1984-2005年黑龙江省主要农区土壤湿度的变化特征

土壤湿度是干旱预报、农业生产、作物布局和农业决策的重要指标之一。应用黑龙江省1984—2005年26个农业气象观测站土壤湿度资料，采用气候倾向率和趋势系数统计方法，分析黑龙江省主要农区土壤湿度的时空变化特征及影响因素。结果表明：土壤湿度空间分布存在明显差异，与气温、降水量空间分布分别呈负相关和正相关，三江平原和中部农区土壤湿度相对偏高，松嫩平原土壤湿度相对偏低；近22a来各地土壤湿度变化主要呈下降趋势，各季节土壤湿度下降幅度不同，秋季下降最显著，春季次之，夏季不显著。研究认为气候、气候变化、农事活动对黑龙江省主要农区土壤湿度分布及变化趋势有重要影响，松嫩平原干旱可能加重，三江平原东部春涝可能得到缓解。

Characteristics of Soil Moisture Variation in Main Agricultural Areas of Heilongjiang Province from 1984 to 2005

Soil moisture is one of the most important indexes for drought prediction, agricultural production, crop layout and agricultural decision making. Based on the soil moisture data of twenty-six agro-meteorological observation stations in Heilongjiang Province from 1984 to 2005, with the statistical method of the climatic tendency rate and trend coefficient, the spatial and temporal characteristics of the soil moisture variation and their influencing factors in the main agricultural areas of Heilongjiang Province were analyzed. The results showed that the spatial distribution of the soil moisture was obvious different. It had positive correlation with the spatial distribution of the air temperature, and negative correlation with the rainfall spatial distribution. The soil moisture was relatively higher in Sanjiang Plain and the middle agricultural areas, while it was relatively lower in Songnen Plain. The soil moisture as a whole showed a decreased trend during 1984 and 2005. The decreasing extent of the soil moisture was different in the different seasons. The soil moisture significantly decreased in turn in autumn and in spring, while the deceased trend of the soil moisture was not obviously in summer. The study showed that the spatial distribution and change trend of the soil moisture were importantly influenced by climate, climate change and agricultural production. The drought disasters might be heavier in Songnen Plain, while the spring flood disasters might be relieved in east parts of the Sanjiang Plain.