【摘要】 川陕地区处于中国800mm等降水量线过渡带的南北两侧,区内分山、川、原3种地形,是退耕还林(草)最早实施区域。基于2001—2014年的MODIS、气温和降水量数据,选取10种植被地带数据,采用Sen+MK检验和时滞偏相关等方法,结合重分类后的4种地貌类型和6类土地利用/覆盖数据,分年内生长季、年际生长季和非生长季的对比、以及植被生长最好的8月与5月、6月、7月、8月、5—6月、6—7月、7—8月、5—8月共8个时间段的相关性3种时间尺度,对川陕地区植被NDVI与气候因子的关系进行了深入探讨。结果表明:1)川陕、陕西和四川年均气温分别以0.02℃/10a、0.01℃/10a和0.03℃/10a(通过0.01显著性水平)的线性速度增加,低于近50年来(1951—2001年)全国的气温增速(0.22℃/10a);2)川陕、陕西、四川尺度上,植被NDVI与同季气温、降水量的相关性一致,与上季的相关性不具一致性。植被NDVI与上季气温、降水量的相关性均高于同季,相较于降水量,与气温呈现出更多的负相关性,其中陕西地区最为显著;3)川陕地区气温变化趋势与全球变暖不同步,植被生长受气温的影响较小或无影响;降水量相较于气温对陕西地区植被生长的影响更大;气温是四川植被生长的主要限制因素。植被覆盖与气温、降水量的相关性在草地、林地和农耕区最为显著。更多还原

【Abstract】 Sichuan-Shaanxi area is located in the north and south sides of the transition zone of 800 mm isohyet in China. The area is divided into three terrains including mountain, river, and grassland, which is the earliest implementation area of returning farmland to forest(grass). Based on the data of MODIS, temperature, and precipitation in 10 vegetation zones from the year 2001 to 2014, the methods of Sen+MK test and time-delay partial correlation are adopted. Combined with 4 geomorphologic types and 6 types of re-classified land use/cover data, the relationship between the NDVI of the vegetation in Sichuan-Shaanxi zone and climatic factors was discussed at three time scales: the comparison within annual growing season, interannual growing season, and non-growing season, the August with the best vegetation growth, and the correlation of eight periods, including May, June, July, August, May—June, June—July, July—August. The results are as follows: 1) The annually average temperature in Sichuan-Shaanxi, Shaanxi, and Sichuan increased linearly at 0.02℃/10 a, 0.01℃/10 a, and 0.03℃/10 a(at 0.01 significant level),which was lower than the national growth rate of temperature(0.22℃/10 a) in last 50 years(1951—2001); 2)In the areas of Sichuan-Shaanxi, Shaanxi, and Sichuan, the correlation between vegetation NDVI and temperature, precipitation in the same season was consistent, but the correlation with that last season was inconsistent. The correlation between vegetation NDVI and the temperature, precipitation in last season was higher than that in the same season. Compared with the precipitation, the vegetation NDVI showed more negative correlation with temperature, and it was the most significant in Shaanxi; 3) The change of temperature in Sichuan-Shaanxi region showed no same trends with global warming, and the vegetation growth was less or not affected by temperature. The influence of precipitation on vegetation growth in Shaanxi was greater than that of temperature. Temperature is a main limited factor in determining vegetation growth in Sichuan. The correlation between vegetation cover and temperature, precipitation was the most significant in grassland, woodland. and farming area.更多还原