Water Body Recognizing and Dynamic Monitoring of Honghu County Based on CIWI Model

With Honghu County in Hubei Province as an example, monitoring the change of water area was helpful to optimal allocation of local water resources and management. According to the spectral characteristics of typical geographical objects in the research area, identification and extraction of water body were firstly conducted, by employing six methods, including single band classification, multiple band classification and four water body indexes. It was proved that the discrimination index of CIWI (Combined Index of NDVI and NIR for Water Body Identification) was the highest, by which the interference of urban noise information could be reduced effectively. Based on CIWI, the dynamic change of the Honghu County water area was monitored by multi-temporal Landsat TM images from 1984 to 2010, and results demonstrated that the Honghu County water area was the smallest (302.314 km2) in 2000, and since then the area extended year by year, reaching to 387.548 km2 until 2010.