稻田——田埂过渡区土壤水分运动与保持特征

发布时间：2018-04-11 13:50

本文选题：稻田—田埂过渡区 + 饱和导水率　；参考：《水土保持学报》2017年02期

【摘要】：为揭示田埂对稻田水分渗漏的影响,以江汉平原典型稻田—田埂过渡区为研究对象,采用室内土壤理化性质分析、水力学参数测定和田间染色示踪等方法量化了过渡区各位点(田内、田埂和灌溉沟)土壤剖面导水与持水性能差异,并揭示了该区域的水流特征。结果表明:(1)不同位点的土壤饱和导水率(Ks)均随土层深度的增加而减小,上层(-20—35cm)高于中、下层(35—65cm),剖面导水性能表现为田埂灌溉沟田内,田埂平均Ks分别是灌溉沟和田内的1.6倍和16.0倍;(2)同一吸力值下不同位点土壤含水量差异较大,田内含水量最高,灌溉沟其次,田埂最低,在持水性能上表现为田内灌溉沟田埂;(3)田埂土壤受动物活动和根系生长影响剧烈,导致其大孔隙(当量孔径0.3mm)含量整体上高于田内,在染色特征上表现为田埂中、下层土壤染色面积显著高于田内。由于稻田-田埂过渡区不同位点土壤的导水和持水能力差异显著,稻田水分不仅可以在田内发生垂直渗漏,还可以通过田埂区域垂直入渗和跨田埂侧流两种方式快速流失,进而加速了稻田水分的散失。
[Abstract]:In order to reveal the effect of field ridge on water leakage in paddy field, a typical paddy field-ridge transition area in Jianghan plain was studied and the physical and chemical properties of soil were analyzed.The difference of water conductivity and water retention in soil profile of transition area (field, ridge and irrigation ditch) was quantified by means of hydraulic parameter measurement and field dyeing tracing, and the characteristics of water flow in this area were revealed.The average Ks of the ridge is 1.6 times and 16.0 times of the irrigation ditch and 16.0 times of the field respectively) the difference of soil water content at different sites under the same suction value is greater, the water content in the field is the highest, the irrigation ditch is the second, and the ridge is the lowest.In water holding capacity, the soil was affected by animal activity and root growth, and the content of macropore (equivalent aperture 0.3 mm) was higher than that in the field, and the dyed characteristic was in the ridge of the field, the water holding capacity of the soil was as follows: the soil was affected by animal activity and root growth, and the content of macropore (equivalent pore diameter was 0.3 mm) was higher than that in the field.The dyeing area of the lower soil was significantly higher than that of the field.Because of the significant difference of soil water conductivity and water holding capacity in different sites in the transition area between paddy field and field ridge, the water content in paddy field can not only be perpendicular to the field, but also be rapidly lost through vertical infiltration in the field ridge area and lateral flow across the field ridge.This accelerates the loss of paddy water.
【作者单位】：地理过程分析与模拟湖北省重点实验室;华中师范大学城市与环境科学学院;
【基金】：国家自然科学基金青年项目(41601215) 湖北省自然科学基金重点项目(2015CFA141) 华中师范大学中央高校基本科研业务项目(CCNU16A05015,CCNU15A05002)
【分类号】：S152.7

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