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 21 毫秒
1.
The North Peixian mining area of China has rich coal resources, with total proven reserves of 2.37 billion tons. However, the underground coal mining activities have resulted in ground collapse, which has caused serious harm to the environment and threatened the lives and properties of local residents. In this study, 12 Sentinel-1A terrain observation by progressive scans (TOPS) mode acquisitions between 30 July 2015 and 13 May 2016 over the abandoned mining area in North Peixian were analyzed using the interferometric synthetic aperture radar (InSAR) time series method to detect the ground subsidence, with the maximum ground subsidence reaching 83 mm/a and an average value of about 12.7 mm/a. The subsidence results derived from the Sentinel-1A TOPS mode dataset were proven to be effective in investigating and monitoring the ground subsidence in the North Peixian mining area. Compared to the rapid deformation during the ongoing period of mining excavation, the ground subsides slowly in abandoned mining areas and shows a linear relationship with time over a relatively long period of time. Spatial correlation between the subsidence distribution and land cover was found, in that the magnitude of the subsidence in urban areas was smaller than that in rural areas, which is associated with the controlled coal mining activities under buildings, railways, and water bodies. The results demonstrate that Sentinel-1A TOPS SAR images can be used to effectively and accurately detect and monitor ground subsidence in a mining area, which is critically important when investigating land subsidence in a large-scale mining area.  相似文献   

2.
Knowledge on area and distribution of land uses plays an important role in district planning. An attempt has been made here to study existing land use pattern and changes in the land use pattern of Bharatpur district. Multi-date remote sensing data (1986 and 1989) has been used for the purpose. Seventeen land use maps on 1∶50,000 scale were prepared. ARC/INFO GIS package has been employed for the land use analysis. GIS package has also been used to relate the land use information to the villages and arrive at tentative comparison of land use as is reported in Census and as obtained from the remote sensing. Major findings in land use pattern of Bharatpur district are a) that the land use pattern in Bharatpur district is not similar to that of general land use pattern prevalent in Rajasthan State as a whole, b) Agriculture is the predominant user of land occupying about 75 percent of the reporting area, c) Forest cover in the district is not very significant and it has been depleted from 5.6 percent to 3.1 percent, d) the area under pastures and tree crops is also negligible and e) Area under waste land (eroded land, undulating terrain with or without scrub and rock out crops has been increased from 6.34 percent to 7.89 percent. The area under salt affected land, sandy area and water logged area has been decreased from 6.83 percent to 2.09 percent.  相似文献   

3.
River basin management and development are most important for utilising and conserving the water resources in any region where the average annual rainfall is highly fluctuating, the North Bengal is one of such region. Though there are a large number of rivers having a large catchment area in the hills and carry a huge amount of water during rainy season but they are completely dry in winter and summer. The upper part of majority of river basins arc highly sensitive to water erosion and land slides due to deforestation, intensive cultivation, increased settlements in sloping and erosion prone areas. So, floods in the rainy season and droughts in summer months are frequent features in North Bengal. In view of this proper management and effective conservation of land and water resources is necessary to develop the region. An integrated river basin management consisting soil conservation, afforestation, flood control, and adoption of suitable cropping pattern is essential for economic development of North Bengal.  相似文献   

4.
Assessment of area under agroforestry in Tehri district of North Western Himalaya, Uttarakhand, India has been done using GIS and remote sensing technology. The study district characterized by hilly terrain with varying elevations from 288 m to more than 2800 m and generally gentle slopes, valleys, flat land covers and agricultural terraces. High-resolution satellite imageries (spatial resolution 5.8 m) were used in this study for land uses and land covers classification. According to unsupervised classification, highest area was found under forest class (65.22%) followed by cropland (20.41%). Considerable area was also found under snow cover (9.45%) in the district. Area under agroforestry was estimated to be 5572.26 ha (1.53%) by this method, whereas it was estimated to be 7029.06 ha (1.93%) by supervised classification. Estimated cropland area comes out to be about 20.0%. An accuracy of 86.5% was found in this classification for agroforestry class. Highest area under agroforestry of 3707.36 ha was obtained in 1200–2000 m elevations followed by 2231.26 ha in 288–1200 m elevations. Negligible area was found on high elevation zones of more than 2800 m. The major agroforestry systems of dominated by Grewia oppositifolia (Bhimal), Celtis australis (Kharik) and Quercus leucotrichophora (Banj) were identified and mapped and remaining systems were grouped as others class. Estimated area under G. oppositifolia, C. australis and Q. leucotrichophora based systems come out to be 2330.82, 1456.80 and 1129.10 ha, respectively. These systems are multiple usufructs are food, fuelwood, fodder, fiber and small timber. It has been observed from the accuracy assessment that the estimates of area under agroforestry obtained under this study are reliable.  相似文献   

5.
Land is one of the prime natural resources. A city grows not only by population but also by changes in spatial dimensions. Urban population growth and urban sprawl induced land use changes and land transformation. The land transformation is a natural process and cannot be stopped but it can be regulated. Many geographical changes at the urban periphery are associated with the transfer of land from rural to urban purpose. There is an urgent need for fast growing areas like Delhi, which can be easily done by high-resolution remote sensing data. Land use/land cover of North West of Delhi has been analyzed for the time period of 1972?C2003. The remote sensing data used in study is Aster image of 2003 with a spatial resolution of 15?m and other data of 1972 Survey of India (SOI) toposheet at the scale of 1:50,000. Supervised digital classification using maximum likelihood classifier was applied for preparing land use/land cover. A change detection model was applied in ERDAS Imagine to find out the land use/land cover during 1972 to 2003. Eight land use classes was identified but main dominated classes were built up and agricultural land. A drastic change has been recorded during 30 years of time i. e. (1972-2003). In 1972, 92.06% of the land was under agricultural practice, which reduced to 64.71% in 2003. This shows 27.35% decrease in agricultural land in three decades. On the other hand built up area was 6.31% in 1972, which increased to 34% in 2003. One of the main cause of this land use change is the population growth due to the migration in the district from small cities and rural areas of Delhi.  相似文献   

6.
1983—1992年中国陆地植被NDVI演变特征的变化矢量分析   总被引：32，自引：2，他引：32  
以NDVI时序资料为基本数据源，综合应用变化矢量分析和主成分分析方法对1983年至1992年中国陆地植被NDVI的变化强度、变化类型及空间结构变化特征进行了分析。研究结果表明在此期间中国陆地植被NDVI变化有以下特点：（1）十年间NDVI变化东西分异明显，东部变化幅度远大于西部。NDVI变化整体表现为稳中略增，增加区主要分布在台湾、福建、四川、河南等地；减少区主要分布在云南省和新疆北部等地。（2）空间结构信息表现了景观异质性，其变化主要发生在南方，反映了植被的生长和衰老过程及地形（山脉走向）变化。  相似文献   

7.
中国陆地生态系统脆弱带遥感模型   总被引：4，自引：0，他引：4  
本研究通过对我国陆地生态系统8个典型样地的植被指数取样实验和图像计算结果发现，这8个样地植被指数随着水、热因子的季节变化，在时间和空间上具有一定的“绿波推移”和“景观更替”规律。在中国东部湿润的季风区（样地1－3），随着纬度的增高，其月平均植被指数与月平均气温有较大的相关。发现降水相对丰沛的地带，热量和光照条件的变化成为植被生长和变化的自然限制因子；而在中国北方森林－森林草原－典型昌原－荒漠草原－荒漠地带上，随着从东部（湿润地区）到西部（干旱地区）干湿条件的更替，月平均植被指数与降水多寡有较大的正相关关系。在8个样地上都呈现出共同的规律，即定向风的分布与植被指数的分布在时间和空间上具有逆相分布的“套合关系”。尤其在时间上有相逆套合关系，这正是中国北方沙尘暴和沙漠化加剧的自然原因。本研究定量地给出了我国陆地不同经纬度带生态系统脆弱季节和累积时间的分布。  相似文献   

8.
土地利用空间数据尺度转换中的精度损失分析   总被引：2，自引：1，他引：1  
在地理信息系统的支持下,利用两种矢栅转换原则对土地利用空间数据进行尺度转换,并对不同栅格大小下,各种土地利用类型的精度损失特征进行了分析.研究结果表明: (1)面积最大值原则(RMA)下,栅格大小< 80 m时,其精度损失均< 2%; 中心值原则(RCC)下,栅格大小< 160 m时,其精度损失均< 2%.(2)在栅格大小为800 m时,水域在面积最大值原则下的精度损失超过50%,在中心值原则下的精度损失超过20%.(3)在空间粒度逐渐增大过程中,面积最大值原则下生成的栅格数据相对误差较大,各地类精度损失的绝对值与栅格大小之间成正相关; 中心值原则下,各地类的相对误差较小且复相关系数均很小,表现出很强的随机性.  相似文献   

9.
建立高精度的地壳运动速度场模型是实现区域大地基准动态维持,反映地面形变,保障基础设施工程建设的重要途径。针对点位分布密集、精度可靠和多年连续重复观测等准确获取区域地壳运动速度场模型的关键问题,通过对山东及周边省份2010年1月—2015年11月连续近6a的130座连续运行参考站点在ITRF2008框架下进行处理,获取时间序列。首次完整建立了山东省地壳运动速度场模型。通过模型分析表明:水平方向,山东省地壳整体向东南方向运动,平均速率为34.3mm/a,运动方向为SE110.25°;垂直方向,鲁中山区及胶东半岛地区地壳较为稳定,鲁北、鲁西等华北平原地区存在显著沉降,最大沉降量位于广饶漏斗区,年沉降量81.6mm/a。  相似文献   

10.
Geomorphology and land use pattern of Visakhapatnam urban – industrial area have been studied using IRS IB and SPOT data. The geomorphic units under structural landforms, fluvial landforms and coastal landforms were identified and appropriate field confirmations were made. The geomorphic units such as inselbergs/residual hills, rolling plains, colluvial plains, fractures, piedmont fans, pediments were identified under structural landforms. The units wind gap, paleo channels, gully land, alluvial plain and natural levee were identified under fluvial landforms. The coastal landforms include sea cave, sea stack, red sediments, beach sands and marshy area. Study of the land use pattern reveals the land use under various categories of residential, planned and un planned, agricultural land, waste land and others. The data will have high relevance and usefulness for urban, industrial and ground water resource evaluations in the context of rapid urbanization and industrialization.  相似文献   

11.
作为一种常见的气象灾害,雾灾严重的影响了人们交通出行等日常生活。基于遥感影像反演的雾微物理参数可在一定程度反映雾灾的发展状况和严重程度,进而对大雾进行有效的监测和预测。本文选取发生于华北地区2007年11月24日13时10分的陆地辐射雾MODIS影像作为试验数据,在大雾生消机理和遥感影像信息提取基础上,构建了大雾路径辐射模型和微物理参数反演算法,成功反演出能见度、含水量、有效粒子半径3个微物理参数,并在湖北省气象局提供的地面观测数据基础上对能见度进行了地面数据验证,得到两者的相关系数为0．9366．地面数据与反演结果相关性较大,数值误差较小,说明反演方法具有可行性。本文进一步应用该模型对发生于华北地区2007年11月21日至11月26日的一次陆地辐射雾MODIS时间序列影像反演微物理参数并进行动态变化分析,总结出大雾具有爆发性产生和重复阶段性发展的特点,能见度主要受大气辐射和水汽供给的影响。其值在50～130m之间变化,和平均含水量、有效粒子半径成反比例关系,共同反映出雾灾的严重程度和发展阶段。  相似文献   

12.
Aerial Photographs of 1:50,000 scale pertaining to Tons Catchment were used for generating a land use map showing cultivated lands, forests land, grass land, barren land with rock outcrops, snow and glaciers. The area was divided into 4 altitudinal Zones. More than 81% lies above 3000 m height and should be left for natural regeneration. Cultivated land occupies 4.97% of the area and is concentrated below 3000 m altitudinal zone and lies along river courses and on river terraces. Distribution of forest lands in altitudinal zone indicates that percent area covered under forest is higher than the average distribution of forest as reported by Seth (1978). Grass and open scrub, barren Innd with rock outcrops, glaciers and snow covered areas occupy 6.8%, 18.1%, 16.5% and 28.0% respectively.  相似文献   

13.
LandStar is a differential global positioning service (DGPS) that provides 24-h real-time positioning for various applications on land, water, and air in North America, Australia, New Zealand, Europe, and Africa. Its focus is on real-time applications requiring a submeter positioning capability such as agriculture, forestry, Geospatial Information Systems (GIS), survey/mapping, and land/vehicular navigation. LandStar uses a Wide Area Network of reference stations to derive DGPS corrections to model the variation of GPS error sources over a large area. These model parameters are used by the Virtual Reference Station processors to calculate standard corrections that are available for all predefined locations in the network. The corrections are transmitted to the user by L-band satellite communication in the standard RTCM SC104 DGPS correction format. This article investigates the performance of the LandStar Mk III system under various operational conditions and assesses its performance in both static and kinematic modes. Four field tests were conducted during 12 months that tested the sysem in clear static and kinematic conditions as well as suboptimal environments associated with low and heavy foliage conditions. Both the accuracy and availability of the system under these conditions is investigated, with an emphasis on whether the above variables are caused by the LandStar system differential corrections, the GPS measurements, or a combination of both. ? 1999 John Wiley & Sons, Inc.  相似文献   

14.
结合高分遥感和多源数据的高原湖泊流域土地利用分析   总被引：1，自引：0，他引：1  
高分一号卫星是为提升我国高分辨率数据自给率自主发射的卫星，在土地利用监测方面具有重要的应用价值。将GF-1卫星影像与多源数据影像进行对比能够挖掘各数据源在土地利用动态监测方面的差异性。本文以云南省杞麓湖流域为研究区，选取最新的Sentinel-2、GF-1和Landsat 8卫星遥感影像进行土地利用分类，以第二次全国土地利用调查数据为基期数据，结合野外实地调研和土地利用转移矩阵开展土地利用现状和演变分析，得出以下结论：①杞麓湖流域的水域、建设用地、耕地和林地自中心向外呈现出圈层分布的特征，与第二次全国土地调查结果相比，水域、耕地、林地3种类型的自然景观面积减少，而建设用地和其他用地受人类活动的影响，面积大幅增加，变化主要集中在杞麓湖周边的纳古镇和河西镇。②Sentinel-2卫星影像与GF-1卫星影像均具有较高的空间分辨率，二者对土地利用变化评估的结果相近，均优于Landsat 8卫星影像，其中GF-1卫星影像具有较高的应用价值。  相似文献   

15.
The land use information collected for Dehlon block of Ludhiana district, Punjab from the analysis of the IRS-1B LISS-II data for the year 1993 and IRS PAN data for the year 1997 and SOI topographical maps for 1964 revealed a large change in the area of different land use categories during the period from 1964 to 1997. The agricultural land covering an area of about 94.14 per cent in 1964 reduced to 90.26 per cent in 1997. while the area under rural settlements increased from 312 ha in 1964 to 1162 ha in 1997. An extra area of about 169 ha under waste land was added during the period under study making total waste land area to about 400 ha in 1997. However, the block lacks the forest cover of the required limit. Considerable change in living environment was observed in the block. Number of persons per unit settlement area (ha) being 213.3 in 1964 reduced to 97.1 in 1991; it indicate that the living standard of the people of the block has improved with the changed cropping pattern and increased agricultural production during the period from 1964 to 1991.  相似文献   

16.
The current study was taken up to investigate the utility of remote sensing and GIS tools for evaluation of Integrated Wasteland Development Programme (IWDP) implemented during 1997–2001 in Katangidda Nala watershed, Chincholi taluk, Gulbarga district, Karnataka. The study was carried out using IRS 1C, LISS III data of December 11, 1997 (pre-treatment) and November 15, 2002 (post-treatment) covering the watershed to assess the changes in land use / land cover and biomass that have changed over a period of five years (1997–2002). The images were classified into different land use/land cover categories using supervised classification by maximum likelihood algorithm. They were also classified into different biomass levels using Normalized Difference Vegetation Index (NDVI) approach. The results indicated that the area under agriculture crops and forest land were increased by 671 ha (5.7%) and 1,414 ha (11.94%) respectively. This is due to the fact that parts of wastelands and fallow lands were brought into cultivation. This increase in the area may be attributed to better utilization of surface and ground waters, adoption of soil and water conservation practices and changes in cropping pattern. The area under waste lands and fallow lands decreased by 1,667 ha (14.07%) and 467 ha (3.94%), respectively. The vegetation vigour of the area was classified into three classes using NDVI. Substantial increase in the area under high and low biomass levels was observed (502 ha and 19 ha respectively). The benefit-cost analysis indicates that the use of remote sensing and GIS was 2.2 times cheaper than the conventional methods. Thus, the repetitive coverage of the satellite data provides an excellent opportunity to monitor the land resources and evaluate the land cover changes through comparison of images for the watershed at different periods.  相似文献   

17.
以肥城市为研究对象,利用最大似然监督分类法对肥城市1994年、2002年的landsat TM和2017年的landsat OLI遥感影像进行土地利用分类,依据土地利用动态度、土地利用转移矩阵对肥城市土地利用变化进行分析。实验表明:近23年来,肥城市土地利用变化明显,其中建设用地面积增加54.22 km^2,林草地面积增加80.87 km^2,耕地面积减少107.02 km^2、水体面积减少17.28 km^2;同时表明在经济驱动、政策引导以及人为因素的影响下肥城市土地利用程度会进一步加深。  相似文献   

18.
多尺度遥感数据的非耕地系数变化特征分析   总被引：2，自引：0，他引：2  
关毅  冯雪力  弓永利  王跃宾 《测绘科学》2011,36(6):192-194,171
本文从非耕地系数的计算公式和遥感数据对地理要素的综合着手,研究在多尺度下非耕地系数的变化特征.研究结果表明:大尺度数据下的非耕地系数比中、小尺度数据下的要大;建立了TM和中巴数据尺度下的非耕地系数之间的数学模型,该模型使得非耕地系数在此两种尺度数据下可以相互转换.通过模型检验,线性模型符合精度要求.  相似文献   

19.
陆地高分辨率重力数据是超高阶重力场模型及其应用研究的基础,但现有的观测技术和手段限制了陆地重力测量的覆盖区域,全球仍有大量的重力测量空白地区.采用残差地形模型空域法,利用高通滤波技术提取航天飞机雷达地形测绘任务(shuttle radar topography mission,SRTM)分辨率3"×3"的V4.1数据短...  相似文献   

20.
瞿伟  徐超  张勤 《测绘工程》2016,25(2):6-10
利用西安市地下水位监测资料,基于水文地质三维结构模型,在不考虑粘土层滞后压缩变形的理想情况下,采用压密方程计算获得西安市抽取地下水可引起的理论地面沉降量及沉降分布特征,结果表明:计算所得沉降显著区位于西安市西南部的高新区及东南部的曲江新区,沉降量呈由北向南递增的特征,与InSAR监测结果整体趋势具有较好的一致性;地面沉降分布特征受到活动地裂缝影响,沉降曲线呈近NE向偏转展布。研究结果可为沉降灾害预防研究提供宏观的参考信息。  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