Study on Spatio-temporal Variation of Forest Disturbance in Lixian by Disturbance Index

Research was made on forest disturbance in time series in Lixian county, Sichuan province by disturbance index. Based on TM remote sensing data, determinations were conducted on forest disturbance during four periods, like 1994-2001, 2001-2007, 2007- 2008 and 2008-2011. The result showed that during the 4 periods, forest disturbance area in Lixian was 437.94ha, 278.46ha, 260.46ha and184.14ha. The main causes were human activities, flood and secondary disasters, Wenchuan Earthquake and its secondary disasters of the earthquake such as landslide and dammed lake. Kappa coefficient was 0.84. Analysis demonstrated that forest disturbance was serious before 2001, but decreased then, indicating healthier forest.