湖北省植被覆盖时空变化及因子研究

Study on the Spatial- temporal Distribution Variation of Vegetation Coverage and Their Natural Driving Factors in Hubei Province

植被覆盖是影响水土流失的重要因子,本文在对湖北省近16年来植被覆盖在不同类型区变化分析的基础上,系统地分析了植被覆盖在不同坡度、土壤、高程的空间分布与时间变化规律,探讨植被覆盖时空变化自然驱动机制。结果表明:平均海拔高、坡度大的武陵山和秦巴山山地丘陵区年际变化NDVI相对值比平均海拔低、坡度小的江南和长江中游丘陵平原区要高,NDVI年际变化趋势增幅也较大,春、夏、秋三季的NDVI值变化幅度也相对较大。年均NDVI退化和改善的区域主要出现在坡度<5°、高程<500m的区域,退化的区域最主要是城镇及周边地区,改善的区域最主要是江汉平原等农作物主产区。

The vegetation coverage is an important impact factor on the soil erosion. Based on the analysis of vegetation coverage changes in the different type areas of Hubei Province from 1998 to 2014, it was analyzed quantitatively the spatial distribution and temporal variation rules of the vegetation coverage in Hubei Province at different slopes, soil types, elevations, rainfalls and temperatures, so as to discuss the natural driving mechanism for the vegetation coverage temporal and spatial variation. The results showed that, the annual variation of NDVI relative values in Wuling Mountain and Qinba Mountains with high average altitude and slope degree were higher than that of in southern hills and the Yangtze Plain with low average altitude and slope degree. And the annual variation trend of NDVI is also larger. The variation range of NDVI in spring, summer and autumn were larger as well. Most annual average NDVI degraded and improved areas were located in the regions with the slope less than 5° and altitude less than 500m. Of which, the degraded areas were mainly located in towns and surrounding areas, while the improved areas were mainly located in the main crop areas at Jianghan Plain.