摘要
为研究土壤侵蚀对土壤水分特征曲线的影响,选择轻、中、重3种侵蚀强度黑土的15个样点,通过测定8个土壤水吸力对应的土壤水分,估算了不同侵蚀强度土壤水分特征曲线Brooks-Corey(BC)模型和Van Genuchten(VG)模型参数,并分析其差异性,比较2个模型模拟不同侵蚀强度黑土土壤水分特征曲线的精度。结果表明:轻、中度侵蚀黑土的田间持水量和凋萎湿度无显著差异,重度侵蚀则与其差异显著,随侵蚀加剧,黑土的持水能力明显降低。BC和VG模型共同的参数饱和含水量和滞留含水量参数值相同,且饱和含水量轻、中度侵蚀差异不显著,重度侵蚀与其差异显著。滞留含水量、形状参数λ和n分别接近于0cm^3/cm^3,0.10和1.10。2个模型反映土壤通气性指标的进气吸力hb和尺度参数α表现出一致性,即中度侵蚀黑土通气性最好。修正了VG模型形状参数m和n之间的关系,与原关系式相比中度侵蚀黑土m降低13%,轻度和重度侵蚀黑土分别降低30%和46%,修正后的VG模型更适合遭受不同强度侵蚀黑土的土壤水分特征曲线模拟。
In order to study the effect of soil erosion on soil-water characteristic curve （SWCC）, soil moisture of 15 sampling plots under 3 erosion intensities （lightly, moderately, and severely eroded） with 8 soil water suctions were measured, which were used to estimate the parameters of Brooks-Corey （BC） model and Van Genuchten （VG） model for SWCC. The differences of parameters between soils under 3 erosion intensities and the simulation accuracies of 2 models were compared. The results showed that lightly and moderately eroded soils were not different for field capacity and wilting moisture, but they were significantly different from severely eroded soil. With the increase of soil erosion intensity, the field capacity of black soil significantly decreased. The value of saturated and residual water contents were the same in 2 models. Saturated water contents of lightly and moderately eroded soils were not different, but they were significantly different with severely eroded soil. The values of residual water content, shape parameters ;t and n were close to 0 cm^3/cm^3 , 0.10 and 1.10, respectively. For soil aeration, the air entry potential hb and scale parameter a showed the similar trend, which indicated that the aeration of the moderately eroded soil was the best. The relationship between the shape parameters m and n of the VG model was modified. Compared with the values in original relationship, the values of m decreased by 30%, 13% and 46% for lightly, moderately and severely eroded soils, respectively. The modified VG model was more suitable to simulate the SWCC for different eroded black soils than BC model.
出处
《水土保持学报》
CSCD
北大核心
2016年第4期116-122,共7页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目"东北黑土区土壤侵蚀对‘作物产量-土壤水分响应关系’的影响"(41371271)
水利部公益性行业科研专项"东北黑土区水土保持措施效益评估及防治技术"(201001026)
