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751.
ABSTRACT: Large-scale groundwater abstraction from the Cretaceous Chalk/Lower Tertiary Basal Sands aquifer system of the London Basin in the last 150 years has developed storage of more than 1000 Mm3. Limited operational recharge was undertaken in the 1950's encouraging further detailed study of the wider possibilities. Following a comprehensive hydrogeological reappraisal, an economic and engineering study and pilot-scale experiments, the Lea Valley has been shown to have the greatest potential for recharge. Artificial recharge into the Chalk at a rate of 9000 m3/d appears possible, through acidised 900 mm diameter boreholes. An understanding of the degree of interconnection between the Chalk and Basal Sands and of the causes of changes in quality of recharged water during storage was shown to be of particular importance to the successful operation of any recharge scheme using this system. A two-layer numerical groundwater model of the 800 km2 area and a surface/groundwater simulation model have been used to assist with the design of the 84,000 m3/d prototype scheme, and will also help in assessing its efficiency. The models will ultimately be used to manage the operation of the first stage development, now coming into use.  相似文献   
752.
ABSTRACT: A graphical procedure for classifying aquifer management strategy is proposed for use as a visual aid. The increasing demand for water, changes in the type of water uses and water sources, and economic consideration indicate that optimal strategies can shift over time. The procedure is described and, as an example, applied to the Tucson Basin. This procedure provides a simple visual tool for nonhydrologists, demonstrates the importance of water use and source interplay, and allows consideration of the time element in managing ground-water resources.  相似文献   
753.
ABSTRACT: ERTS-1 satellite imagery has been evaluated as a means of providing useful watershed physiography information. From these data physiographic parameters such as drainage basin area and shape, drainage density, stream length and sinuosity, and the percentage of a watershed occupied by major land use types were obtained in three study areas. The study areas were: (1) Southwestern Wisconsin; (2) Eastern Colorado; and (3) portions of the Middle Atlantic States Using ERTS-1 imagery at 1:250,000 and 1:100,000 scales it was found that drainage basin area and shape and stream sinuosity were comparable (within 10%) in all study areas to physiographic measurements derived from conventional topographic maps at the same scales Land use information can be usefully extracted for watersheds as small as 30 mi2(78 km2) in area. Improved drainage network and density information is obtained from ERTS-1 imagery in dissected areas such as Southwestern Wisconsin, but in heavily vegetated areas (Middle Atlantic States) or areas with little physical relief (Eastern Colorado) low order streams are difficult to detect and the derived drainage densities are significantly smaller than those obtained from standard maps. It is concluded that ERTS-1 imagery can be employed to advantage in mean annual runoff prediction techniques and in providing or maintaining land use information used in the calibration and operation of watershed models.  相似文献   
754.
ABSTRACT. The Nation has entered a new era of water quality management in which land use policy and regulation must assume an increasingly important role. The benefits of tertiary and advanced waste treatment may be offset by contradictory land use and pollution from land runoff. Unless land use planning and controls are included in water quality management, land-imposed constraints on water quality can be anticipated. Pollution from major types of land runoff are reviewed with respect to sources, effects, and control procedures. Emphasis is given to land use practices and controls. The crucial issue with regard to the latter is lack of land use policies at federal, state, and local levels. State legislation establishing guidelines and minimum standards for land use regulation by local government is required. The dependency of water quality on land use points to the fallacy of attempting to provide for comprehensive water pollution control outside the context of comprehensive land-water resource planning and management.  相似文献   
755.
生态补偿已成为生态环境管理领域的热点问题。本文基于CiteSpace可视化文献分析工具,以CSSCI数据库中1998—2018年的期刊论文作为数据源,以"生态补偿"为关键词进行文献检索,通过共被引、关键词共现分析以及聚类分析等,探讨生态补偿研究领域的知识基础以及研究热点与前沿。结果表明:①生态补偿研究的发文数量经历了缓慢上升、快速增长、平稳增加三个阶段;②生态补偿研究作者集中度较高,发行期刊涵盖经济学、地理学、生态学、制度经济学等多个学科,反映出生态补偿是一个多学科交叉的研究主题,生态补偿研究的综合性不断增强;③依据关键词知识图谱,"国家重点生态功能区""生态环境""可持续发展"等成为最新研究热点;④新时期生态文明建设下,"草原生态补偿""支付意愿""转移支付""退耕还林"等成为生态补偿研究的最新前沿话题。  相似文献   
756.
Monitoring Parks Through Remote Sensing: Studies in Nepal and Honduras   总被引:3,自引:0,他引:3  
The effectiveness of parks as management regimes is hotly contested. Much of the current discussion centered around comparisons of management regimes can be traced to a dearth of cross-site quantitative evaluations. Remote sensing provides a particularly effective tool for this purpose, yet analysis of remotely sensed data requires fieldwork to interpret human activities and the socioeconomic and political contexts that relate to land cover change. This paper examines the effect of establishment of the Celaque National Park, Honduras, and the Royal Chitwan National Park buffer zone, Nepal, on limiting deforestation. In Celaque, the park itself has been largely successful in maintaining forest cover. However, recent changes in land use patterns have led to increasing pressure on the park boundaries, exacerbated by the lack of involvement of local residents. In the Royal Chitwan National Park, in contrast, participatory approaches towards co-management have been implemented over the past decade in the park buffer zone. With significant incomes derived from ecotourism, complete protection of the buffer zone forest has been adopted, leading to significant regrowth of tree cover. However, local decision-making power is limited, and buffer zone management has largely proven successful due to the investment and support provided by international donor agencies. These two case studies demonstrate the utility of remote sensing and Geographical Information Systems analysis in providing a spatiotemporal perspective for assessing management policies. They also demonstrate the importance of fieldwork to provide a nuanced understanding of the socioeconomic and institutional conditions affecting the outcomes of forest management regimes.  相似文献   
757.
Protected Area (PA) management is a complex issue that requires the consideration of many factors and relationships. A conceptual framework for the analysis of biodiversity change, local human communities, and PA management was put forward, accordingly. Under the framework, we investigated the economic status, livelihood activities, biodiversity use and perceptions of local communities, and the land use history in Wolong Biosphere Reserve, southwestern China through household survey and document review in order to gain a better understanding of the complexity of PA management. According to the land use history, the preservation of agro-biodiversity, and the raising of productivity, ecological rehabilitation and the regulation of the human pressures are indispensable in the management of the reserve. Livelihood activities and the perceptions of local communities were largely determined by the socioeconomic background, which has important implications in solving the conflicts or incompatibilities in the reserve. In Wolong Biosphere Reserve, it is beneficial to support local farmers in solving their socioeconomic problems such as the overabundance of labor force and the lack of livelihood alternatives. Without this, there will be scarcely any effective biodiversity conservation and successful reserve management in the long term.  相似文献   
758.
土地利用地学知识可应用于LIS智能化分析及辅助遥感影像解译,是国土信息化工程建设中值得深入研究的重要技术环节之一.明确了土地利用地学知识概念,构建了多数据源的土地利用地学知识体系,针对不同数据源分析了土地利用地学知识的获取及表达,并着重对土地利用地学知识辅助遥感影像解译进行了阐述,指出采用知识辅助高分辨率遥感影像解译是亟待深入开展研究的课题.  相似文献   
759.
以重庆市北碚区为代表,论述了川东平行岭谷区自然景观的垂直分异特征,并在此基础上对该区域进行了综合分区,再结合各分区内土地的自然特征采取不同的措施,从而做到因地制宜地发展各项生产.  相似文献   
760.
Integrated rice-fish culture: Coupled production saves resources   总被引:9,自引:0,他引:9  
Rice is a key component in global food security, as it is the main ingredient in the daily diets of around 3 billion people, especially in Asia. Like all agricultural production, rice cultivation depends on scarce natural resources. This article briefly outlines the utilization of land and water in rice production, and suggests an approach for optimizing use efficiency, namely through the combination of rice and fish culture. The authors argue that the utilization of land and fresh water is optimized through integrated and complementary production of rice and fish — two basic foods items in daily local diets. The article reviews currently available scientific literature on integrated rice‐fish systems. Rice‐fish culture systems are briefly characterized, and respective yield potential and interactions between rice and fish are discussed. Results of socio‐economic surveys regarding the adoption of integrated rice‐fish culture are summarized. The article also reviews literature on the impact of fish culture on rice field ecology as outlined in studies on weed infestation, insect populations, and greenhouse gas emissions. The article concludes that rice‐fish culture can be an option to help rice producing countries keep pace with soaring domestic demand for food, especially fish. Integrated rice and fish culture optimizes the benefits of scarce land and water resources through complementary use, and exploits the synergies between fish and plant.  相似文献   
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