基于多尺度分割的煤矿区典型地物遥感信息提取

根据煤矿区典型地物类型的特点,研究遥感影像信息提取时面向对象分类方法的最优分割尺度问题。试验结果表明:在适于不同地物提取的最优分割尺度下,充分利用煤矿区影像对象的光谱、形状、纹理以及类间相关等特征,并综合应用隶属函数法和最邻近分类法,能有效地提取出煤矿区地物信息,与最大似然分类法相比,能够较好地消除"椒盐现象",其总体分类精度可提高26.2%。     

银川平原土壤盐渍化与中低产田遥感应用研究

土壤盐渍化是影响农业生产与生态环境的一个重要因素。长期以来,宁夏银川平原的次生土壤盐渍化问题十分突出,形成了许多盐渍型中低产田,影响和制约了区域农业的可持续发展。主要采用遥感解译方法提取了银川平原土壤盐渍化的分类与分布的现状信息。在此基础上,依据中低产田的分类标准,将相关的耕地类型、土壤肥力、作物产量、灌排水指标等因子转化成数字化专题图层,采用多源信息复合分类的方法,通过“综合分析,主导因子判定”实现了GIS辅助下的中低产田分类,为遥感和地理信息系统技术在土壤盐渍化和中低产田调查研究中的应用,探索出了一条可行的途径。     

基于3S技术的干旱区绿洲土壤盐渍化动态监测

选择生态环境脆弱的艾比湖地区绿洲为研究对象,采用1990年、2001年、2010年3期TM和ETM+影像为数据源进行土壤盐渍化分类,对研究区20 a土壤盐渍化动态变化进行了统计与分析。研究结果表明,非盐渍化土壤分布的面积最为广泛,但动态变化最为缓慢;轻度盐渍地经历了先增加后减少的过程,中度盐渍地在这20 a里一直呈现出下降的趋势;重度盐渍地在1990年分布面积最多,为366.35 km2;极重度盐渍地分布面积最少,但面积变化最为剧烈。     

基于ENVI的遥感影像分类

传统的遥感影像是依据地物的波谱信息来进行分类的。这往往会产生"同物异谱,异物同谱"的问题,使得分类精度和效果不理想。因此本文采用基于专家知识的决策树C4.5法,利用地物的波谱信息、归一化植被指数、主成分分析等特征构建决策树,与监督分类中的支持向量机法、最小距离法去比较。实验结果表明,几种分类方法中,决策树法分类法的分类规则易于理解,准确率较好,所需分类时间短,总体分类效果最为理想,验证了决策树法在遥感影像分类领域的优势。     

基于LBV变换的遥感影像多步骤分类法研究

面对与日俱增的遥感数据,如何快速准确地进行影像分类成为遥感领域亟待解决的问题。本文在前人的基础上提出了一种基于LBV变换的遥感影像多步骤分类方法。L:地物的总辐射水平,集中反映了裸地的信息;B:地物的可见-红外光辐射平衡,是地面水分状况和水体存在的一个良好指标;V:地物辐射随波段变化的方向和速度向量,能集中反映地面植被状况。多步骤分类法遵循由易到难的原则,能克服类别之间的互相影响,从而提高分类精度。文章结合LBV变换和多步骤分类法的优点对影像进行了分类,结果表明该方法简单易行,且能达到良好的分类精度。     

基于遥感的龙海市水田专题信息提取方法研究

以Landsat-7ETM⁺图像为基本资料,采用人机交互式非监督分类法、最大似然法和谱间关系阈值法分别提取龙海市水田信息。研究表明,3种方法各有优缺点,后2种方法提取精度较高,其中,谱间关系阈值法在分析不同类型水体与其背景地物光谱特征差异的基础上,挖掘谱间结构,总结各地物相分离的规律,因此提取效果最好。     

基于面向对象层次分类法的输电线路走廊地表覆盖分类

随着国产卫星遥感影像在电力部门的应用日益深入,利用高分辨率国产卫星遥感影像对输电线路走廊地区进行快速准确的地表覆盖分类成为现实。本文以湖北省输电线路走廊为研究对象,通过多种地物分类方法对比试验,综合利用高分辨率影像的光谱、纹理、形状等特征优势,以"高分一号"影像为例探索出面向对象的层次分类法,快速实现了地物的精确提取,可用于输电线路走廊地区山火评估及预防。研究结果表示,面向对象的层次分类法对于输电线路走廊地物快速分类是可行的并且能达到较高的精度。     

遥感技术在林果种植区调查中的应用研究

利用遥感技术可以准确、快捷地获取各类林果种植信息,为林果农业种植结构调整、产业发展提供科学依据。本文选择阿克苏市及温宿县为研究区,以ALOS、HJ等卫星数据为主要信息源,采用林果光谱特征分析、地物反射率分析、地物植被指数分析、林果影像特征分析等方法进行林果种植区、种类、树龄的遥感解译识别。经过实地验证和精度的分析与评价,得到的林果种植信息具有较高的精度,能解决实际中的部分应用问题。     

利用MRF方法的高分辨率影像道路提取

高分辨率遥感影像提供了地物更丰富的信息,包括光谱信息、地物结构、形状、纹理以及地物之间的空间关系等多方面的信息。面向对象的影像分析方法以目标地物为研究对象,充分考虑目标地物的形状、结构及空间关系等信息进行目标的提取和分析,是当前高分辨率信息提取技术的主要方法。研究了采用面向对象目标的思想将MRF方法应用于高分辨率遥感影像的道路目标提取中,并进行了道路提取实验。     

激光荧光技术用于地物遥感的可能性研究

本文从植被、土壤的荧光光谱特征和系统的信噪比等出发.分析讨论了激光荧光技术用于地物遥感的可能性。     

Hyperspectral Satellite Data in Mapping Salt-Affected Soils Using Linear Spectral Unmixing Analysis

Development of salt-affected soils in the irrigated lands of arid and semi-arid region is major cause of land degradation. Hyperion hyperspectral remote sensing data (EO-1) was used in the present study for characterization and mapping of salt-affected soils in a part of irrigation command area of Indo-Gangetic alluvial plains. Linear spectral mixture analysis approach was used to map various categories of salt affected soils represented by spectral endmembers of slightly, moderately and highly salt-affected soils. These endmembers were related to surface expression of various categories of salt-affected soils in the area. The endmembers were selected by performing minimum noise fraction (MNF) transformation and pixel purity index (PPI) on Hyperion (EO-1) data with reference to high resolution LISS IV data and field data. The results showed that various severity classes of salt-affected soils could be reliably mapped using linear spectral unmixing analysis. A low RMSE value (0.0193) over the image was obtained that revealed a good fit of the model in identification and classification of endmembers of various severities of salt affected soils. The overall classification accuracies for slight, moderate and highly salt-affected soils were estimated of 78.57, 79.81 and 84.43% respectively.     

Assessment of land degradation hazards,etah district,uttar pradesh using landsat data

To understand the nature of land degradation and factors responsible for it, investigations were carried out in Etah district with an area of 4.45 lakh hectares. For identification of soil/land degradation problems, multidate Landsat, TM spectral bands and FCC were used. It is observed that salt-affected soils are sharply depicted by light and dark gray mixed tone on band 3, while they are not clear on band 4. Flood plain and waterlogged soils are clearly observed on band 4. Band 6 (10.3 – 12.5 µm) helps in separation of broad zones of coarse and fine-textured soils, active flood plain of rivers, and eroded and gullied lands. The confusion between coarse-textured droughty soils and salt-affected areas in TM FCC (2, 3, 4) could be eliminated by use of band-6 data in combination with FCC. For delineation of problematic areas, two approaches were followed viz. (i) physiographic approach, and (ii) direct approach. In the physiographic approach landscape map associated with image characteristics was prepared. Further the image interpretation units were interpreted for land degradation hazards. With this approach physiography and soil relationship and the degradation problems vis-a-vis soil units could be established and ameliorative measures as per soil condition can be suggested. In direct approach, the problematic areas as per predetermined key were demarcated. Out of 4.45 lakh ha of the area, 1.99 lakh ha is affected by various soil degradation problems, like droughty soils, flooding hazard and salinity and alkalinity which cover 22.1%, 50.0% and 27.9%, respectively. To study the distribution of a salt-affected lands, major physiographic boundaries were superimposed over the land degradation map prepared by direct approach. It is observed that 81.5% of the salt-affected areas lie in the old alluvial plain while 18.5% is in recent flood plain.     

Characteristics,Distribution and Genesis of Salt-Affected Soils in Punjab

The extent of salt-affected soils in Punjab based on the 1984 Landsat-MSS data (FCC) has been investigated. The area of salt-affected soils has decreased from 0.699 million ha in 1972 to 0.488 million ha in 1984. The 1972 extent of salt-affected soils is based on the available maps and interpretation of ERTS pictures. The morphological, physical, chemical and minerological characteristics of salt-affected soils in Punjab are described. These soils are charaterised by high pH, ESP and EC but lack columnar or prismatic structure. The highest salt accumulation is observed at the surface and decreases with depth. The only sodium containing silicate mineral identified in these soils is albite. The development of salt-affected soils in Punjab is intimately connected with fluctuation of ground water. These soils have been formed by a combination of topographic, climatic, hydrological and geochemical conditions conducive for the accumulation of brackish waters at or near soil surface.     

Remote sensing approach for watershed based resources management in the Sikkim Himalaya: A case study

Integrated and environmentally sustainable development strategies have become inevitable for micro-level planning these days. The usefulness of remotely sensed data from earth resource satellites for watershed management is discussed for an eastern Himalayan watershed covering 39.09 km² area. The biophysical conditions were assessed based on field experience. The SPOT HRV-I MLA and PLA scenes were interpreted for land use/cover categories and associated characteristics. These parameters were found to be significant towards evolving the management priorities for development of agriculture, soil conservation, afforestation and rain water harvesting structures in ecologically fragile Himalayan region. The remote sensing inputs were important in deriving the relevant details faster and precisely.     

黄河三角洲盐碱地动态变化遥感监测

运用多期陆地卫星图像数据,结合野外调查及采样分析,对黄河三角洲近15a来盐碱地的动态变化进行了监测.研究区内发现盐碱地面积呈不断扩大趋势,不同类型的盐碱地变化不同:轻盐碱地不断增多,重盐碱地逐渐减少,光板地先增后减.盐碱地数量方面的增减并没有对盐碱地在不同土地类型中的空间分布格局产生太大影响.     

Saline degradation of Indian agricultural lands : A case study in Khambhat Taluka,Gujarat state (India), using satellite remote sensing

In certain agricultural fields of Khambhat Taluka in Gujarat State, the salinity has increased considerably rendering the land completely infertile. The occurrence of salinity in this area can be attributed partly to subsurface sea‐water ingress and partly to improper land and water management practices prior to implementation of irrigation. Landsat MSS or TM and IRS IA LISS II data was used to test the feasibility of delineating saline soils by both visual image interpretation and digital analysis. The study of saline soils using multi‐temporal Landsat images of the year 1977, 1983, and 1987, indicated an evident increase in saline areas in past few years. The Soil Brightness Index (SBI) generated from the IRS‐IA data by the application of MSS equivalent coefficients brought out different categories of soil degradation. The supervised classification scheme aided in generating various salinity levels. The analysis of the soil samples of the above area exhibited increasing values of Electrical Conductivity (ECe), and the soluble cations with increasing levels of salinity.     

Soil Loss Mapping for Sustainable Development and Management of Land Resources in Warora Tehsil of Chandrapur District of Maharashtra: An Integrated Approach Using Remote Sensing and GIS

The study area is characterized by low and fluctuating rainfall pattern, thin soil cover, predominantly rain-fed farming with low productivity coupled with intensive mining activities, urbanization, deforestation, wastelands and unwise utilization of natural resources causing human induced environmental degradation and ecological imbalances, that warrant sustainable development and optimum management of land resources. Spatial information related to existing geology, land use/land cover, physiography, slope and soils has been derived through remote sensing, collateral data and field survey and used as inputs in a widely used erosion model (Universal Soil Loss Equation) in India to compute soil loss (t/ha/yr) in GIS. The study area has been delineated into very slight (<5 t/ha/yr), slight (5–10 t/ha/yr), moderate (10–15 t/ha/yr), moderately severe (15–20 t/ha/yr), severe (20–40 t/ha/yr) and very severe (>40 t/ha/yr) soil erosion classes. The study indicate that 45.4 thousand ha. (13.7% of TGA) is under moderate, moderately severe, severe and very severe soil erosion categories. The physiographic unit wise analysis of soil loss in different landscapes have indicated the sensitive areas, that has helped to prioritize development and management plans for soil and water conservation measures and suitable interventions like afforestation, agro-forestry, agri-horticulture, silvipasture systems which will result in the improvement of productivity of these lands, protect the environment from further degradation and for the ecological sustenance.     

Remote sensing and GIS application for land quality assessment for coffee growing areas of Karnataka

An assessment of land quality was carried out for coffee-growing areas of Karnataka using satellite image, toposheets and soil studies. The investigation focused on monitoring soil processes that control the land quality using satellite data in order to identify the land qualities that are ideal for coffee-growing; to identify the status of land qualities of coffee-growing areas using satellite imageries, toposheets and soil resource maps and to characterise land quality using soil studies in selected areas. The land quality was characterised using climatic data, terrain analysis and soil attributes. From the study it was observed that coffee growing lands of Gabbugal and Kelagur have best land qualities and coffee-growing areas of Balur and Nellikkad have moderate land qualities. Satellite image and aerial photographs were successfully used for monitoring the land quality and its changes in these areas. For optimum utilization of available natural resources on a sustainable basis, timely and reliable information on soils regarding their nature, extent and spatial distribution along with their potential and limitations is very important. The efficiency and accuracy of data are improved when remote sensing data products such as aerial photographs and satellite image are used.     

Mapping salt-affected soils in Sangrur district (Punjab) using aerial photo-interpretation technique

A detailed-reconnaissance soil survey of the Sangrur district was undertaken through systematic aerial photo-interpretation technique and a soil map on 1: 50,000 scale showing the association of soil series prepared. The salt-affected soils have been grouped into 4 soil associations and 8 soil series based on the diffrences in texture, drainge, profile development and degree of deterioration. The salt-affected soils are found both in plains and Channels. The piain unit without distinct parcelling (barren) white and fine textured tones represented the association of salic Natraqualfs (Ghabdan series) and Aquic Natruststalfs (Kaheru series). The piain units partly cultivated whitish-gray, fine to medium textured tones consisted of a association of Natraquic Calciorthids (Langrian and Narikc series) and Natraquic Camborthids (Isri Series). Lastly, the piain units with pattern of dark-tone and light mottles (mottled-iones,) distinct parceiling, cultivated consists of Typic Ustochrepts (Balewal series), Aquic Camborthids (Phaguwala series) and Natraquic Calciorthids (Marike series). The filled up Channels whitish-gray tones, concave relief, cultivated comprise wet soils (Jatwan series) which have been classified as Aeric Halaquepts. It is found that about 17% of the mapped area in Sangrur district is salt-affected, out of which 12% consisiing Ghabdan, Kaheru, Langrian and Isri series is severely salt-affected and rest 5% consisting, Phaguwala, Narike and Jatwan series is moderately to slightly affected.     

石屏县土地更新调查的影像解译结果分析

利用2005年SPOT-5高分辨率卫星影像,运用RS、GIS、GPS等新的技术手段,分析、提取了石屏县土地利用变化信息。结果显示,石屏县新的土地控制面积为3 041.37km2,与2004年变更调查统相比较,现有辖区面积增加0.53km2。土地利用类型以农业用地为主,面积达25.40 536×104hm2,占总土地面积的83.53%。通过以高分辨率卫星影像进行更新调查,有效掌握石屏县土地利用状况和动态变化,查清土地利用结构,调整土地供应,有效利用土地资源提供了翔实的基础资料和科学依据。