Land Cover Land Use Classification Using Multi-sensor,Multi-temporal Satellite Data; Mekong Delta, South Vietnam

摘要

Remote sensing data, Landsat-ETM, JERS-OPS/SAR data in Mekong River delta (Lat 10°30'-10°45', Lon 106°45'-107° 00') were processed for Land-cover Land-use classification. The delta, a flood plane of Mekong River, comprises of a river network formed due to huge freshwater supply from the Mekong basin for millions years. On the other hand during dry period, low river discharge tends to back flow of ocean water due to tides (3-4 m) along the drainage system, causing salt water intrusion into upstream results salt water contamination into the environment. Therefore, the land-cover consists of salt marshes with dense Mangrove forest including other kind of brackish water flora. JERS-OPS images were processed to discriminate the Land-cover classes. Not like in the other areas, wetlands consist of both freshwater and brackish water where, Agriculture, aquaculture, salt mashes. Capability of discriminating those classes are difficult using optical sensor data, hence multi sensor and multi-temporal approaches have been made to overcome the situation to improve the results. The processing technique adopted in this study is to identify major classes which contain similar spectral characteristics and mask out to segregate major classes. This will enhance the image seperability to perform secondary classification to each segregated major classes and avoid mixing among classes. Near Infra Red (NIR) band of optical sensors allowed to separate three major classes such as water, wetlands and vegetation. However, vegetation represents Mangrove forests, Plantations, paddy and other agricultural crops while the wetlands consist of salt marshes with sparse mangroves and other brackish water flora, mud flats, and aquaculture practices a challenge for image processing. Multi-temporal and multi sensor data allows to overcome the challenge by means of changing nature of land use pattern. Methodology and the results of this work are discussed in this paper in detail.