塔里木沙漠公路防护林土壤水分特征曲线模型分析与比较  

Analysis and comparison of models for soil water characteristic curves of Tarim Desert Highway Shelterbelt

作　　者：丁新原 周智彬[1,2] 雷加强[1] 王永东[1] 鲁晶晶[1,2,3] 黎小娟 

机构地区：[1]中国科学院新疆生态与地理研究所,新疆乌鲁木齐830011 [2]荒漠与绿洲生态国家重点实验室,新疆乌鲁木齐830011 [3]中国科学院大学,北京100049

出　　处：《干旱区地理》2015年第5期985-993,共9页Arid Land Geography

基　　金：水利部公益性行业科研专项(201401049);中国科学院战略性先导科技专项(XDA05050504)

摘　　要：应用压力膜仪对塔里木沙漠公路防护林地0-150 cm范围的土层进行土壤水分特征曲线的脱水试验,并选取Gardner模型和VG模型对实测数据进行了拟合分析与比较。结果表明：（1）实测的土壤水分特征曲线可准确地反映土壤结构的差异性,各土层的曲线特征与其基本物理性质一一对应,即容重较小、粉粘粒含量较多的土层其持水性较强,饱和含水率和凋萎含水率也较高;物理性差异小的土层间,其土壤水力性质接近。（2）由VG模型得到的土壤饱和含水率均值为0.429 cm3·cm-3,凋萎含水率均值为0.040 cm3·cm-3。由Gardner模型得到的各土层由于各层的物理性状差异造成持水性由强到弱,依次为0-5 cm,40-60 cm,100-150 cm,60-100 cm,5-40 cm;土壤易效水与难效水的平均临界点水势值为1.5×105Pa,均值凋萎含水率对应的水势值为15.0×105Pa。以上结果均较符合砂质土地的实际情况。（3）两种模型均可用于拟合防护林沙质土的土壤水分特征曲线,但VG模型在低吸力段的拟合精度较高,Gardner模型在中吸力段的拟合精度稍高,整体上,VG模型的模拟效果优于Gardner模型。旨在揭示高矿化度咸水滴灌条件下塔里木沙漠公路防护林不同土层的土壤水分曲线特征及其最优拟合模型,为之后开展区域水盐运移数值模拟等研究提供理论依据。In this paper,the soil water characteristic curves for different depths from 0 cm to 150 cm of the soil in Tarim Desert highway shelterbelt were measured with Pressure Membrane Apparatus and were analyzed with van Genuchten Model and Gardner Model,of which the differences were compared. The results showed as follows：（1）The structural differences among the depths of the soil profile could be reflected by the measured soil water characteristic curves,resulting from the correspondence between the features of the curves and the soil basic physical properties at different depths of soil. Briefly,the characteristics that the capacity of soil water retention was stronger,the saturated moisture content and residual moisture content were higher,which were consistent with the features that the soil bulk was smaller and the proportion of the silts and clays were higher. Meanwhile,the capacities of soil water retention were similar as the differences of soil physical properties in various depths were slight.（2）Based on van Genuchten Model,the averages of soil saturated moisture capacity and wilting coefficient were 0.429 cm3·cm-3and 0.04 cm3·cm-3. Based on Gardner Model,from strong to weak,the capacities of soil water retention for different depths were followed by 0-5 cm,40-60 cm,100-150 cm,60-100 cm and 5-40 cm,respectively;overall,the suction on wilting coefficient was 15×105Pa and it took 1.5×105Pa as the boundary point of suction for the readily available water and the resistant available water.And all the above results were reasonable,which were according with the properties of the sandy soil.（3）The fitted precision of van Genuchten Model was higher in the low suction less than 1.0×105Pa while the fitted precision of Gardner Model was a little higher in the above suction from 1.0×105Pa to 15.0×105Pa. However,on the whole,the former was superior to the latter on fitting the soil water characteristic curves,because the results of correlation coefficients and root-mean-square errors between simulated

关 键 词：土壤水分特征曲线 压力膜仪 VG模型 Gardner模型 塔里木沙漠公路防护林 

分 类 号：S714.2[农业科学—林学]