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1.
根据玉溪中心城区降水特性和城市发展状况,对玉溪城市雨水可利用潜力进行分析和评估。玉溪中心城区多年平均降水量973mm,多年平均雨水可利用量2 200万m~3;现状年均雨水可利用量占城市年均总用水量的30%,利用潜力巨大;一般年份雨水可利用效益约合8034万元。随着玉溪海绵城市建设的深入开展,城市雨洪资源的综合利用将得到充分发挥和应用。建议在玉溪海绵城市建设试点工作中,建立完善的监测评估体系,加强城市水文监测调查评价,促进玉溪"海绵城市"可持续发展。  相似文献   

2.
美国城市雨水污染法律对策及其对我国的启示   总被引:2,自引:0,他引:2  
我国城市雨水污染对水体造成的危害已经日益凸现,是传统点源污染防治之外必须同时加以重视的一个重要方面.我国现行的关于雨水污染治理的政策和立法却远远落后于现实的需求和技术领域的研究进展,有待进一步完善,主要表现为<水污染防治法>中缺乏对城市雨水污染类型的确认,现行排水许可适用范围的不确定性,以及雨水治理技术经济激励的缺位等等.通过对我国和美国对城市雨水污染的治理模式以及立法政策的考察,本文探讨了符合我国具体情况的源头治理与末端治理相结合的双重治理模式,并且提出了相应的具体立法建议,如修改<水污染防治法>、<城市排水许可管理办法>、<城市规划法>等相关立法,构建双重管理体制,创设雨水费等一系列的经济激励机制等等.  相似文献   

3.
运用数据包络分析方法(DEA),从城市土地的投入和产出角度,对全国30个省会城市的城市用地经济效益进行比较研究。研究结果表明:(1)在全国30个城市(包括直辖市和部分省会城市),仅上海、杭州、广州和昆明等4个城市为DEA有效城市,即在现有的经济、社会、技术条件下,投入产出达到最佳状态,其余26个城市为非DEA有效城市;(2)南京和哈尔滨处于规模效益递减的发展阶段,上海、杭州、广州和昆明处于规模效益不变的发展阶段,其余24个城市都处于规模效益递增的发展阶段;(3)30个省会城市的城市土地利用经济效益发展极不平衡,呈现东高西低的格局,且城市土地利用普遍不集约;最后对如何提高城市用地经济效益提出了相应的改进措施。  相似文献   

4.
基于DEA模型的城市用地经济效益比较研究   总被引:12,自引:0,他引:12  
运用数据包络分析方法(DEA),从城市土地的投入和产出角度,对全国30个省会城市的城市用地经济效益进行比较研究。研究结果表明:(1)在全国30个城市(包括直辖市和部分省会城市),仅上海、杭州、广州和昆明等4个城市为DEA有效城市,即在现有的经济、社会、技术条件下,投入产出达到最佳状态,其余26个城市为非DEA有效城市;(2)南京和哈尔滨处于规模效益递减的发展阶段,上海、杭州、广州和昆明处于规模效益不变的发展阶段,其余24个城市都处于规模效益递增的发展阶段;(3)30个省会城市的城市土地利用经济效益发展极不平衡,呈现东高西低的格局,且城市土地利用普遍不集约;最后对如何提高城市用地经济效益提出了相应的改进措施。  相似文献   

5.
城市雨水利用是解决城市水资源短缺和减轻内涝灾害的手段之一。以南京市某小区为例,在分析南京市降雨特征的基础上,利用1〖DK〗∶500地形图资料计算了不同降雨保证率条件下该小区屋面雨水可收集量,分析了雨水收集利用在减轻城市内涝方面的作用,并提出了设置地面蓄水池的4条原则,在此基础上调查分析了该小区设置地面蓄水池的可行性。结果表明:在降雨保证率为50%时,通过屋面年可收集利用的雨量为114 272 1 m3;在日降雨量为500和955 mm(南京市多年平均年最大日降雨量)时,屋面雨水利用可减少214%和112%的地表径流;小区内可设置蓄水池的建筑屋面面积占总屋面面积的55%,其中住宅和其他类建筑中可设置蓄水池的建筑屋面面积比例占77%  相似文献   

6.
黄土高原半干旱区雨水利用与可持续农业发展研究   总被引:5,自引:0,他引:5  
黄土高原半干旱区是一个特定的生态类型和重要的农业区域 ,严重的水土流失和频繁的干旱是该区农业可持续发展的主要制约因素。本文在分析雨水利用可行性的基础上 ,提出了农业发展的有效模式———集水型生态农业 ,它不仅适应于当地的雨水等自然资源条件 ,更适应生产力发展水平 ,易于在农户水平上推广 ,并且具有显著的经济、生态和社会效益 ,是实现该区农业可持续发展的战略性举措 ,同时也为“退耕还林 (草 )”开发战略的实施提供了一个思路  相似文献   

7.
本文通过介绍国内外雨洪利用的研究现状,借鉴国内外城市雨洪资源综合利用与治理的经验,分析了聊城市雨洪资源现状,重点提出了适合聊城市的雨水收集蓄存方式和处理利用方法。  相似文献   

8.
农地城市流转中不同权利主体的福利均衡分析   总被引:4,自引:1,他引:3  
以福利经济学为理论基础,探讨了农地城市流转中不同权利主体的福利变化;通过建立农地城市流转的福利分配模型,得出结论:社会福利绝对量的大小和各权利主体所得相对量的大小均与一定阶段内农地城市流转的速度密切相关;政府应确定一个公平、合理的征地价格,才足以弥补农民失地后损失的经济收益和社会保障;并通过构建农地城市流转的社会福利函数,分析了社会福利最大化的实现条件,结果表明:必须按照农业用地边际生产效益等于非农用地边际生产效益的原则配置土地资源,方可兼顾农地非农化配置的效率和公平,并实现土地资源的可持续利用;最后,针对土地市场机制、收益分配机制和失地农民的社会保障机制提出了相关的政策建议.  相似文献   

9.
农户作为农业生产经营的基本主体,农户参与农业生态转型行为是我国农业转型的关键。预期效益和政策激励是影响农户参与农业生态转型的两个重要方面,两者作用如何是值得探讨的重要命题。本文基于山东省两县级市507份设施蔬菜农户调查数据,分析农户参与农业生态转型的影响因素,并运用ISM模型判定各影响因素的内在关联关系和层次结构。研究发现:第一,预期效益中的环保型技术成本预期、废弃物回收利用成本预期对农户农业生态转型参与行为具有阻碍作用,预期效益中的收入预期对农户农业生态转型参与意愿具有促进作用。第二,政策激励中的政府监管和政策补贴对农户农业生态转型参与行为具有明显的靶向指导作用。第三,环保型技术成本预期、废弃物回收利用成本预期等预期效益因素是表层直接因素;政府监管、政策补贴等政策激励因素是深层根源因素。因此,要推进优质优价农产品市场机制形成,提供农业生态转型示范模式。推动设施蔬菜生产的绿色化、优质化、品牌化建设,加强按照环境友好型方式生产出来的绿色蔬菜的辨识度。重视绿色蔬菜示范基地建设,探索可复制可推广的农业生态转型模式,增强农户进一步参与农业生态转型信心。同时,政策约束与政策激励结合,落实农业生态转型政策激励。运用大数据科学制定农业政策,对污染环境、影响农产品质量安全的农业生产方式要严格禁止,并采取经济惩罚措施。对环境友好型生态农业生产方式要加以鼓励引导,对生态循环农业生产给予适当补贴,同时强化政策执行和舆论监督。  相似文献   

10.
自2013年以来,中国频繁出现大规模和持续性的雾霾天气,诸多地方政府不得不采取一系列措施来治理雾霾污染,其中包括广为效仿的机动车限行政策,但其实施效果在不同城市却显示出较大差异性。本文对实施限行政策的11个典型城市的PM2.5浓度进行结构突变点的筛选,并通过控制风速、雨水、湿度、温度等气象因素,建立多元回归模型以分析PM2.5浓度与机动车限行政策的相关性。结果发现,气象因素对于各城市的雾霾污染有着不同的影响。其中,风级、降雨、温度在大部分城市是负向且显著的影响,湿度在部分城市是正向且显著的影响。本文根据限行效果的不同将11个城市分为三类:限行有效、限行无效和限行效果不显著城市。为了进一步考察不同类型的典型城市限行的效果为何不同,选取了北京、天津、西安三个城市从经济、产业、能源以及交通等四个维度进行对比分析,发现不同类型的城市由于城市形态及雾霾成因各不相同,雾霾污染的治理措施也需要"因地制宜"。基于此,本文对不同形态的城市雾霾污染治理提出以下建议:(1)当城市发展处于高经济-低污染形态时,机动车限行政策是雾霾污染治理的有效手段,但治理的根本在于控制城市机动车保有量,优化城市发展职能,降低城市人口密度;(2)当城市发展形态处于高经济-高污染形态时,机动车限行政策不是城市治理雾霾污染的最有效手段,政府应加快产业结构转型升级,优化能源消耗结构,加大污染治理投资力度;(3)当城市发展处于中、低经济-高污染阶段时,机动车限行政策无效,城市发展应注重优化投资结构,转变产业发展模式。  相似文献   

11.
Latin America comprehends notable variations in terms of natural environment, availability of natural resources, living standards, and demographic patterns. Latin America is a mosaic of cultures, post- and pre-Columbian. The rich variety of life forms discovered and described by chroniclers and traveling naturalists in the Neotropics contributed to the proposal, in mid-XVIIIth century, of a new system of classification and a scientific code of nomenclature for all organisms. Biodiversity was, for many centuries, a source of resources to be exploited in natura. In scientific circles, its inventory became the domain of taxonomists. But modern technology showed how important the miriad of life forms really are as sources of chemical molecules to be engineered as drugs and reassembled as novel manufactured products. We are on the brink of a new agricultural and medical revolution, thanks to the techniques of genetic engineering, which will lead eventually to the elimination of hunger and malnutrition.In this essay, the Brazilian environmental and social heterogeneity will serve as an example to illustrate some key points, which have influenced sustainability policies. The Amazon deforestation and indigenous knowledge (IK), subjects often associated with areas of high biodiversity, are usually the focus of environmental debates. The importance of IK in integrating development, reducing poverty and sustainability are considered together with the intellectual property rights of native populations.In the World Summit on Sustainable Development (WSSD) Implementation Plan, a few paragraphs were dedicated to Latin America, because of the pre-existing Action Platform on the Road to Johannesburg 2002, approved in Rio de Janeiro in October 2001. This paper calls attention to the need to draw up specific environmental policies for a region which shows an extremely high cultural and biological diversity, associated with a high availability of forests and water, among other resources.  相似文献   

12.
The size of shells in some freshwater pulmonate mollusk species abundant in Western Siberia (Lymnaea fragilis, L. terebra, Planorbis planorbis, and Anisus leucostoma) is relatively large in the south and decreases in the north. It is supposed that this phenomenon is explained by the fact that the season with conditions allowing the growth of mollusks is shorter in the north than in the south of Western Siberia.  相似文献   

13.
湘鄂赣地理位置优越,农业资源丰富,稻谷、茶叶、麻类、棉花、油料、柑桔和淡水产品、禽蛋、肉类等在我国居有重要的地位,因此,大力发展三省农业生产,对我国人民实现小康生活具有战略意义。今后,要加速专业化区域化进程。我们找出生产潜力所在:改造低产田、低产园、低产水面;开发“三高”技术;开垦荒地、荒山、荒水;适当提高复种指数。通过建设,三省主要农产品将自给有余,还可满足国内外市场的需要。努力方向:高效农业开发——综合农业开发,吨粮田开发,玉米带开发,饲料稻开发,山区开发;合理布局农业生产;深化农业商品基地建设,发展综合利用,搞活商品流通;全面提高农业现代化水平,加强农业社会服务体系。  相似文献   

14.
Integration of indigenous knowledge and ethnoscientific approaches into contemporary frameworks for conservation and sustainable management of natural resources will become increasingly important in policies on an international and national level, both in countries that are industrialised and those that have a developing status. We set the scene on how this can be done by exploring the key conditions and dimensions of a dialogue between ȁ8ontologiesȁ9 and the roles, which ethnosciences could play in this process. First, the roles of ethnosciences in the context of sustainable development were analysed, placing emphasis on the implications arising when western sciences aspire to relate to indigenous forms of␣knowledge. Secondly, the contributions of ethnosciences to such an ȁ8inter- ontological dialogueȁ9 were explored, based on an ethnoecological study of the encounter of sciences and indigenous knowledge in the Andes of Bolivia, and reviewed experiences from mangrove systems in Kenya, India and Sri Lanka, and from case-studies in other ecosystems world-wide, incl. Australia, Burkina Faso, Ecuador, Ethiopia, Guatemala, Indonesia, Nepal, Niger, Philippines, Senegal, South-Africa and Tanzania.  相似文献   

15.
We review studies of the effects of low ambient ozone concentrations on morbidity that found a negative coefficient for ozone concentration. We call this a Paradoxical Ozone Association (POA). All studies were in regions with methyl ether in gasoline. All but one study carefully controlled for the effects of other criterion pollutants, so the phenomenon cannot be attributed to them. One was in southern California in mid-summer when ozone levels are highest. Because ozone is created by sunlight, the most plausible explanation for a POA would be an ambient pollutant that is rapidly destroyed by sunlight, such as methyl nitrite (MN). A previously published model of engine exhaust chemistry suggested methyl ether in the fuel will create MN in the exhaust. MN is known to be highly toxic, and closely related alkyl nitrites are known to induce respiratory sensitivity in humans. Support for the interpretation comes from many studies, including three linking asthma symptoms to methyl tertiary butyl ether (MTBE) and the observation that a POA has not been seen in regions without ether in gasoline. We also note that studies in southern California show a historical trend from more significant to less significant ozone-health associations. The timing of those changes is consistent with the known timing of the introduction of gasoline oxygenated with MTBE in that region.  相似文献   

16.
The use of quantitative data for constructing prognostic maps of the dynamics of ecosystem degradation and restoration by nonlinear simulation methods is a topical field of landscape ecology. This method of dynamic cartography is based on fiberwise comparison of data on the state of Chernye Zemli (the Kalmyk Republic, Russia) in different years and the detailed analysis of the period on which the prognosis was based. For this purpose, materials of repeated aerial and satellite photography obtained during a long period (1954–1993) were used. Comparison of maps characterizing the dynamics of Chernye Zemli between 1958 and 1993 allows prognostic electronic maps for the next 10–15 years (with a five-year interval) to be drawn and land prognosis for the next 20–30 years (1998–2023) to be obtained. Deceased  相似文献   

17.
Information regarding the distribution of volatile organic compound (VOC) concentrations and exposures is scarce, and there have been few, if any, studies using population-based samples from which representative estimates can be derived. This study characterizes distributions of personal exposures to ten different VOCs in the U.S. measured in the 1999-2000 National Health and Nutrition Examination Survey (NHANES). Personal VOC exposures were collected for 669 individuals over 2-3 days, and measurements were weighted to derive national-level statistics. Four common exposure sources were identified using factor analyses: gasoline vapor and vehicle exhaust, methyl tert-butyl ether (MBTE) as a gasoline additive, tap water disinfection products, and household cleaning products. Benzene, toluene, ethyl benzene, xylenes chloroform, and tetrachloroethene were fit to log-normal distributions with reasonably good agreement to observations. 1,4-Dichlorobenzene and trichloroethene were fit to Pareto distributions, and MTBE to Weibull distribution, but agreement was poor. However, distributions that attempt to match all of the VOC exposure data can lead to incorrect conclusions regarding the level and frequency of the higher exposures. Maximum Gumbel distributions gave generally good fits to extrema, however, they could not fully represent the highest exposures of the NHANES measurements. The analysis suggests that complete models for the distribution of VOC exposures require an approach that combines standard and extreme value distributions, and that carefully identifies outliers. This is the first study to provide national-level and representative statistics regarding the VOC exposures, and its results have important implications for risk assessment and probabilistic analyses.  相似文献   

18.
19.
In early 1980 an extension agent was assigned to the rural municipality of Bangui, Ilocos Norte, Philippines to work on development projects – in particular the improvement of the supply of safe water for drinking and sanitation. After many months of visiting spring sites and meeting with community leaders, a small part of the municipality was selected to build a gravity fed piped water system. Although the system took many months to plan, identify funding and construct, the 600 community members were ultimately rewarded with house to house connections that enabled them to achieve per capita water consumption levels above the minimum levels recommended by the World Health Organization. Of course, money was critical to ensure the project’s success, but many other factors played an equally critical role. For instance, without the active participation of the community and the unwavering support of the community leadership the project would not have survived the initial planning stage. Also, the extension agent played a critical role by acting as a conduit between funding agencies, the Bureau of Public Works and the community. The primary lesson to be learned from this experience is that the success of rural development projects is largely driven by the synergy between the community, technical support, financial support, and agents of change such as extension agents. If any of these ingredients had been lacking, the project result would likely have been far different.  相似文献   

20.
Variation in the reproduction of Varroa jacobsoni mite was studied in relation to the expansion of the range of its parasitism on the honeybee. Geographic differences in the seasonal dynamics of mite reproduction in the nests of bee families were revealed. Variation in the sex ratio of mites and the factors inhibiting their reproduction at the northern boundary of the honeybee range are considered. The forms of parthenogenetic reproduction in V. jacobsoni are discussed.  相似文献   

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