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1.
Dynamics of land use/cover changes and the analysis of landscape fragmentation in Dhaka Metropolitan, Bangladesh 总被引：3，自引：0，他引：3
Rapid urban expansion due to large scale land use/cover change, particularly in developing countries becomes a matter of concern since urbanization drives environmental change at multiple scales. Dhaka, the capital of Bangladesh, has been experienced break-neck urban growth in the last few decades that resulted many adverse impacts on the environment. This paper was an attempt to document spatio-temporal pattern of land use/cover changes, and to quantify the landscape structures in Dhaka Metropolitan of Bangladesh. Using multi-temporal remotely sensed data with GIS, dynamics of land use/cover changes was evaluated and a transition matrix was computed to understand the rate and pattern of land use/cover change. Derived land use statistics subsequently integrated with landscape metrics to determine the impact of land use change on landscape fragmentation. Significant changes in land use/cover were noticed in Dhaka over the study period, 1975–2005. Rapid urbanization was manifested by a large reduction of agricultural land since urban built-up area increased from 5,500?ha in 1975 to 20,549?ha in 2005. At the same time, cultivated land decreased from 12,040 to 6,236?ha in the same period. Likewise, wetland and vegetation cover reduced to about 6,027 and 2,812?ha, respectively. Consequently, sharp changes in landscape pattern and composition were observed. The landscape became highly fragmented as a result of rapid increase in the built-up areas. The analysis revealed that mean patch size decreased while the number of patches increased. Landscape diversity declined, urban dominance amplified, and the overall landscape mosaics became more continuous, homogenous and clumped. In order to devise sustainable land use planning and to determine future landscape changes for sound resource management strategies, the present study is expected to have significant implications in rapidly urbanizing cities of the world in delivering baseline information about long term land use change and its impact on landscape structure. 相似文献
2.
利用大布苏地区1996年和2001年两个时相的TM遥感图像,获取不同时期的土地利用信息,分析了大布苏地区土地利用时空变化,借助FRAGSTATS软件进行了景观格局变化研究。研究结果表明,土地利用变化的总趋势是水域、荒草地减少,居民用地、耕地增加,土地利用综合程度指数降低;从景观尺度上看,斑块密度、多样性指数、优势度和均匀度指数减小,最大斑块指数、景观形状指数增加。 相似文献
3.
50余年来岩溶山地近郊村域土地利用与景观格局演变——以贵州省清镇市王家寨地区为例 总被引：1，自引：1，他引：0
选取贵州省清镇市近郊村域王家寨地区为研究对象,在GIS支持下,利用该区域1963年、1982年、2005年、2010年和2015年5期土地利用图形数据叠加分析,提取出研究区50余年来的土地利用/覆盖信息,并结合相应的社会经济统计数据,分析了其驱动力因子,其结果表明:(1)1963—2015年间,土地覆盖类型的总体变化为高被草地和平坝旱耕地明显减少,低被草地、农村居民点、工矿用地、公路用地面积大幅增加,其中,平坝旱耕地有向经济效益更高的土地利用方式转变的趋势;（2）景观格局演变的总体趋势是:自1963年起,斑块数量、斑块密度持续增加,到2015年呈下降趋势,而最大斑块指数逐年减小,形状趋于不规则,同时,近50年景观的多样性指数持续增加;（3）区内土地利用/覆盖和景观格局呈阶段性变化,从1963年到2005年,坡地土地利用活动较强,2005年后,平地土地利用强度增加、农业逐渐转型、聚落持续扩展;（4）区内土地利用及景观格局的变化主要受经济、人口和政策因素的影响。 相似文献
4.
基于景观生态学的喀斯特生态脆弱区土地利用/覆被变化评价——以贵州猫跳河流域为例 总被引：3，自引：1，他引：2
通过运用遥感、地理信息系统以及全球卫星定位系统等技术手段,借助于景观生态学中的景观格局指数以及构建生态价值指数,对位于贵州中部典型喀斯特地区的猫跳河流域1973年以来的土地利用/覆被变化及其对整个区域生态环境状况的影响以及近30年来土地利用的合理性进行了评价。研究表明,在过去的30年间,研究区的土地覆被发生了显著的变化,并对区域的生态环境造成了深刻的影响。1973- 1990年,猫跳河流域的景观趋于破碎化,斑块总数从3 438个增加到3 619个,生态服务价值指数从3 626. 58降低到3 343. 47,土地利用具有明显的不可持续性; 1990- 2002年,猫跳河流域的景观破碎度降低,斑块数量从1990年的3 619个减少到3 312个,整个流域的生态服务指数从3 343. 47上升到3 738. 4,生态环境质量开始向好的方向发展。 相似文献
5.
时空过程表达是时空数据分析、规律发掘等研究热点的基础。本文从土地利用/地表覆盖变化(land use/cover change,LUCC)时空数据分析和规律发掘应用角度出发,提出了一种基于过程对象的时空过程表达模型,阐述了该模型的时空过程判定方法和存储管理方法。该模型将地表覆盖斑块看作时空对象,将斑块自身变化和相互转化以对象时空过程的形式表达;通过时空过程的组合来表达空间范围更广的时空变化,使斑块变化与景观格局总体变化联系起来。该模型可用于面状地理实体的时空演变模拟和变化规律挖掘等。通过对黑龙江大兴安岭地区地表覆盖时空过程对象的建立、检索与分析,验证了模型的有效性。 相似文献
6.
河北小山火山地处渤海之滨,是渤海西岸地壳活动最直接的证据,其典型性、多样性和自然性在国内非常罕见,具有独特的科学研究意义。该火山地质遗迹保护区基本全被第四系覆盖,而高精度磁测方法可研究第四系覆盖区地质特征,是寻找火山遗迹边界、区内典型地质构造的必要手段。本研究主要分析了小山火山地质遗迹保护区的磁场分布特征;通过对磁异常进行化极、向上延拓等处理,基本查明保护区内岩浆岩和沉积地层的分布范围,圈定了火山遗迹的边界,并推断存在多条断裂。本研究可为小山火山地质遗迹的保护工作提供可靠的基础资料,对地质遗迹景观点的划分、保护区的整体合理规划等具有重要的参考价值。 相似文献
7.
岩溶湖泊湿地流域作为景观格局变化的热点研究区域,探讨景观格局动态变化及预测趋势,为岩溶流域生态安全研究提供科学依据。应用遥感与地理信息系统技术,结合普者黑岩溶湖泊湿地流域实际情况,分别对该地区1990、1995、2000、2005、2010、2015 年6 期遥感影像进行分类、解译,系统地获取地区景观格局状况,分析动态变化特征,并运用CA-Markov 模型对未来湿地景观格局进行模拟预测。结果表明:1990?2015年普者黑岩溶湿地流域景观格局随时间变化显著,景观破碎化程度总体呈现增加趋势,斑块数（NP）从861增加到889,景观类型的优势斑块面积在逐渐增加,而多样性指数从1.064下降到0.966;2020?2030年普者黑岩溶湿地流域建筑用地、农地和湿地景观类型面积在增加,农地和林地在减少,其中,较为突出的是建筑用地占有率由2.79%上升到2.97%,农地占有率60.12%增加到60.74%,湿地占有率6.67%上升7.02%,而林地占有率由26.70%下降到26.40%。景观格局进行预测可以发现湿地面积、建筑用地面积和农地变化幅度最大,本文相关研究和预测结果可为普者黑流域生态保护提供一定的建议和参考。 相似文献
8.
Conservation efforts often neglect the importance of monitoring of protected areas, which is key to adaptively managing dynamic landscapes. In many developing countries, like Trinidad, protected areas are set aside as a result of an agreement with an international conservation organization, often resulting in inadequate planning and monitoring of the protected area. Monitoring of protected areas allows for an examination of the conservation scheme implemented and enables improved conservation decisions to be made. The research presented provides an example of the use of technology in monitoring conservation strategies in two protected wetlands, Caroni and Nariva, in Trinidad. Remote sensing and fragmentation analyses are used to quantify land cover change within these two protected wetlands. Results show that the classification of Caroni immediately identifies a shift towards anthropogenic land cover types, suggesting an increase in human activity within the park. This finding is further supported by the continuous measures used, such as decreases in mean NDVI and greenness values suggesting a decrease in the amount or health of the vegetation. While the classification of Nariva suggests a return to natural land covers, the continuous measures of land cover change indicate the opposite. Land cover change analyses are limited in Trinidad and in the Caribbean in general, partly due to satellite data availability, thus this research presents remote sensing and landscape fragmentation analyses as new tools for monitoring land cover change and conservation effectiveness in Trinidad. 相似文献
9.
基于RS和GIS的喀斯特山区生态系统构成与格局及转化分析——以贵州毕节地区为例 总被引：3，自引：2，他引：1
为了更好地了解贵州省毕节地区生态系统类型的构成、格局与转化特征,本文基于面向对象分类和空间统计与分析技术,对毕节地区2000年和2010年生态系统类型进行提取,并对生态系统构成、格局和转化特征进行定量分析。结果表明:从生态系统构成和格局看,2010年研究区生态系统类型以林地和耕地为主,分别占研究区面积的42.65 ％和42.51 ％;2000和2010年该区均具有较高的斑块数和较小的平均斑块面积,说明该地区景观破碎化程度较高;2010年斑块总数较2000有所减少,表明研究区景观连通性得到改善,景观整体趋于规整化;2010年旱地斑块总面积和平均斑块面积有所减少,针叶林、草地则增加,显示该地区退耕还林还草项目的实施有所成效;旱地和针叶林的聚集度都增加,表明二者连通性增强、景观更加集中。从生态系统转化特征看,2000-2010年,研究区生态系统类型间转化总面积为1 298.25 km2,面积明显减少的是旱地和水田,明显增加的主要为林地、草地,土地面积转移矩阵显示旱地主要向林地、草地转化;受旱地面积较大影响,毕节、黔西、大方的面积变化和生态系统转化剧烈程度都较大,8个县（市）的生态系统类型相互转化强度值均为正值,可见生态系统覆被类型均向着较好的方向发展。 相似文献
10.
Based on the Landsat TM data in 1988 and 2002, the GIS technique and Fragstats software were used to calculate the land use
conversion matrix and eight landscape metrics at landscape and patch class levels in upstream, midstream, and downstream regions
of Nenjiang River basin. The characteristics of land use and landscape pattern changes in each region during 1988–2002 were
analyzed. The results show the followings: 1) During the period from 1988 to 2002, farmland and construction land area increased,
while the areas of forestland, grassland, and unutilized land decreased in all three regions. The conversion trends from forestland
and grassland to farmland were obvious. The conversion from forestland to farmland mainly occurred in the upstream region,
whereas the conversion from grassland to farmland primarily occurred in the midstream and downstream regions. 2) The water
area in the upstream and midstream regions enlarged, mainly due to the increase of water impounded area as a result of the
construction of reservoirs. Comparatively, the water area in the downstream region decreased, and it mainly occurred in the
east part of downstream region with concentrated lakes and swamps. 3) The degree of landscape fragmentation increased in each
region. The controlling ability of forestland was weakened, and its patch shape became more complicated. In contrast, the
controlling ability of farmland was reinforced, and the connectivity among patches increased. 4) The landscape pattern shows
some gradient features. From the upstream to downstream regions, the disturbance of human activities on dominant patches was
intensified, and consequently, the landscape fragmentation extent and heterogeneity were enhanced. 相似文献
11.
Ruifeng Zhao Yaning Chen Huarong Zhou Yiqing Li Yibing Qian Lihua Zhang 《Environmental Geology》2009,57(2):455-464
The wetlands in the middle and lower reaches of the Tarim River are a rich area of biodiversity and natural resources in the
inland arid region of China. However, this wetland area has decreased in size during the past several decades. Water quality
and biodiversity has declined due to expanded agricultural activities since 1960s. Using remote sensing (RS), geographic information
system (GIS) and global positioning system (GPS) techniques, we investigated the dynamics, spatial patterns and fragmentation
of the wetlands in the middle and lower reaches of the Tarim River from 1980 to 2000. We found that the total area of the
wetlands was reduced by 45.8% and the density of the patches increased four times from 1980 to 1990. From 1990 to 2000, though
the total area of the wetlands slightly increased the number of the patches increased three times and the density of the patches
doubled. Based on the analyses of transition matrixes, diversity and fragmentation indexes, and spatial distribution alternation
of the wetlands, we found the landscape diversity and fragmentation indices increased while wetland dominance index decreased
dramatically. Among the wetland types, the areas of the river-channel, reservoir and pond wetlands increased while the areas
of the lake and marsh wetlands decreased continuously. 相似文献
12.
选择地处生态环境脆弱地区的晋陕蒙接壤地区能源化工基地的大柳塔矿区为研究区,利用1986年8月2日和2007年9月7日的TM卫星图像数据为信息源,应用遥感技术对其土地利用/覆盖变化进行研究。通过图像处理,划分出7种土地利用和地表覆盖景观类型,根据获取的景观类型变化参数对其结构与变化特征进行分析,得出研究区的生态变化趋势与驱动力。结果表明,煤矿大规模开采以来,研究区景观结构稳定性减弱,破碎度增强,人类活动在研究区生态环境变化过程中起主导作用。在矿区生态环境恢复中,应提高自然植被景观类型的有效规模,有利于增强生态系统的稳定性。 相似文献
13.
青藏高原木里矿区及其周边土地覆被变化及景观格局脆弱性响应 总被引：1，自引：0，他引：1
矿区开发会导致周边土地覆被及景观格局发生剧烈变化, 但目前对青藏高原典型矿区及其周边土地覆被长时间序列变化缺乏动态监测, 尤其缺乏对景观格局脆弱性响应特征的深入认识, 因此无法针对矿区合理开发和生态修复等提出有效的科学指导。通过遥感技术和土地变化科学研究手段, 以及景观格局脆弱性概念, 对青藏高原北部木里矿区及周边1975 - 2016年土地覆被时空变化和景观格局脆弱性进行分析和评估。结果表明： 木里矿区在2000年后剧烈扩张, 导致周边土地覆被面积缩减, 其中高寒草甸湿地面积损失最大, 其次为其他和高寒草甸。矿区开发对周边生态系统的间接影响效应在逐渐增大, 表现为水域面积减少, 高寒草甸湿地出现退化以及矿区发生少量逆转。受矿区扩张影响, 区域景观格局脆弱性不断增强, 可能对周边生态系统服务功能产生负面影响。因此, 未来矿区的生态修复和规划过程中, 应当优化景观格局, 降低景观格局脆弱性。研究成果可为青藏高原及其他生态脆弱地区的矿区合理开发规划及生态修复等工程提供一定参考。 相似文献
14.
Michal Klaučo Bohuslava Gregorová Uglješa Stankov Vladimir Marković Polina Lemenkova 《Central European Journal of Geosciences》2013,5(1):28-42
The Sitno Natura 2000 Site covers an area of 935,56 hectares. The Sitno region is significant due to the number of rare and endangered species of plants, and as a result is considered a location of great importance to the maintenance of floral gene pools. The study area suffers human impacts in the form of tourism. The main purpose of this study is to the measure landscape elements, determine the ecological significance of habitats within the Sitno area, and from this data, organize the study area into conservation zones. The results of this landscape quantification are numerical values that can be used to interpret the quality of ongoing ecological processes within individual landscape types. Interpretation of this quantified data can be used to determine the ecological significance of landscapes in other study areas. This research examines the habitats of Natura 2000 Sites by a set of landscape metrics for habitat area, size, density, and shape, such as Number of patches (NP), Patch density (PD), Mean patch size (MPS), Patch size standard deviation (PSSD) and Mean shape index (MSI). The classification of land cover patches is based on the Annex Code system. 相似文献
15.
近30年吉林市景观格局变化及气候效应 总被引：2，自引：0，他引：2
在ArcGIS、ENVI、Excel和FRAGSTATS软件支持下, 利用景观指数中的斑块数量、最大斑块指数、斑块密度、周长面积分维数、聚集度和香农多样性指数, 对1980年、1995年和2010年的吉林市景观格局进行了分析。结果表明:近30年间吉林市斑块数量、斑块密度、周长面积分维数和香农多样性指数呈先增加后减少的趋势, 聚集度呈先减少后增加的趋势, 最大斑块指数逐渐减少;林地景观面积、草地景观面积一直在减少, 湿地景观面积呈先增加后减少趋势, 旱田景观面积逐渐增加。在东北地区气候变化背景下, 吉林市景观格局的变化对该区气候产生了一定的影响, 使该区气温上升、降雨量减少。吉林市景观格局变化与气温、降雨量变化的空间分布格局有较好的对应关系。 相似文献
16.
Urban landscape extraction and analysis based on optical and microwave ALOS satellite data 总被引：2，自引：2，他引：0
Accurate mapping of urban land cover from satellite data provides essential input to urban landscape analysis, modelling and urban ecosystem studies. Additionally, analysis of urban landscape metrics will provide a positive step towards comprehensive understanding of the features of urban landscape structure and further planning. In the present study, multi-spectral Advanced Land Observing Satellite (ALOS)/Advanced Visible and Near Infrared Radiometer type 2 (AVNIR-2) images and ALOS/Phased Array type L-band Synthetic Aperture Radar (PALSAR) dual-polarized (FBD) microwave images were used to extract urban land cover information by applying the decision tree method, and additional Advanced Space borne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER/GDEM) was used to reduce the effects of mountains in Synthetic Aperture Radar (SAR) images due to high backscattering from urban construction land. A set of landscape metrics, such as landscape diversity, edge density and landscape shape indices with supplementary ecological meanings, were chosen to quantitatively analysis urban landscape patterns in arid environments. The overall accuracy assessment result was 91.50%, and the experimental results demonstrate that synergetic use of optical and SAR ALOS data has the potential and advantages for Arid Urban Region mapping, while the decision tree method showed intuitive simplicity and computational efficiency. The quantitative analysis results of landscape metrics showed that distribution of landscape types in Urumqi city were inhomogeneous, the urban landscape dominated by a few classes. Urbanization in this region has resulted in dramatic increases in patch density (PD), edge density (ED) and landscape shape complexity. 相似文献
17.
S Vazeed Pasha K V Satish C Sudhakar Reddy P V V Prasada Rao C S Jha 《Journal of Earth System Science》2014,123(7):1481-1490
The invasion of alien species is a significant threat to global biodiversity and the top driver of climate change. The present study was conducted in the Great Rann of Kachchh, part of Kachchh Biosphere Reserve, Gujarat, India, which has been severely affected by invasion of Prosopis juliflora. The invasive weed infestation has been identified using multi-temporal remote sensing datasets of 1977, 1990, 1999, 2005 and 2011. Spatial analyses of the transition matrix, extent of invasive colonies, patchiness, coalescence and rate of spread were carried out. During the study period of three and half decades, almost 295 km2 of the natural land cover was converted into Prosopis cover. This study has shown an increment of 42.9% of area under Prosopis cover in the Great Rann of Kachchh, part of the Kachchh Biosphere Reserve during 1977 to 2011. Spatial analysis indicates high occupancy of Prosopis cover with most of the invasion (95.9%) occurring in the grasslands and only 4.1% in other land cover types. The process of Prosopis invasion shows high patch initiation, followed by coalescence, indicating aggressive colonization of species. The number of patches within an area of < 1 km2 increased from 1977 to 2011, indicating the formation of new Prosopis habitats by replacing the grasslands. The largest patch of Prosopis cover increased from 144 km2 in 1977 to 430 km2 in 2011. The estimated mean patch size was 7.8 km2 in 1977. The mean patch size was largest during 2011, i.e., 9 km2. The annual spread rate for Prosopis has been estimated as 2.1% during 2005–2011. The present work has investigated the long term changes in Prosopis cover in the Great Rann of Kachchh, part of Kachchh Biosphere Reserve. The spatial database generated will be useful in preparing strategies for the management of Prosopis juliflora. 相似文献
18.
景观指数的粒度变化效应 总被引：66，自引：0，他引：66
本文以延河流域的1:250000和1:500000土地利用图为对象,以景观格局分析程序Fragstats3.3为分析工具,探讨了不同比例尺条件下景观指数随粒度增加的变化特征.研究结果表明,随着粒度值由25m到400m的逐渐增加,除斑块丰富度外的景观指数均具有明显的尺度效应,其中聚集度和集合度没有尺度转折点,其他指数具有明显或不明显的尺度转折点.对比分析1:250000和1:500000土地利用格局指数的计算结果可以发现:1)尺度转折点不是一个值,而是一个相对较小的区间;2)尺度转折点与研究图件的比例尺有关,比例尺越大,所发生的第一次尺度转折点的粒度就越小;3)第一尺度域是选择适宜粒度的较好取值范围.对延河流域1:250000土地利用图进行景观指数计算的适宜粒度范围是70～90m,1:500000土地利用图的适宜粒度范围是90～120m. 相似文献
19.
Vegetation recovery and landscape change assessment at Chiufenershan landslide area caused by Chichi earthquake in central Taiwan 总被引：1，自引：1，他引：0
This study discusses vegetation recovery and land cover change with reference to the Chiufenershan landslide, a major disaster
caused by the Chichi earthquake, 21 September 1999. Image classification technology, landscape indicators from multi-temporal
remotely sensed data and a field survey provide the data. Image differencing methods and threshold values coupled with pre-
and post-quake satellite images were used. Multi-temporal images in combination with various vegetation indices were drawn
on to classify land cover patterns and discuss differences and suitability of indices. Landscape indicators and field investigations
fed into an investigation of vegetation recovery and landscape change. The study results show that the best image classification
system is original wavebands coupled with a cropping management factor index (CMFI). The land cover analysis shows that areas
of forest and grass are increasing and areas of landslide are decreasing. From the field investigation, because the left and
right sides of the landslide area were not disturbed by the earthquake, their calculated similarity index is the highest (30.08%).
Miscanthus floridulus is the most dominant pioneer plant at the landslide collapse area with an importance value index (IVI) of 63.6%. 相似文献
20.
塔里木河下游生态输水后植被景观格局动态变化研究 总被引：7，自引：3，他引：4
2000-2005年, 塔里木河流域管理局先后7次向塔里木河下游断流区进行了生态输水, 输水河道两岸的植被得到了一定的恢复. 以2000-2005的中巴资源卫星CCD影像为主要数据源, 获得了6 a的植被/非植被二值图, 并计算各年的景观格局指数, 分析了6 a植被景观格局的变化. 结果表明: 植被景观动态度在第四时段(2003-2004年)最大, 为47.83%; 在第三时段(2002-2003年)最小, 为-1.39%; 2000-2005年植被景观的动态变化呈正向趋势. 2000-2005年, 植被景观斑块个数与景观形状指数增加, 蔓延度指数下降了36.9, 斑块结合度指数均高于99, 表明研究区的植被景观破碎化程度、分离程度增加, 而景观类型联通性较高. 植被斑块面积均处于增加趋势且远离河道植被恢复率越小, 但植被景观的比重仍小于50%, 说明非植被类型是研究区的基质类型, 组成了景观的最大斑块. 针对缓冲区Zone 1, 植被景观的平均分维数处于减小趋势且2005年的斑块个数最小, 斑块结合度指数处于增加趋势, 表明近河道区域植被较为稳定, 受生态输水的干扰度较小, 植被景观斑块之间越来越聚集. 6 a间Zone 1的植被最大斑块指数均大于10%, 远高于其它5个缓冲带, 表明离河道越近植被景观的优势度最大. 相似文献