Abstract:
Increasing human activities bring remarkable pressure to the ecologically vulnerable island ecosystems. Comprehensive and accurate ecological evaluation is the basis of island protection and management, however, it puts forward high requirements for the data of field observations. The island field investigation is relatively difficult and costly due to its clear spatial isolation and terrain condition complexity. The rapid development of remote sensing technology has provided abundant data source for the island ecological evaluation, and it is urgent to explore how accurately and comprehensively the island ecosystem can be evaluated based only on remote sensing data. In the present study, 18 inhabited islands in Changhai County (Liaoning Province, China) were selected to demonstrate an island ecological evaluation based only on remote sensing data. It provided a feasible method to reduce the cost. A total of 10 types and 27 sub-types of land covers were systematically depicted and the ecological information of remote sensing was utilized to establish the island remote sensing ecological index (IRSEI), which contains three components namely landscape, vegetation, and soil. The indices were calculated at 30×30 m grid scale and island scale, and their correlations with the geographical parameters were analyzed at the grid and island scales. The results indicated that altitude, slope, and distance to coastline have positive correlations with IRSEI at the grid scale, and altitude and slope have higher contributions than distance to coastline; at the island scale, distance to mainland has a positive correlation with IRSEI. This study has validated the comprehensiveness and accuracy of IRSEI for assessing island ecosystem and its spatial exhibitions at different scales, and this index can be applied to similar studies on island ecosystems in different regions and at multiple spatial and temporal scales.