十堰市植被指数时空变化特征及其对气候变化的响应

Spatiotemporal Variation Characteristics of Normalized Difference Vegetation Index and Its Response to Climate Change in Shiyan City

摘要: 基于2005~2024年MOD13Q1-NDVI数据与1 km分辨率气象数据集，采用趋势分析、Hurst指数、Pearson相关分析，系统揭示十堰市植被覆盖时空演变特征，并从年际、空间与月尺度分析NDVI对气温、降水的响应规律。结果表明：① 近20年十堰市年均NDVI呈显著上升趋势，增速为0.024/10a，夏季NDVI最高，冬季增长速率最快；② 空间上NDVI呈“南北山地高、中部河谷低”分布格局，植被改善区集中于汉江沿岸，城镇周边零星退化，整体稳定性强且未来持续向好；③ 从逐年变化来看，NDVI与气温显著正相关，与降水量呈不显著负相关，月际尺度分析表明，生长季内十堰市NDVI受气温的影响并不显著，6~7月当月降水、5月前期降水对植被促进作用显著。

Abstract: Based on MOD13Q1-NDVI datasets and 1-kilometer resolution meteorological data from 2005 to 2024, trend analysis, Hurst exponent calculation and Pearson correlation analysis were adopted to systematically explore the spatiotemporal evolution characteristics of vegetation coverage. The response of NDVI to air temperature and precipitation was further analyzed at interannual, spatial and monthly scales. The results show that: (1) The annual average NDVI in Shiyan City has presented a significant increasing trend over the past 20 years with an annual growth rate of 0.024 per decade. NDVI peaks in summer, while its growth rate reaches the maximum in winter; (2) Spatially, NDVI follows a spatial pattern of high values in southern and northern mountainous areas and low values in central river valleys. Vegetation improvement areas are mainly distributed along the Hanjiang River, with sporadic degradation around urban built-up areas; overall vegetation conditions feature strong stability and will keep improving in the future; (3) At the interannual scale, NDVI is significantly positively correlated with air temperature yet insignificantly negatively correlated with precipitation. Monthly-scale analysis indicates that air temperature exerts no remarkable influence on NDVI during the growing season, whereas concurrent precipitation in June~July and Preseason precipitation in May impose prominent positive promoting effects on vegetation growth.