1. Postdoctoral Fellow, Center for Geographic Information Science, Academia Sinica, No. 128, Sec. 2, Academia Rd., Taipei, Taiwan 115.
2. Ph.D. Candidate, Dept. of Bioenvironmental Systems Engineering, National Taiwan Univ., No.1, Sec. 4, Rd. Roosevelt, Taipei City, Taiwan 106.
3. Associate Professor, Dept. of Civil and Water Resources Engineering, National Chiayi Univ., 300 Syuefu Rd., Chiayi City, Taiwan 600.
4. Professor, Dept. of Bioenvironmental Systems Engineering, National Taiwan Univ., No.1, Sec. 4, Rd. Roosevelt, Taipei City, Taiwan 106 (corresponding author).