The purpose of this study is to develop an assessment framework of ecological security at the watershed scale to meet the need of watershed management, and to assess ecological security using this framework in the middle and lower reaches of Hanjiang River Basin (in Hubei Province, China). The states and their changes of ecological security in the study region are investigated with the support of ERDAS and ARC/INFO platform. The results show that the ecological security index (P) values in 1995 and 2000 were 0.685 and 0.699 respectively in the study region. While in 2005 and 2010, the P values...
