祁连山国家公园生态安全评价

Ecological Security Assessment of Qilian Mountain National Park of China

国家公园生态安全评价不仅可以探索被评价区域的生态环境状况,还可以明确区域生态演变趋势,为当地相关部门预防和控制生态环境恶化提供科学建议。祁连山国家公园是中国西部重要的生态安全屏障、黄河流域重要水源产流地及生物多样性优先保护区域。目前,对祁连山国家公园的生态安全评价多以PSR模型为基础,运用主观确权法和综合指数法进行评价,忽略了生态系统及其功能本身与生态安全之间的内在联系,其结果缺乏客观实际性。本研究将生态系统服务功能指标列入生态安全评价体系当中,从自然资源条件和生态状况两方面选取20个指标构建评价体系,对祁连山国家公园的12个行政区2018年度生态安全进行评价。通过熵权法确定各个指标的权重,用模糊综合评价法计算出不同层次的隶属度,根据障碍度模型确定影响祁连山国家公园生态安全的主要障碍因子。结果表明:(1)祁连山国家公园由东向西生态安全等级呈逐渐下降趋势,生态安全指数从3.57(天祝县)降到1.97(阿克塞);(2)天祝县、门源县、祁连县、凉州区的生态安全等级为安全,永昌县和民乐县为临界安全,肃南县为较不安全,山丹马场、肃北县、天峻县、阿克塞县、德令哈市为不安全;(3)影响祁连山国家公园生态安全的主要障碍因子有森林覆盖率、叶面积指数和载畜力,其平均障碍度分别为11.07%、9.70%、8.39%。研究结果可为优化祁连山国家公园管理制度和生态保护措施的制定提供理论依据。

Assessment on the ecological security of a national park in China facilitate defining the ecological environment on a reginal scale and its evolution trend, and it is beneficial to actions guided by local government to prevention and control of deterioration of regional ecological environment.Qilian Mountain National Park was constituted with a purpose of building up a fundamental ecological security defense in western China, an original water source of the Yellow River Basin, and a priority area of biodiversity protection.Most ecological security assessments of Qilian Mountain National Park were performed based on PSR model with Subjective Weight Determination Method and Comprehensive Index Method;however, the internal relationship between ecosystem and its function and ecological security was not included in the assessments, making their conclusion unpractical.In this study, 12 administrative districts in Qilian Mountain National Park were selected as cases for a proper evaluation of ecological security of the whole Park in 2018. 20 ecosystem service function indicators selected from two aspects of natural resource conditions and ecological conditions were introduced in the ecological security evaluation system. Entropy weight method was used to determine the weight of each index, and fuzzy comprehensive evaluation method was used to calculate the membership degree of each level. Then main obstacle factors affecting the ecological security of Qilian Mountain National Park were determined by obstacle degree model.The following results are listed here:(1) The ecological security level of Qilian Mountain National Park gradually decreased from east to west in the Park, with an obvious drop from 3. 57( Tianzhu county) to 1. 97(Aksai county) in the ecological safety value.(2) According to Ecological Security Level Standard, it found that combined with the result of fuzzy comprehensive evaluation, Tianzhu, Menyuan county, and Liangzhou district were safe, but Yongchang and Minle county at critical in safety, Sunan county at low safe level, and Shandan Machang,Subei county, Tianjun county, Aksai county, and Delingha were judged as unsafe.(3) The main obstacles to ecological security were forest coverage, leaf area index, as well as livestock carrying capacity, with average obstacle degree of 11. 07%, 9. 70%, and 8. 39%, respectively. The conclusions will provide a theoretical basis for optimizing the management policy of Qilian Mountain National Park and formulation of ecological protection measures.