珠江三角洲快速城市化地区生态安全研究——以佛山市为例

Regional Ecological Security of Rapidly Urbanizing Pearl River Delta,China: A Case Study of Foshan City

借助于统计学分析方法、Landsat7ETM+遥感影像解译及GIS综合评价手段,构建了相对生态压力比值REP、相对剩余生态容量值R REC及相对生态风险度指数RERI,对珠江三角洲快速城市化的典型城市佛山市进行了区域开发的生态承载力分析及生态风险度评价,揭示了佛山市域的生态安全总体态势及问题成因;并从区域可持续发展角度提出应重视在区域开发中尽可能科学合理地维护林地、湿地、农田、城市防护林带等自然及半自然景观要素的系统性与连续性,从宏观尺度上引导城市集聚并对城市化的不良生态后果予以积极预防和有效调控,从而降低城镇化的生态风险。

Foshan city is the third biggest city in Guangdong province and typically one of the fast developing cities of Pearl River Delta,which has been one of the most prosperous economic zones but meanwhile one of the areas characterized with serious ecological degradation within China＇s coastal economic regions since the late 1970s.Therefore,Foshan was selected as a case for the study on ecological security situation during the recent rapid urbanization process.Based on statistical methodology,Landsat 7 ETM ＋ interpretation by remote sensing software and GIS based integrated assessment,the local ecological capacity assessment,which was calculated with REP （Relative Ecological Pressure）and RREC （Relative Residual Ecological Capacity）,and the ecological risk assessment,which was calculated with RERI（Relative Ecological Risk Index）,were performed to demonstrate the total environmental situation,ecological consequences and causes for Foshan regional development.Results show that among the various districts of Foshan the REP levels rank in decreasing order as Chanchen〉Nanhai〉Shunde〉Gaoming〉Sanshui,whereas the RREC levels rank in decreasing order as Chanchen 〈Nanhai 〈Shunde 〈Gaoming〈Sanshui. Furthermore,the maximum value of REP level at Chanchen was 3.8 times of the minimum value of REP level at Sanshui,the former was characterized with high REP due to intensive human activities,while the latter was characterized with low REP due to relatively low human activities. All these findings obtained also indicated that,in brief, the development pattern of Foshan is still at rapid industrializing level with high environmental risks.Also,the RERI value,which was used to reveal spatial distribution of environmental risks,ranges between 0.416 and 3.553,and given the socio-economic level and human activities the RERI value level can be divided into five sublevels as lower risk areas（0-0.55）,low risk areas（0.56-1.10）,moderate risk areas（1.11-1.65）, high risk areas（1.66-2.20）,and higher risk areas（2.21-2.75）.Correspondingly,the differentiation of RERI value level can be interpreted as an indicator to joint effects of natural and anthropogenic factors.Besides,in the point of view of sustainable development and practical ecological management on the citywide scale,the natural and semi-natural landscape components which widely range from forest,wetland and farmland to urban protection forest etc.should be taken into careful consideration during future development plans for this rapid urbanizing region. Nevertheless,it should also be noted that systematic hierarchy and continuity of all the above mentioned natural and semi-natural landscape components should be maintained and even reshaped according to scientific and rationale principles,so it is possible and practical to make plans for urban agglomeration at regional level.Hence,it is also realistic to effectively prevent and control the adverse ecological consequences during rapid urbanization.