Background One of the main factors of soil erosion is rainfall. Rainfall erosivity is an important indicator for studying soil erosion due to rainfall, and it is one of the important parameters of many soil erosion models. Correct calculation of rainfall erosivity has important practical significance for soil erosion and soil and water conservation in the study area.In order to study the temporal and spatial distribution characteristics of rainfall erosivity in the Nu river basin. Using the daily rainfall data of 6 weather stations in the Nu river basin from 1961 to 2010.

Methods The methods used in this paper mainly include calculating the rainfall erosivity of the basin by using the daily rainfall erosivity model, Mann-Kendall nonparametric statistical method for the mutation calculation, and interpolating the rainfall and rainfall erosivity of the basin using the inverse distance weight interpolation method in Arcgis 10.2 software. The temporal and spatial distribution of force. In order to provide a certain reference for soil and water conservation work in Nu river basin.

Results The results show that, the average annual rainfall of Nu river basin was 774.93 mm, and the average annual rainfall erosion force was 1 842.45(MJ·mm)/(hm²·h). Among them, the rainfall changed suddenly in 1978, and the rainfall erosion force was 1966. In 1973 and 1976, the rainfall occurred, and the rainfall and rainfall erosion force in the basin showed a trend of high in the southeast and low in the northwest. The annual distribution of rainfall erosion force was mainly concentrated in summer, accounting for 48.71%, and the smallest in winter, accounting for only 5.9%.

Conclusions The spatial distribution of rainfall and rainfall erosion force in the Nu river basin is similar, and the impact of erosive rainfall on rainfall erosion force is greater. The research results can provide a certain technical reference for soil and water conservation and ecological restoration in the Nu river basin.