To improve the water use efficiency of slope

cracks on slope

surface runoff

bottom leakage and soil storage were measured by the method of soil spraying

and the water distribution on slope was analyzed under irrigation and rainfall conditions. The results showed that the distribution of soil cracks on slope was not uniform

and the soil cracks tended to decrease from the top slope to the bottom. The total area of cracks on sunny slope was greater than that on the shady slope. Water distribution characteristics under irrigation condition varied from different slope directions. On the sunny slope

0.02% of the water was dissipated through evapotranspiration

7.00% of the irrigation water moved along the slope forming surface runoff

10.00% of water turned into the bottom leakage and 53.00% of the irrigation water was stored in soil. The ratios of evapotranspiration

surface runoff

bottom leakage and soil moisture were 0.01%

35.00%

0.25% and 39.00% on the shady slope respectively. With the growth of vegetation coverage

the surface runoff formed by irrigation decreased and the soil water storage increased. Rainfall intensity had a significant effect on water distribution characteristics. About 95.00% of the rainfall was stored in the soil under the light rain

and the amount of bottom leakage and surface runoff reached the maximum under moderate and heavy rain conditions respectively. With various rainfall intensities

surface runoff on shady slopes was 1.1~3.0 times higher than sunny slopes. The sunny slopes had a higher water use efficiency with greater amount of bottom leakage than the shady slopes. These results could provide a scientific reference for the effective use of water in the highway slope greening.