共查询到20条相似文献，搜索用时 234 毫秒
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以三江平原具有典型湿地特征的建三江区为例,首先采用不同时间段归一化植被指数（NDVI）差值的变化监测人类活动改变的土地利用变化程度,然后结合遥感图像多尺度分割法,分析湿地系统的8种类型空间干扰格局,计算干扰度（PD）、干扰邻近度（PDD）及二者的相关性。结果表明：研究区土地利用类型变化对多尺度干扰格局的分布有明显影响,耕地、草地和沼泽地总干扰率较高,变化频繁;水域、林地和沼泽在干扰类型C1、C2中分布较广,但干扰值低,面积小;耕地分别占干扰类型C7、C8的74.38%和61.76%,干扰值高且面积大,说明耕地是建三江区湿地系统的主要干扰源。干扰邻近度说明干扰在一定尺度上发生,当干扰度PD＆lt;0.4或PD＆gt;0.7,且干扰邻近度PDD＆gt;PD时,干扰对周边土地类型必定产生影响。本研究为湿地生态系统脆弱性和恢复力的评价提供有效的生态特征指标。 相似文献
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Wei Su Zhong-Ping Sun Dao-Liang Li Raaj Ramsankaran Xiang Zhu Xiang-Yun Guo 《Journal of the Indian Society of Remote Sensing》2009,37(4):631-645
Vegetation condition monitoring has been done from 1975 to 2000 in the waste dump of Haizhou opencast coalmine area, China,
using remote sensing techniques with the objective of improving our understanding of the temporal and spatial variation of
vegetation recovery in the mining dump. Four historical vegetation indexes (NDVI, VF, soil brightness and vegetation greenness)
from two Landsat 2 MSS images and two Landsat 5 TM images are extracted and analyzed. For the purpose of comparison and analysis
two improved techniques such as normalization grading of change slope and image segmentation were used in this study. Based
on the results obtained through the above analysis two conclusions are derived: (1) vegetation recovery in the study area
is in an improved condition, (2) two remote sensing based vegetation indexes such as VF and NDVI are the optimal parameters
to monitor vegetation condition, which could be used as the indicators of land reclamation progress in the mining area. 相似文献
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Inderjit Singh 《Journal of the Indian Society of Remote Sensing》1989,17(2):15-21
Ranikhet tahsil being situated in mountaineous region of the Himalaya has been influenced by fast changes in forest cover and landuse during the recent past. Remote sensing technique has been employed to monitor the changes in forest cover and imporant landuse classes. Landsat MSS (FCC) and Landsat TM (FCC) of 1972 and 1986 respectively has been visually interpreted. The study highlights the potential of remote sensing techniques for monitoring the changes in forest cover and land use classes. 相似文献
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Abstract Landsat Thematic Mapper (TM) data have been used to monitor land cover types and to estimate biophysical parameters. However, studies examining the spatial relationships between land cover change and biophysical parameters are generally lacking. With the integration of remote sensing and Geographic Information Systems (GIS), these relationships can be better explored. The research reported in this paper applies this integrated approach for detecting urban growth and assessing its impact on vegetative greenness in the Zhujiang Delta, China. Multi‐temporal Landsat TM data were utilized to map urban growth and to extract and identify changes in vegetative greenness. GIS analyses were conducted to examine the changing spatial patterns of urban growth and greenness change. Statistical analyses were then used to examine the impact of urban growth on vegetative greenness. The results revealed that there was a notably uneven urban growth pattern in the delta, and urban development had reduced the scaled Normalized Difference Vegetation Index (NDVI) value by 30% in the urbanized area. 相似文献
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Balaji B. Maruthi Sridhar Robert K. Vincent Wentworth B. Clapham Subramania I. Sritharan John Osterberg Christopher M.U. Neale 《国际地球制图》2013,28(8):649-662
Saltcedar (Tamarix ramosissima), an invasive shrub species, has successfully invaded large extents of several riparian zones in the western United States and northern Mexico. Mapping the distribution and abundance of saltcedar over these large areas through a multi-seasonal, cost-effective monitoring approach using satellite remote sensing is very essential. Ground truth surveys were conducted at 79 locations where the spectral reflectance measurements of vegetation, type of plant species, plant heights, soil samples and GPS co-ordinates were recorded. All the sampling was designed to coincide with the satellite overpass period. The Landsat TM colour-composite spectral ratio image (normalized difference vegetative index (NDVI), R 1,5 and R 1,7 as green, blue and red) can clearly identify and map the areas infested with saltcedar. The Landsat image analysis shows that these spectral ratios can be applied to multiple satellite overpasses for monitoring the seasonal progression of the saltcedar growth over time. 相似文献
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The geologic features indicative of Cu, Pb, Zn mineral deposits in a area are fractures (structure), and host rock sediments. Datasets used include Cu, Pb, Zn deposit points record, geological data, remote sensing imagery (Landsat TM5). The mineral potential of the study area is assessed by means of GIS based geodata integration techniques for generating predictive maps. GIS predictive model for Cu, Pb, Zn potential was carried out in this study area (Weixi) using weight of evidence. 相似文献
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Basnyat P. McConkey B. Meinert B. Gatkze C. Noble G. 《Geoscience and Remote Sensing Letters, IEEE》2004,1(1):7-10
Successfully delineating management zones that differ in crop productivity is an important component of site-specific management. We compared the effectiveness of the digitally scanned color aerial infrared photographs and digital Landsat Thematic Mapper (TM) data for delineating within-field zones. The zones delineated using normalized difference vegetation index (NDVI) from TM data explained 34% of field yield variance compared with 9% for that from digitally scanned color aerial infrared photograph data. The zones from NDVI using Landsat TM were better able to capture spatial differences in plant growth and relatively stable soil attribute of surface soil organic carbon. 相似文献
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Forest cover plays a key role in climate change by influencing the carbon stocks, the hydrological cycle and the energy balance. Forest cover information can be determined from fine-resolution data, such as Landsat Enhanced Thematic Mapper Plus (ETM+). However, forest cover classification with fine-resolution data usually uses only one temporal data because successive data acquirement is difficult. It may achieve mis-classification result without involving vegetation growth information, because different vegetation types may have the similar spectral features in the fine-resolution data. To overcome these issues, a forest cover classification method using Landsat ETM+ data appending with time series Moderate-resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data was proposed. The objective was to investigate the potential of temporal features extracted from coarse-resolution time series vegetation index data on improving the forest cover classification accuracy using fine-resolution remote sensing data. This method firstly fused Landsat ETM+ NDVI and MODIS NDVI data to obtain time series fine-resolution NDVI data, and then the temporal features were extracted from the fused NDVI data. Finally, temporal features combined with Landsat ETM+ spectral data was used to improve forest cover classification accuracy using supervised classifier. The study in North China region confirmed that time series NDVI features had significant effects on improving forest cover classification accuracy of fine resolution remote sensing data. The NDVI features extracted from time series fused NDVI data could improve the overall classification accuracy approximately 5% from 88.99% to 93.88% compared to only using single Landsat ETM+ data. 相似文献
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针对土地利用遥感分类方法多样、分类精度高低不一等问题,该文以土地利用变化明显的唐山市路南区、路北区为研究区域,并以中分遥感影像Landsat 8OLI为信息源,在对地类样本进行可分离性分析的基础上,建立研究区土地利用分层分类体系。通过监督分类实验,选择分类效果最好、分类精度最高的最大似然分类器进行地类初分;通过绘制归一化植被指数(NDVI)、归一化建筑指数(NDBI)、两指数差值(NDVI-NDBI)的曲线及地类光谱特征曲线,建立决策树分类规则,进行地类再分。该方法可以较好地完成多种土地利用二级地类的划分,有助于提高中分影像土地利用分类效率。 相似文献
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作为驱动地表与大气之间能量交换的关键物理量,地表温度在众多领域中都发挥着重要作用,包括气候变化、环境监测、蒸散发估算以及地热异常勘探等。Landsat热红外数据因其时间连续性和高空间分辨率等特点被广泛应用于地表温度反演中。本文详细地介绍了Landsat热红外传感器及其可用的数据与产品的现状,梳理了2001年—2020年20年间基于Landsat热红外数据的地表温度遥感反演与应用的相关文献发表及互引情况,系统地综述了基于Landsat热红外数据的地表温度反演算法,包括基于辐射传输方程的算法、单窗算法、普适性单通道算法、实用单通道算法和分裂窗算法等。在此基础上,进一步介绍了每种算法的参数化方案,包括地表比辐射率和大气参数的估算方法。最后针对Landsat热红外数据地表温度遥感反演提出了未来可能的发展趋势与研究方向。 相似文献
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陆地卫星TM图像含有丰富的光谱信息,SPOT全色波段图像数据分辨率较高,因此,如何将这两种图像数据有效地结合起来,在遥感应用领域中显得越来越重要。本文研究了SPOT和TM图像数据的数字复合方法。结果表明,复合后的图像提高了分辨率,增加了光谱信息。 相似文献
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Prasun K Gangopadhyay Kuntala Lahiri-Dutt Kanika Saha 《International Journal of Applied Earth Observation and Geoinformation》2006
Raniganj and Jharia regions together have been for long the single largest coal supplier in India, now contributing about a quarter of the total output in the country. Numerous reasons such as improper mining techniques and policy, as well as unauthorized mining caused surface and subsurface coalfires in these areas. These coalfires burn millions of tonnes of valuable coal resources, creating severe environmental problems and posing enormous operational difficulties of mining. After first use of remote sensing as a tool to identify coalfires in 1960s, with the time, the efficiency of remote sensing to identify and monitoring coalfires has been well established by several researchers. With the knowledge of local geological setting and density sliced surface temperature image the spatial distribution of coalfires can be revealed. The present paper makes an attempt to identify temperature anomalies of the Raniganj coalbelt to locate the spatial distribution of coalfires. Landsat Thematic Mapper (TM) thermal band data was used to calculate surface temperature along with NDVI (normalized vegetation index) derived emissivity. 相似文献
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本文讨论了以热带森林植被为主体的再生资源的面积动态变化监测。研究中包括两个部分。首先,我们利用多时相遥感图像对大面积的西双版纳州进行地类判读,系统地分析了森林植被的动态变化。其次,利用Landsat MSS和TM数据对自然保护区的动态变化进行了包含无监督分类和归一化差值植被指数分析的数字图像处理,变化分类也相当符合实际。总的实验结果表明,这种监测方法是很有效的,可在再生资源监测中特别是在森林植被监测中加以推广应用。 相似文献