京津冀生态屏障区人类活动对生态安全的影响

使用SWAT（Soil and Water Assessment Tool）和InVEST（Integrated Valuation of Ecosystem Services and Tradeoffs）模型分别模拟计算了滦河和潮河流域水源涵养、面源污染、干旱特征和生境质量等指标，在此基础上使用压力-状态-响应（PSR）模型建立了生态安全评价体系，以面源污染、生境质量和土地利用特征等人类活动对生态安全的影响作为切入点，以子流域为评价单元，评价了研究区生态安全，分析了各层指标对生态安全的影响.结果表明，2010年和2015年研究区总体生态安全状态等级均为敏感级，生态安全评分综合指数分别为0.50和0.48.研究区生态系统整体较为稳定，空间上各子流域之间生态安全状态存在较大差异.面源污染和城镇扩张等人类活动对生态安全的影响较大.林地和草地评分较低，可能与种植结构和景观格局有关.水源涵养量值增加和生境稀缺性值下降，说明加大水源涵养能力建设和降低生境稀缺性是提高生态安全的有效措施.

The impacts of human activities on ecological security in the ecological barrier zone in Beijing-Tianjin-Hebei region

Water conservation, non-point source pollution and ecological quality indices of the Luanhe and Chaohe river basin were analysed using SWAT (Soil and Water Assessment Tool) and InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) model, respectively. Based on the results, the basin ecological security evaluation indices system (PSR model) was established to assess the ecological security in the region. The PSR model was constructed on the sub-basin scale and was focused on the impact of human activities on ecological security, such as non-point source pollution, habitat quality and land use characteristics. The impacts of each index on ecological security were identified in this study. The results showed that in 2010 and 2015, the values of the comprehensive index of ecological security were 0.50 and 0.48, respectively. The ecological security in 2010 and 2015 were both at sensitive level. The overall ecosystem of the study area was stable. However, the ecological security pattern demonstrated spatial heterogeneity. Human activities such as non-point source pollution and urban expansion had a more obvious impact on ecological security. The impacts of forest and grassland impact on ecological securitiy were relatively low, which showed that the ecosystem might be related to planting structure and landscape pattern to some extent. Specifically, the water conservation value increased, and the habitat scarcity value decreased in the response level, which indicated that increasing water conservation capacity and reducing habitat scarcity were the key and effective measures to improve ecological security level.