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| Prediction for debris flow runout zones based on spatial distribution of unconsolidated material in watersheds |
| Fan Jianrong1, Zhang Huaizhen1,2, Guo Fenfen1,2,Liu Fei1,2 |
| 1. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences & Ministry of Water Conservancy, 610041, Chengdu;2.Graduate University of the Chinese Academy of Sciences, 100049,Beijing:China |
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Abstract Based on SPOT remote sensing images, the landslides induced by “5·12” earthquake were identified. These landslides often supplied the sediment for debris flow. Combining with GIS, spatial distribution of sediment supply was analyzed. Firstly, we defined the function T(s) of debris flow gully’s sediment supply and the relative spatial distribution function F(x), and calculated the distribution integration W and the relative distribution integration D of by sediment supply debris flow to quantitatively describe the spatial distribution of sediment supply of debris flow gully. Taking five debris flows as example, which locate in the upper drainage basins of Minjiang River, near to Yingxiu Town, Wenchuan County, parameters W and D were calculated. Then we used W and D for estimation of these debris flow depositional zones, including the maximum depositional distance L and the maximum depositional width B. The results show that, sediment supply mainly distributed in below middle internal relief zones in five debris flows; sediment supply in zones was near to main gully; the estimated values of L and B approximated to the measured values in five debris flows zones when W and D were introduced.
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Received: 01 September 2011
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