黑龙江省土壤冻融期气象要素变化特征

黑龙江省春季土壤冻融剧烈，土壤湿度和温度受土壤冻融影响较大，利用黑龙江省64个气象观测站1961—2018年的逐日最高气温、最低气温、平均气温、降水量、地温资料及34个农气观测站人工观测的1981—2018年的土壤湿度资料，分析土壤冻结期间的气象要素变化，研究春季土壤冻融过程中湿度和温度的变化。结果表明：土壤冻结期从北向南缩短，且逐年缩短，冻结期平均气温从北向南升高，逐年上升，降水量西部少、东部和北部多，逐年增加；春季冻融次数平原少、山区多，逐年减少。春季融雪开始日期由北向南提前，并且呈现逐年提前的趋势，融雪期升温速率北部、东部低，中部、南部高；在春季冻融过程中，土壤湿度随着土壤深度的增加而增多，东部土壤湿度受土壤融冻影响最大；在整个冬季土壤冻结期间，北部、中部及东部土壤湿度是增加的，且随着土壤深度的增加，土壤湿度增加的越多，而西部土壤湿度是减少的，且随着土壤深度的增加，土壤湿度减少的越少；春季土壤冻融期间，0 cm平均地温全省平均在-17.3~22.1 ℃之间，南部与全省变化趋势基本一致，升温趋势明显，而北部升温速度明显慢于南部。

Characteristics of changes of meteorological factors during freezing and thawing period in Heilongjiang Province

The freeze-thaw of soil is intense， which affects greatly humidity and temperature of soil in spring in Heilongjiang Province. Based on the data of maximum temperature， minimum temperature， mean temperature， precipitation， ground temperature of 64 meteorological stations of 1961—2018 and humidity of the soil of 34 agrometeorological stations of 1981—2018. It analyzed the factors of meteorological during soil freezing. It also studied the changes of humidity and temperature during freezing and thawing in spring. The main conclusions are as follows： The period of soil freezing was shortened from north to south and it was shortened year by year. The average temperature of soil freezing increased from north to south and it increased year by year. The precipitation was less in the west and more in the east and in the north， it increased year by year. The number of freeze-thaw times in spring was less in the plain and more in the mountainous and it was decreasing year by year. The start date of snowmelt was advancing from north to south and the trend was advancing year by year. The warming rate of snow melting was lower in the north and east， higher in the middle and south. Humidity of the soil increased with the increasing of soil depth， and humidity of the soil was affect mostly in the east during freezing and thawing in the spring. During the freezing of the whole winter， Humidity of the soil in the north， middle and east increased， and with the increase of soil depth， the more humidity of the soil increased， while the humidity of the soil decreased in the west， and with the increase of soil depth， the less humidity of the soil decreased； During freezing and thawing in the spring， the average ground temperature of 0 cm was between -17.3 ℃ to 22.1 ℃， the change trend of the south and the whole province was the same basically， the heating trend was obvious， while the heating rate in the north was obviously slower than that in the south. The warming rate of snow melting period is low in the north and east， high in the middle and south.