摘要
利用环境^137Cs示踪技术和物理示踪法相结合的方法定量研究川中丘陵区耕作侵蚀对土壤总侵蚀的贡献，获得如下结论：（1）在4．7％-35．6％的坡度范围内总土壤侵蚀速率为6．21—138．16t／（hm^2·a），侵蚀主要发生在坡上部和坡中部；（2）在中等坡度（16．6％-25．1％），耕作侵蚀速率为21．67—63．07t/（hm^2·tillage pass），占总侵蚀速率的42．27％-45．65％；在陡坡（35．6％），耕作侵蚀速率为54．04t/（hm^2·tillage pass），占总土壤侵蚀速率的83．99％。耕作侵蚀主要发生在坡耕地的上部，从中部到下部耕作侵蚀相对较小；（3）在整个坡耕地上土壤侵蚀表现为以下空间分布：上坡以耕作侵蚀为主；中坡耕作侵蚀速率变小，水蚀作用加剧；下坡至坡脚两者均以沉积为主。研究结果表明，耕作侵蚀在一定的景观范围内是十分严重的，其侵蚀速率甚至超过了水蚀。因此在制定相应的土壤保持措施时，必须充分考虑耕作侵蚀的作用，才能有效地控制土壤侵蚀。
The ^137Cs technique and physical tracer method were used to quantitatively research the contribution of tillage erosion to total soil erosion in the Sichuan Basin, China. The results showed that the soil erosion occurred on positions from the crest to midst of slopes with a rate of 6.21 - 138.16 t · ha^-1· yr^-1 when the slope gradient ranges from 4.7% to 35.6%. Tillage erosion usually occurs on the crest and upper slope positions and the soil accumulates at down slope positions. The tillage erosion rate ranges from 21.67 to 63.07 t · ha^-1 · yr^-1 and accounts for 42.27 -45.65% of total erosion rate on the slopes with the gradients of 16.6% -25.1%. Meanwhile, on the steep slope （35.6%）, the tillage erosion rate is 54.04 t· ha^-1· yr ^-1 and accounts for 83.99% of total erosion rate. Tillage erosion is the dominant erosion process on the crest and upper slope. However, water erosion plays an important role on the mid-slope position and the soil deposits at the foot of slopes. The results showed that tillage erosion is one of the important erosion processes in the Siehuan Basin and would be more severe than water erosion in some landscape positions. Therefore, it is important to correctly assess tillage erosion to make the proper planning of soil conservation.
出处
《山地学报》
CSCD
北大核心
2006年第B10期64-70,共7页
Mountain Research
基金
国家重点基础研究发展规划（973）项目（2003CB415202和2006CB403203）
