IDENTIFYING WETLAND CHANGE IN CHINA'S SANJIANG PLAIN USING REMOTE SENSING

Maximum likelihood supervised classification and post-classification change detection techniques Were applied to Landsat MSS/TM images acquired ill 1976. 1986, 1995. 2000. and 2005 to map land cover changes ill the Small Sanjiang Plain ill northeast China. A hotspots study identified land use changes ill two National Nature Reserves. These were the Honghe National Nature Reserve (HNNR) and the Sanjiang National Nature Reserve (SNNR). Landscape metrics Were Used ill both reserves to identify marsh landscape pattern dynamics. The results showed that the Small Sanjiang, plain had been subject to much change. This resulted from direct and indirect impacts of human activities. Direct impacts, resulting ill marsh loss, were associated with widespread reclamation for agriculture. Indirect impacts (mainly ill HNNR) resulted from alterations to the marsh hydrology and this degraded the marsh ecosystem. Marsh landscape patterns changed significantly due to direct impacts ill SNNR between 1976 and 1986 and again between 2000 and 2005 and, ill HNNR between 1976 and 1986. Indirect impacts ill HNNR after 1986 appeared to cause little change. It was concluded that effective wetland protection measures are needed. informed by the change analysis.