共查询到20条相似文献,搜索用时 93 毫秒
1.
大西南的旅游资源丰富而独特,但开发程度低、经营粗放、发展整体性差、组合效益低.本文根据近年来的研究,从大西南的整体对其旅游资源进行分区及评价、并分析其开发的市场条件,提出了开发途径。 相似文献
2.
西南水电资源开发及其经济发展 总被引:1,自引:2,他引:1
大西南地区是我国水能资源的主要蕴藏地区(约占全国的70%),但开发率相对较低.在介绍西南地区丰富的水电资源及其开发现状的基础上,分析了加快西南水电开发的可能条件和重要意义,最后针对开发中存在的主要问题,根据市场经济原则和具体情况提出了对策和建议. 相似文献
3.
高速公路对旅游业的意义影响深远.针对泉三高速公路泉州段沿线的旅游资源,阐述了泉三高速公路对泉州段沿线旅游发展的影响,分析了泉州段沿线旅游资源开发现状,提出资源整合的原则和对策,并对整合后的区域旅游发展进行了展望. 相似文献
4.
本文旨在对中国各城市高铁出行情况与人群环境健康影响进行大数据分析。文中的环境健康影响指将高铁出行过境次数引入经典泊松回归模型,进而直接得到各城市人群环境健康受到高铁出行的影响。另外,为了更好地分析高铁出行下的人群环境影响,笔者在计算环境影响指数时将受影响人群分为高铁沿线城市本地人群(PED)和过境人群(TPED)。最后总结分析了全国范围内环境健康受过境次数影响的程度大小。通过计算结果可得,华北、华中、四川盆地等地区的大城市,人口多、过境车次多、空气质量相对较差,PED和TPED值较高。华中、华南、西南边境地区城市的空气质量较好,PED和TPED值较低。另外,就特定高铁线路的环境健康影响而言,京津、郑西高铁沿线的PED和TPED值较高;广深、合福、沪昆高铁沿线的PED和TPED值较低。 相似文献
5.
6.
亚欧第二大陆桥沿线中部地区生态环境现状及综合治理研究刘建甫,顾家(新疆维吾尔自治区科学技术委员会乌鲁木齐830011)2沿线中部地区生态环境与经济发展要求的基本适应性分析2.1沿线中部地区的开发建设与生态环境变迁2.1.1前苏联在中亚三国的开发建设和... 相似文献
7.
近几十年来,我国西南喀斯特地区生态环境退化严重,石漠化面积迅速扩大,林地覆盖率急剧下降,成为制约我国西部大开发生态建设中不可回避的重要科学问题,严重影响了西南地区社会、经济的可持续发展。喀斯特地区土层薄且侵蚀严重,土壤中的有机碳和营养盐主要来自地表枯枝落叶层的分解及累积。在气候变暖、陆地生态系统土壤温度升高、土壤有机碳急速流失和土壤质量退化的背景下,分析不同林下凋落物量和降解动态以及土壤有机碳库积累差异,揭示西南喀斯特地区不同林地凋落物归还量及其对土壤碳库积累的贡献具有极其重要的意义,将为喀斯特地区林地恢复重建和石漠化遏制工作提供科研依据。 相似文献
8.
本文分析了西南地区旅游资源的现状,探讨了西南旅游资源的分区,并结合我国当前大力发展第三产业的要求,提出了开发西南旅游资源的对策。 相似文献
9.
10.
11.
ABSTRACT: Irrigated agriculture is one of the most important water-use sectors in terms of total water diversion and consumptive use. For at least the last 25 years, improving irrigation efficiency has been a widely advocated and accepted goal. This paper uses a sample of 16 Bureau of Reclamation irrigation projects to examine the pattern of average irrigation efficiency and change in efficiency over time. In general, the highest average efficiencies are found in the arid Southwest while the lowest are found in the semi-arid to sub-humid Great Plains region. Over the 22-year period of analysis, there has been no observable trend toward improvement in efficiency at any of the projects. 相似文献
12.
Reuben N. Weisz Charles L. Towle 《Journal of the American Water Resources Association》1977,13(5):1035-1046
ABSTRACT: In the past, researchers have applied a variety of analytical techniques for maximizing the present value of a stock resource - simulation, calculus of variations, stochastic dynamic programming, and optimal control theory. This paper presents a more operational approach - linear programming. A simplified, broadly drawn example from Southwest agriculture is used for demonstrating the model's structure and output. The method is based on a set of state transformation operations that prevent the additivity assumption of linear programming from being violated. 相似文献
13.
Jenny L. Plummer 《Journal of the American Water Resources Association》1994,30(4):595-603
ABSTRACT: The arid Southwest of the United States is confronted with increasing water demands and a limited resource. Past efforts to meet water demand have been directed toward development of scarce water resources. While development programs have been successful in stretching available supply, few feasible development options remain. Furthermore, heavy water utilization has affected water quality within drainage basins. It seems likely that water management will play a much more significant role in water resource allocation in the future. This paper will examine water development activity in the Southwest to date. Attention will be given to several of the problems that have arisen. The paper will then examine water management options. Particular attention will be given to water management options being implemented in the State of Arizona. 相似文献
14.
Bryan L. Swift 《Journal of the American Water Resources Association》1984,20(2):223-228
ABSTRACT: An attempt was made to review all available data on the extent and status of riparian ecosystems in the U.S.A. This report presents a synthesis of the findings, including some estimates of how much land was originally covered by woody riparian vegetation, and how much remains in that condition today. A synopsis of information is presented on the status of riparian ecosystems in each of 10 regions: California, Pacific Northwest, Rocky Mountain, Arid Southwest, Plains-Grasslands, Lake States, Corn Belt, Mississippi Delta, Northeast-Appalachian, and Southeast. Woody riparian plant communities once covered an estimated 75 to 100 million acres of land in the contiguous 48 states. Mankind has converted at least two-thirds of that nationwide acreage to other non-forest land uses and it is estimated that only 25 to 35 million acres of riparian plant communities remain in a near natural condition. Across the country, loss of riparian acreages is directly attributable to water resource development (especially channel modification and water impoundment), floodplain clearing for agriculture, and urbanization. In many states of the arid west, the midwest, and the lower Mississippi alluvial valley, riparian vegetation has been reduced in area by more than 80 percent. Riparian woodlands are one of this country's most heavily modified natural vegetation types. 相似文献
15.
处于城市化、工业化发展转型期,经济增长快速且环境荷载具有刚性的中国而言,走低碳化道路已经成为当前的必然选择.未来一段时期,不仅工业和城市要承担减排义务,农业同样肩负重任.作为发展中国家的发展中地区,农村推行CDM的作用显著,以农村为依托的农业执行CDM的意义深远.在CDM基础上,针对中国农业生态环境,通过总结农业发展CDM的内部条件和外部环境因素提出相关对策建议. 相似文献
16.
Poulomi Ganguli Auroop R. Ganguly 《Journal of the American Water Resources Association》2016,52(1):138-167
We examine the robustness of a suite of regional climate models (RCMs) in simulating meteorological droughts and associated metrics in present‐day climate (1971‐2003) over the conterminous United States (U.S.). The RCMs that are part of North American Regional Climate Change Assessment Program (NARCCAP) simulations are compared with multiple observations over the climatologically homogeneous regions of the U.S. The seasonal precipitation, climatology, drought attributes, and trends have been assessed. The reanalysis‐based multi‐model median RCM reasonably simulates observed statistical attributes of drought and the regional detail due to topographic forcing. However, models fail to simulate significant drying trend over the Southwest and West. Further, reanalysis‐based NARCCAP runs underestimate the observed drought frequency overall, with the exception of the Southwest; whereas they underestimate persistence in the drought‐affected areas over the Southwest and West‐North Central regions. However, global climate model‐driven NARCCAP ensembles tend to overestimate regional drought frequencies. Models exhibit considerable uncertainties while reproducing meteorological drought statistics, as evidenced by a general lack of agreement in the Hurst exponent, which in turn controls drought persistence. Water resources managers need to be aware of the limitations of current climate models, while regional climate modelers may want to fine‐tune their parameters to address impact‐relevant metrics. 相似文献
17.
The Guinean rain forest (GRF) of West Africa, identified over 20 years ago as a global biodiversity hotspot, had reduced to
113,000 km2 at the start of the new millennium which was 18% of its original area. The principal driver of this environmental change
has been the expansion of extensive smallholder agriculture. From 1988 to 2007, the area harvested in the GRF by smallholders
of cocoa, cassava, and oil palm increased by 68,000 km2. Field results suggest a high potential for significantly increasing crop yields through increased application of seed-fertilizer
technologies. Analyzing land-use change scenarios, it was estimated that had intensified cocoa technology, already developed
in the 1960s, been pursued in Cote d’Ivoire, Ghana, Nigeria and Cameroon that over 21,000 km2 of deforestation and forest degradation could have been avoided along with the emission of nearly 1.4 billion t of CO2. Addressing the low productivity of agriculture in the GRF should be one of the principal objectives of REDD climate mitigation
programs. 相似文献
18.
19.
Modern agriculture is subject to a metaphysical as well as an ethical critique. As a casual review of the beliefs associated with food production in the past suggests, modern agriculture is embedded in and informed by the prevailing modern world view, Newtonian Mechanics, which is bankrupt as a scientific paradigm and unsustainable as an agricultural motif. A new holistic, organic world view is emerging from ecology and the new physics marked by four general conceptual features: Each level of organization from atoms to ecosystems (1) exhibits emergent properties, (2) exerts downward causation from whole to part, (3) is a systemically integrated whole, (4) the parts of which are internally related. Organic agriculture has been favourably compared with industrial agriculture by the United States National Academy of Science's Board on Agriculture. Aldo Leopold was among the first to criticize industrial agriculture and to envision a new motif for agriculture informed by ecology. A future post-modern ecological agriculture will help to solve the ethical problems engendered by modern mechanical agriculture. 相似文献
20.
Michael S. Carolan 《Local Environment》2006,11(4):421-431
After the last few decades in which the importance of 'local' knowledge has been emphasized, attention must now turn to better understanding how such knowledge is communicated to certified experts (scientists) and vice versa. This paper examines how expert knowledge is co-produced in agriculture by local and non-local experts for the benefit of both. The argument is informed by an empirical case study of sustainable farmers and agriculture professionals in Iowa. While much has been written about how the conventional and sustainable models of agriculture rest upon different epistemological orientations, little has yet been said about how those different experts (local and certified) interact with each other. Building upon the work of H. M. Collins and Robert Evans, and their tripartite model of expertise (of no, contributory, and interactional expertise), I investigate the different forms of expertise that exist within agriculture. In doing so, specific focus is placed upon interactional expertise for creating meaningful exchanges (or interactions) between scientists and non-scientists. 相似文献