2000—2020年呼伦贝尔地区归一化植被指数时空变化及其对气候的响应

利用2000—2020年MOD13Q1和气象观测数据, 结合Sen趋势分析、M-K显著性检验、变异系数、Hurst指数、相关系数等对呼伦贝尔地区归一化植被指数(NDVI)时空变化及气候响应进行分析。结果表明: 呼伦贝尔地区多年生长季平均NDVI为0.63, 平均年变化倾向率为0.028/10 a, 大部分地区呈增加趋势, 其中大兴安岭森林大部及岭西耕地增加显著。呼伦贝尔地区生长季NDVI的平均变异系数为0.08, 其中呼伦贝尔草原西部的波动较大。Hurst指数表明, 呼伦贝尔地区生长季NDVI整体变化呈反持续性趋势, 结合现有NDVI变化趋势, 未来将呈下降趋势, 对生态环境的保护工作较为不利。大兴安岭森林生长季NDVI与气温呈正相关, 耕地与草原区呈负相关, 而呼伦贝尔大部分地区的生长季NDVI与降水普遍呈正相关, 其中呼伦贝尔草原和大兴安岭两麓耕地的生长季NDVI与降水相关显著, 说明气温是制约北部大兴安岭森林生长的主要因素, 而降水是制约呼伦贝尔草原生态平衡和农牧业发展的主要因素。

Temporal and spatial change of NDVI and its response to climatic conditions in Hulun Buir region from 2000 to 2020

Using MOD13Q1 data and meteorological observation data from 2000-2020, the temporal and spatial variation of the Normalized Difference Vegetation Index (NDVI) and its climatic response in Hulun Buir were analyzed using Sen trend analysis, M-K significance test, coefficient of variation, Hurst index, and correlation coefficient methods.The results show that the annual average NDVI in Hulun Buir is 0.63 during the growing season, and the annual average tendency rate is 0.028 per decade.Most regions show an increasing trend, especially in most forest areas and farmlands in the west of Daxing'anling.The average coefficient of variation in NDVI in Hulun Buir is 0.08 during the growing season, and the fluctuation in the grassland distribution in the western part of Hulun Buir is larger.The Hurst index indicates that the overall change of NDVI in the Hulunbuir area during the growing season shows an anti-persistent trend.Combined with the current change trend of NDVI, it shows a downward trend in the future, which is unfavorable to the protection of the ecological environment.As a whole, there is a positive correlation between NDVI and temperature in the forest during the growing season, while negative correlation between cultivated land and grassland.Generally, precipitation has a positive correlation with NDVI in most areas of Hulun Buir during the growing season, especially in cultivated land at the foothills of Hulun Buir grassland and Daxing'anling.That indicates that temperature is the main factor to mediate forest growth in northern Daxing'anling, while precipitation restricts the ecological balance between Hulun Buir grassland and the development of agriculture and animal husbandry.