This paper deals briefly with the advantages of applying remote sensing images to the study of dunes and emphatically describes the image characteristics of various types of dunes in deserts. Formation mechanisms of some kinds of dunes are tentatively put forward according to their morphological features on the remote sensing images. Some problems are also discussed such as the significance of the remote sensing interpretation of dunes in line selection and the relationship between blown sand and line selection for railway and highway construction.
This paper has analyzed technically the requirements for the data obtained from the Earth Observation Resource Satellite in the main application fields of land resource in the next 10 years and studied the relationship between spatial resolution and minimal drawing unit as well as between spatial resolution and maximal drawing scale. On such a basis, the requirement for the spatial resolution of Chinese Earth Observation Resource Satellite is brought forward.
Leaf area index (LAI) is an important biophysical parameter, and remote sensing provides the probability for the LAIretrieval. LAIinversion based on the model is the main orientation of the LAIretrieval, and the multi-angle data are important parameters in the model-based inversion. The new airborne multi-angle sensor AMTIScan obtain the simultaneous multi-angle and high-resolution data. Using the AMTISdata based on the three-dimensional radiative transfer model, an inversion experiment on a wheat field in Shunyi was carried out on the basis of the AMTISmulti-angle data and the prior information. And the result was verified with the measured LAIdata. The inversion precision and rate were improved by adjusting the soil classification and the matching table. The main errors in the process of inversion are also analyzed in this paper.
Researches have demonstrated that the linear features of the cultivation land usually have exaggerative appearance on SARimages, which will affect the accuracy of crop mapping on SARimages. In this study, the authors measured lots of widths at the half brightness of linear features such as channels, dykes, roads and ridges in rice fields on SARimages, and then made comparisons with results of field investigation. On such a basis, the probability distribution of widths at half brightness of linear features and the cultivation land coefficients for rice field mapping were calculated, which could give necessary correction and hence improve accuracy in rice area mapping. Some suggestions for further researches are also put forward.
Due to the fast social and economic development in its valley, the Shiyang River has experienced tremendous environmental changes, especially in the past decade. It is rather difficult to detect the long-period and complex changes of water quality merely by means of traditional measurements. In this paper, the remote sensing technology was used to monitor and evaluate the water quality in the Shiyang river. Combining the TMdata with the pollutant in the water, the authors developed an inversion model, with which one can easily evaluate the content of pollution in the water by using the TMdata. The historical Landsat (TM) data obtained in four consecutive years were employed to extract the changing information of the river water. The results show an alarming fast increasing trend of pollution in the river. The method was used to extract the water pollution information in the river, and the results show its good performance with a monitoring accuracy of 84%, suggesting a great potential of this method in this field .
TM data are major remote sensing data at present and can perfectly meet the needs of identifying active fractures. The remote sensing technology and the high-precision TM image were applied in Chuanshan peninsula, eastern Zhejiang province. Rapid and accurate identification of active fractures was achieved. 23 fractures and 7 active fractures were recognized. The study shows that the remote sensing technology can overcome such shortcomings of the traditional surveying methods as long periodicity, high cost and impossibility of making in site investigation at many places.
The Bohai Bay Coast is the most typical muddy coast in China. Through the collection and subsequent computer-processing of various sorts of data such as historical documents, topographic maps measured repeatedly in the past 130 years, air-photos, MSS, TMand ETM images for different time-phases, the authors obtained a number of results refined by information enhancement and information overlapping. Such results are helpful to reveal the shoreline migration of the area in the last century.
The investigation of sloping farmland, especially that with slope steeper than 25°, is an important task in soil resource investigation and evaluation during the development of western China. DEMis a digital elevation model produced by computer system. It can make topographic analysis, simulate geomorphologic shape, and display geomorphologic characteristics and topographic position directly. With the 1:10000 scale relief map as an example and under the support of Arc/Info software of GIS, the authors formed DEM through digitizing the topographic contour map. The slope map computed and derived by the DEM was taken as the basic material and, with the integration of the landuse map and related material and the application of GISto comprehensive analysis, the data of sloping farmland were obtained. In the whole process, computer processing occupies the dominant position and human interference is suppressed. Therefore, the efficiency is high.
This paper describes the survey of Zhoushan archipelago and Ningbo deepwater port group by using TM/ETM+, SPOT, ERS-2 SAR and NOAA-AVHRR remotely sensed data and other general data. TM/ETM+ and SPOT remote sensing images were used to obtain the information of port conditions, shoreline types and storage fields. Images of ERS-2 SARwere employed to survey the oceanic environment factors such as front and internal wave. TM/ETM+ and NOAA-AVHRR data were utilized to detect the suspended sediments. On the basis of the surveying results, the assessment of the deepwater port resources in the study area is brought out.
With the data of Landsat TMand ETMas the main information resources, this paper deals with the results of investigating the land-use changes in Shunde District, Foshan City. The changes of land-use in agriculture, aquiculture, urbanization and traffic from 1990 to 2000 as well as the developing trend of this area are analyzed. Some problems are pointed out which need to be solved for the sustainable development of economy.
Based on the principle of SARand Landsat TM, and by analyzing the spatial profile of the image, this paper compares the advantages and disadvantages between SAR and TM in the monitoring of the destroying of cultivated land, and discusses the effective way to monitor the land use situation.