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| Relationship between side evaporation of gully cliff and environment aridization in Loess Plateau |
| Zheng Jiyong1,Li Yuyuan2,Shao Mingan1,2,Wang Quanjiu1,3 |
1.State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Northwestern A & F University and CAS,712100,Yangling,Shaanxi;2.Institute of Geographic Sciences and Natural Resources Research,CAS,100101,Beijing;3.Xi'an University of
Technology,710048,Xi'an: China |
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Abstract The intensive soil erosion in the Loess Plateau leads to a distinct increment of ground drape due to the formation of numerous erosion gullies,increases the loss of soil moisture by evaporation,and finally speeds up the environment aridization in the Loess Plateau.To testify this viewpoint,an experiment was conducted at a typical gully bank in the water-wind erosion crisscross region in the north China.Neutron tubes were installed at the bank region of a gully with different distances of 20cm,100cm,200cm,300cm,400cm,500cm and 600cm apart from the gully margin.Soil moisture distribution and dynamic variation of the soil water storage were monitored.The results showed that soil moisture increased with distance from the gully margin in the range of 0 to 500cm,which proved the external existence of side evaporation at gully cliff.The increments of soil water storage in the layer from 0 to 300cm at different distances from the gully margin had no significant difference when rainfall occurred,however,the closer the site to the gully margin,the faster soil moisture loss through evaporation.The change of soil moisture loss(implied) that the side evaporation of gully cliff speeded up the environment aridization in the Loess Plateau.The confirmation of power function relationship between soil water storage and distance apart from the gully margin presented a preliminary base for the quantificational study of side evaporation of gully cliff on accelerating environment aridization in the Loess Plateau.
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Received: 31 August 2005
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