Effect of land use pattern on runoff and sediment yield on slopelands in Loess Hilly region.

In Anjiagou watershed of Gansu Province,15 runoff plots were selected and designed,for analysis of effect land use pattern on runoff and sediment yield on slopelands through variance analysis,multiple comparisons and correlation analysis of the hydrological monitoring data of the runoff plots at a year scale from 1986 to 1999,and also the relationship of annual rainfall with annual runoff and sediment yield per unit area of slope lands.Results show that on slopelands the same in slope gradient,significant differences existed among 5 runoff plots different in land use pattern in annual runoff and sediment yield per unit area,showing an order of sloping farmland artificial grassland arbor land natural grassland shrub land;and within the studied range of slopes(10°～20°),no significant difference in annual runoff per unit area was observed between runoff plots the same in land use pattern,but significant differences were detected between runoff plots under farmland and artificial grassland;and no significant relationship of annual rainfall with annual runoff and sediment yield per unit area on the slope lands.