This paper deals with the construction of a new generation information platform for researches on resources and environment on the basis of modern information technology, especially VR technology, and also discusses the functions that the platform should possess and the ways of its implementation.
As a synthetic surveying method, the remote sensing technology was developed vigorously in 1970's. At present, remote sensing is being used widely in many fields, such as agriculture, forestry, water conservancy, geology, geography, meteorological forecast, marine surveying, and environment control. In this paper, the authors have summarized the significance, method and prospect of the application of remote sensing technology to the study of land covering and land utilization. With further improvement, remote sensing technology will surely serve as an important means for providing the governments with data of sustainable development.
In this paper, a model is constructed for evaluating the potential geological hazards in areas designated as the class C building classification on the slope land. The development of unstable slope land often concurs with dangerous geological hazards. Various mass movement hazards, such as landslide, slump, creep, and mudflow, may be triggered by indiscriminate development activities on slope land with high hazard potential. Government land management administration often lacks both adequate tools and data to assess the potential hazards which are likely to concur with the development of certain areas. It is critical for the land manager to integrate data from various sources within the government agencies, and to use the geographic information system as an able assistant to obtain speedy and proper evaluation results.
In this study, the authors chose Daxing County of Beijing as the experimental field in view of its varied landuse styles. Based on analyzing the data-acquisition ways, covering periods, operation conditions, costs, techniques and equipment conditions of some high resolution satellites such as Indian IRS, Korean KOMPSAT-1 and American IKONOS, the authors conducted researches on the feasibility of performing dynamic monitoring of landuse with remotely-sensed data, determined some important technical parameters in high resolution data, analyzed the range of gray level and characteristics of histogram for principal landuse styles, and summarized the spectral characteristics of different types of landuse and land cover. In addition, the spectral characteristics of merged images were analysed, the largest scale of mapping was determined, the monitoring results of different data sources such as IRS and TM, KOMPSAT-1 and TM as well as SPOT and TM were compared, the recognition capacities of different combinations of high resolution data and multi-spectral data were differentiated, the interpretation signatures of land usage dynamic monitoring were established, and some crucial technical problems were solved. A set of operational and practical technical methods and producing procedures have been set up, which serve as great technical supports to national land resources investigation.
Based on the spectral test and analysis of rock samples from the gold-polymetallic mineralized districts of Mangya area, Qinghai Province, this paper has studied the spectral characteristics of the altered rocks and wall rocks related to gold-polymetallic mineralization as well as their spectral differences within the corresponding TM bands. On such a basis, a model is established for quantitative extraction of the remote sensing information on mineralized alterations and, in addition, the information concerning mineralized alteration is extracted by means of TM images.
It is very important to study saline evolution by means of remote sensing images. Based on field survey and previous information, this paper points out that the older lake banks are discovered by Canadian Radarsat-1/S1 SAR images in Jilantai saline area are relicts of lake evolution since Late Pleistocene. On such a basis, the evolutionary process of Jilantai saline lake and the regularity of climate changes in Jilantai saline area are discussed in detail.
This paper presents the results of a study examining the backscatter signatures of various targets as a function of time. The characteristics of a target may show seasonal changes. If so, the backscatter signatures of the target should vary as a function of time. This serves as the basis of using multi-temporal SAR images to discriminate and classify a variety of targets. This study was carried out in Zhaoqing test site in Guangdong Province of China. The geometric characteristics of various targets and their backscattering mechanism were analyzed. The temporal backscatter of targets was emphasized and the backscatter signatures of targets as a function of time were summed up. Twelve types of land cover were classified using multi-temporal Radarsat data and, in addition, a land cover map was produced based on the classification results.
Being one of the three biggest bayou deltas of China, the neoteric and modern Yellow River Delta, raised since 1855, is composed of seven sub-deltas. Due to the lack of laboratory data, this paper has to use Landsat TM remotely-sensed data to analyse band ratios and principal components. The authors enhanced the spectral information of ferruginous oxides and analysed frequency histograms and statistical values of the second principal component of seven sub-deltas. On such a basis, the surface environmental differences of the neoteric and modern Yellow River Delta are discussed tentatively and briefly, which provides a useful train of thought for applying the remote sensing technology to solving geographical problems.
