Spatiotemporal Evolution Analysis and Prediction of Land Ecological Security Based on PSR-GM(1, 1) Model—Taking the “3 + 5” Urban Agglomeration Around Changzhutan as an Example

土地生态安全评价是保障土地资源可持续利用的重要基础，对于识别潜在风险、评估当前生态安全状况及指导区域国土空间规划有着不可或缺的意义。环长株潭城市群作为长江中游城市群重要组成部分与湖南省经济活动的核心区域，深入剖析其土地生态安全时空演变特征及预测其未来趋势，对推动城市群生态文明建设进程具有显著的促进作用。本研究基于2012~2022年统计数据，以环长株潭城市群8个地级市为研究对象，通过PSR模型建立土地生态安全评价指标，运用熵权TOPSIS对其土地生态安全进行综合评价，并运用灰色预测模型GM(1, 1)探究其未来趋势。研究结果表明：(1) 在时间序列演化上，2012~2022年间，环长株潭城市群的土地生态安全水平实现了显著提升，其中2020年达到了11年来的最佳状态；(2) 在空间序列上，环长株潭城市群在生态安全空间上存在差异，主要表现为“北部高、南部低”的空间分布特征，土地生态安全整体格局呈现出由低水平向高水平演变的轨迹。(3) 在预测结果上，2023~2026年环长株潭城市群土地生态安全值将呈上升趋势，土地生态安全状态等级由“良好级”上升为“安全级”。Land ecological security assessment is an important basis for ensuring the sustainable use of land resources, and is of indispensable significance for identifying potential risks, assessing the current ecological security status, and guiding regional territorial spatial planning. As an important part of the urban agglomeration in the middle reaches of the Yangtze River and the core area of economic activities in Hunan Province, the urban agglomeration around Changzhou-Zhuzhou-Zhutan has a significant role in promoting the construction of ecological civilization in the urban agglomeration by deeply analyzing the spatiotemporal evolution characteristics of land ecological security and predicting its future trend. Based on the statistical data from 2012 to 2022, this study took 8 prefecture-level cities in the urban agglomeration around Changzhou-Zhuzhou-Zhuhai-Tan as the research object, established the evaluation index of land ecological security through the PSR model, comprehensively evaluated the land ecological security by using the entropy weight TOPSIS, and explored its future trend by using the gray prediction model GM(1, 1). The results show that: (1) In terms of time series evolution, the level of land ecological security in the Changzhou-Zhuzhou-Zhuzhou-Tan urban agglomeration has been significantly improved from 2012 to 2022, and the 2020 year has reached the best state in 11 years; (2) In terms of spatial sequence, there are differences in the spatial security of the urban agglomeration around Changzhou-Zhuzhou-Zhuhai-Tan, which is mainly characterized by the spatial distribution characteristics of “high in the north and low in the south”, and the overall pattern of land ecological security shows a trajectory of evolution from low level to high level. (3) In terms of the prediction results, the land ecological security value of the urban agglomeration around Changzhou-Zhuzhou-Zhutan will show an upward trend from 2023 to 2026, and the land ecological security status level will be increased from “good level” to “safe level”.