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671.
广东省耕地资源的动态变化特征   总被引:3,自引:0,他引:3  
耕地资源问题已成为制约广东省农业以至社会经济发展的主要因素之一。本文通过分析该省耕地资源数量、质量变化特征及各地区耕地资源的流失、净增减情况,得出耕地资源动态变化特征,并简要地阐述了产生这些变化的机制和原因,最后提出了保护耕地资源的基本对策  相似文献   
672.
云南木本食用油料资源及其开发   总被引:2,自引:0,他引:2  
食用油料木本化对我国具有重要的战略意义。云南具有丰富多彩的木本食用油料树种,本文记述了云南具有重要开发价值的32 科84 种食用油料树种,并提出了它的三个开发利用的方向。  相似文献   
673.
张光生 《资源开发与市场》1999,15(6):374-375,378
本文分析了皖南生态旅游资源的优势特征,提出了组建皖南生态旅游开发联合体,加强区域旅游形象建议和宣传促销工作,精心设计生态旅游路线等措施。  相似文献   
674.
地理信息系统(GIS) 是集计算机科学、地球科学、信息科学为一体的高新技术。目前,GIS技术已广泛用于资源管理、环境监测、环境评价、灾害评估、区域流域环境规划等众多领域,已成为国内外环境管理的有效决策支持工具。本文介绍了GIS技术在金华江流域水污染控制决策方面的应用, 其中重点介绍了在GIS支持下,金华江流域水污染决策模型( 水质模型) 的建立、程序设计和实现  相似文献   
675.
ABSTRACT: The 1990s have featured a rapid proliferation of “watershed initiatives” in the western United States and elsewhere. Watershed initiatives are ad hoc, voluntary associations typically featuring both governmental and non-governmental actors organized together to collaboratively seek new strategies for addressing water and related natural resource problems at physically relevant regional scales. These efforts are a response to historical and sociopolitical trends that have resulted in increasingly ineffective forums and processes of resource management decision-making, and that have subordinated the role of local stakeholders in problem-solving efforts. In most cases, watershed initiatives appear to provide a pragmatic vehicle for resource managers and stakeholders to address common concerns in a more efficient manner than is otherwise possible, and as such, deserve further application and continued support.  相似文献   
676.
ABSTRACT: As part of the National Assessment of Climate Change, the implications of future climate predictions derived from four global climate models (GCMs) were used to evaluate possible future changes to Pacific Northwest climate, the surface water response of the Columbia River basin, and the ability of the Columbia River reservoir system to meet regional water resources objectives. Two representative GCM simulations from the Hadley Centre (HC) and Max Planck Institute (MPI) were selected from a group of GCM simulations made available via the National Assessment for climate change. From these simulations, quasi-stationary, decadal mean temperature and precipitation changes were used to perturb historical records of precipitation and temperature data to create inferred conditions for 2025, 2045, and 2095. These perturbed records, which represent future climate in the experiments, were used to drive a macro-scale hydrology model of the Columbia River at 1/8 degree resolution. The altered streamflows simulated for each scenario were, in turn, used to drive a reservoir model, from which the ability of the system to meet water resources objectives was determined relative to a simulated hydrologic base case (current climate). Although the two GCM simulations showed somewhat different seasonal patterns for temperature change, in general the simulations show reasonably consistent basin average increases in temperature of about 1.8–2.1°C for 2025, and about 2.3–2.9°C for 2045. The HC simulations predict an annual average temperature increase of about 4.5°C for 2095. Changes in basin averaged winter precipitation range from -1 percent to + 20 percent for the HC and MPI scenarios, and summer precipitation is also variously affected. These changes in climate result in significant increases in winter runoff volumes due to increased winter precipitation and warmer winter temperatures, with resulting reductions in snowpack. Average March 1 basin average snow water equivalents are 75 to 85 percent of the base case for 2025, and 55 to 65 percent of the base case by 2045. By 2045 the reduced snowpack and earlier snow melt, coupled with higher evapotranspiration in early summer, would lead to earlier spring peak flows and reduced runoff volumes from April-September ranging from about 75 percent to 90 percent of the base case. Annual runoff volumes range from 85 percent to 110 percent of the base case in the simulations for 2045. These changes in streamflow create increased competition for water during the spring, summer, and early fall between non-firm energy production, irrigation, instream flow, and recreation. Flood control effectiveness is moderately reduced for most of the scenarios examined, and desirable navigation conditions on the Snake are generally enhanced or unchanged. Current levels of winter-dominated firm energy production are only significantly impacted for the MPI 2045 simulations.  相似文献   
677.
ABSTRACT: A wide variety of regional assessments of the water-related impacts of climatic change have been done over the past two decades, using different methods, approaches, climate models, and assumptions. As part of the Water Sector research for the National Assessment of the Implications of Climatic Variability and Change for the United States, several major summaries have been prepared, looking at the differences and similarities in results among regional research projects. Two such summaries are presented here, for the Colorado River Basin and the Sacramento River Basin. Both of these watersheds are vitally important to the social, economic, and ecological character of their regions; both are large snowmelt-driven basins; both have extensive and complex water management systems in place; and both have had numerous, independent studies done on them. This review analyzes the models, methods, climate assumptions, and conclusions from these studies, and places them in the context of the new climate scenarios developed for the National Assessment. Some significant and consistent impacts have been identified for these basins, across a wide range of potential climate changes. Among the most important is the shift in the timing of runoff that results from changes in snowfall and snowmelt dynamics. This shift has been seen in every regional result across these two basins despite differences in models and climate change assumptions. The implications of these impacts for water management, planning, and policy are discussed.  相似文献   
678.
ABSTRACT: The U.S. Army Corps of Engineers conducted an assessment of Great Lakes water resources impacts under transient climate change scenarios. The integrated model linked empirical regional climate downscaling, hydrologic and hydraulic models, and water resource use sub-models. The water resource uses include hydropower, navigation, shoreline damages, and wetland area. The study is unique in that both steady-state 2°CO2 and transient global circulation model (GCM) scenarios were used and compared to each other. The results are consistent with other impact studies in that high scatter in regional climate among the GCM scenarios lead to high uncertainty in impacts. Nevertheless, the transient scenarios show that in the near-term (approximately 20 years) significant changes could occur. This result only adds to the urgency of creating more flexible and robust management of water resources uses.  相似文献   
679.
水资源定价方法的初步探讨   总被引:9,自引:0,他引:9  
谢标  杨永岗 《环境科学》1999,20(3):100-103
根据水资源的特点,分析了开展水资源定价研究的目的和意义,设计了水资源存在价值及其经济价值确定方法的研究思路,研究认为,探讨水资源存在价值应考虑其本身的价值和环境容量虚幻成本2方面;水资源经济价值则包括水淘汰存在价值和水资源转化为水资源商品后物化的使用价值,这里的使用价值又包含水资源污染治理及损害成本、稀缺性价值、边际运行成本和边际时间成本等4个方面,在以上分析的基础上,给出了水资源定价的计算模型,  相似文献   
680.
环境信息公开——一项新的环境管理手段   总被引:15,自引:0,他引:15  
环境信息公开是继指令性控制手段和经济手段后一项新的环境管理方法。该手段通过对环境信息的公开来加强环境管理的公众参与和监督,从而促使污染者重视环境保护,加强污染治理。文中对环境信息公开的作用和类型作了简要的阐述,并重点介绍了企业环境信息公开的设计原则、方法和步骤。同时以呼和浩特市为例,对企业环境信息公开的方案进行了初步的设计。   相似文献   
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