研究选取内蒙古苏尼特右旗,通过分析2015年5月至2016年12月日降水数据和同期不同深度土壤(0~ 10 cm, 10~ 20 cm, 20~ 30 cm, 30~ 40 cm和40~ 50 cm)含水量日连续观测数据,探讨降水事件对荒漠草原土壤含水量的影响。结果表明: ①降水量对表层土壤(0~ 10 cm, 10~ 20 cm)含水量影响最剧烈,且2层土壤含水量与降水量存在显著的正相关关系,其余3层土壤含水量对降水事件响应不显著。② 0~ 10 cm、10~ 20 cm土壤层的最小有效降水量分别为6.4 mm和8.33 mm。③结合最小有效降水量进一步推导0~ 10 cm及10~ 20 cm土壤层的有效降水转化率发现,0~ 10 cm土壤最大有效降水转化率可达到95%,但是大部分都是在70%左右; 10~ 20 cm最大有效降水转化率可达90%,但是大部分都是在50%左右。
英文摘要:
Climate change has become as one of the global issues in common concern. Water is one of the main limiting factors in semiarid grasslands. The change of precipitation pattern results in the change of soil moisture status. The effect of precipitation events on soil moisture content in desert steppe was studied based on the analysis of the daily precipitation data from May 2015 to December 2016 and the daily continuous observation data of soil moisture content at different depths (0 - 10 cm,10 - 20 cm,20 - 30 cm,30 - 40 cm and 40 - 50 cm). The results showed that: ① The effect of precipitation on topsoil (0 - 10 cm and 10 - 20 cm) moisture content was the most significant,and there was a significant positive correlation between the soil moisture content of these two layers and precipitation. The response of soil moisture content of other three layers to precipitation events was not significant; ② The minimum volumes of effective precipitation to 0 - 10 cm and 10 - 20 cm soil layers were 6.4 mm and 8.33 mm respectively; ③ Inferred the minimum effective precipitation, it was found that the conversion rate of effective precipitation to soil moisture in 0 - 10 cm layer could be as high as 95%,but it was mostly about 70%; it could be as high as 90% in 10 - 20 cm soil layer,but it was mostly about 50%.