Assessing Sediment-Nutrient Export Rate and Soil Degradation in Mai-Negus Catchment, Northern Ethiopia

Table 2

Sediment yield and other related parameters of the different landforms in the Mai-Negus catchment, northern Ethiopia.

Landform	SV (m^3)	SM (t)	A (Km^2)	dBD (t m^−3)	STE (%)	SSY (t Km^−2 y^−1)
Rolling hills	1,024	1,566	1.25	1.53	63	1,254
Mountainous	3,579	5,762	1.82	1.61	55	3,165
Central ridge	4,761	7,568	3.20	1.59	57	2,366
Valley	4,327	5,884	2.52	1.36	66	2,335
Plateau	965	1,408	1.21	1.46	62	1,164
Escarpment	3,212	4,786	2.40	1.49	69	1,994
Reservoira	343,776	388,467	12.40	1.13	99	1,958
Average	51,663	59,349	3.54	1.45	67	2,034
Standard deviation	128,818	145,143	3.07	0.17	14.80	690

SV: annual sediment volume; SM: annual sediment mass; A: drainage area; dBD: dry bulk density; STE: sediment trap efficiency; SSY: area specific sediment yield.
aSediment in volume and mass is total amount of sediment accumulated in the reservoir over 16 years (1994–2009). SSY coming from the whole catchment area (12.40 km²) was calculated after the depth of the spatially distributed pits opened in the reservoir sediment was measured, georeferenced, and then interpolated through Thiessen polygons in a GIS environment.