Soil erosion control measures on degraded sloping lands: A case study in Midlands of Nepal

This paper presents the results of inserting erosion control works in a degraded river terrace slope of Midlands, Nepal. Gully surface erosion was monitored. Countermeasures adopted for gully erosion were check dams, channel protection and plantation works. They reduced the gully head retreats by 14 to 73 percent in three studied gullies after the countermeasures were fully functional. Gully head expansion takes place by the formation of cracks in the dry season followed by block collapse in the wet season. Surface erosion rate on laterite slopes varied from 0.03 to 1.53 cm y⁻¹ depending on land cover and slope gradient. Conservation works such as terrace construction combined with compost application was found to be effective for the vegetation recovery on the degraded slope. Conservation works should be based on the use of local materials and techniques that can yield direct benefit to the local population.

Keywords:

• gully
• surface
• countermeasure
• bamboo
• check dam

Acknowledgements

This study was based on the field monitoring works executed by the Water Induced Disaster Prevention Technical Centre Project/Government of Nepal and Japan International Cooperation Agency and the authors. Part of the study was funded by the Grant-in-aid from the Ministry of Education, Science, Sports and Culture, Government of Japan. We thank Mr. Masaki Hiruma, Mr. Shambu Prasad, Ms. Shoko Suzuki and Mr. Sohan Kumar Ghimire for their contribution in monitoring works.