摘要
The runoff and soil loss were assessed <em>in situ</em> at the scale of 2.12 m<sup>2</sup> 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<sup>-2</sup> to 197 g<span style="white-space:nowrap;">·</span>m<sup>-2</sup>, 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<sup>-2</sup>) and high in the advanced dongas (237 g<span style="white-space:nowrap;">·</span>m<sup>-2</sup>). 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.
The runoff and soil loss were assessed <em>in situ</em> at the scale of 2.12 m<sup>2</sup> 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<sup>-2</sup> to 197 g<span style="white-space:nowrap;">·</span>m<sup>-2</sup>, 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<sup>-2</sup>) and high in the advanced dongas (237 g<span style="white-space:nowrap;">·</span>m<sup>-2</sup>). 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.
作者
Julien Avakoudjo
Félix Alladassi Kouelo
Valentin Missiako Kindomihou
Pierre Irénikatché Akponikpe
Anastase Hessou Azontonde
Brice Augustin Sinsin
Tobi Moriaque Akplo
Mahugnon Socrate Agonvinon
Julien Avakoudjo;Félix Alladassi Kouelo;Valentin Missiako Kindomihou;Pierre Irénikatché Akponikpe;Anastase Hessou Azontonde;Brice Augustin Sinsin;Tobi Moriaque Akplo;Mahugnon Socrate Agonvinon(Laboratory of Applied Ecology of the Faculty of Agronomic Sciences of the University of Abomey-Calavi, Abomey-Calavi, Benin;Laboratory of Soil Microbiology and Microbial Ecology, Faculty of Agronomic Sciences of University of Abomey-Calavi, Abomey-Calavi, Benin;Research Unity of Soil Physic and Environmental Hydraulic, Faculty of Agronomy, University of Parakou, Parakou, Benin;Laboratory for Soil Science, Water and Environment, Agricultural Research Centre of Agonkanmey, National Institute for Agricultural Research of Benin, Abomey-Calavi, Benin)
