Taking Jiuxian Town as an example, this paper recovers the processes of gully development and soil erosion of the Loess Yuan Region in Luochuan County since Yuan Dynasty (A.

The model could be used for simulating rill evolution processes on loess slopes, in which the rainfall and micro\|landform are corresponding to the disarranged input and the rills are corresponding to the regular output.

According to the topographic characteristic parameters of ephemeral gully at loess steep hillslopes,the mold of ephemeral gully shape at initial stage was made to quantify the change processes of ephemeral gully headcut advance,gully-wall collapse and channel deep-cutting in three stages(the beginning,middle and late stages) of ephemeral gully development.

This thesis is used a dual-box system (one is test box located down-slope and the other is feeder box located at up-slope) to simulate the ephemeral gully development and to quantify impacts and mechanism of up-slope runoff and sediment on ephemeral gully erosion process.

The length and width of the anatomical crowns,the length and the width of the developmental grooves and the angles formed by the two sides of the developmental grooves were measured.