三江平原土壤湿度记忆性及其与水热气候条件的关系

A memory of soil moisture and its relation with hydrothermal climatic conditions in the Sanjiang Plain

利用1982—2020年三江平原19个国家气象观测站土壤湿度及同期降水、气温数据,基于相关系数和自相关系数统计方法,分析了黑龙江省三江平原土壤湿度记忆性及与降水、气温之间的关系。结果表明:春、夏季三江平原土壤湿度记忆时间均在10—40 d,各层土壤湿度记忆性的空间分布以中间层(10—20 cm)土壤湿度平均记忆时间最长,呈上下层递减的趋势;春季三江平原10—20 cm土层土壤湿度的记忆时长平均20 d,夏季平均17 d;夏季土壤湿度记忆性强度大于春季,空间分布以三江平原西部的记忆性较强,随着土层的增加土壤湿度记忆性有增大的趋势。降水是三江平原土壤湿度主要来源,受降水和气温协同作用的影响,夏、秋季土壤湿度与同期降水量、温湿指数均存在显著的正相关关系;春季土壤湿度与前期秋冬季降水亦呈显著正相关,与前期温湿指数呈负相关,前期秋冬季气温的升高会促进土壤的融冻,从而使当年春季土壤水分增加。

Based on the data on soil moisture,precipitation,and temperature at 19 national meteorological stations in Sanjiang Plain from 1982 to 2020,the correlation coefficient and autocorrelation coefficient were used to analyze the soil moisture memory and its relationship with precipitation and temperature in Sanjiang Plain of Heilongjiang province.The results show that the memory time of soil moisture in spring and summer in Sanjiang Plain varies between 10-40 days.The average memory time of soil moisture in different layers is the longest in the middle layer(10-20 cm),and the lower layer shows a decreasing trend.The average memory time of 10-20 cm soil layer in spring and summer in Sanjiang Plain is 20 days and 17 days,respectively.The memory intensity of soil moisture in summer is higher than that in spring,and the memory intensity of soil moisture in the west of Sanjiang Plain is stronger,and the memory intensity of soil moisture tends to increase with the increase of soil layer.Precipitation is the main source of soil moisture in Sanjiang Plain.Under the synergistic effect of precipitation and temperature,soil moisture in summer and autumn has a significant positive correlation with precipitation and temperature and humidity index in the same period.Soil moisture in spring is also positively correlated with precipitation in autumn and winter and negatively correlated with temperature and humidity index in the early period.The increase of temperature in autumn and winter in the early period will promote soil thawing and freezing,thus increasing soil moisture in the spring of that year.Understanding the persistence of soil moisture anomaly is beneficial to climate prediction,drought evaluation,and agricultural production.