内蒙古典型草原区近40年气候变化及其对土壤水分的影响

分析气候变化对草原区土壤水分的影响对了解草原退化原因、恢复草原生态环境有重要的指导意义。根据近40年气象资料和近20年的土壤水分观测资料,利用线性趋势等数理统计方法,分析了内蒙古典型草原区气候变化趋势和对土壤水分变化的影响,得出内蒙古典型草原区近40年气候变化趋势与全球气候变化规律相似;影响土壤湿度的气象因子主要是降水和蒸发,温度通过影响蒸发而间接影响土壤湿度,蒸降差是分析气候变化对土壤水分影响的直观指标。气候变暖导致蒸发加剧,在降水增加不明显的条件下,加速了土壤干旱化程度。

Analysis of Climate Change and Its Effect on Soil Moisture over Inner Mongolia Typical Steppe in Recent 40 Years

The analysis of climate change and its effect on the soil moisture of grasslands has great significance to the understanding of the reasons for grassland degradation and the recovering of the grassland ecosystem.Based on the 40year climate data and 20-year observational data of soil moisture,the climate change trend and its effect on soil moisture over the Inner Mongolia typical steppe are analyzed by using the linear trend method,etc.The results show that the 40-year climate change trend over the Inner Mongolia typical steppe is similar with that of the global climate;the main factors influencing soil moisture are precipitation and evaporation,but air temperature influences indirectly the soil moisture through affecting evaporation.The difference between evaporation and precipitation is a direct index for analyzing the effect of climate change on soil moisture.Climate warming results in the increase of water evaporation,and thus accelerates the drying rate of soil under the condition of insignificant precipitation increase.