Many studies had attempted to characterize chemical weathering process by focusing on geochemisty of river particulate and sediment . the sediment geochemistry may reflect and compare with the carbonates and silicates weathering degree by introducing the chemical index of alteration ( cia ) and new sediment index of variation ( siv ) and elemental molar abundance ratio of the sediment . the one main objective of this study would provide and compare the relative weathering intensities of silicates and carbonates with the different basins 2沉积物地球化学与化学风化进程和机械剥蚀率化学风化指数与化学风化率属于表征化学风化作用意义不同的函数，前者为相对概念反映流域岩石在原岩基础上己发生淋溶作用的深度，主要受到了气候因子的深刻影响(中国流域沉积物化学风化指数由北到南呈有规则的递增序列，气候因子对风化进程的影响掩盖了岩性的巨大差异) ，而化学风化率含义是指单位流域面积岩石风化淋溶产生的离子绝对总量。
