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为了研究内蒙古草原返青期对气候的响应,利用2001—2011年的遥感增强型植被指数(EVI)反演内蒙古草原区的返青期,并结合同期研究区内34个气象站点的气温和降水量数据,对该地区返青期的线性趋势及其对气候要素的时空响应特征进行分析.结果表明:内蒙古草原气象站点间的春季水热条件和返青期差异明显,总体上研究区南部的返青期偏早,在研究区中部和北部的返青期偏晚,最大相差46 d;在研究时段内,草原返青期在8%的站点上有显著的变化趋势.在时间序列上,24%的站点的返青期与其前期气温显著负相关,50%的站点返青期与其前期降水量显著负相关,早春气温的升高和降水量的增加会促进返青期的提前.空间分布上,在降水量充沛且降水量增加较快的区域,返青期提前趋势越大;反之,在降水量缺乏以及降水量减少较快的地区,返青期没有提前甚至有推迟趋势;气温对返青期趋势的作用比降水更复杂,这是由于气温的升高在带来草原返青所需热量的同时,加重了部分地区的干旱胁迫.
In order to study the response of climate change in Inner Mongolia prairie returning period, the retrogradation period of grassland in Inner Mongolia was retrieved using the remote sensing enhanced vegetation index (EVI) from 2001 to 2011. Based on the data of temperature and precipitation of 34 meteorological stations in the same period, , The linear trend of returning greening period in the region and its spatio-temporal response characteristics to climatic elements were analyzed.The results showed that there were significant differences between the spring hydrothermal conditions and the turning-back period in Inner Mongolia grassland meteorological stations. , With the maximum difference of 46 days in the middle and the northern part of the study area, with a maximum difference of 46 days. During the study period, the turning-green stage of the grassland showed a significant trend at the 8% site. In the time series, 24% Negatively correlated with the temperature of the previous period, and 50% of the stations returning to greening stage were significantly and negatively correlated with the previous precipitation. The increase of the early spring temperature and the increase of the precipitation will promote the advancement of the greening period. In the spatial distribution, with abundant precipitation and precipitation On the contrary, in the regions where the precipitation is scarce and the precipitation is decreasing rapidly, there is no advance or even postponement of the rejuvenation period; the return of temperature to the return The role of the trend is more complex than rainfall, which is due to elevated temperatures in the grasslands turn green at the same time bring the heat required, adding to the stress of drought in some areas.