Simulation analysis of the effects of disturbances on landscape pattern dynamics in Jiangjiagou Watershed
LIN Yong-Meng-; Cui-Feng-; Ge-Yong-Gang-; Wang-Dao-Jie
1.College of Forestry,Fujian Agriculture and Forestry University,350002,Fuzhou;2.Institute of Mountain Hazards and Environment,Chinese Academy of Sciences & Ministry of Water Conservancy,610041,Chengdu: China
Abstract:Aimed to discuss landscape pattern dynamics and the effect of disturbances for landscape pattern,aerial photographic images at the scale of 1∶23000 taken in 1973 and Quickbird images taken in 2006 were used.From the images,we distinguished twelve landscape types within our study area: sloping field,paddy,terrace,residential land,broad-leaved forest,coniferous forest,grassland,shrub,bare rock,gully,debris flow fan,and road.Based on GIS technology,landscape indices including diversity index,dominance index,evenness index,etc.and compartment theory were used to analyze the changes of spatial pattern for twelve landscape elements and simulate landscape dynamics under different disturbance scenarios.The results showed that: in the whole,the landscape diversity and dominance changed insignificantly,while evenness and fragmentation changed significantly from 1973 to 2006,and overall landscape spatial pattern altered significantly.In the part,the main changed landscape types were broad-leaved forest,coniferous forest,shrub and sloping field.Meanwhile,the simulation of landscape dynamics under different disturbance scenarios showed that the landscape diversity index and evenness index increased in short term and then decreased due to landscape pattern dominated by one or several landscape elements under disturbances.