ISSN:0143-1161    

DOI:10.1080/01431169508954367

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The environmental sensitivity to oil pollution is addressed in the Loire estuary, an area of very high economical and recreational value. The first part of the paper deals with the evaluation of remote sensing images (SPOT, Landsat Thematic Mapper and ERS-1 radar). The availability of the right images with respect to low tide conditions is discussed. Well-established classifications are used for both visible and radar images, which produce mainly geomorphological information: coastline, sediments, vegetation. Living resources at risk are compiled mostly out of ancillary data, i.e., maps and reports. These two types of information lead to ranking the shoreline in terms of its ecological sensitivity. Man-made objects and human activities are also incorporated. After collecting all relevant data, we examine in a second part how to merge them and produce environmental sensitivity maps, using both CAD (Computer Assisted Design) and GIS (Geographic Information Systems) tools.

ISSN:0143-1161    

DOI:10.1080/01431169508954368

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Methods were developed to extract population and dwelling unit data from a high-resolution multi-spectral SPOT image using an integrated digital image analysis and GIS approach for the Hong Kong metropolitan area, which is characterized by high population densities and mixed land use located in multifunctional structures. These methods include different forms of regression models linking spectral radiance values of image pixels with population densities, as well as with high and low residential densities. It was found that accurate estimates of population and dwelling units could be obtained at the macro level for the whole study area using any one of these models. However, at the micro level, the accuracy tended to be low because of the difficulty in discriminating residential use from non-residential use in multifunctional buildings in a satellite image.

ISSN:0143-1161    

DOI:10.1080/01431169508954369

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

By the end of this century, the global population will increase by another billion people, making a growing threat to the natural resources. The situation in developing countries is critical, and only less than 10 per cent of low income countries are having an increasing annual growth rate of their forest and woodland areas. Population control is beyond the curriculum of environmental scientists although resources management is a timely important topic to them. Newly developed satellite remote sensing and GIS have crucial roles in this field, but the application of these sciences is showing large differences in developed and developing countries. A number of barriers for remote sensing and GIS in developing countries have been identified. Clear recognition of these limitations gives valuable solutions, which we have forwarded here as a cycle of solutions. A simple case study is included in this paper to explain the research steps, alternative low cost routings and the usefulness of a satellite data based small GIS project.

ISSN:0143-1161    

DOI:10.1080/01431169508954370

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Human needs transform the land to different activities and the quantifiable information of these dominating activities are necessary to develop future planning. In this paper three techniques, geometrical shapes and growth concept, causal modelling concept, and category rate concept are developed which are used to assess built-up areas for 2001. The shapes of built-up areas for 13 places in a Tuni region of Andhrapradesh has been estimated by imagery and incorporated in order to estimate future built-up areas by the rating method. The variables which are caused by land growth are identified and used in causal modelling to estimate future built-up areas. The areas and rates of influencing variables were used as input in the Cross Classification method.

ISSN:0143-1161    

DOI:10.1080/01431169508954371

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In this study we evaluate the possibilities of the airborne sensor CASI (Compact Airborne Spectrographs Imager) when applied to mapping of variables characteristic of an ecologic and forestry inventory, i.e., wood biomass, leaf biomass, leaf area index (LAI), canopy cover, etc. The use of multiple regression techniques has made possible to obtain correlation values between 0.76 and 0.94 (p<0.05), between radiometrical and forestry data. The extrapolation ability of the models obtained has been verified starting from the comparison among different flight lines and several groups of sample areas.

ISSN:0143-1161    

DOI:10.1080/01431169508954372

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Landsat-5 TM images over a forest area in Sweden were calibrated to reflectance. Using images for each summer from 1984 to 1991, changes in the sensor responseoffsetwere found for TM bands 1 to 4. The aerosol optical thicknesses were estimated from horizontal visibility and the sensor deterioration was estimated by assuming a constant lake reflectance. The reflectance changes to be detected in a forest are small compared with the differences between absolute calibrated images. Statistical relative calibration, followed by the scaling of the residuals to reflectance, is therefore recommended for making local reflectance changes comparable over time.

ISSN:0143-1161    

DOI:10.1080/01431169508954373

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

This paper is concerned with subpixel modelling of land cover estimation. A new method is presented to estimate the abundance of different cover types within individual pixels. Several linear and non-linear multivariate calibration techniques are compared with respect to their ability to establish a relation between pixel values and fractions of ground cover. The method is demonstrated using Landsat-TM imagery and data from Dutch heathlands. By using an optimization procedure for matching field data to image data, a solution was found for the problem of positioning errors in the training set formation.

ISSN:0143-1161    

DOI:10.1080/01431169508954374

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The spectral reflectance of soils is required for effective use of remote sensing products. The absence of studies concerned with spectral reflectance of the soils from the tropical region in the 400 to 2500 nm spectral range is the main motivation of this research. The objective of this study was to present spectral reflectance data from different tropical soil types. This spectral characterization was done through measurements of the bi-directional reflectance factor of 111 selected soil samples, grouped in 14 tropical soil classes, taken from 53 sites (São Paulo State, Brazil). The measurements were made with a spectroradiometer operating in the 400 to 2500 nm region of the electromagnetic spectrum. Each soil sample is associated to a set of physical and chemical analyses data, with part of these published in descriptive reports of soil surveys.

ISSN:0143-1161    

DOI:10.1080/01431169508954375

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Multi-temporal TM data, collected in 1987, has been processed in order to map twenty land-use categories over an area of 32 000 km2. Geometrical correction is accomplished by applying digital correlation techniques between TM images and a Ground Control Points (GCPs) data base. The data base, consisting of over 1000 GCPs, is composed of 15 by 15 pixels sub areas centred at UTM coordinates of all the control points used in previous studies. Principal components derived from multi-temporal data were subjected to unsupervised classification, and the spectral classes obtained were labelled using a semiautomatic process. The overall classification accuracy obtained is 85.6 per cent.

ISSN:0143-1161    

DOI:10.1080/01431169508954376

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor