Department of resources and environmental sciences, Hunan Normal University, Changsha, China.
Department of geography and land engineering, Yuxi Normal University, Yuxi, China.
PLoS One. 2019 Aug 1;14(8):e0220747. doi: 10.1371/journal.pone.0220747. eCollection 2019.
The purpose of this study was to explore the correlations between land use/cover change and cultivated land ecological security in flatland and mountainous areas. Firstly, the spatiotemporal variation characteristics of land use/cover change are described in conjunction with ArcGIS10.5 software based on remote sensing images of 2005 and 2015. Then, by establishing a pressure-support framework as an assessment indicator system and developing an improved BP neural network model via a genetic algorithm with the help of MATLAB2016a, the spatiotemporal dynamic changes of cultivated land ecological security in Yuxi City from 2005 to 2015 are evaluated. The results showed that the transformation of farmland area accounted for a large proportion of increased constructive land and land use/cover spatial variations were significantly different among counties, which manifested the changes in farmland and the construction land in flatland areas but also facilitated a mutual transformation of forest and grass in mountainous areas. Moreover, ecological security status presented a clear difference among counties due to their different land use/cover changes. The ecological security state of the flatland expressed a higher ecological pressure and lower ecological support, so the security grade was IV. Otherwise, the ecological security was superior and the security grade was level II or I in the mountainous areas. Thus, protection strategies for ecological security should be differentiated in the flatland areas and mountainous areas due to their different ecological security status brought by land use/cover change.
本研究旨在探讨平原和山区土地利用/覆被变化与耕地生态安全之间的相关性。首先，利用 ArcGIS10.5 软件结合 2005 年和 2015 年的遥感影像，描述土地利用/覆被变化的时空变化特征。然后，通过建立压力-支撑框架作为评估指标体系，并借助 MATLAB2016a 中的遗传算法改进 BP 神经网络模型，评估 2005 年至 2015 年玉溪市耕地生态安全的时空动态变化。结果表明，耕地面积的转化占建设用地增加的很大比例，各县之间土地利用/覆被的空间变化差异显著，这既体现了平原地区耕地和建设用地的变化，也促进了山区森林和草地的相互转化。此外，由于土地利用/覆被变化的不同，各县的生态安全状况存在明显差异。平原地区的生态安全状况表现出较高的生态压力和较低的生态支撑，因此安全等级为 IV。而在山区，生态安全状况较好，安全等级为 II 级或 I 级。因此，由于土地利用/覆被变化带来的不同生态安全状况，应在平原和山区采取不同的生态安全保护策略。
