The ability to model habitat use and change in distribution of habitat is of considerable importance in wildlife management. In this study, Muntjac abundance obtained from auto-triggered cameras and habitat variables, such as elevation, aspect, slope, whole light sky space (WLS), forest cover type, forest cover type diversity, distance to river' and distance to road, were used to explain habitat selection and to identify areas of high use potential of Muntjac in natural forest of southern Taiwan. The model 15 based on the multivariate regression statistic coupled with Geographic Information System (GIS) technology to incorporate spatial correlation of wildlife-habitat relationship. Calculations were made with the GIS to generate spatial habitat variables and to produce a map containing habitat use potential that could not otherwise be independent by independent perusal of any single map layer. Confirmation of the accuracy of predictions of Muntjacs' habitat distribution was assessed with both survey data and exPert'5 evaluation. Results shown that this technique is a useful tool for habitat mapping on a landscape scale.

Due to its high spatial resolution, IKONOS imagery has a very high potential for large-scale topographic mapping. The focus of this investigation is performing the geometric correction for the IKONOS satellite images. Since raw image data would, in general, not be provided by the satellite company, we have developed a method that performs the rectification of IKONOS GEO images. We also considered the occlusions caused by terrain and buildings, thus, the generated orthoimages will be called the True "Orthoimage". The proposed scheme includes the following steps (1) the correction of relief displacement for GCPs, (2) the performing of two dimensional transformation between the ground coordinate system and the image coordinate system, (3) the performing of back projection for each pixel in the orthoimage, (4) the use of DTM to calculate the relief displacement for the pixel in the previous step, and (5) image resampling. Relief corrections for buildings and occlusion process will also be handled toward generation of true orthoimage. The experimental results indicate that the generated orthoimages, including the ones by using DTM and the one considering building effects, may reach an accuracy of 2m, when 6 GCPs were employed.

SPOT images of Central and Northern Taiwan were used for identifying landslides and obtaining a distribution map of landslides. Three phases were adopted in this study, one is combining an image classification and a threshold of indices of greenness, and brightness values. Second is a modification of the above-result by on-screen interpretation of the classified image in a 3D perspective. Last is a further comparison with those interpreted from aerial photographs. It is concluded that a minimum identifiable unit of landslides on SPOT image would be larger than 3 pixels. Landslides in an area of near residential or farmlands, or landslides which are partially-vegetated, are usually overlooked because they are not be readily distinguishable with the environments. Thus, stereo-interpretation of conventional aerial photographs identifies a lot more landslides in these areas. Nevertheless, the advantage of large coverage of 60 km of a SPOT image as compared to 1~3 km coverage of an aerial photograph would intrigue the applications of emergent enumeration of hazards, However, a scheme combining both advantages of SPOT and aerial photographs is a sound solution for providing a single source of standardized information about landslides in Taiwan. The statistics of landslides obtained in this study by air-photos shows that the majority of the landslides are smaller than 1 hectare; whereas, most of the landslides are in an area size between 1 to50 hectares and most of them are in a gradient of 15 to 30 degrees.

The accuracy of flight lines of photogrammetry is essential for acquiring aerial photos that satisfy the desired scale. For instance, accurate flight lines based on 1/17000 aerial photos are usually required to produce 1/5000 image maps. The purpose of this research is to utilize DTM (Digital Terrain Model), GIS, and GPS to derive digital flight lines as the reference of photogrammetric mission planning for producing 1/5000 image maps. Using GIS and DTM with 40 meter grids, we can depict the terrain relief and determine the datum of base maps as well as photo scale. Then the digital flight lines can be derived using flight mission planning software. By using DTM and 3-D visualization techniques, the accuracy of flight lines can be verified, and simulated images of the terrain can be obtained. The results achieved in this research are: 1. GIS was used to establish the database of 1/5000 image maps of Taiwan. Accurate digital flight lines for GPS aided aerial photography can be created rapidly by using the statistical analysis and overlapping functions of GIS. 2. The derived digital flight lines can be used as reference for photogrammetric mission planning for 1/5000 image maps. 3. The techniques of verifying the accuracy of flight lines Using DTM and 3-D visualization can be applied to GPS aided aerial photography. 4. The sun's altitude and DTM can be used to simulate shadows in images, which is useful for selecting proper time for acquiring aerial photos in order to minimize the shadow effect in mountain areas.

The high-resolution and high-mobility remote sensing system mounted on helicopters had been completed. By using the observation data of airborne multi-spectral system, a rapid and accurate assessment of relevant information regarding the rice yield and growth stages can be provided for pertinent researches and applications, such as the effects caused by insects or variable rates of nitrogen fertilizer application. The main aim of this paper was to develop a quasi real-time evaluating model for yield prediction in high-resolution scale based upon rice information of spatial variation and dynamic growth status. The results showed that the distribution of predicted yield with airborne multi-spectral observations was very reasonable when compared with the ground truth. Thus, applying airborne multi-spectral data for yield prediction is very practical and is helpful to the precision agriculture management system.

Typhoon Babs invaded Taiwan from October 25 to 27, 1998. Strong rainfall damaged Taiwan seriously. The flooding in watermelon farm along the Cho-Shuei River is one of the cases. We tried a new approach to monitor the flood in Cho-Shuei River basin. In this study, RADARSAT-1 SAR images of Cho-Shuei River basin before and during typhoon Babs in the same region were collected and compared to determine where the flood was occurred. Because the field survey was carried out about 6 months after the disaster, a third ERS-2 SAR image was requested to quantitatively determine whether there was water-covered area or not. It is found that the threshold of microwave backscatter difference is around 6dB. Other methods were also used to examine the area where flooding was suspected. The hydrological data collected during Typhoon Babs were plugged into a simple hydrological model to calculate the water level during the typhoon. The results are consistent with the SAR observations. Finally, local farmers were interviewed and their descriptions supported our conclusions. It is concluded that the SAR images is an effective tool on river basin flooding monitoring. The method may be extended to monitor flooding in urban area or coastal area.