蓄水坑灌条件下系统温度及土壤体积质量对饱和导水率的影响试验研究

Experimental Study on Influence of System Temperature and Soil Volume Mass on Saturated Hydraulic Conductivity under Water-storage Pit Irrigation

蓄水坑灌法是根据我国北方地区干旱和水土流失双重问题而提出的一种新的灌溉方法,在山丘区果林灌溉中具有广泛的应用前景。研究并分析了不同系统温度、不同土壤体积质量对饱和导水率的影响。试验结果表明:在同一土壤体积质量的条件下,土壤饱和导水率随着温度的升高而呈现增大的趋势;在同一土壤体积质量条件下,温度较低时(T≤20℃),饱和导水率随温度变化曲线较缓,反之,温度较高时(T≥20℃),曲线较陡。在同一系统温度条件下,土壤饱和导水率随着土壤体积质量的增大而呈现减小的趋势;在同一系统温度条件下,饱和导水率随体积质量变化的曲线逐渐变缓,其斜率逐渐减小。从敏感性上分析,土壤饱和导水率对土壤体积质量的变化较为敏感。土壤体积质量越大,饱和导水率随温度的变化越大;系统温度越低,饱和导水率随体积质量变化越大。

Water-storage pit irrigation method is a new irrigation method which is put forward according to the problems of drought and soil erosion in north China, and has a wide application prospect in fruit wood irrigation for mountain areas. The effects of differ- ent system temperature and soil volume mass on saturated hydraulic conductivity are analyzed in this paper. The experimental results show that under the same soil volume mass condition, the soil saturated hydraulic conductivity shows the increase tendency with the increase of temperature; the curve of its changing with the temperature is reIatively slow at the temperature less than or equal 20 ℃ while relatively steep at the temperature larger than 20 ℃. Under the same system temperature condition, the soil saturated hydraulic conductivity shows the decrease tendency with the increase of soil volume mass; the curve of its changing with the soil volume mass is gradually slow and its slope gradually decreases. The soil saturated hydraulic conductivity is more sensitive to the change of soil volume mass. The bigger the soil volume mass, the bigger the change of saturated hydraulic conductivity with temperature. While the lower the system temperature, the greater the change of saturated hydraulic conductivity with volume mass.