成渝地区双城经济圈生态安全格局识别及改善对策

成渝地区双城经济圈位于我国长江上游第二阶梯，具有重要的生态屏障功能。基于“源地-廊道”法，选取生境维持、土壤保持、产水服务三大生态系统服务功能作为主要评价指标，识别该区域生态源地，在综合考虑土地利用类型和社会经济要素的情况下设置阻力面，利用最小累积阻力模型提取生态廊道，构建了区域生态安全格局，识别出现存主要问题。研究表明：(1)全区生态源地共507处，共计面积67191km²,主要分布在东西南三方的山地区域；(2)区域整体呈现“三翼-多轴”的生态安全格局，保证了区域生态安全；(3)区域生态安全格局存在生态源地空间分布不均、生态源地破碎、生态源地与人类活动冲突、生态廊道脆弱四大问题。通过进一步讨论问题背后的原因，提出了对应的改善对策，相关结果有望为成渝地区双城经济圈的国土空间布局建设规划提供参考。

Identification and optimization of ecological security pattern in the Chengdu-Chongqing Economic Zone

Chengdu-Chongqing Economic Zone (CCEZ) is located in the second step of the upper reach of the Yangtze River, China. It is characterized by a vitally ecological barrier for maintaining ecological security of the middle and lower reach of the Yangtze River. Identifying the ecological security pattern (ESP) of the CCEZ and their functional problem are thus in urgent needs. This work used "source-corridor" method for identifying ESP of the CCEZ. The method consisted of three steps:identifying ecological sources, setting resistance surface, and extracting ecological corridor. Firstly, three major ecosystem service functions, namely soil conservation, habitat maintenance, and water yield service, were selected as evaluation indicators for recognizing ecological sources of the CCEZ. Then the resistance surface of the CCEZ was generated in a traditional way with carefully considering of land use types and socio-economic factors. Lastly, the ecological corridors were extracted by using the least cumulative resistance model applied to the resistance surface. Thus, the ecological security pattern was identified with the extracted ecological sources and corridors. Finally, the major problems for functioning the ecological security pattern was recognized and the corresponding suggestions for solving such problems were proposed as well. The main results were as follows. (1) There were 507 ecological sources in the CCEZ with a total area of 67191 km² and were mainly distributed in the mountainous areas in the east, west and south of the CCEZ. (2) With respect to the ecological security pattern, it was generally characterized by a "three wings with multiple arises" which refered to the spatial distribution of the identified ecological sources and corridors. (3) The currently ecological security pattern of the CCEZ had four main problems need to be paid attention:the spatial distribution of ecological sources were uneven, the ecological sources were in fragmentation patterns, many ecological sources were in conflict with human activities spaces, and many ecological corridors were fragile. Therefore, the reasons behind these weaknesses were discussed and the corresponding improvement strategies were suggested in this paper. The findings of this work is expected to be helpful for providing a guidance for planning land use of CCEZ in the future.