新型W-OH材料对南方典型侵蚀土壤入渗和产流产沙的影响

Effects of new polyurethane material(W-OH)on infiltration and runoff and sediment yield of two typical erodible soils in South China

新型W-OH材料在我国水土保持领域获得了广泛的应用,但其相关理论滞后于实践。以南方2种典型侵蚀土壤——第四纪红黏土区红壤(以下简称“红黏土”)和崩岗区红壤(以下简称“崩岗土”)为对象,通过室内入渗实验和室外人工模拟降雨试验,分析不同W-OH体积分数喷施下2种典型侵蚀土壤的入渗和水沙特征。结果表明:1)红黏土和崩岗土养分贫瘠,质地上红黏土砂、粉、黏粒质量分数相当,崩岗土砂粒质量分数超过2/3,黏粒质量分数仅约5.4%;2)W-OH喷施显著降低了2种土壤的入渗率,随着体积分数的增大(0~7%),红黏土平均入渗率从6.98 mm/min降低到1.42 mm/min,崩岗土从5.26 mm/min降低到2.01 mm/min;3)5%W-OH喷施后使红黏土平均产流率增大190%,产沙率下降73.9%,使崩岗土平均产流率增大37.3%,产沙率降低62.1%,W-OH喷施增大了产流,但也明显减少了土壤流失;4)W-OH的喷施对2种土壤在模拟降雨前、后和24 h后3个时间点的平均含水量影响并不明显。研究可为进一步将W-OH应用于南方第四纪红黏土区和崩岗区红壤水土流失治理提供理论依据。

[Background]The new polyurethane material(W-OH)has been widely used in soil and water conservation in our country,but its related theories lag behind its practice.Therefore,the study chose the two typical erosion soils red clay of slope cultivated land and arenosol of collapsing gully as objects and analyzed their infiltration and water-sand characteristics under the spraying of different W-OH concentrations.[Methods]Studying how much the new W-OH material influences the typical southern erosion soil in the infiltration,runoff and sediment was conducted.by indoor infiltration experiments and outdoor artificial simulated rainfall tests.[Results]1)The nutrient of red clay soil and collapsing gully soil was infertile.The content of sand,powder and clay soil in red clay was almost equal.The content of sand in collapsing gully soil was more than 2/3,and the content of clay was only about 5.4%.2)The spraying W-OH obviously reduced the infiltration rate of the two kinds of soils.With the increasing concentration(0-7%),the average infiltration rate of the red clay soil decreased from 6.98 to 1.42 mm/min and the collapsing gully soil decreased from 5.26 to 2.01 mm/min.The spraying of W-OH had a better effect on reducing the infiltration rate of red clay soil than that of collapsing gully soil.3)The red clay soil sprayed with 5%W-OH showed an increase of 190%in the average flow rate and a decrease of 73.9%in the rate of sediment yield.The collapsing gully soil sprayed with W-OH showed similarly an increase of 37.3%in the average flow rate and a decrease of 62.1%in the rate of sediment yield.The spraying of W-OH increased runoff and decreased soil loss obviously.4)The spraying of W-OH presented an inconspicuous impact on the average moisture content of the two kinds of soils before,after rainfall and 24 h later.[Conculsions]This study may provide a theory basis for W-OH's further application to the control of water loss and soil erosion in arable land of southern slope and collapsing gully.