山西黄河流域不同土地利用类型NDVI时空变化及其对气温、降水的响应

目的]了解山西黄河流域不同土地利用类型NDVI时空变化及其对气温、降水的响应关系,对该流域生态保护、修复和高质量发展具有重要的意义。方法]基于1998—2018年NDVI数据,利用NDVI变化趋势、变异系数、空间自相关等方法,对山西黄河流域不同土地利用类型NDVI时空变化特征及其与气温、降水的关系进行分析。结果]不同土地利用类型NDVI变化趋势均呈向好态势,草地和林地覆盖状况优于整体水平。NDVI在空间上整体呈南北纵列、高低相间的分布格局,吕梁山和太岳山—中条山高,西部高原丘陵区和汾河谷地低。NDVI变化趋势的空间异质性显著,植被以显著改善为主。林地改善趋势的稳定性最好。NDVI表现出明显的空间集聚性特征,其中耕地NDVI变化趋势聚集特征最明显。不同土地利用类型NDVI对降水的敏感性强于气温。结论]山西黄河流域不同土地利用类型NDVI时空变化差异显著,并对气温和降水存在响应关系,此研究将为该流域生态保护和建设提供更精准的植被恢复数据及其和气温、降水关系的基础资料。

Temporal and Spatial Changes of NDVI of Different Land Covers and Their Responses to Temperature and Precipitation in the Yellow River Basin of Shanxi

Objective]Understanding the temporal and spatial changes of NDVI of different land use types and their responses to temperature and precipitation is of great significance to the ecological protection, restoration and high-quality development of the Yellow River Basin in Shanxi. Methods] Based on NDVI data from 1998 to 2018, the methods of mathematical such as NDVI change trend, coefficient of variation, and spatial autocorrelation were used to illustrate temporal and spatial variation characteristics of NDVI of different land covers in the Yellow River Basin of Shanxi and their relationship with temperature and precipitation. Results] The NDVI change trend of the whole region and different land cover showed a positive trend, and the coverage of grassland and woodland was better than the overall level. NDVI as a whole showed a spatial distribution pattern of north-south arrays and mosaic of high and low levels, value of NDVI was high in Lüliang Mountain and Taiyue-Zhongtiao Mountain, and it was low in western plateau hills and Fenhe Valley. The spatial heterogeneity of the NDVI change trend was significant, and the vegetation was mainly improved significantly. The improvement trend of woodland had the best stability. NDVI presented obvious spatial agglomeration characteristics, among which the change trend of cultivated land NDVI was the most obvious. The sensitivity of NDVI of different land types to precipitation was stronger than that of temperature. Conclusion] The spatial and temporal variation of NDVI varied significantly among different land use types in the Yellow River Basin of Shanxi Province, and there was a responsive relationship to temperature and precipitation. This research can provide more accurate basic data for vegetation restoration and its relationship with temperature and precipitation for the ecological protection and construction of the Yellow River Basin in Shanxi.