Water Erosion in the Donga Soils in Subhumid Zone in West Africa

• 作者: Anastase Hessou Azontonde Brice Augustin Sinsin Félix Alladassi Kouelo Julien Avakoudjo Mahugnon Socrate Agonvinon Pierre Irénikatché Akponikpe Tobi Moriaque Akplo Valentin Missiako Kindomihou
• 来源期刊: 环境保护(英文)
• 学科: 农学
• 关键词: W National Park Land Use Areas Dongas RUNOFF EROSION Soil Loss
• 年，卷（期）: hjbhyw_2020,（12）
• 页码范围: 1073-1088
• 页数: 16页
• 分类号: S15

摘要

The runoff and soil loss were assessed <em>in situ</em> at the scale of 2.12 m² plots during the rainy season of 2010 to better understand the determinants and magnitude of the massive soil loss and land subsidence (donga) in the sub-humid zone of Africa in Karimama, North Benin. The experimental design was a split plot with two factors: the topography in 3 modalities (upstream, center and downstream of the donga) was assigned as main plot factor and the degree of degradation of dongas in 2 modalities (beginner dongas and advanced dongas) was assigned as subplot factor. Runoff water was collected through a storage system composed of two tanks. Data were collected on 36 plots (9 plots per donga × 4 dongas). The runoff varies significantly from one site to another for the rainy episode of October 10, 2010. It is twice as high in land use areas (5.87 mm) as in W Park (2.32 mm;l.s.d. = 1.81 mm). From upstream to downstream, runoff and soil loss increased from 2.4 mm to 85.3 mm and 80 g<span style="white-space:nowrap;">·</span>m^-2 to 197 g<span style="white-space:nowrap;">·</span>m^-2, respectively. Runoff is high in the early dongas (7.60 mm) and low in the advanced dongas (5.68 mm) in contrast to lower soil loss in the early dongas (34 g<span style="white-space:nowrap;">·</span>m^-2) and high in the advanced dongas (237 g<span style="white-space:nowrap;">·</span>m^-2). The low value of soil loss with respect to the magnitude of the phenomenon suggests the probable occurrence of other soil loss mechanisms to be elucidated.