干旱区中小尺度不同作物地段土壤湿度对气候变化的响应关系研究

The Response of Different Crops Soil Moisture to Climate Change on Small and Medium Scale in Arid Areas of China

以甘肃省靖远县为研究对象,基于农业气象站1981-2000年作物生长季土壤湿度、气温和降水观测资料,采用最小二乘法和统计分析方法及Mann-Kendall方法,分析了研究区表层(0~50 cm)土壤湿度时空变化特征及其对气温、降水量等气候变化的响应。研究结果表明:同一作物类型地表各层土壤湿度随时间的变化规律基本一致,而不同作物类型各层土壤湿度变化则差别较大。不同深度土壤湿度多年平均值则与种植作物类型有一定的关系;其中春小麦地块土壤湿度从上到下依次为低~高~低变化即呈"凸型"变化;而春玉米地块土壤湿度从上到下依次为高~低~高变化即呈"凹型"变化。气温与土壤湿度的关系随种植作物类型和土层深度不同而存在一定的差异;降水与土壤湿度的关系与种植作物类型和土层深度均无关,但它们的关系随作物类型和土层深度敏感程度有一定差别;而径流量与土壤湿度的关系随作物类型不同有着完全相反的表现。

Jingyuan county of Gansu province was selected as a research object. Based on the observation data of soil moisture, temperature and precipitation in crop growing season from 1981 to 2000 in agricultural meteorological stations, statistical analysis methods, Mann-Kendall method and Least square method were applied to analyze the data of the surface soil （0 ~ 50 cm） , the spatial and temporal variations of soil moisture and the response of different crops soil moisture to climate change are studied. The results showed that the surface soil moisture change rule in each layer was basically consistent to the same crop types; however, the soil moisture change in each layer was greatly different for different crop types ; the multi-years average soil humidity in different depth has a certain relation with the planting of crops type ; therein, the soil moisture change process of spring wheat was convex type with the change characteristic of low to high to low from top to bottom ; while the soil moisture variation of spring corn was concave type with the change characteristic of high to low to high from top to bottom. The relationship between air temperature and soil moisture was different due to different planting crop types and soil depth. The relationship between precipitation and soil moisture has nothing to do with planting crop types and soil depth, but the relationship have certain otherness for the types of crops and the sensitivity of soil depth. While the relationship between soil moisture and runoff has opposite characteristic for different crop types.