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首页> 外文期刊>Earth Surface Processes and Landforms: The journal of the British Geomorphological Research Group >Gully erosion in the Siwalik Hills, Nepal: estimation of sediment production from active ephemeral gullies
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Gully erosion in the Siwalik Hills, Nepal: estimation of sediment production from active ephemeral gullies

机译：尼泊尔Siwalik Hills的沟壑侵蚀：估算活动性临时沟产生的沉积物

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A simple field-based monitoring programme was established in a small catchment (area 4-6 km(2)) to find the rates of gully erosion in the Siwalik Hills, Nepal. The rates are used to estimate the amount of sediment produced by gully erosion in the catchment. Three large and active gullies were selected with areas ranging from 0.44 to 0.78 ha. Aerial photographs taken in 1964, 1978 and 1992 were ortho-rectified and used to study the dynamics of gully heads. The same gullies were also monitored manually using an orthogonal reference system fixed by erosion pins around the gully heads. Results from the aerial photos indicated that the gullies expanded remarkably over the period from 1964 to 1992, by 34 to 58 per cent. Head-retreat rates during that period were 0.48, 0.55 and 0.73 m a(-1) and average annual sediment evacuation was estimated as 2534+/-171, 959+/-60 and 2783+/-118 m(3) a(-1) for the three gullies respectively. From the field measurement, estimated volumes were found to vary from 731+/-57 to 2793+/-201 m(3) a(-1) over the monitoring period of two years. It was also found that the gullies produce sediment which accounts for up to 59 per cent of the sediment produced from surface erosion in the headwater catchment. The findings are useful for planning and executing appropriate control measures and constructing a sediment hazard map at the catchment scale. Copyright (C) 2006 John Wiley & Sons, Ltd.
机译：在一个小流域（面积4-6 km（2））中建立了一个基于现场的简单监视程序，以查找尼泊尔Siwalik Hills的沟壑侵蚀率。这些比率用于估算流域内因沟壑侵蚀而产生的沉积物数量。选择了三个大型活动沟壑，面积在0.44至0.78公顷之间。分别校正了1964年，1978年和1992年拍摄的航拍照片，并将其用于研究沟壑的动态。还使用由侵蚀销钉固定在水沟头周围的正交参考系统手动监测这些水沟。航拍照片的结果表明，在1964年至1992年期间，水沟明显增加了34％至58％。在此期间，头顶撤离速度分别为0.48、0.55和0.73 ma（-1），年平均沉积物疏散估计为2534 +/- 171、959 +/- 60和2783 +/- 118 m（3）a（- 1）分别用于三个沟渠。通过现场测量，发现在两年的监视期内，估计体积从731 +/- 57到2793 +/- 201 m（3）a（-1）不等。还发现，沟渠产生的沉积物占源头流域表面侵蚀产生的沉积物的59％。这些发现对于规划和执行适当的控制措施以及在流域尺度上建立沉积物危害图很有用。版权所有（C）2006 John Wiley＆Sons，Ltd.

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