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81.
对我国地震旅游资源开发利用的探讨 总被引:3,自引:0,他引:3
为开发和利用地震旅游资源,发展旅游经济,本文探讨了地震旅游的内容、特点、意义和功能;列出了震迹旅游资源和震记旅游资源的主要景点目录;提出了开发地震旅游活动应作好的几项工作;以期推动此项工作的开展。 相似文献
82.
Albert Rango Victor van Katwijk 《Journal of the American Water Resources Association》1990,26(1):135-144
ABSTRACT: The snowmelt-runoff model (SRM) was used to produce accurate simulations of streamfiow during the snowmelt period (April-September) for ten years on the Rio Grande Basin (3419 km2) near Del Norte, Colorado, U.S.A. In order to use SRM in the forecast situation, it was necessary to develop a family of snow cover depletion curves for each elevation zone based on accumulated snow water equivalent on April 1. Selection of an appropriate curve for a particular year from snow course measurements allows input of the daily snow cover extent to SRM for forecast purposes. Data from three years (1980, 1981, and 1985) were used as a quasi-forecast test of the procedure. In these years forecasted snow cover extent data were input to SRM, but observed temperature and precipitation data were used. The resulting six-month hydrographs were very similar to the hydrographs in the ten simulation years previously tested based on comparisons of performance evaluation criteria. Based on this result, the Soil Conservation Service (SCS) requested SRM forecasts for 1987 on the Rio Grande. Using the same procedure but with SCS estimated temperature and precipi-tation data, SRM produced a forecast hydrograph that had a r2= 0.82 and difference in seasonal volume of 4.4 percent. To approximate actual operational conditions, SRM computed daily flows were updated every seven days with measured flows. The resulting forecast hydrograph had a R2= 0.90 and a difference in volume of 3.5 percent. The method developed needs to be refined and tested on additional years and basins, but the approach appears to be applicable to operational runoff forecasting using remote sensing data. 相似文献
83.
环境补偿制度——解决环境问题的经济手段之一 总被引:4,自引:0,他引:4
为了保护环境,使环境资源可持续利用,应该建立环境补偿制度。环境补偿制度是解决环境问题的有效手段之一。本文从环境补偿的概念出发,对环境补偿制度的理论基础,建立目的、征收原则及对象等内容进行了探讨。 相似文献
84.
Further studies on the influence of zeolite type A on metal transfer in the activated sludge process
Investigations were carried out to determine the effect of zeolite type A on metal removal by activated sludge using laboratory activated sludge simulations. They were operated at constant aerator sludge age and settler surface loading. Different concentrations of raw zeolite and zeolite extracted from washing powder (0, 15, 30, 60, 120 mgl?1) were introduced into the simulations. The zeolite was added at two degrees of calcium exchanged for sodium, 25 and 75% of the maximum exchange capacity. Metals were added at concentrations typical of mixed domestic-industrial waste waters. The results show that there was no adverse effect on metal removal by the laboratory activated sludge simulations in the presence of zeolite type A. 相似文献
85.
自1997年在死海地区的大气边界层中观测到午间臭氧浓度迅速下降的现象后,研究学者们即对该地区的臭氧耗损现象(ozone depletion events,简称ODEs)展开了研究.而在此之前,大气边界层内的ODEs现象普遍被认为只会发生在极地地区的特殊大气现象.本文综述了关于死海地区ODEs研究的发展历史,主要展示了促... 相似文献
86.
This article suggests that Asia’s groundwater socio‐ecology is at an impasse. Rapid growth in groundwater irrigation in South Asia and the North China plains during the period 1970–95 has been the main driver of the agrarian boom in these regions. India, Pakistan, Bangladesh and China account for the bulk of the world’s use of groundwater in agriculture. On the plus side, groundwater development has provided sustenance to agrarian economies and millions of rural livelihoods. On the downside, it has created chronic problems of resource depletion and quality deterioration. While problems of groundwater depletion, pollution and quality deterioration are indeed serious, so are the consequences of the degradation of the resource for those that have come to precariously depend upon groundwater irrigation. Three problems currently afflict groundwater use: depletion due to overdraft; water logging and salinization; and pollution due to agricultural, industrial and other human activity. The pathology of the decline in groundwater socio‐ecology reflects a remarkably similar pattern across regions. The critical issue for Asia now is: what might be done to sustain and revive these groundwater socio‐ecologies vital to the region’s economy? This article reviews a variety of techno‐institutional approaches. However, transposing lessons from the industrialized world uncritically in the Asian context may not work. A more nuanced understanding of the peculiarities of Asia’s groundwater socio‐ecology is needed. 相似文献
87.
石墨烯对高等植物幼苗的毒性及机理探究 总被引:1,自引:0,他引:1
随着石墨烯产品的广泛应用和潜在的环境释放,其对生态环境的影响已引起广泛关注。为探讨石墨烯对高等植物生长的影响,探究了其对黄瓜幼苗和玉米幼苗生长的影响及其致毒机理。结果表明,水培条件下,不同浓度的石墨烯(10、50、100、500、1 000和2 000 mg·L~(-1))处理植物幼苗15 d后,对植物幼苗的生长具有抑制作用。且随着处理时间和石墨烯浓度的增加,植物幼苗生长的所有指标,包括根/地上部鲜重和干重、根长、根尖数、株高和叶面积均相应降低。另外,黄瓜幼苗比玉米幼苗对石墨烯更加的敏感。进一步研究发现,石墨烯与黄瓜幼苗根部直接接触导致的物理损伤、氧化损伤,以及营养耗竭是其致毒机理。而石墨烯对玉米幼苗的致毒机理包括物理损伤和营养耗竭。本研究为石墨烯的环境风险评价提供了基础数据。 相似文献
88.
Because choice is conflict, decision-making is necessarily about conflict resolution. Choices are necessary because the options
are mutually exclusive but the nature of this inherent conflict varies. Typically, these conflicts are multidimensional. In
coasal zones, the complex interactions between systems makes decision-making particularly complex; in particular, environmental
interests are themselves frequently in conflict. In making a choice, it is important to determine why that choice is necessary
in the first place.
There are further conflicts about the objectives to be satisfied by the decision process; between the determination of the
best outcome and the best decision process. Social scientists centre upon the requirement for a fair decision process rather
than upon seeking an optimum outcome. Unlike physical scientists who seek more and better information, social scientists focus
upon the development and maintenance of institutions. 相似文献
89.
Even though “sustainable development” seems to have emerged as the development paradigm of the 1990s, a great deal of vagueness
still surrounds the meaning, definition, and theoretical underpinnings of the concept. There is also a general lack of emphasis
on the spatial dimension of sustainable development when developing relevant conceptual or environmental accounting frameworks.
In clarifying the concept, this article proposes a definition that explicitly incorporates the temporal as well as the spatial
dimension of sustainability. It also develops a logically consistent conceptual framework for the analysis and evaluation
of sustainable development, following a spatial systems approach. Five interconnected aspatial subsystems or subsets of a
spatial system are identified and their respective operational dimensions discussed. A proposed composite index calleddegree of stainable development (DSD) and its five component indicators are also outlined. The difficulties involved in operationalizing the DSD measure
and the conceptual framework are noted, and the various tasks that need to be undertaken in this regard are specified. It
is concluded that future research utilizing the proposed conceptual framework should not only foster the development of appropriate
methodologies for the comparative evaluation of sustainable development at global, national, or regional scales, but also
offer insights to appropriate decision makers at various levels regarding available options and alternative actions for the
healthy development of their respective societies. 相似文献
90.
Optimization of tourism impacts within protected areas by means of genetic algorithms 总被引:1,自引:0,他引:1
The search for a balance between nature conservation and tourism development within protected areas is becoming an increasingly multifaceted problem worldwide, as outlined by an increasing number of authors and highlighted at several international events. Since it is unlikely that all management objectives will reach their optimum values simultaneously, an optimization approach is required to meet multiple, conflicting goals and to obtain an overall trade-off in terms of the conceived objectives. 相似文献