Flood threatens human being lives and assets in the coastal area and land submergence. Monitoring and controlling the extent of flood area, the field survey is laborious and enormously dangerous. Remote sensing technology takes the advantage of safety, economics, and synoptic view to obtain the information of flood water and land submergence quickly. The frequent non-availability of cloud-free multi-spectral data precludes optical remote sensing of flood area, especially during the period of maxi­mum water spread. By virtue of day and night observation and cloud penetration capability, the active microwave data from Synthetic Aperture Rader (SAR) offers a tremendous potential for mapping and monitoring the extent of land submergence. In this study, multi-temporal data included ERS SAR and SPOT MSS images were used to analyze and delineate flood water boundaries of Gangshan during the typhoon Doug pass through Taiwan on August, 1994. From the analysis result with microwave and optical data, satellite images can map flood area easy and manifestly and have a good agreement with field information. This study indicates that remote sensing mapping and analysis of flood area using multi-temporal satellite data is available. The advanced study need carry on and promote it to beneficial applications.

A SPOT satellite digital image was used for remote bathymetric mapping in the northeast coast of the Shye-Cherng set net. This work represents the first know attempt at water depth extraction for this region by using SPOT satellite data. To validate the ocean color single-reflectance water extraction algorithm results, this research also used a conventional shipboard surveying method. This method provides water depth information for a series of latitude and longitude points along zigzag transect. After tidal error correction, the computed water depth from the ocean color single-reflectance algorithm (SRA) agreed with the shipboard surveying, and the average error was 0.5±l.2 meter. The results suggest SPOT satellite has higher spatial resolution; meaning it could provide temporal and spatial information along Taiwan's coastal area for near-shore set net fishery. It also can be used for monitoring shallow water depth changes that are caused from erosion and deposition. This technique would be very useful for environmental studies of shallow water ecosystem

Satellite-sensed advanced very high resolution radiometer (AVHRR) sea surface temperature (SST) data over summers (1997-2000) were used to analyze the variability of the summer upwelling off the Vietnam coast. Empirical orthogonal function (EOF) analysis of the spatial variance for 35 nearly cloud-free composite images was performed. The first gradient EOF mode shows the alongshore structure of the cold upwelled water. The second mode reveals the variation of the cross-shore SST gradient. The EOF analysis also displays the impact of the 1997 El Niño and 1998 La Niña events on the summer upwelling off Vietnam coast. The stronger monsoon wind caused the stronger upwelling but the weaker horizontal SST gradient during 1997 El Niño summer. The opposite situation occurred during the 1998 La Niña summer.

Sea Surface Temperature (SST) data from 1982 to 2001 obtained from National Centers for Environ­mental Prediction (NCEP) at National Oceanic and Atmospheric Administration (NOAA) were used to calculate global and regional SST trends by linear regression. The global SST trend is 0.11 ¡Ó 0.03ȼJ/ decade during 1982-2001. In seasonal analysis, the warming trend is stronger in boreal summer than that in boreal winter. The SST trends in most areas are positive, except for some regions where are negative, e.g. equator Pacific and high latitude in the southern Pacific. The SST trends in the northern hemisphere and the southern hemisphere are 0.17 ¡Ó 0.04ȼJ/decade and 0.06 ¡Ó 0.03ȼJ/decade, respectively. The highest warming trend is in the northern Atlantic Ocean.

QuikSCAT backscatter and DMSP SSM/I radiance data are used to derive sea ice motion for both the Arctic and Antarctic region using the wavelet analysis method. Sea ice motion of the Arctic for fall/winter/ spring time derived from NSCAT, QuikSCAT and SSM/I data agree well with ocean buoy observations. Both comparisons of result from QuikSCAT and SSM/I with buoys are compatible, and their ice tracking results complement each other. Sea-ice drift daily results from QuikSCAT, SSM/I and buoy data can be merged to generate composite sea ice motion maps for more complete coverage of sea ice motion. In the Antarctic, a case study shows that sea ice motion derived from NSCAT/QuikSCAT data is predominantly forced by and consistent with the surrounding wind field. Based on a series of daily Arctic sea-ice drift maps in December 1999, it is found that the major circulation patterns are changing and shifting significantly within every four to seven days and they are dominated by wind forcing.

In situ reflectance spectra and water quality data (Chlorophyll-a, Suspended Particulate Matter, temperature, and salinity) in different parts of a highly turbid tropical river were collected. Performance of typical remote sensing ocean colour bands for retrieval of SPM (Suspended Particulate Matter) and Chl-a (Chlorophyll-a) were examined. For suspended particulate matter retrieval, 520nm and 625nm bands were tested. It was found that 625nm band performs better than the 520nm band. As none of the current ocean colour satellites (e.g. MODIS, and SEAWIFS) are equipped with the 625nm bands, this result supports the importance of the 2 upcoming ocean colour satellites (ENVISAT-MERIS and ADEOS 2-GLI), both equipping with 625nm band, for SPM retrieval in a highly turbid condition. Chlorophyll-a retrieval was examined at the 2 typical Chlorophyll-a retrieval bands, 443nm, and 490nm. Almost no correlation (correlation coef­ficient ~ 0.00) were found between 443nm/555nm band ratio and Chl-a concentration. In contrary, though under highly turbid (SPM 4-25mg/l) environment, reasonably good correlation (0.83) is found between 490nm/555nm band ratio and Chl-a concentration (0-3.3ug/l). This result suggests that 490nm band is capable to reasonably retrieve Chl-a concentration up to around 3.3 ug/l even in a highly turbid tropical coastal river.