川中丘陵区土壤侵蚀及其P值的确定

The Soil Erosion and P Values in Hilly Area of the Central Sichuan

运用川中丘陵区四种土壤母质类型5个观测点历年的数据,定义了可蚀模数和产流模数,通过关联和曲线回归分析,阐明旱作制抗水蚀的能力为聚土免耕>横坡种植>顺坡种植;坡旱地的侵蚀量 Q 和径流深 Z 与降雨量 R 的最佳回归关系:Q=a+b1nR 和 Z=A十BR定量描述了坡地旱作制下的水土流失特征。通过比较曲线方程确定了聚土免耕、横坡种植和顺坡种植的 P 值分别为0.29,0.49和1。结果得出,坡地旱作制下的土壤侵蚀方程应修正为:Q=K(t).C(t).P.S.L·ln(R-c~^(a/b)。

Based on the datum over the years from 5 observation points with 4 kinds of soil parent material in hilly area of the central Sichuan,the module of erosion and runoff yield are definited. Using the correlative and regression analysis,it clarifies the resistance of no tillage for soil and water loss is stronger than contour tillage,that of contour tillage is stronger than along slope tillage,and it reveals the regressional equations between rainfall(R)and erosion amount(Q)or runoff deepness(Z)are as follows:Q=a+blnR and Z=A+BR.By comparing regressional equations,its determing P values are 0.29,0.49 and 1 for no tillage,contour tillage and along slope tillage respectively.According to research conclusions,the soil erosion equation under tillage system of dry-slope land is=K(t)·C(t)·P·S·L·ln(R-e^(-a/b)).This eqution is in keeping with fact by examination.