西藏草地生态安全评价研究——基于生态系统服务价值改进的生态足迹模型

Assessment on grassland ecological security in Tibet based on ecological footprint model improved by ecosystem services value

西藏草地生态安全建设是国家生态安全屏障建设的重点内容。对西藏草地生态承载力和生态安全程度进行评价研究,对于认识草地生态安全现状、提升草地生态安全程度、巩固生态安全屏障建设具有重要意义。基于生态系统服务价值改进的生态足迹模型,测算人均草地生态盈亏指数、草地可持续利用指数、草地生态压力指数和草地生态协调系数,运用熵权模糊综合评价法对2010-2020年西藏全区及西藏七地市的草地生态安全状况进行评价。评价结果显示:1)西藏全区草地生态安全程度波动上升,生态安全等级一直保持在“很安全”状态。2)七地市中,那曲市和山南市草地整体生态安全程度最高,林芝市、日喀则市和阿里地区草地生态安全程度相对较高,拉萨市与昌都市草地生态安全程度相对较低。总的来说,西藏草地生态安全屏障功能良好,但同时面临草地盈余空间分布不平衡、草地生态协调度偏低、部分地市草地生态压力增大等现象,生态安全格局需进一步巩固。

The ecological security of grassland in Tibet is the key content of the construction of ecological security barriers in China.The assessment of grassland ecological carrying capacity and ecological security in Tibet is of great significance for grasping the current situation of grassland ecological security,improving the degree of grassland ecological security,as well as consolidating the construction of ecological security barriers.Based on ecological footprint model improved by ecosystem services value,we calculated the per capita grassland ecological deficit(if negative)index,the grassland sustainable use index,the grassland ecological tension index and grassland ecological coordination coefficient,and used the entropy-weighted fuzzy comprehensive assessment method to evaluate the grassland ecological security status of Tibet as well as seven cities(districts)in Tibet from 2010 to 2020.The assessment results show that:1)The grassland ecological security degree in Tibet has experienced a fluctuation rise,and the ecological security level has been maintained in a“very safe”state.2)Among the seven cities(districts),the overall degree of grassland ecological security of Nagqu and Lhoka is the highest,while that of Nyingchi,Xigaze and Ngari is relatively high,and that of Lhasa and Qamdo is relatively low.In general,the function of grassland ecological security barrier in Tibet is well,but it faces the problems of unbalanced spatial distribution of grassland surplus,low degree of grassland ecological coordination and increasing of grassland ecological pressure.The ecological security pattern in this region needs to be further consolidated.