柴达木盆地植被物候时空变化及其对气候变化的响应

发布时间：2018-08-04 21:07

【摘要】：基于TIMESAT3.2平台对获得的柴达木盆地2000—2015年的MODIS NDVI数据资料进行拟合,用动态阈值法提取盆地植被的返青期、枯黄期以及生长季长度3个主要物候参数,分别分析了柴达木盆地16年的植被物候和气候因子(气温和降水)的空间分异特征及时空变化趋势,并对两者进行偏相关性分析,结论如下:(1)柴达木盆地植被返青期整体以推迟为主,枯黄期推迟和提前的面积大致相当,生长季整体缩短。(2)在返青期推迟、生长季缩短的大趋势下,一些区域如盆地边缘的山脉河谷、盆地中东部冲洪积扇核心区、东部和北部山间盆地等地返青期提前、枯黄期推迟,生长季延长。(3)柴达木盆地气温和降水呈环状或半环状分布,植被覆盖区总体升温,但趋势不显著,降水量东部显著增多,中西部有所减少。(4)柴达木盆地植被物候对气温和降水变化的响应区域差异明显,在低海拔水体分布较多的相对湿润区随气温升高返青期提前、枯黄期推迟,对降水响应不明显;在海拔较高的山体上部随气温升高返青期推迟、枯黄期提前,随降水的增多返青期提前、枯黄期推迟。
[Abstract]:Based on TIMESAT3.2 platform, the MODIS NDVI data of Qaidam Basin from 2000 to 2015 were fitted, and three main phenological parameters were extracted by dynamic threshold method, such as green stage, yellow period and length of growing season. The spatial differentiation characteristics of vegetation phenology and climatic factors (temperature and precipitation) in Qaidam Basin for 16 years are analyzed, and the partial correlation between them is analyzed. The main conclusions are as follows: (1) the vegetation of Qaidam Basin is mainly delayed in the green stage, the area of the deferment and advance of the yellow period is about the same, and the whole growing season is shortened. (2) under the trend of the deferment of the green returning period and the shortening of the growing season, Some regions such as mountain valleys on the margin of the basin, alluvial fan core areas in the central and eastern part of the basin, intermountain basins in the east and north of the basin, etc., are in the early green stage, the low yellow period is delayed, and the growing season is prolonged. (3) the temperature and precipitation in the Qaidam basin are distributed in annular or semi-annular form. The vegetation cover area generally heats up, but the trend is not obvious, the precipitation in the eastern part increases significantly, and the central and western regions decrease. (4) the response of vegetation phenology to the change of temperature and precipitation in Qaidam Basin is obviously different. In the relatively humid areas with the increase of temperature, the yellowing period was delayed, and the response to precipitation was not obvious in the relatively humid areas with the increase of temperature, but in the upper part of the mountain body at higher altitude, the green returning period was delayed with the increase of temperature, and the yellowing period was earlier. With the increase of precipitation, the turning green period was advanced, and the yellow period was delayed.
【学位授予单位】：河北师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q948.1

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