The Impacts of Wetland Cultivation on the Regional Temperature Based on Remote Sensing –A Case Study in Naoli Watershed of Sanjiang Plain, Northeast China

The cold-humid ecological effect is one of important ecological functions of wetland, which was declined dramatically because of wetland cultivation. We aim to describe how the wetland cultivation affects the regional climate in this study. We derived four years (1976, 1986,1995 and 2000) data of wetland distribution in Naoli watershed of Sanjiang plain, Northeast China by Landsat TM/ETM; The trend of annual maximum/minimum air temperature was analyzed by Mann-Kendall trend test, the relationship between wetland area and annual maximum/minimum air temperature was also represented by linear regression, and the results show that: the annual maximum/minimum air temperature had increased from 1956 to 2005, and the increased rate of minimum air temperature was highest; the impacts of wetland cultivation on the air temperature was seriously, especially on the annual minimum air temperature.