论文部分内容阅读
为探明浑善达克沙地土壤湿度的时空变化规律 ,于 1 998一 1 999年在浑善达克沙地中部取样分析了地形和植被与土壤含水量的相关性及生长季内土壤含水量的动态。发现在坡度 <1 5°时 ,随坡度的增大 ,土壤含水量降低 ,在坡度 >1 5°时 ,沙丘阴坡上土壤的含水量随坡度的增大而增加。高沙丘阳坡的土壤含水量 ,受坡度的影响很小 ,略有降低。由于沙地土壤类型复杂 ,土壤剖面变异也比较大 ,所以随深度的增加土壤含水量的变化规律也不同。土壤含水量的动态特征在不同土层也有差异 ,表土层 ,春末夏初之前土壤比较干 ,以后在波动中上升 ,8月份土壤含水量比较大 ,8月底以后又迅速下降到春末夏初的水平。心土层则在前期土壤比较湿润 ,而后逐渐下降 ,在 6月中旬至 7月中旬出现土壤含水量的低谷 ,7月中以后又逐渐升高 ,并在 8月底达最大含水量 ,9月中旬后又降到年初的水平。6、7月间含水量的低谷可能是由于植物大量耗水造成的。表土层和心土层 (70 cm以上土层 )在 9月上旬基本降到了5月初的水平。但底土层土壤含水量在波动中升高 ,9月上旬虽有所下降 ,但仍高于 5月初的土壤湿度。在某些地形部位 ,随植被盖度的增加 ,土壤含水量有增大的趋势。
In order to find out the temporal and spatial variation of soil moisture in Hunshandake Sandy Land, the correlation between topography and vegetation and soil water content was analyzed in the middle of Hunshandake Sandy from 1998 to 1999 and the content of soil in the growing season Water dynamics. It is found that the soil water content decreases with the increase of slope when the slope is less than 15 °. When the slope is more than 15 °, the soil moisture content on the slope on the dune increases with the increase of slope. The soil moisture content of the high dune sunny slope is slightly affected by the slope, slightly lower. Due to the complex types of soil in sandy land and the large variation of soil profile, the variation of soil water content with depth is also different. The dynamic characteristics of soil water content are also different in different soil layers. The topsoil, dry soil before spring and early summer and early summer are relatively dry, and then rise in fluctuation. Soil moisture content in August is relatively large, and then quickly drops to the late spring and early summer after the end of August s level. Soil and soil layer in the earlier wet soil, and then gradually declined in mid-June to mid-July soil moisture appeared in the trough, gradually increased after mid-July and reached the maximum moisture content in late August, mid-September Later dropped to the beginning of the year. The trough of moisture content in June and July may be due to the large amount of water consumed by plants. Topsoil and heart soil (70 cm or more soil) in early September basically dropped to early May level. However, the soil moisture content of the bottom soil layer increased during the fluctuation, though it decreased in early September, but it was still higher than the soil moisture content in early May. In some terrain areas, with the increase of vegetation cover, soil moisture content tends to increase.