Leaf Area Index Estimation by Using Remote Sensing Technique in Khao Phra Wihan National Park

摘要

Different vegetation types and other land cover types in Khao Phra Wihan National Park, Sisaket province have been classified by using 30 m resolution digital data of LANDSAT-5 TM. Leaf area estimation and tree data such as dimensions in girth, height, species list and crown cover of 30 field plots were collected. Then spectral reflectance value of each plot was correlate to the tree data and field plot characteristics. The tree data were use to derive leave area index by allometry equation of tropical forest, which is LA = 0.5101 (D~2H)~(0.5912) and finally use to determine a relationship to the satellite data in band ratio models. Then a best equation and model was selected using highest coefficient of determination (r~2) to calculate the leaf area. The results show that Transformed Vegetation Index (TVI) using LANDSAT TM bands of green, red and near infrared gives the best relationship for leaf area index estimation using linear regression, i.e. y = 21524TVI-18560,(r~2 = 0.6364). An average leaf area is 37,241.34 m~2/ ha . While the reflectance in infrared range fits in logarithmic model y = 9991NDVI~(1.7742) (r~2 = 0.672). An average leaf area of 37,014.73 m~2 / ha~(-1) is estimated for the National Park.