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1.
湿地景观格局的动态变化与区域土地利用/覆盖格局的变化有着十分紧密的联系。以纳帕海、碧塔海和属都湖三块高原湿地所在的云南省香格里拉县建塘镇为例,在遥感和GIS技术的支持下,对该区域1974、1987和2000三期Landsat TM(ETM)影像进行了解译,分析了26 a间的土地利用/覆盖变化规律,并结合景观格局动态分析的方法,借助FRAGSTATS软件定量分析了该区景观格局特征及其动态变化。结果表明:该区土地利用/覆盖状况变化显著,主要土地利用/覆盖类型有林地以822 hm2/a的速度在大面积减少,并主要转为灌木林地,使得后者在26 a间扩大高达17倍,变化幅度最大。建设用地和耕地的面积分别扩大了6倍和2倍,而草地和雪地面积持续减少。相应地,该区景观格局定量分析显示,有林地的斑块密度增大而平均斑块面积减小迅速,呈破碎化趋势,灌木林地的斑块密度、平均斑块面积均增加,草地则与之相反均减小,耕地的斑块密度降低而平均斑块面积增加,在不断融合成大斑块,其余各景观单元斑块密度增大平均斑块面积减小,同时各斑块几何形状在1987年变化最剧烈,景观格局趋于复杂。 相似文献
2.
基于TM和ETM+遥感分析的石家庄市土地利用/覆被变化研究 总被引：25，自引：10，他引：15
文章利用Landsat的TM 和ETM+数据,对石家庄市1987年和2001年的土地利用/覆被进行分类,并对这一期间发生的土地利用/覆被变化进行了定量分析。结果显示:研究区主要土地利用/覆被类型可以划分为城市用地、居住用地、农田、菜地、林地、果园、草地、水体、沙地/裸地等9类;研究区域发生的土地利用/覆被变化主要由近年来的快速城市化过程引起。变化较大的土地利用类型为城市用地、农田、菜地和林地;变化较大的区域主要分布在城市的边缘和市区的东部及西北部。 相似文献
3.
ABSTRACT. Tropical montane forests are known for their ecological importance. Most montane forests in Ecuador have been converted to agriculture, and those that remain are concentrated on the eastern cordillera. Understanding of land‐use‐land‐cover change in this ecological zone is inadequate. Using remote sensing (Landsat tm, spot ) and fieldwork, we document land‐use‐land‐cover change in two watersheds on Ecuador's eastern cordillera (Cañar Province). During the 1990s the region experienced a 0.58 percent annual rate of deforestation, but two areas within it show active signs of re/afforestation. Although conversion of forest to pasture for cattle grazing continues, human migration to the United States is likely to affect the trajectory of future land‐use‐land‐cover change. 相似文献
4.
江汉平原土地利用的时空变化及其驱动因素分析 总被引：31，自引：4，他引：27
采用遥感、GIS一体化技术,利用1989～1990、1995～1996和1999～2000年获取的三期陆地资源卫星图像,对江汉平原土地利用10年变化和以1995～1996年为界的前后两个5年变化的时空特征进行了分析,并探讨了变化的驱动因素。结果表明,该区的土地利用在不同的时间及空间尺度上有明显不同的特点。10年间,耕地减少近5万hm2,其中,前5年的减少量占多数,达6783%。各类建设用地总计增加了156万hm2,其中,前5年的增加量是后5年的2倍。水域面积在10年间增加了达到354万hm2,后5年的增幅不到前期的1/2。土地利用变化最快的区域均处于工业经济较发达、城市化较快的地区如武汉、仙桃,变化最慢的区域在监利、松滋、天门等地。政策、社会经济与科技因素对土地利用随时间尺度的变化有决定性的影响。 相似文献
5.
基于Landsat TM/ETM数据的锡林河流域土地覆盖变化 总被引：29，自引：2，他引：27
根据1987年、1991年、1997年和2000年4期Landsat TM/ETM影像的土地利用/土地覆盖分类结果,运用地理信息系统空间分析方法,分析了内蒙古锡林河流域1987~2000年间各土地利用类型及草甸草原、典型草原、荒漠草原的数量变化和空间变化特征。分析结果显示,锡林河流域土地利用/土地覆盖变化的主要特征为草甸草原、典型草原面积的大幅减少和荒漠草原、农田和沙漠化土地面积的大幅增加及城镇的扩张。其中面积增加最大的是荒漠草原,增加了2328 km2;相当于1987年荒漠草原面积的56 %。农田和城镇面积逐年增大,分别从1987年的114.3 km2和25.2 km2增加到2000年的332.1 km2和43.6 km2。面积减少最多的是羊草＋丛生禾草、羊草＋杂类草等优良高产温带典型草原类型,共减少2040 km2。草甸草原面积亦呈逐年减少的趋势,从1987年的1103 km2减少到2000年375 km2,面积减少了65.9 %。农田、沙化地及城镇等非草原土地利用类型面积增加了62.5 %。 相似文献
6.
采用1987、1999年和2008年3期TM卫星数据, 对额济纳绿洲2000年黑河分水前后土地覆被变化进行了研究, 并分析了额济纳绿洲土地覆被变化的驱动因素。结果表明:(1)从不同覆盖等级的面积变化来看, 额济纳绿洲的主体是中植被覆盖区。1987-1999年额济纳绿洲的植被呈退化趋势。2000年黑河分水后至2008年, 额济纳绿洲植被退化的趋势已得到缓解。(2)从不同土地利用类型的面积变化来看, 额济纳绿洲的主体是戈壁。1987-1999年额济纳绿洲植被退化, 荒漠化趋势明显。2000年黑河分水后至2008年, 植被有所恢复, 退化趋势得到了遏制。(3)影响土地覆被变化的主要有3类因素。第一主成分与人为因素密切相关, 说明过去的十几年额济纳绿洲的土地覆被变化主要受到人类活动影响。第二主成分与地表径流量、年降水量、年均风速有较大的相关, 第三主成分与地下水埋深有较大的正相关, 表明气候因素对额济纳绿洲的土地覆被变化也有一定程度的影响。根据以上结果, 提出应对策略:(1)保证来自中上游的地表径流供给;(2)合理利用地下水资源;(3)增加技术支持, 实现宏观调控。 相似文献
7.
中国建设用地规模变化及其影响因素 总被引：1，自引：0，他引：1
建设用地是经济社会活动的重要基础, 建设用地规模变化与经济社会发展有着密切的关系, 深入分析中国建设用地规模及其变化的影响因素, 对于正确认识中国土地利用中存在的问题及其未来改革创新方向具有深远意义。基于1996 年和2007 年的中国土地利用变更调查数据及经济社会统计数据, 采用逐步回归分析方法, 分别对1996 年和2007 年中国建设用地规模及其变化同经济社会因素的相关关系进行了定量研究。结果发现, 1996 年和2007 年中国建设用地规模同经济社会因素的相关关系有所不同。1996 年中国建设用地规模与非农产业产值、总人口正相关, 与城镇居民人均收入负相关;2007 年建设用地规模仅与总人口呈正相关关系。1996-2007 年间中国建设用地规模变化仅与财政收入变化、城镇人口变化呈正相关, 与非农业产值变化没有显著的相关关系。这一结果表明, 1996 年中国建设用地规模与经济社会发展状况相对比较协调, 2007 年则变得不够协调, 1996-2007 年间建设用地规模增加的主要动力源于地方政府对土地财政的严重依赖性和中国的快速城镇化, 与产业发展和经济增长的协同性较弱。建设用地规模增加与经济社会发展的失调不利于中国社会经济的可持续发展, 从长远来看, 需要改革不合理的财政体制和土地征用制度。 相似文献
8.
北京丰台区农村居住用地变化及与人口相关模型 总被引：12，自引：1，他引：12
采用GIS技术和统计分析技术，基于1984年，1992年，1996年和1999年4期土地利用图件和数据，分析了1984－1999年期间北京丰台区农村居住用地变化过程及地域分异特征；提出并应用特征均值探讨了农村人均居住用地和人居密度变化的过程和趋势，以行政村为基本单元，利用1999年农村居住用地数据与对应的农村人口数据建立了表达式为Sv=11.324e^0.0006pv的农村居住用地与人口相关模型；用1992年数据对模型进行检验和误差分析的结果表明，模型适用地域为北京近郊且不邻近卫星城镇的农村区。 相似文献
9.
卧龙自然保护区土地利用变化对土壤性质的影响 总被引：24，自引：2，他引：24
森林景观受干扰后的次生演替、人工林种植与农业耕作等在许多方面影响着土壤性质的变化。研究选取了四川卧龙自然保护区作为研究地点 ,阐述湿润高山区的土地利用方式与土壤性质之间的关系。选择了六种典型的土地利用方式加以比较 ,方差分析结果表明 ,不同土地利用之间土壤容重、全氮、有机碳、速效磷、速效钾的含量差异显著。相比之下 ,农田土壤养分含量偏低 ,而灌丛有着较高的有机碳、总氮与有效氮含量。 0～ 4 0cm土壤碳的储量变化幅度不大。综合土壤退化指数表明 ,坡耕地 ,撂荒地与人工林有土壤退化的趋势 ,而灌丛与次生林对土壤的性质有着改善的作用。人工林年龄与土壤有机碳、有机氮的含量正相关。 相似文献
10.
1974-2011年白洋淀土地覆盖时空变化特征 总被引：1，自引：0，他引：1
在野外调查的基础上,运用遥感和地理信息系统技术对1974年、1979年、1984年、1987年、1989年、1991年、1996年、2001年、2006年和2011年10期遥感影像进行解译和分析,揭示了白洋淀近37年土地覆盖动态变化。结果表明:近37年白洋淀土地覆盖类型变化极为复杂,主要表现为水体、芦苇地、耕地3种土地覆盖类型相互转化。1974-2011年,水体面积从58.01 km2上升到80.07 km2,芦苇地面积从104.94 km2下降到72.95 km2,水生植被从14.02 km2下降到4.27 km2。1974-2011年,耕地、水体、芦苇地、居民点转化为其它类型的比例相对较小,分别为39.25%、34.46%、53.74%和18.15%。水体面积增加主要分布在地势较低的东部和北部地区,水体面积减少主要分布在地势较高的西南地区。水位变化、入淀径流量变化、淀区气候变化、人类活动及管理政策是白洋淀土地覆盖变化的驱动因子。研究揭示了白洋淀土地覆盖与人类活动的相互作用关系,对白洋淀土地管理和生态系统服务可持续供给具有重要意义。 相似文献
11.
Landscape transformations in savannas of northern South America: Land use/cover changes since 1987 in the Llanos Orientales of Colombia 总被引：2，自引：0，他引：2
This study presents a detailed spatial, quantitative assessment of the land use/cover changes (LUCC) in the savanna region of Llanos Orientales in Colombia. LUCC was determined from multitemporal satellite imagery (Landsat and CBERS) from 1987 to 2007. Systematic landscape transitions were identified and put in the context of population change and economic activity. The results showed that during the period 1987 to 2007, 14% of the study area underwent some kind of land use/cover change, with most change occurring in the last decade. Systematic transitions were observed from flooded savannas to crops and exotic pastures. An important land cover change was linked to the expansion of palm oil plantations from 31 km2 in 1987 to 162 km2 in 2007. The observed changes are shown to be related to the economic and market-oriented-development from before 1970 to the present day. Based on the future economic development plans, the Llanos Orientales will continue to undergo significant change as an estimated 70% of the 17,000 km2 have been identified for conversion to plantation, or for petroleum and mining purposes. We provide recommendations for future economy integrated conservation, by proposing the implementation of a Llanos ecological network. 相似文献
12.
Tina Svan Hansen 《Singapore journal of tropical geography》2005,26(2):170-190
This paper focuses on the large‐scale land use and land cover changes that have taken place in Sarawak state, East Malaysia over the three decades of 1972‐2002. Results are presented from a detailed land use and cover change (LUCC) study in the Niah River catchment using satellite imagery, questionnaire surveys and interviews. Successive waves of land cover changes have taken place. Large forest areas have been logged and gradually replaced by oil palm plantations, which now occupy more than 40 per cent of the total land area in the catchment. Concurrently, small‐scale farming systems have also changed. Formerly dominant Iban shifting cultivation practices are increasingly being replaced by cash crop production on permanent fields and impacted by off‐farm activities involving many ethnic groups. It is argued that land cover changes are continuous and complex processes involving a large number of variables which can be analysed for different time periods at various scales. 相似文献
13.
2000-2010年中国退牧还草工程区土地利用/覆被变化 总被引：1，自引：0，他引：1
在3S技术支持下,结合景观格局定量分析方法,基于30 m分辨率的土地利用/覆被数据,对中国退牧还草工程区2000-2010年土地利用/覆被时空分布特征进行研究。通过利用土地利用转移矩阵和动态度来判定土地利用变化的速度和区域差异,并在斑块类型和景观水平上分析研究区景观格局特征,探讨土地利用格局变化的生态效应。结果表明：①近10年来,研究区土地利用/覆被类型以草地和其他类用地为主,整体内部结构稳定少动。草地变化面积仅占2000年草地总面积的0.37%;林地、湿地、耕地和人工表面的面积均有所增加;其他类用地面积有所减少。②全区土地综合动态度均小于0.1%,土地利用/覆被变幅较小,除人工表面较活跃外,其他各类型变化相对缓慢,且各省土地利用区域差异较小。③研究区内景观基质未发生改变,区域景观破碎度递减,景观多样性水平上升,景观聚集度和连续性微弱下降,景观整体保持较完整态势。退牧还草工程的实施使土地利用/覆被结构和景观格局均得以优化。 相似文献
14.
《Applied geography (Sevenoaks, England)》2006,26(2):129-152
This article uses remote sensing and spatial modeling to quantify and analyze land change in Mexico's largest protected area, the Calakmul Biosphere Reserve. Change trajectories are identified within distinct property regimes and between the Reserve's core and buffer zones. A parcel-level spatial econometric model identifies the driving forces of land use change in two communities located along the eastern edge of the Reserve, the locus of increased deforestation in 1987–1996. The study assesses the role of biophysical variables, locational context, household socioeconomics and institutional factors in driving deforestation. The results address the effectiveness of reserves and other state policy instruments in protecting forests. 相似文献
15.
In order to advance land use and land cover change (LUCC) research in Nepal, it is essential to reconstruct both the spatiotemporal distribution of agricultural land cover as well as scenarios that can explain these changes at the national and regional levels. Because of rapid population growth, the status of agricultural land in Nepal has changed markedly over the last 100 years. Historical data is used in this study, encompassing soils, populations, climatic variables, and topography. Data were revised to a series of 30 m grid cells utilized for agricultural land suitability and allocation models and were analyzed using a suite of advanced geographical tools. Our reconstructions for the spatiotemporal distribution of agricultural land in Nepal reveal an increasing trend between 1910 and 2010 (from 151.2 × 102 km2 to 438.8 × 102 km2). This expanded rate of increase in agricultural land has varied between different eco, physiographic, and altitudinal regions of the country, significantly driven by population changes and policies over the period of this investigation. The historical dataset presented in this paper fills an existing gap in studies of agricultural land change and can be applied to other carbon cycle and climate modeling studies, as well as to impact assessments of agricultural land change in Nepal. 相似文献
16.
Causes of land salinization were determined via land cover and hydrological process change detection in a typical part of Songnen Plain. The area of saline land increased from 4627 km2 in 1980 to 5416 km2 in 2000, and then decreased to 5198 km2 in 2015. The transformation between saline land and other land covers happened mainly before 2000, and saline land had transformation relationship mainly with cropland, grassland, and water body. From 1979 to 2007, groundwater depth fluctuated to increase and was mainly deeper than 3.3 m. Spatially, the area of the region where groundwater depth was deeper than 3.3 m increased from 46.7% in 1980 to 84% in 2000, while the area of the region almost occupied the whole region after 2000. Precipitation and evaporation changed little, while runoff decreased substantially. Shallow groundwater, change of cropland, grassland, and water body induced from human activities and decrease of runoff and increase of irrigation and water transfer from outer basin were the main reasons for land salinization before 2000. After 2000, groundwater with relatively great depth could not exert great influence on land salinization. Protection of grassland and wetland prevented the increase of the area of saline land. 相似文献
17.
A geospatial approach to assessing land change in the built-up landscape of Wa Municipality of Ghana
《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2012,112(2):121-135
ABSTRACTUrban landscapes are changing in response to changes in socio-economic conditions. Land change scientists seek to understand these land dynamics in the coupled human-environment system of urban landscapes. This study assessed land change in the built-up area of Wa Municipality between 1986 and 2016 using Landsat images. We used the Support Vector Machine algorithm for classifying the images. We recorded image classification accuracies of 97%, 95%, 92% and 96% for the 1986, 1996, 2006 and 2016 classified images, respectively. Our study finds that over the 1986–2016 period, agricultural land and bare land transitioned to build-up land by 9.23% and 3.79%, respectively, as compared to 2.79% for vegetation and 0.05% for water. Our in-municipal level analysis thus shows that urban landscapes could expand more sustainably by targeting other dominant land categories instead of the vegetation cover. The findings in this paper could serve as a spatial model for planning and reducing the unintended socio-ecological impacts of expansion in the built-up area. 相似文献
18.
Land cover change affects surface radiation budget and energy balance by chang- ing surface albedo and further impacts the regional and global climate. In this article, high spatial and temporal resolution satellite products were used to analyze the driving mechanism for surface albedo change caused by land cover change during 1990-2010. In addition, the annual-scale radiative forcing caused by surface albedo changes in China＇s 50 ecological regions were calculated to reveal the biophysical mechanisms of land cover change affecting climate change at regional scale. Our results showed that the national land cover changes were mainly caused by land reclamation, grassland desertification and urbanization in past 20 years, which were almost induced by anthropogenic activities. Grassland and forest area decreased by 0.60% and 0.11%, respectively. The area of urban and farmland increased by 0.60% and 0.19%, respectively. The mean radiative forcing caused by land cover changes during 1990-2010 was 0.062 W/m2 in China, indicating a warming climate effect. However, spatial heterogeneity of radiative forcing was huge among different ecological regions. Farmland conversing to urban construction land, the main type of land cover change for the urban and suburban agricultural ecological region in Beijing-Tianjin-Tangshan region, caused an albedo reduction by 0.00456 and a maximum positive radiative forcing of 0.863 WIm2, which was presented as warming climate effects. Grassland and forest conversing to farmland, the main type of land cover change for the temperate humid agricultural and wetland ecological region in Sanjiang Plain, caused an albedo increase by 0.00152 and a maximum negative radiative forcing of 0.184 W/m2, implying cooling climate effects. 相似文献
19.
Two Landsat images, acquired in 1987 and 2008, were analyzed to evaluate desertification processes in central North Kurdufan State (Sudan). Spectral Mixture Analysis (SMA) and multitemporal comparison techniques (change vector analysis) were applied to estimate the long-term desertification/re-growing of vegetation cover over time and in space.Site-specific interactions between natural processes and human activity played a pivotal role in desertification. Over the last 21 years, desertification significantly prevailed over vegetation re-growth, particularly in areas around rural villages. Changes in land use and mismanagement of natural resources were the main driving factors affecting degradation. More than 120,000 km2 were estimated as being subjected to a medium-high desertification rate. Conversely, the reforestation measures, adopted by the Government in the last decade and sustained by higher rainfall, resulted in low-medium re-growth conditions over an area of about 20,000 km2.Site-specific strategies which take into account the interactions of the driving factors at local scale are thus necessary to combat desertification, avoiding any implementation of untargeted measures. In order to identify the soundest strategies, high-resolution tools must be applied. In this study the application of spectral mixture analysis to Landsat data appeared to be a consistent, accurate and low-cost technique to identify risk areas. 相似文献
20.
利用1995、2005和2015年3期Landsat遥感数据,提取新疆喀什地区喀什市土地覆被/土地利用信息,并将各时期用地分类数据分别转入50 m×50 m的矢量网格单元,建立基于矢量网格单元的土地覆被/土地利用网格图,探讨喀什市1995-2015年土地覆被/土地利用时空变化特征及驱动因素;通过叠加分析,研究时期内各用地类型之间相互转换和替代关系。结果显示：（1）1995-2015年间喀什市土地覆被/土地利用变化剧烈,以建设用地面积变化最为显著,20 a间面积增加近3倍,未利用地和绿地面积均有所减少,水体的面积变化显现波动态势。（2）1995-2015年喀什市建设用地扩张主要以"摊大饼"式的外延扩张为主,但也伴随少量内部填充的集约式增长模式,通过回归分析,建设用地面积的增加与城市人口的增加和社会经济的发展具有紧密的正相关关系。（3）建设用地在扩张过程中主要侵占和替代了未利用地和绿地,并且绿地的增加与减少和未利用地的侵占与被侵占有着直接关联。 相似文献