中国东部土壤温度、湿度变化的长期趋势及其与气候背景的联系

Long Term Trends of Soil Moisture and Temperature Change in East China in Relationship with Climate Background

利用1971—2000年中国722站逐月的土壤温度资料和1981—1998年178站逐旬的土壤湿度观测资料,分析了中国东部土壤温度、湿度变化的长期趋势及其与气温、降水变化的关系。结果表明:①我国东部土壤温度的变化在年际—年代际时间尺度上存在明显的区域性差异,其中东北地区表现为持续上升型,而西北东部—华北、江淮和西南—华南地区均为先降后升型;②1970—2000年代,土壤温度的变化在东北以及西北东部—华北地区有显著的上升趋势,而在江淮和西南—华南地区,总体而言变化趋势不显著。此外,1980—1990年代,各区域土壤湿度的变化趋势均不显著;③在年际—年代际尺度上,各区域土壤温度和气温的变化具有显著的正相关关系,而土壤湿度与土壤温度的变化普遍呈负相关关系,其中尤以西北东部—华北地区最为显著。而在较长的时间尺度上,土壤湿度与降水的变化仍然存在较好的正相关关系。

Based on the data of monthly mean soil temperature from 722 stations over 1971-2000 and soil moisture observations from 178 agrometeorologieal stations during 1981-1998, the long term trends of soil temperature and soil moisture in East China and their relationship with the change of surface air temperature and precipitation are analyzed. The results indicate that ： （ 1 ） There are obvious regional differences in the variation of soil temperature in East China The soil temperature change in Northeast China displays an increasing trend, while in the other parts of East China, such as North China, the Yangtse-Huaihe river Valley and Southwest-South China, the soil temperature change shows a trend of from dropping at first to rising afterwards. （2） From the 1970s to the 1990s, the soil temperature change in Northeast China and North China displays an increasing trend. However, the trend of soil temperature change in the Yangtse-Huaihe River Valley and Southwest-South China is not obvious in general. Generally, from 1981 to 1998, the trends of soil moisture are not obvious in each subregion. （3） From inter-annual to inter-decadal timescales, there is an evident positive correlation between the soil temperature and surface air temperature in all parts of East China. Meanwhile, soil moisture is positively correlated with precipitation, and negatively correlated with soil temperature. The negative correlation of soil temperature and soil moisture in North China is most notable.