Prediction of Wetland Vegetation Distribution in Hongze Lake

Freshwater wetlands in Hongze Lake play a significant role in the local ecological balance. Therefore the state-level Jiangsu Sihong Hongze Lake Ecological Reserve has been established for the protection of rare birds and their habitats in the lake. Wetland in the lake has been changing in the past 30 years. The information on the change trends of the wetlands is important to the management of the reserve. In the paper, logistic model has been used for the prediction of wetland vegetation distribution in Hongze Lake. Field data on soil, water depth and the occurrences of wetland vegetation were collected in September, 1998. Slope data were derived from DEM of the study area. Then the logistic model was used to explore the relationship between the presence of wetland vegetation and biophysical variables. Then the model was used for the prediction of the wetland vegetation distribution of Hongze Lake in 2000. The Landsat 7 ETM+ acquired on September 16, 2000 was used for the classification of the wetland vegetation. The classification results of imagery of 2000 were compared with the results of the model prediction. The comparison showed that 87.3% of wetland vegetation predicted by the model matched the classification results of ETM+ imagery.