A study on the characteristics of water erosion in rural settlements - a case study of three typical rural areas in North Shaanxi.

It was found from the analysis of observation data during 2003 to 2005:(1)that the special underlying surface of rural settlements the in abundant and coarse sediment area in North Shaanxi could generate surface runoff easily,and then form water loss,which made the underlying surface generat more water flow rate(the average runoff coefficient of the whole area in 2003 was 0.27,the figure changed to 0.34 in 2004 ),meanwhile,the water erosion intensity got stronger and stronger (the average erosion intensity of the whole area is 1 698.7 t/km2 in 2003,while in 2004 was 5 434.3 t/km2 ).The average erosion intensities of the roads,open space and yards were 7 348 t/km2,6 873.2 t/km2,2 081.7 t/km2,which reached serious erosion,except the courtyard erosion being slight erosion.So water erosion in rural settlements should be studied and treated.(2)Sediment size of water erosion was predominated by semi-coarse silt( 0.01 to 0.05 mm),occupying more than 43%.From a regional perspective,the content of granule silt was less and less from the south to the north,and the coarse was more and more.On the other hand,as time went by,the granule silt contents decreased gradually(0.05 μm),while coarse silt(50 μm) increased.