Remote Sensing of Forest Health Monitor- An Illustration of Tamsui River Mangrove Natural Reserve

• Main Authors: Tzu-Yi Wang, 王慈憶
• Other Authors: Chaur-Tzuhn Chen
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/59357857609969289261

碩士 === 國立屏東科技大學 === 森林系 === 94 === Forest health monitoring (FHM) is important for forest management. The spectral characteristics of satellite images can be used in large areas for estimating vegetation index (VI) and leaf area index (LAI). The VI and LAI are important indices for grading forest healthy. This study was conducted in the mangrove of Kandelia obovata in Tamsui River Mangrove Natural Reserve, and utilized the multi-temporal SPOT images in different growing seasons between 1994 and 2005. We applied normalized difference vegetation index (NDVI) to detect the changed of decennium and seasonal variation in Tamsui River Mangrove Natural Reserve. We also incorporated the NDVI, hydrology data and water quality data to analyze the conservation issue of the Tamsui River Mangrove. The results revealed that the mangrove NDVI increased from 0.265 to 0.465 in past ten years. The results showed that there were significant differences among the seasonal changed of NDVI, 0.450 0.045 in summer, 0.407 0.054 in spring, 0.321 0.067 in autumn, and 0.316 0.075 in winter. The river pollution index (RPI) of Tamsui River mangrove in 1994 RPI=1, and 6.75 in 2005. The results can not be obtained from the satellite images, and needs to be further studied. LAI is an important factor used to determine the nutrient cycle in a forest ecosystem. Traditionally, the investigation of LAI did not only require a great deal of time and manpower, but also was difficult to estimate the spatial distribution in a large study area. In this study, we integrated the NDVI which was analyzed from SPOT satellite image and the ground surveying data which was collected from LAI-2000 plant canopy analyzer (Li-Cor Inc., NY). The NDVI and LAI were used to construct a simulating relation model. LAI-2000 data was use for mapping the LAI spread of Kandelia obovata in Tamsui River Mangrove Natural Reserve. We discussed the implication of using remotely sensed data to estimate LAI model that was taken from the spatial and temporal variations. The coefficients of determination (R2) calculated for relationships between the NDVI and LAI showed that summer (R2=0.622) was superior to other seasons. The results of assessing metal contamination in mangrove sediments from Tamsui River Mangrove Natural Reserve showed that metal contamination was not a menace to the mangrove, since it was adsorbed by the mangrove.