The results show that soil samples are transitional and dispersive soil because of rich montmorillonoid, plenty of sodium-ion and strong alkalescence.

Clay is dispersed in a low salinity of the water (or pure water) because of the mutual repulsion forces ion over mutual attraction, lead to soil particles dispersive clay.

The effect of scouring water on dispersive clay is very obvious, but the effect of filling water is small on the soil from Xijiao and Sanping reservoirs.