西藏朋曲流域水电工程地质灾害危险性评价

朋曲流域地质灾害类型多样,对水电工程建设和下游居民的人身财产安全产生了严重威胁。本研究以2009年SPOT5遥感影像为数据源,在研究区地质背景基础上,从基本环境因素、诱发因素和历史因素三个方面选取了坡度、岩性、断层密度、年均降雨量、植被覆盖度和灾害发育密度六个评价因子,通过改进模糊层次分析法获得各因子的相对权重,确定研究区危险性的量化指标。用GIS空间分析功能进行加权叠加,最终生成地质灾害危险性分级图,从而完成对朋曲流域水电工程的地质灾害危险性综合评价。结果表明,朋曲流域的地质灾害总体的危险度为中等,曲当厂址与聂当拉闸址分布于高危险区内,应加强对两处地质灾害的监测。     

东辽河流域人工湿地处理技术应用研究

人工湿地技术由于低成本的特点,被广泛的应用于污水处理以及河道整治等方面。不同湿地植物筛选及配比、不同填料的添加以及不同湿地流经方式,对湿地的处理效果都会产生一定的影响。以东辽河流域生态湿地为例,文章分别对植物筛选、生态湿地污水处理效果等方面进行了探讨。而对于北方地区来说,秋冬季节水温较低,容易产生冻结,而当前人工湿地处理技术冬季运行成本又相对较高且效果不稳定。因此水温的控制将成为东辽河流域人工湿地处理技术研究的关键;降低运行成本,保持持续稳定的处理效果将成为后续研究的重点内容。     

北运河流域(北京段)畜禽养殖污染现状及防治对策研究

畜禽养殖业产生的畜禽粪污对空气、土壤、地表水及地下水均会造成污染.调研了北运河流域(北京段)畜禽养殖业现状,分析了其污染空间分布及粪污处理方式,并提出了畜禽养殖存在的主要问题.结合国内外研究及北运河流域(北京段)概况,从布局、粪污处理、资金投入等方面提出了应对措施与建议,为环境管理部门开展畜禽养殖污染防治提供借鉴与参考.     

基于子流域的北运河流域(北京段)畜禽养殖空间布局研究

根据北运河流域(北京段)畜禽养殖业污染特点及其粪便与农作物养分供求关系,采用养分平衡法对各子流域畜禽养殖粪便养分实际排放量、实际负荷量、主要作物最大养分需求量、作物所需畜禽粪便养分最大负荷量、畜禽养殖承载力进行了核算,结果表明北运河干流、沙河流域、温榆河干流、凉水河流域和蔺沟河流域的畜禽实际承载量已超过畜禽土地承载力,研究结果对于环境部门加强畜禽养殖污染防治和农业部门合理进行农业规划有重要参考意义.     

渭河陕西段潜流带沉积物重金属变化初步分析

为厘清潜流带沉积物重金属时空变化及与水量交换、沉积物颗粒结构间的关系,于2013年春夏两季对渭河陕西段5个研究断面66个测试点位沉积物的野外原位渗透系数、颗粒粒径、重金属含量进行分析.结果表明:影响渭河沉积物渗透系数的主要因素是沉积物粒径,同时沉积物垂向分层、排列组合也影响其渗透性能;沉积物重金属Cu、Zn、Pb、Cd质量分数在垂向上不同深度其含量大小不同,在时间上总体呈现春季夏季,富集系数(EF指数)分析结果显示春季Cu、Zn(除华县)、Pb(除眉县)、Cd富集严重且主要受人为输入源影响,夏季除Cd元素外,Cu、Zn、Pb的EF值均1.5,说明其含量主要来源于地壳和岩石圈的自然风化过程;Pearson相关分析发现粘土与粉砂(粒径0.075 mm)百分比与沉积物重金属质量分数呈弱相关,重金属粒径效应不显著,粒径不是控制重金属含量的主要环境影子;对单一重金属垂向不同深度含量进行相关性研究发现除Cd外,其余3种重金属在垂向上的相关系数均0.5(p0.01),说明单一重金属在垂向上具有同源性且存在相互迁移与转化.     

An Integrated Flood Disaster Prevention System for the Sustainable Development of the Yangtze River Basin

An overview of the flooding history of the Yangtze River Basin (YRB) indicates the tendency ofmore frequent occurrence of flood disasters in the area due to intensified human activities anddeterioration of the ecological environment of waters.According to records,flood disastersoccurred every83years in YRB before1 5 2 4,while during the period1 5 2 5～ 1 85 1 the frequencyincreased up to once every2 0 years on the average.It further increased to once every5 yearsduring 1 92 5～ 1 949and onc…     

VARIABLES INDICATING NITRATE CONTAMINATION IN BEDROCK AQUIFERS,NEWARK BASIN,NEW JERSEY1

ABSTRACT: Variables that describe well construction, hydrogeology, and land use were evaluated for use as possible indicators of the susceptibility of ground water in bedrock aquifers in the Newark Basin, New Jersey, to contamination by nitrate from the land surface. Statistical analyses were performed on data for 132 wells located throughout the Newark Basin. Concentrations of nitrate (as nitrogen) did not exceed the U.S. Environmental Protection Agency maximum contaminant level of 10 milligrams per liter (mg/L) in any of the water samples (U.S. Environmental Protection Agency, 1991). Variables that describe hydrogeology and well construction were found not to be statistically significant in relation to concentrations of nitrate. This finding can be attributed to the complex nature of flow in bedrock aquifers and mixing of water from shallow and deep water-bearing zones that occurs within these wells, which are constructed with long open intervals. Distributions of nitrate concentrations were significantly different among land-use groups on the basis of land use within both a 400 and an 800-m radius zone of the well. The median concentrations of nitrate (as N) in water from wells in predominantly urban-residential (2.5 mg/L) and agricultural areas (1.8 mg/L) were greater than the median concentration of nitrate in water from wells in predominantly undeveloped areas (0.5 mg/L).     

利用冬春气候条件发展长江中游大麦生产

大麦是世界四大谷类作物之一,以适应性强、抗塑性强、抗逆性好、用途广而在世界各大洲广为种植。二次世界大战后,随着经济发展,大麦产量由６０年代的９９７０．０万ｔ增加到１９９４年的１５８７２．８万Ｔ,长江 中游历来是我国大麦的主要种植之一,随着我国经济的发展,大麦生产经况愈下,成为我国进口量最大的农产品之一,其种植面积由１９６１年７７．９２７万ｈｍ＾２降为１９９５年的８．３４８万ｈｍ＾２,与世界经济越发     

REGIONAL WATER QUALITY MANAGEMENT BY THE GENERALIZED REDUCED GRADIENT METHOD1

ABSTRACT: A river basin-wide water quality management system is considered. The river receives thermal as well as organic wastes. At-source treatment of these pollutants is imposed to control the basin-wide water quality. The related water quality standards are: the minimum DO concentration, the maximum allowable BOD concentration, the maximum allowable stream temperature, and the allowable rise in stream temperature. The general dynamic mathematical model representing water quality in streams and the thermal effects on BOD and DO concentrations is presented. The model is highly nonlinear in nature. The optimal management problem involving the model is solved by a recently developed nonlinear propgramming technique - the generalized reduced gradient (GRG) method. Comparison of results obtained by the GRG method vs. dynamic programming, and of results using a more realistic mathematical model vs. a simple model are presented. The analysis procedure can be applied to designing new and examining existing water quality programs, and to study the influence of alternate policies and constraints.     

WATER FOR ENERGY: AN APPROACH TO COMPREHENSIVE IMPACT ASSESSMENT1

ABSTRACT: The effects of energy development on the water resources of the Colorado River and Great Basin regions is expected to be substantial. Complex physical, economic and institutional interactions may be expected. Most research on these impacts appears single purpose, fragmented, uncoordinated, and often inaccessible to potential users - particularly those with responsibility for energy/water policy and program decisions. A comprehensive, integrative framework for assessing alternative water allocation decisions is outlined, taking a heuristic decision making model for evaluating impacts on maximization of gross (or net) regional product, and regional social welfare, and for assessing the region's contribution to national objectives. The suggested model provides a structure for application and integration of data of various kinds to a range of situations arising from possible impacts from energy proposals. The focus is on water and energy relationships but the model may provide a framework for comprehensive analysis of a variety of environmental actions and resulting system perturbations and effects.