1982—2013年内蒙古植被返青期动态监测及其对气候变化的响应

Vegetation SOS dynamic monitoring in Inner Mongolia from 1982 to 2013 and Its responses to climatic changes

【目的】研究内蒙古植被返青期对气候变化的敏感性。【方法】基于1982—2013年GIMMS NDVI 3g数据,使用累积NDVI的Logistic曲线曲率极值法,线性趋势分析方法,对内蒙古地区(除去荒漠植被稀少区)32年间植被返青期进行识别和提取,分析内蒙古植被返青期的时空变化规律,以及不同植被类型的返青期对气温、降水变化的响应。【结果】(1)内蒙古植被返青期开始在4月26日至5月23日之间。(2)在1982—2013年间内蒙古植被返青期总体呈现推迟趋势,以2010年为转折点,转折点之前返青期没有明显的提前或推迟的现象;转折点之后,返青期呈现逐年推迟趋势。(3)内蒙古植被返青期与气象因子的关系:4月植被返青期与温度呈现负相关的面积占72.5%,4月植被返青期和降水呈现负相关的面积占55.9%,由此得出4月温度升高和降水增加都会促进返青期提前。与降水相比,返青期与温度的相关程度更高。(4)不同植被类型的返青期与温度、降水的相关关系:森林区的返青期与4月温度的相关性最为显著,通过了0.01显著性检验水平。草地区的返青期与4月降水增加的相关性通过0.01显著性检验水平。【结论】通过研究内蒙古植被返青期的时空变化规律,探索植被返青期与气象因子的关系,为增强对气候变化的应对能力、指导当地的农牧业生产具有重要的理论和实际价值。

[Purpose]To study the SOS(start of season)of Inner Mongolia to climate change.[Method]This article is based on 1982-2013 GIMMS NDVI 3g data,using the cumulative NDVI Logistic curve curvature extremum method,Linear trend analysis method,and SOS was identified and extracted in Inner Mongolia during the 32 years(except for the desert vegetation scarce area),and the spatial and temporal variation of SOS was analyzed and the responses of temperature changes and precipitation changes to SOS in different vegetation types[.Result]The results show that:(1)the average SOS in Inner Mongolia from 1982 to 2013 is between April 26 and May 23.(2)The SOS in Inner Mongolia showed a postponing trend from 1982 to 2013.With 2010 as a turning point,there was no obvious advance or postponement of SOS before the turning point.After 2010,the SOS tended to be delayed year by year.(3)Relationship between SOS and meteorological factors in Inner Mongolia:In April,the area with negative correlation with temperature was 72.5%.The area of negative correlation between precipitation and precipitation in April was 55.9%.So it can be concluded that the increase of temperature and increase of precipitation in April will promote the advancement of SOS.Compared with precipitation,SOS is more related to temperature.(4)Relationship between SOS,temperature and precipitation in different vegetation types:The correlation between SOS and the temperature in April was the most significant,and it passed the significance test of 0.01.The increase of precipitation in April promoted the advance of SOS,and the correlation between the increase of precipitation in April of grassland and SOS passed the significance test of 0.01.[Conclusion]By studying the spatial temporal changes of vegetation returning green period in Inner Mongolia,the relationship between the vegetation returning green period and meteorological factors is explored,which has important theoretical and practical values for enhancing the ability to cope with climate change and guiding local agricultural and pastoral production.