1Anzaku, I. M.; 2Ishaya, K. I., & 3Ogah,
A. T.
1,Department of Science, Bayero University, Kano, Kano State,
Nigeria
2,3,Department of Geography, Nasarawa State University, Keffi,
Email: mamman.iliyasu@yahoo.com
ABSTRACT
This study assessed the morphometry and morphology
of gullies in Nasarawa State. Both primary and secondary data source were
employed for this study. The primary data were collected from direct field
observation and measurements. Secondary data were gathered through the review
of relevant literature. A recommendation survey to ascertain the general
characteristics of gullies in the state was carried out with the aid of
topography map of the study area. Lafia, Wamba and Karu LGA was selected from
each senatorial district to represent the study area has an undulating
topography and Furley (1996) observed that variation in topography could modify
occurrence of land degradation. Variable were measured or divided randomly from
each of the thirty-six-gully site in the study area. Twelve gully sites were
selected from each Government representing the study area. The results
generated from the field were subjected to statistical and laboratory analysis.
The results of the findings revealed that gullies in Lafia and Wamba LGA of
Nasarawa state are more affected 80% Kilema gully site in Lafia LGA recorded
the highest intern of gully length 315m followed by Traffic in Wamba LGA 303m,
UngwaSharu in Lafia LGA recorded the highest figure in term of gully length
325m followed by Traffic in Wamba LGA 285m respectively. In term of gully in
the study area, it recorded number 21.2m, traffic in Wamba LGA 20.3m, Gangare
wawa in Wamba LGA and Akurba in Lafia LGA recorded the same figure 17.3m,
respectively. Gully site in Mama, in Wamba LGA and Uke in Karu LGA of the study
area, recorded the last figure 4m in width magnitude. In term of area, gully
site in Marhai in Wamba LGA, Mararaba in Karu LGA and UngwaTiv. In Lafia LGA
recorded the highest number 0.21m2 and Adogi gully site in Lafia LGA
recorded the last of 0.5m2. Majority of the gullies in the study
area are characterized by U-S shape cross-section 60% and V-shape 30% U and
V-shape 10%. The findings also revealed the results of the mean value of volume
of soil loss in the study area was 14200.39tonnes/ha in all the gullies in the
study area. The mean values of large gullies length were 254.77, depth was
11.86, while that of very small gullies was length 65.16, depth was 4.66 and
slope angle was 9.0. Gullies in the area are long- narrow linear to rectangular
shaped. 55.6% of gullies are at their continuous stage of development while
44.4% of gullies were at their continuous stage of development.
Keywords: Erosion, Gully erosion, Morphometry and Morphology.