2000~2010年陕北地区植被NDVI时空变化及其与区域气候的关系

采用相关关系分析、空间统计分析和叠置分析,研究陕北地区2000~2010年植被NDVI的时空变化特征,并从温度和降水2个方面分析植被NDVI变化与区域气候的关系。研究表明,该地区植被NDVI经历了从相对快速增长到小幅波动,再到平稳增长3个阶段。其中,陕北中东部区域植被覆盖增加显著,北部变化不大,南部略微下降。同期该区域气候干热化趋势有所改善,植被覆盖变化与区域气候相关性不高,气候对植被覆盖的影响主要表现为对植被生长期年内韵律的控制方面。

Spatio-temporal Change of Vegetation NDVI and Its Relations with Regional Climate in Northern Shaanxi Province in 2000-2010

Correlation analysis, spatial statistical analysis and overlay analysis are carried out to investigate spatial distribution pattern and variation characteristics of vegetation NDVI, and to analyze the relations between vegetation NDVI and regional climate from the views of temperature and precipitation respectively. The results indicate that the vegetation NDVI change shows three periods during 2000-2010: relatively-rapid growth stage in 2000-2002, slightly fluctuate stage in 2003-2005, and steady growth stage in 2006-2010. Vegetation NDVI change varies in different regions. In the loess hilly area of the central and eastern region of northern Shaanxi Province, the vegetation cover increased significantly, while in the wind drift sand area of the northern region, the vegetation cover change was small, and in low-mountain hilly area of the southern region, the vegetation cover slightly decreased. The precipitation was going on a declining curve in 2000-2010, while the temperature undergoing an upward trend in the same period. However, this dry-heating climate trend has been slightly restrained over the past years. The vegetation cover is positively related to precipitation and temperature in some areas,while in other areas it is negative. The linear relation is not obvious. Climate mainly impacts growth rhythm of vegetation in growth period, while temperature is a very important factor to inhibit vegetation growth in summer, and precipitation’s impact on vegetation growth is obviously hysteretic.