安家沟流域不同土地利用方式水土流失对影响因素变化的响应

Response of soil and water loss to changes of influ⁃encing factors under different land use patterns in Anjiagou watershed

【目的】探究不同土地利用方式对水土流失的影响因素,以期为黄土丘陵沟壑区进一步开展生物措施工程提供理论依据。【方法】以定西市安家沟流域径流场2005-2020年雨季的降水量、径流量和产沙量监测数据为依据,探究不同土地利用方式的径流泥沙变化,并对影响因素进行相关和回归分析。【结果】不同土地利用方式土壤含水率排列顺序为封禁地>沙棘地>油松地>人工草地>农地,且随坡度的增大依次减小,20~40 cm土层土壤含水率最高,达到14.75%。【结论】不同土地利用方式径流由大到小的排列顺序为农地>人工草地>油松林地>封禁>沙棘地,侵蚀模数由大到小的排列顺序为农地>油松林地>人工草地>封禁>沙棘地,≤1 mm根系参数的排列顺序与侵蚀模数的排序刚好相反。以上研究可以为黄土丘陵沟壑区进一步开展生物措施工程提供理论依据。

【Objective】The study was carried out to explore the water loss of different land use modes and the in⁃fluencing factors of land use modes on soil and water loss,in order to provide theoretical basis for further biological measures engineering in loess hilly and gully area.【Method】This study was based on the monitoring data of rainfall,runoff and sediment yield in the Anjiagou watershed in Dingxi City,Gausu Province during the rainy season from 2005 to 2020.The change of runoff and sediment under different land use patterns and different growth years was studied.Correlation and regression analysis were made on the influencing factors.【Result】The results showed that the order of soil moisture content in different land use modes was enclosed land>sea buckthorn land>Chinese pine land>artificial grassland>agricultural land,and it decreased with the increase of slope.The soil moisture con⁃tent decreased with the increase of slope gradient.The highest soil moisture content was in 20~40 cm soil layer.The value reached 14.75%.【Conclusion】The order of runoff depth in different land use modes from large to small was agricultural land>artificial grassland>tabulaeus tabulaeus forest>restricted land>sea buckthorn land.The or⁃der of erosion modulus from large to small was agricultural fields>Chinese pine fields>artificial grassland>Closure>sea buckthorn land..The order of root parameters≤1 mm was opposite to that of erosion modulus.There⁃fore,the project of returning farmland to forest and grassland could effectively reduce the harm caused by soil erosion in loess hilly and gully region.The above research could provide theoretical basis for further development of biological measure engineering in loess hilly and gully region.