古尔班通古特沙漠南缘丘间地土壤水分特征曲线及模拟

发布时间：2018-02-25 03:33

本文关键词： 土壤水分特征曲线模型拟合古尔班通古特沙漠丘间地　出处：《水土保持学报》2017年01期 　论文类型：期刊论文

【摘要】：为研究干旱荒漠地区土壤水分特征的变化规律并探讨土壤水分特征曲线拟合模型的适宜性,以古尔班通古特沙漠南缘丘间地为研究对象,应用压力膜仪测定了丘间地剖面各土层(0—150cm)的土壤水分特征曲线,结合土壤容重、颗粒分布及饱和含水率等性质,分析了丘间地不同土层水分特征和孔隙大小的分布状况,明确了Gardner模型和van Genuchten模型拟合的适用性。结果表明:(1)丘间地剖面砂质土壤释水量伴随吸力呈规律性变化,低吸力段(0~100kPa)各土层水分特征曲线走势陡直,释水性强;中高吸力段(100~1 500kPa)曲线趋于平缓,持水性强。水分曲线特征与其物理性质一致,各土层物理性质差异较小,曲线的差异也较小。(2)丘间地剖面各土层大孔隙由上到下不断增加且20—40cm土层的小孔隙最多,有助于春季积雪融化迅速入渗到土壤里贮存,对植物吸收利用水分有重大意义。(3)两模型都能很好地拟合丘间地的土壤水分特征曲线,VG模型的拟合效果优于G模型,但G模型形式简单、参数少且易于求解,更便于实际应用。
[Abstract]:In order to study the variation law of soil moisture characteristics in arid desert area and the suitability of fitting model of soil moisture characteristic curve, the study object is Goulbantong Gute desert south margin between hills. The soil moisture characteristic curves of each soil layer in the interdome profile were measured by pressure film instrument. The distribution of soil moisture characteristics and pore sizes in different soil layers were analyzed in combination with soil bulk density, particle distribution and saturated moisture content. The applicability of Gardner model and van Genuchten model was confirmed. The results showed that the water release of sandy soil in the cross-hill profile changed regularly, and the water release curve of each soil layer in the low suction section was steep and strong. In the middle and high suction section, the curve tends to be gentle and has a strong water holding capacity. The characteristics of the water curve are consistent with its physical properties, and the physical properties of each soil layer have little difference. The difference of curve is also small. (2) the porosity of each soil layer increases continuously from top to bottom and the small pore of 20-40 cm soil layer is the most, which is helpful for the snow melt and infiltration into the soil to store rapidly in spring. The two models can fit the soil water characteristic curve between hills very well. The fitting effect of VG model is better than that of G model, but the G model is simple in form, few in parameters and easy to solve, which is more convenient for practical application.
【作者单位】：中国科学院新疆生态与地理研究所荒漠与绿洲生态国家重点实验室;中国科学院大学;北京师范大学全球变化与地球系统科学研究院;
【基金】：重大科学研究计划项目“973”(2013CB429905) 国家自然科学基金项目(41601107,41671032,U1303181)
【分类号】：S152.7

【参考文献】