黄土丘陵区缓坡地不同土地利用方式的产流效应

探讨缓坡土地利用方式与水土流失之间的作用机制,对于黄土丘陵沟壑区水土流失治理具有积极意义。利用中国科学院安塞水土保持综合试验站2009—2011年间小区定位监测数据,探讨缓坡谷子地(F)、柳枝稷地(S)、撂荒地(A)、2/3谷子-1/3柳枝稷地(FS)、2/3谷子-1/3撂荒地(FA)5种土地利用方式的产流效应,结果表明:1)缓坡谷子地(F)的径流量最大,受短历时高强度降雨影响显著;2)7月是产生径流的敏感时期;3)土地利用方式S、A、FS、FA与F相比,具有不同程度的减流效应,减流效应大小顺序为A>S>FA>FS;4)植被覆盖度的增加对减少缓坡产流量起到积极作用,但当降雨量、降雨强度较大时,植被覆盖削减径流的作用会被减弱。

Effect of different land use types on runoff on gentle slopes：A case study in the loess hilly area, China

Study on the action mechanism between land use types and soil erosion on gentle slopes is of significance on controlling water and soil erosion in the loess hilly area. Based on the study in research plots （from 2009 to 2011 ） at Ansai Integrated Experimental Station of the Chinese Academy of Sciences, effects of different land use types on runoff on gentle slope were discussed. Five land use types were selected, including millet field （ F）, switchgrass field （ S）, abandoned land （ A）, two-thirds millet and one-third switehgrass field （FS）, two-thirds millet and one-third abandoned land （FA）. The results showed that： 1 ） Compared with the other four land use types（ S, A, FS, FA） , runoff produced in millet field （F） was the most, and runoff was affected with high rainfall intensity significantly. 2） In the whole observation period, July was the sensitive time of producing runoff. 3） Compared with millet field （F） , other four land use types（ S, A, FS, FA） had positive effects on runoff reduction to different extent, and rank of the effect was A〉S〉FA〉FS.4） For the five land use types（F, S, A, FS, FA）, increase of vegetation coverage was beneficial to runoff ruduction but the effect could be weakened when rainfall and rainfall intensity were large.