祁连山大野口流域土壤水热空间变化特征研究

土壤水热对水源涵养功能的发挥影响较大,为了研究流域空间上的水源涵养功能变化规律,在祁连山大野口流域布设90个土壤水热监测探头,对已取得的100多万个数据采取相关分析、变异系数等方法,研究土壤水热空间的变化特征.结果表明:随海拔增大,土壤水分呈波动性增大趋势,增大率约为2.35%·(100m)^-1,土壤温度呈波动性降低趋势,降低率约为0.74℃·(100m)^-1.半阴坡土壤水分比半阳坡高1.2倍、比阳坡高1.7倍,半阳坡土壤水分比阳坡高1.4倍.半阴坡土壤温度比半阳坡低1.6倍、比阳坡低2.2倍,半阳坡土壤温度比阳坡低1.3倍.土壤水分与其深度呈二次函数的抛物线变化关系,土壤温度与其深度呈线性函数关系,深度每增加10 cm,其温度降低约0.536℃.亚高山灌丛林比乔木林土壤水分高1.5倍、比草地高1.7倍,乔林比草地土壤水分高1.2倍.亚高山灌丛林比乔木林土壤温度低1.6倍、比草地低2.3倍,乔木林土壤温度比草地低1.4倍.高海拔半阴坡灌丛林土壤温度变化最剧烈,低海拔阳坡草地土壤变化较小.研究成果可为探索流域水资源管理及利用提供科学依据和参考资料.

Research on the spatial variation characteristics of soil moisture and temperature in Dayekou basin of the Qilian Mountains

Soil water and temperature impact greatly the function of water conservation. In order to study space change of water conservation function in a basin, the Dayekou basin in the Qilian Mountains has been chosen to study the spatial variation characteristics of soil temperature, and one million data has been obtained by 90 detectors of soil moisture and temperature, which has been analyzed by using the methods of variation coefficient. Results showed that:(1) There is a variation trend that soil moisture increases with altitude by a rate of about 2.35%·(100m)^-1, and soil temperature decreases with altitude by a rate of about 0.74℃·(100m)^-1.(2) The soil moisture on half-shady slopes is 1.2 times higher than that on half-sunny slopes, and 1.7 times higher than that on sunny slopes, and the soil moisture on half-sunny slopes is 1.4 times higher than that on sunny slopes. The soil temperature on half-shady slopes is 1.6 times lower than that on half-sunny slopes, and 2.2 times lower than that on sunny slopes, and the soil temperature on half-sunny slopes was 1.3 times lower than that on sunny slopes.(3) The correlation between soil moisture and depth is a quadratic parabola relation, with a linear temperature decreasing rate of about 0.536℃ per 10 cm.(4) The soil moisture under sub-alpine scrub forest is 1.5 times higher than that under arbor forest, 1.7 times higher than that under grass, and the soil moisture under arbor forest is 1.2 times higher than that under grass; The soil temperature under sub alpine is 1.6 times lower than that under arbor forest, and 2.3 times lower than under grassland. The soil temperature under arbor forest is 1.4 times lower than that under grassland.(5) The variation of soil temperature is the most severe on high altitude and half shady slopes, and the variation of soil temperature under grassland is the lowest on low altitude slopes and sunny or half-sunny slopes. This research conclusion is useful for searching river basin water balance and water conservation function, adjusting and managing stand structure and utilizing water resources.