|Huang, Chi hua|
Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 4/16/2000
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Most gullies have the common feature of having water flowing in them and staying wet during the wet season. These field observations led to the hypothesis that hillslope seepage may have contributed to the formation of rills and gullies in areas with tight subsoil layers. This hypothesis was tested in the laboratory under a multiple-box system. The multiple-box system consists of separate but independent soil boxes in a sloping cascade such that runoff and sediment from aN upslope box can be discharged into a downslope one. A water supply system was used to create the artesian seepage condition. Experimental results showed severe rilling under seepage conditions and the erosion was significantly reduced under drainage conditions, indicating a strong near-surface hydraulic gradient effect on erosion. These results also imply that profile drainage can be considered as effective erosion control measure at seepage prone areas. Field practices to control seepage-induced gully erosion include: a) installation of tile drains along grass waterways to alleviate wetness along drainage channels; b) placing crushed stones over tile drains to intercept trickle flow runoff; c) using winter cover crops to both 'pull' moisture from the soil and provide both above- and below-ground biomass protection, and d) installation of water and sediment control basins to regulate the runoff discharge through the standpipes and tile drains. This presentation also demonstrates the cooperative effort between research (i.e., ARS) and field implementation (NRCS) agencies in developing an erosion research program and enhancing the scientific basis of erosion control practices.