关键词: 生态效率, 扩展火用分析, 生态经济系统, 彭阳县, 驱动机制

Abstract: Shorelines play important roles in protecting aquatic ecosystem. Due to inappropriate and excessive utilization, erosion and damage have been found in parts of shorelines. Thus, how to rationally exploit and use shorelines has become an increasing concern. In this study, the city of Zhuhai was taken as an example to conduct an ecological sensitivity evaluation. A 500 m buffer zone along shorelines in Zhuhai was made and within this buffer zone, factors such as slope, the normalized difference vegetation index, the importance of biodiversity protection, and distance from shoreline to the basic farmland and fragile ecosystem were selected and single factor and multifactor ecological sensitivity evaluations were conducted. We then assigned the maximum sensitivity level observed within the buffer zone to the shorelines. In the meantime, the overlapping and ordering method was developed to identify the key affecting factors in a given sensitive area. Accordingly, recommendations of development and utilization of shorelines were proposed. Results showed that: (1) The single factor and multifactor ecological sensitivity evaluations showed the similar spatial pattern, which was generally at low sensitivity (nonsensitive or lightsensitive) in the study area, with a relatively few moderate and highsensitive areas clumped in the districts of Doumen and Xiangzhou; (2) For the ecological sensitivity evaluation of single factors, the area percentage for each ecological sensitivity level varied with factor level. The largest area percentages of high sensitivity level occurred under these factor conditions: slope between 25-45 degree, normalized differences vegetation index higher than 0.45, moderate biodiversity protection importance, distance to the basic farmland within 300-500 m, and distance to the fragile ecosystem less than 100 m; (3) The key affecting factors in lightly, moderately and highly sensitive areas were the distance to basic farmland, the distance to basic farmland along with the importance of biodiversity protection, and the distance to fragile ecosystem along with the importance of biodiversity protection; (4) Different development and utilization measures should be taken for shorelines of different sensitive levels, i.e., strictly controlling development, restricted development, and harmonious protection in the high sensitivity areas, moderate sensitivity areas, and light/nonsensitivity areas, respectively.

Key words: extended exergy analysis, Pengyang County, eco-economic system, driving mechanism, eco-efficiency