首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
基于大连市土地利用空间数据,选用斑块数、斑块分离度、景观多样性指数、优势度指数、均匀度指数、生态环境指数等景观特征指数,从斑块和景观两个尺度对大连市土地利用空间格局进行定量评价,揭示其对区域生态环境的影响。结果表明:(1)旱地景观是大连地区面积最大、分布最广、连续性最强的基质景观;其次,林地景观的面积比例也较大;水田、草地和水域的面积比例较小。(2)城乡用地景观的斑块数最多,其次为林地;旱地景观斑块分离度最小,为0.03其次为林地景观,为0.08;沼泽景观的斑块分离度最大,为2.06。(3)大连市的生态环境指数为0.43,与辽宁沿海其他城市相比较,其生态环境质量的总体状况较好,但仍有提升空间。  相似文献   

2.
基于土地利用变化的辉南县生态脆弱性时空变化分析   总被引:3,自引:0,他引:3  
山区平原过渡地带因其地质、地貌的特殊性而担负着自然地域界面的作用,并表现出更高的生态环境脆弱性,研究其脆弱性变化对山区平原生态安全预警非常重要。特别是从土地利用方式改变评价其生态脆弱性,对于土地利用方式调整和规划具有重要指导意义。本文以地处山区平原过渡区的辉南县为例,在分析其土地利用变化基础上,参照生态价值评估体系并结合周围生态环境敏感因子,建立生态脆弱性综合评价指标,对研究区1986年以来环境脆弱性的时空变化进行评价和分析。评价结果如下:(1)从不同用地类型看,生态综合指数大小顺序依次为林地、草地、水域、未利用地,其次是耕地和建设用地。(2)脆弱性时间变化特征:由于土地利用变化,特别是林地减少和耕地、建设用地增加,导致生态贡献指数、生态稳定性指数和生态综合指数显著下降,分别由1986年的2.999、3.324和6.322减小为2006年的2.828、3.032和5.861。(3)空间变化特征:全区范围内生态环境综合指数下降显著,表现为低值区域范围扩大,高值区域范围明显减小。高值区范围由1986年的33217.95ha缩小为2006年的1283.40ha,而低值区的范围则由1986年的86550.87ha扩大为2006年的98084.83 ha。(4)地区差异性:虽然三个生态指数在整体上呈现下降,但是不同子流域其变化表现出显著的差异性,总体上呈现东南山区减小,而西北平原区呈现不明显的增加特点。本文研究结果表明,导致研究区生态脆弱性的主要原因为林地减少和耕地增加。从保护生态环境角度,控制耕地增加和林地减少是有效防范措施。  相似文献   

3.
[目的]引用俞孔坚的景观安全格局理论,借助Arc GIS10、Conefor Sensinode2.2和In VEST2.2.0制图软件构建青龙满族自治县景观生态安全格局,针对景观生态安全格局各组分的分布特点,提出相应的生态规划对策,以期为青龙满族自治县维护生态系统稳定、合理进行生态规划提供借鉴。[方法]首先,综合考虑斑块自身特征属性和外界环境因素,通过景观斑块质量评价来识别源地;其次,根据最小累积阻力模型构建最小累积阻力面并划分为3个最小累积阻力等级,分别对应生态保育区、生态防护区和生态培育区3个生态功能区;最后,确定生态廊道和战略点。[结果]源地占研究区总面积的3.59%,源地内耕地、园地、林地、草地、水体所占比例分别为0.14%、0.25%、66.86%、17.21%、15.54%;生态保育区占研究区总面积的34.98%,生态保育区内耕地、园地、林地、草地、水体、其他用地所占比例分别为6.73%、8.69%、49.32%、29.57%、3.40%、2.29%;生态防护区占研究区总面积的36.40%,生态防护区内耕地、园地、林地、草地、水体、其他用地所占比例分别为10.31%、18.57%、37.68%、26.67%、1.87%、4.91%;生态培育区占研究区总面积的28.62%,生态培育区内耕地、园地、林地、草地、水体、其他用地所占比例分别为11.31%、15.57%、39.80%、26.70%、2.28%、4.34%;沿景观低阻力区分布有7条生态廊道;有8个战略点。[结论]文章所构建景观生态安全格局基本符合青龙满族自治县实际情况,各景观生态安全格局组分有不同的特点,对应有相应的生态规划对策。  相似文献   

4.
研究目的:探讨矿区景观生态修复策略和技术,以改善矿区景观格局和矿区生态环境质量,保证矿区可持续发展。研究方法:利用RS数据,采用GIS技术和生态景观指标分析方法。研究结果:1987 — 2008年间,斑块连通度、斑块密度、香农多样性指数、均匀度指数增大,优势度指数减低,表明景观破碎化程度提高,多样性增大,生态系统稳定性降低,但耕地面积和最大斑块指数减小最大,耕地的边缘密度增大和连通度降低;水域用地的面积增大,最大斑块指数增大,斑块边缘密度增大和连通度降低,主要原因是采矿造成农地塌陷、地表积水、部分塌陷地被复垦为鱼塘用地等。为此,提出一系列的生态修复模式和生态修复措施,加大对矿区景观生态的斑块—廊道—基底的构建。  相似文献   

5.
采用生态服务价值法对大庆市1996-2007年土地利用变化引起的生态服务价值变化进行了研究,结果表明土地利用类型面积变化为:草地耕地水域未利用地林地建设用地。耕地、林地、水域、建设用地呈增加态势,而其他地类则减少。其中水域增幅最大,达42.31%;牧草地减幅最大,达4.13%。11年间大庆市生态系统服务价值总量增加324506.61万元,主要得益于水域面积的增加,耕地、林地的增加对生态系统服务价值量的增加也起到了一定的作用。这表明大庆市生态建设取得了成效,生态环境质量有所提高。  相似文献   

6.
矿区土地复垦界面要素的演替规律及其调控研究   总被引:11,自引:0,他引:11  
提出了矿区土地复垦界面的概念,分析了矿床开采对潜水位的影响及矿山土特性,提出了复垦土壤生产力指数的修正模型和复垦土地生产力的熵流模型;提出了土地利用多样性指数、矿区水土流失的表现形式和控制方法与复垦界面生态系统能流模型;讨论了矿区土地复垦与生态重建相结合的方法  相似文献   

7.
川滇生态屏障区生态承载力研究——基于生态足迹模型   总被引:1,自引:0,他引:1  
利用供需模型对2010年川滇生态屏障区的生态环境承载力进行监测,通过计算分析生态足迹和生态承载力数据,并构建供需平衡模型(ECCI)估算和评价区域的生态环境承载力。结果表明:该区域主要以生态盈余为主且云南省的生态承载力优于四川省,其中处于生态盈余指数均值达0.35,处于生态赤子的5个县指数均值达1.78,处于生态平衡状态的4个县指数均值达0.97。从县域尺度分析发现:若尔盖县及红原县人均生态足迹均高达14hm~2/人,区域内草地退化严重,处于严重超载。从生态承载力的构成分析发现:草地的人均生态足迹达2.94hm~2/人,化石能源用地的人均生态足迹达0.452.94hm~2/人,均超出了生态承载力的范围,出现了生态赤字,可持续发展面临着严峻的挑战。对此,提出几点建议。  相似文献   

8.
基于3S的平朔矿区土地利用及景观格局演变研究   总被引:2,自引:0,他引:2  
研究目的:以2001年、2004年和2009年3个时段的TM遥感影像为主要数据源,采用景观格局指数分析平朔矿区土地利用和景观格局演变的特征,为矿区土地管理、生态重建建设提供必要的科学依据。研究方法:文献分析法,实证分析法。研究结果:矿区范围内林地、草地、建设用地、矿坑采掘区、矿坑边坡、排土场、矿坑剥离区面积增加,耕地、水域、未利用地面积减少;由于受人为因素的干扰,各类型的景观格局有不同程度的变化,整体景观破碎程度增加,景观多样性增加,形状越来越不规则,各斑块类型在景观中呈现均衡化和多样化方向发展。研究结论:在立足长远目的的基础上,土地复垦措施为矿区的生态重建奠定了重要基础,有效地指引了矿区的可持续规划,但是生态重建的社会、经济、生态环境等的多元性决定了矿区土地复垦内容和标准应随其不断调整优化。  相似文献   

9.
由土地利用变化导致的生态系统服务价值的变化可以作为一个反映土地利用变化环境效应的重要 量化指标。该文参考谢高地等人提出的单位面积生态服务价值系数,对涞水县2001~2010年的土地利用变 化及其对生态系统的影响和驱动因素进行了分析研究。结果表明,2001~2007年和2007~2010年土地利用 类型变化差异较大。2001~2007年,耕地面积有大幅减少,林地、草地面积大幅增加,2007~2010年,耕 地、草地、居民点及工矿用地面积增加明显,园地、林地、滩涂和裸地减少;2007~2010年的土地利用变 化率明显高于2001~2007年;由于林地、滩涂面积的减少和居民点及工矿用地面积的增加,使得整个研究 期生态系统服务价值净减少4 024.47万元;整个研究期间内各项生态系统服务功能都出现不同程度的衰 退。农用地和非农用地经济生态位在研究期内呈波动变化,导致其两者的差值也呈波动变化。驱动因素分 析表明,前期政策因素影响较大,后期社会经济指标对生态系统起负向作用。由于该区特殊的地理位置和 相对薄弱的经济基础,该区域迫切需要处理好经济发展与生态环境的关系,提高土地利用集约度,合理调 整产业结构,进一步完善生态补偿机制等以实现区域生态建设与经济发展互促双赢。  相似文献   

10.
以伊春市2003~2008年的统计数据为基础,利用生态足迹模型对伊春国有林区的生态足迹、生态承载力进行分析,结果表明:从整体上看,伊春林区生态盈余较多,生态压力指数较小,处于安全状态,但是生态盈余度与生态压力指数整体呈下降趋势;从单个因子来看,草地均处于生态赤字状态,林地对伊春生态盈余的贡献率最大,剔除林地后的生态压力指数处于稍不安全状态。针对伊春生态安全现状,提出将生态足迹作为一种地方生态环境考核指标、通过合理规划来控制牧草地的开发利用、发展低耗能、低污染的绿色环保产业等建议。  相似文献   

11.
The theory of demand and supply implies a positive relationship, or “price transmission” between the prices of products at different stages of manufacturing. This relationship was investigated with quarterly prices of softwood stumpage in the US South, and national prices of forest products, from 1977 to 2002. All prices, net of inflation, were found to be nonstationary and there was no evidence of co-integration between prices. Vector autogressive models, augmented by Granger causality tests and multiplier analysis showed that there was a one-to-one permanent positive response of the southern sawtimber stumpage price to a permanent change in the national lumber price. There was also a one-third permanent positive response of the national paper price to a permanent change in the national pulp price. There was no relation between regional pulpwood prices and national pulp or paper prices. When price transmission was significant, the full adjustment took about 2 years.  相似文献   

12.
Owners, local residents, government, and conservation organisations can express divergent preferences in the development and management of local woodlands. The perceptions of these four groups were examined, in the context of three community woodlands in Eastern England, using an ecosystem function framework. In a pilot study, residents were able to allocate a relative importance to woodland ecosystem services which were then related to “regulation”, “habitat”, and “production” or “information” functions. However residents also placed importance on negative services or “dis-services” associated with the woodland ecosystem. Therefore a fifth category of “dis-services” was included in the main survey which included 84 local residents, three woodland owners, three government institutions, and six representatives from conservation groups. Each of the four groups placed greatest importance on services associated with habitat (16–39% of the total importance) and information (30–50%) functions suggesting, in this example, mutual interest in the use of woodlands as a habitat or recreational resource. By contrast a potential area of difference was the particularly high importance placed by one owner on dis-services such as fly tipping. In addition the woodland owners placed higher importance (10–20%), than local residents and conservation groups (7–9%), on the productive services of the wood. This suggests a need for communication when production-related operations affect recreation. The ecosystem function framework appears to be a useful approach for highlighting potential tensions and areas of mutual interest in the management of semi-natural ecosystems.  相似文献   

13.
China is one of the largest wine importing countries in the world and is poised for continued import growth in the future. Increased wine purchases throughout China have given rise to persistent fraud where fake wines are packaged and sold with counterfeit contents and labels. For exporting countries like France, counterfeit wines displace market share, damage foreign brand reputation, and cause distrust in consumers who are aware of counterfeiting problems throughout the country. We examine the impact of fraudulent wine events (as measured by negative media reports) on Chinese wine demand differentiated by supplying country. We employ the Rotterdam demand system and a switching regression procedure to estimate import demand and compare results across different media variable specifications. Results consistently show that negative reports disproportionately affect French wine regardless of how the media variable is specified. This is not surprising because most fraudulent events involve French wine counterfeits.  相似文献   

14.
In recent years earthquakes and their secondary hazards have claimed the largest number of lives of all large natural disasters. Some of the world’s most earthquake-prone zones are also areas of high population density. The impact is magnified by vulnerability factors including non-enforcement of building codes, knowledge gaps, urban poverty and poor governance capacity to manage and reduce earthquake risks. Poor security of land tenure and property rights increases the vulnerability of people and affects their ability to respond to natural disasters.Earthquake recovery and reconstruction provides very significant challenges for land agencies, with these challenges differing from one country to the next due to differences in the local context. Drawing on contrasting case studies in Haiti, Nepal and New Zealand this paper identifies the common post-earthquake land administration functions and challenges that may apply to many contexts. These lessons provide land agencies and other key stakeholders with a summary of the challenges an earthquake poses for land administration at different post-disaster stages. We also discuss the policy and regulatory, institutional, operational and preparedness lessons for land administration. From these lessons we propose a framework for evaluating the earthquake-responsiveness of a land administration system. This framework can be used by a land agency in an earthquake prone region, or where an earthquake has recently occurred, to assess what challenges to land administration might occur in the event of an earthquake, and the preparedness of their land administration system.  相似文献   

15.
This paper analyses poverty and calorific undernourishment in the Indian state of Gujarat, where high and market‐led industrial growth has resulted in rapid economic improvement. The study is carried out through a combination of secondary and survey‐based data. We conclude that the neoliberal agenda of uncontrolled, outward‐looking growth has not resulted in significant reduction of poverty or malnourishment in rural areas. Furthermore, while land ownership is officially used as a proxy for wealth distribution, class position appears a better predictor of poverty status in the rural areas than landownership per se. At the policy level, there is a need to revive the agrarian economy and create new non‐agricultural assets, and the primary focus in the state must shift to the distribution of created assets rather than a single‐minded focus on growth.  相似文献   

16.
This paper tests the ‘systems of innovation’ hypothesis for a selection of crops in Ghana and Burkina Faso that have shown significant growth in production over an approximately 20-year period. The question is whether such growth can only occur if supported by a system of innovation. Using two indicators (a common understanding on objectives and priorities, and a high level of interactivity), we find little evidence for the existence of anything that might be considered a high functioning system of innovation.  相似文献   

17.
The values ascribed to industrial tree plantations are often controversial. Hence knowledge of their perceived impacts is important for improving their integration in rural landscapes. In 2016 we conducted household surveys with 606 respondents living in villages adjacent to acacia, teak and pine plantations across three islands in Indonesia (Java, Borneo, Sumatra). Results show that perceptions toward pine and teak plantations tend to differ from those toward acacia pulpwood plantations in several ways. Pine and teak plantations are perceived to have a higher number and variety of benefits and services, a higher number of positive impacts, a better environmental record, and to present more opportunities to local people for use of plantation land and products for improving rural livelihoods. In addition, we find that villagers around acacia pulpwood plantations tend to seek economic development and infrastructure to open up remote areas, yet their expectations were often only partially met. Recommendations from our analysis include: the role of the State in plantations must be clarified and potentially reinforced; the role of institutions as intermediaries is fundamental; and contributions by communities to design of management plans should be accommodated.  相似文献   

18.
Large‐scale tree plantations in high rainfall upstream areas can reduce fresh water inflows to river systems, thereby imposing external costs on downstream irrigation, stock and domestic water users and wetland interests. We take the novel approach of expressing all benefits and costs of establishing plantations in terms of $ per gigalitre (GL) of water removed annually from river flows, setting upstream demands on the same basis as downstream demands. For the Macquarie Valley, a New South Wales sub‐catchment of Australia’s Murray‐Darling Basin, we project changes in land and water use and changes in economic surpluses under two policy settings: without and with a policy requiring permanent water entitlements to be purchased from downstream parties, before plantation establishment. Without the policy, and given a high stumpage value for trees ($70/m3), upstream gains in economic surplus projected from expanding plantations are $639 million; balanced against $233 million in economic losses by downstream irrigators and stock and domestic water users for a net gain of $406 million, but 345 GL lower mean annual environmental flows. With the policy, smaller gains in upstream economic surplus from trees ($192 million), added to net downstream gains ($138 million) from sale of water, result in gains of $330 million with no reduction in environmental flows. Sustaining the 345 GL flow for a $76 million (406–330) reduction in gains to economic surplus may be seen to cost only $0.22 million/GL; but this is much lower than the market value of the first units of that water to agriculture and forestry.  相似文献   

19.
Fieldwork shows that many Sierra Leonean producers do not receive the official producer price for their coffee and cocoa, due to the concentration of buying stations, credit relations, the small quantities offered for sale, and the lack of marketing knowledge of the numerous and unorganized farmers. To the traders underpayment may seem economically justifiable to a certain extent, but to the farmers it means poverty and debt. A new village marketing centre project aims at remedying this situation and has already led to higher prices. Although no longer allowed to take their "just" share from the producers, traders are still willing to deal with the new centres.  相似文献   

20.
The cost of accessing healthcare can be a major determinant of disease prevalence, which in turn has short‐ and long‐term welfare implications on poor households. In response, governments in developing countries often resort to subsidizing the cost of drugs, which, while perhaps easier to administer, may not always be the most effective way of addressing healthcare cost. In this regard, we analyze the impact of different types of household level health expenses on disease incidence and agricultural production efficiency. We use data from the 2006 Uganda National Household Survey, which covered approximately 7,400 households. The results suggest that a 10% increase in consultation, medicine, and hospitalization expenses would reduce malaria incidence respectively by 35.6%, 20.5%, and 21.3 %, which translates into a 1.1%, 0.6%, and 0.6 % decrease in agricultural inefficiency, respectively. The results indicate that helping poor households meet expenses for consultation through subsidies or eliminating consultation fees has a larger impact on malaria incidence and agricultural productivity among poor rural households than subsidizing the cost of medical drugs, the most common avenue chosen by developing country governments in the fight against the disease.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号