Ecological risk classification.

Conducting ecological risk assessment of fragile ecological landscapes is a prerequisite for building an ecological security pattern and a necessary consideration for sustainable development. Engebei ecological demonstration zone is a typical ecologically fragile area located in the Kubuqi Desert. To explore the ecological status of Engebei, an ecological risk assessment model is used to assess its ecological risk, and the spatial correlation analysis is conducted based on the Moran index. The optimal grain size is obtained through grain size effect analysis, which is the foundation of landscape pattern analysis. The landscape ecological risk assessment model is constructed by the landscape indexes. Based on the division of small ecological risk zones, a spatial correlation analysis of ecological risks is conducted on Engebei. Results manifest that: (1) Overall, from 2005 to 2021, its spatial distribution features of landscape ecological risk level are relatively-high and high in the middle, and gradually reduce in the north-south direction, as shown below: the relatively-low ecological risk areas are widely spread, and the overall risk index decrease from 0.1944 to 0.1940; the area of low and high-level ecological risk areas show a decreasing trend, which decrease by 5.0102 km2 and 1.3132 km2 respectively; the area of relatively-low, middle, and relatively-high-level ecological risk areas increase by 0.2655 km2, 3.7803 km2, and 2.4852 km2, respectively. (2) The ecological risk value is correlated positively with spatial distribution, and the spatial aggregation forms are primarily low-low and high-high. (3) The ecological risk values in Engebei have a significant spatial correlation, and the spatial distribution shows a clustering effect, which is consistent with the spatial distribution. The study has certain reference value for the development and comprehensive regulation of ecological construction in Engebei, even in other ecologically fragile areas.

开展脆弱生态景观（fragile ecological landscapes）的生态风险评估（ecological risk assessment）是构建生态安全格局（ecological security pattern）的前提，亦是可持续发展（sustainable development）的必要考量。恩格贝生态示范区（Engebei ecological demonstration zone）是坐落于库布其沙漠（Kubuqi Desert）的典型生态脆弱区（ecologically fragile area）。为探究恩格贝的生态现状，本研究采用生态风险评估模型（ecological risk assessment model）开展生态风险评估，并基于莫兰指数（Moran index）进行空间关联分析。通过粒度效应分析（grain size effect analysis）获取最优粒度，该粒度是后续景观格局分析（landscape pattern analysis）的基础。本研究通过景观指数（landscape indexes）构建景观生态风险评估模型（landscape ecological risk assessment model），在划分小型生态风险分区的基础上，对恩格贝地区开展生态风险空间关联分析。

研究结果显示：（1）整体而言，2005年至2021年期间，研究区景观生态风险等级的空间分布特征呈现“中部高、较高，南北方向逐步降低”的格局，具体表现为：较低生态风险区与低生态风险区广泛分布，整体风险指数由0.1944降至0.1940；低风险区与高风险区面积均呈下降趋势，分别减少5.0102 km²与1.3132 km²；较低、中等、较高风险区面积分别增加0.2655 km²、3.7803 km²与2.4852 km²。（2）生态风险值在空间分布上呈显著正相关，空间聚集形式以低-低聚集与高-高聚集为主。（3）恩格贝地区的生态风险值存在显著空间相关性，空间分布呈现聚集效应，与前述空间分布格局相符。

本研究对恩格贝乃至其他生态脆弱区的生态建设开发与综合整治具有一定参考价值。