Susumu Ogawa1*, Haruki Miyasaka2 and Naoki Okada3
1Graduate School of Engineering, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
2Graduate School of Agricultural Life Science, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
3Center for Spatial Information Science, The University of Tokyo, 5-1-5 Kashiwanoha, Chiba 277-8568, Japan
*E-mail address: ogawasusumu@nagasaki-u.ac.jp
(Received May 4, 2012; Accepted August 1, 2012)
Abstract. In the Mojos Plain, Bolivia, artificial lakes distribute widely as remains of the Mojos Culture. The artificial lakes were supposed to function as fish cultivation and reservoirs for agriculture. The objective of this study was to extract artificial lakes and river systems from SAR images with image processing and to identify the distribution of the artificial lakes for the preliminary research on the Mojos Culture. 700 artificial lakes and 380 natural lakes were extracted from 136 scenes of SAR images, and the shape factor distinguished between natural and artificial lakes. Fractal dimensions were also used for discrimination between natural and artificial lakes, but difference of the values for mass and edge fractals was small and the discrimination was difficult. The center location of artificial lakes was at 14°25´S and 65°15´W, 60 km northwest of Trinidad, the capital of Beni State. Big artificial lakes distribute in upper streams of the Beni and Mamore Rivers, and they might relate with agriculture irrigation, while most of small artificial lakes distribute along the Mamore River and their function might be fishing and aquaculture in a small scale.
Keywords: Fractal, Image Processing, Mojos Plain, SAR, Shape Factor