SIMULATION OF TEMPORAL CHANGES IN RAINFALL-RUNOFF CHARACTERISTICS,COON CREEK BASIN,WISCONSIN1

ABSTRACT: Streamflow for 67 years was simulated for Coon Creek at Coon Valley, Wisconsin, for three conditions in the drainage basin: (1) conditions in the 1930s; (2) conditions in the 1970s, excluding flood-detention reservoirs; and (3) conditions in the 1970s, including flood-detention reservoirs. These simulations showed that the changes in agricultural practices over 40 years (1940–80) reduced the 100-year flood by 53 percent (from 38,900 to 18,300 cubic feet per second). The flood-detention reservoirs reduced the 100-year flood by an additional 17 percent (to 15,100 cubic feet per second). The simulation was accomplished by calibrating a precipitation-runoff model to observed rainfall and runoff during two separate periods (1934–40 and 1978–81). Comparisons of model simulations showed that differences between the model calibrations for the two periods were statistically significant at the 95 percent confidence level.     

PESTICIDES IN GROUND WATER: DO ATRAZINE METABOLITES MATTER?1

ABSTRACT: Atrazine and atrazine-residue (atrazine + two metabolites - deethylatrazine and deisopropylatrazine) concentrations were examined to determine if consideration of these atrazine metabolites substantially adds to our understanding of the distribution of this pesticide in groundwater of the midcontinental United States. The mean of atrazine.residue concentrations was 53 percent greater than that of atrazine alone for those observations above the detection limit (> 0.05 μg/l). Furthermore, a censored regression analysis using atrazine-residue concentrations revealed significant factors not identified when only atrazine concentrations were used. Thus, knowledge of concentrations of these atrazine metabolites is required to obtain a true estimation of risk of using these aquifers as sources for drinking water, and such knowledge also provides information that ultimately may be important for future management policies designed to reduce atrazine concentrations in ground water.     

INTEGRATED RIVER BASIN OPTIMIZATION: MODELING ECONOMIC AND HYDROLOGIC INTERDEPENDENCE1

ABSTRACT: This paper presents an integrated optimal control model that optimizes economic performance of reservoir management in watersheds in which there are significant economic and hydrologic interdependencies. The model is solved using the General Algebraic Modeling System (GAMS). Results show that application of this model to New Mexico's Rio Chama basin can increase total system benefits over historical benefits by exploiting complementarities between hydroelectricity production, instream recreation, and downstream lake recreation.     

城市可持续发展政策的取向与反思

本文对城市可持续发展进行了概述，从物理环境、经济环境和社会环境的相互作用的角度分析了城市可持续发展的政策取向，对当今的可持续发展的政策进行反思，提出了建立环境公平促进可持续发展的政策思路。     

山岳型宗教旅游地的土地利用分析--九华山风景名胜区实证研究

九华山风景名胜区是山岳型宗教旅游地。通过对九华山风景区的实地调查，总结了该类旅游地的土地利用特点，即统一性和协调性、难以变更性、总量有限性，并进行了土地利用沿革、变更和影响方面的分析。利用层次分析法从生存指标、发展指标、社会指标、环境指标和智力指标5个方面对九华山风景区的土地利用进行了定量讨论，认为九华山风景区土地利用问题现阶段主要集中在九华街景区、花台景区和柯村景区。在此基础上，对九华山风景区土地的可持续利用提出了相应的对策。     

北京市耕地面积变化趋势预测及保护对策研究

耕地资源是人类生存和发展最重要的物质基础，也是不可再生的稀缺资源。特别是北京这样的国际大都市，人地矛盾十分突出，每寸土地都显得弥足珍贵。基于1996-2005年北京市的耕地面积数据，利用灰色模型预测方法建立GM（1，1）模型，对北京市2006-2010年的耕地面积变化趋势进行预测。预测结果显示，北京市耕地面积在未来几年内将呈现出持续减少的趋势，2010年耕地面积将比1996年减少约1／2。针对这种趋势和北京市的实际情况，提出了相应的耕地保护对策。     

安徽省土地资源人口承载力的动态研究

基于《安徽省统计年鉴》，对全省近10年的土地资源、粮食生产及人口增长状况进行了分析。在此基础上，运用相关数学模型对2005-2020年全省人口数量、耕地面积和粮食单产分别进行了预测。为了提高预测精确度，取各种预测方法的平均值。根据安徽省情将其划分为温饱型、小康型和富裕型三档生活标准，分别探讨了预测期内安徽省土地承载力状况，提出了相应的发展对策和建议，为全省发展粮食生产提供科学依据。     

政策干预对提高煤矿职工素质影响探讨

煤矿井下作业人员素质低,是煤矿事故多发的重要原因之一.建议从大幅度提高煤矿井下人员工资待遇,吸引高素质人才从事煤矿工作;全方位开展煤矿职业培训工作,坚持先培训后就业,实行煤矿从业准入制;对现在岗的煤矿从业人员分期分批进行培训,实现煤矿从业人员持证上岗;政府出台政策,强制煤矿企业开展职工岗位技术培训和安全培训等4个方面着手,切实提高煤矿从业人员的整体素质,减少煤矿事故的发生.     

关于区域环境保护政策的思考

本文从通过分析我国环境保护政策存在的缺口和目前对这种理念的研究进展,并根据环境问题本身的特性以及环境问题产生的背景差异提出重新确立环境保护政策的调控范围的观点,并提出了这种观点对于对我国环境保护政策以及环境保护工作的重要意义。     

科尔沁沙地沙漠化研究进展

科尔沁沙地是目前我国沙漠化发展较为迅速的地区之一,也是我国沙漠化研究程度比较高的地区之一.近50年来,该区沙漠化研究经历了流沙治理、沙漠化过程及其整治的区域性综合研究和沙漠化机理及其整治的典型研究3个阶段,在沙漠化过程、动态监测、灾害评估、综合整治防治等方面都取得了大量成果.根据目前的研究现状和存在问题,以及科尔沁沙地的实际情况,提出了今后应进一步加强研究的4个领域,即:沙漠化监测评估标准的统一和规范化;农田土壤风蚀的实验观测和控制措施的试验示范研究;沙尘暴灾害的监测、预警和影响评估;防沙治沙技术与模式的集成和进一步推广等.