this study including theoretical design for sedimentation retention basin and computation of flow, sediment transport and deposition during the artificial impoundment of retention basin for BMP‘s utilization. Theoretical design will provide a useful function as a first line defense against the movement of sediments and transport of pollutants into the Tai Lake while the assessment of sediments deposition will help to make its proper use and periodic cleanup.     

种养殖耦合的海水农业系统研究

本研究建立了养殖耦合的海水农业系统,结果表明,种养殖耦合的海水农业系统对污染物具有良好的净化效果,对Chl.去除效果尤其显著,污染物NO3-N、NO2-N、NH4-N、TP、COD、TN、Chl.的去除率分别为:58.11、58.61、62.86、54.45、52.62、46.84和85.69%.用养殖废水种植蔬菜,实现了废水无害化和资源化的统一,具有较好的经济、生态效益.     

贴近"三农" 提高防震减灾实效

根据辽宁省地震的历史与现状,地震灾害与经济发展的利害关系,阐述了防震减灾工作体系建设的要点,并结合该要点指出了在农村、农民和农民工中存在的防震减灾薄弱环节,提出了具有防震减灾实效的建议.     

区域农业可持续发展的生态安全评价——以福建省为例

在国内外已有研究的基础上, 提出了福建省农业可持续发展生态安全评价的指标体系, 从时 间尺度上对福建省农业可持续发展的生态安全进行了动态评价。结果表明, 1981 年以来农业生产 环境安全指数和农业资源安全指数总体下降, 农村社会发展指数不断升高; 区域农业可持续发展生 态安全综合指数则经历了下降、快速上升和快速下降三个阶段。以2003 年为例, 对福建省农业可持 续发展生态安全的主要障碍因素进行诊断表明, 农业可持续发展生态安全的威胁主要来自于农业 资源安全和农业生产环境安全两方面。农业资源安全、农业生产环境安全和农村社会发展对农业可 持续发展生态安全的限制作用依次为45.32%、33.92%和20.76%。最后, 为提高福建省农业可持续 发展的生态安全水平, 提出了相关的政策和建议。     

不同资源环境梯度下吉林西部生态经济系统能值分析

利用能值方法,从东南-西北方向选取吉林西部长岭、乾安、大安、镇赉四县市进行不同资源环境梯度下生态经济系统演变的对比分析。结果表明1989-2001年研究区多项能值指标差异明显:①系统稳定性方面,降水相对较多的长岭和乾安稳定性强于镇赉和大安。能值密度及能值投入率为长岭>乾安>大安>镇赉。能值产出以及能值积累量呈增大趋势,增幅长岭>乾安>大安>镇赉;②系统产出结构变化显著,虽然种植业比例有所下降,但一直是长岭、乾安的主导产业,镇赉、大安畜牧业超过种植业成为主导产业,系统平均能值产出率为长岭(1.89)<乾安(1.96)<大安(1.99)<镇赉(2.29);③环境负载率长岭<乾安<大安<镇赉,可持续发展指数则相反;④资源环境条件尤其是降水是该区生态经济系统状态的重要影响因素。     

Mason Valley Groundwater Model: Linking Surface Water and Groundwater in the Walker River Basin,Nevada1

Carroll, Rosemary W.H., Greg Pohll, David McGraw, Chris Garner, Anna Knust, Doug Boyle, Tim Minor, Scott Bassett, and Karl Pohlmann, 2010. Mason Valley Groundwater Model: Linking Surface Water and Groundwater in the Walker River Basin, Nevada. Journal of the American Water Resources Association (JAWRA) 46(3):554-573. DOI: 10.1111/j.1752-1688.2010.00434.x Abstract: An integrated surface water and groundwater model of Mason Valley, Nevada is constructed to replicate the movement of water throughout the different components of the demand side of water resources in the Walker River system. The Mason Valley groundwater surface water model (MVGSM) couples the river/drain network with agricultural demand areas and the groundwater system using MODFLOW, MODFLOW’s streamflow routing package, as well as a surface water linking algorithm developed for the project. The MVGSM is capable of simulating complex feedback mechanisms between the groundwater and surface water system that is not dependent on linearity among the related variables. The spatial scale captures important hydrologic components while the monthly stress periods allow for seasonal evaluation. A simulation spanning an 11-year record shows the methodology is robust under diverse climatic conditions. The basin-wide modeling approach predicts a river system generally gaining during the summer irrigation period but losing during winter months and extended periods of drought. River losses to the groundwater system approach 25% of the river’s annual budget. Reducing diversions to hydrologic response units will increase river flows exiting the model domain, but also has the potential to increase losses from the river to groundwater storage.     

安徽沿江地带生态农业可持续发展的实证考察——以芜湖一市三县为例

伴随工业化而出现的现代“石油农业”,在200年的时间里,严重破坏了人类赖以生存的自然生态环境,农业污染带来的食品污染直接危害着人类的健康,从而迫使各国转而研究可以替代“石油农业”的可持续农业发展模式。生态农业由此应运而生。中国改革开放以来,因为工业化和农业现代化的快速推进,已经造成国土环境的严重污染,而中部地区都是农业大省,在人口压力必须自我消化的背景下,唯有大力发展生态农业才可能步入经济社会可持续发展的正常轨道。本课题是基于安徽沿江地带芜湖市及所辖三县的实证调研,试图通过对芜湖地区生态现状和生态农业发展的制度环境分析,为安徽农业可持续发展提供一个可资借鉴的参照样本。