TY  - JOUR
T1  - Vulnerability Studies of Sensitive Watershed Areas of Owerri South East
Nigeria Using Digital Elevation Models
AU - AC-Chukwuocha, Ngozi AU - A. Ngah, Sab AU - C. Chukwuocha, Akajiaku 
JO  - Research Journal of Applied Sciences
VL  - 13
IS  - 12
SP  - 711
EP  - 717
PY  - 2018
DA  - 2001/08/19
SN  - 1815-932x
DO  - rjasci.2018.711.717
UR  - https://makhillpublications.co/view-article.php?doi=rjasci.2018.711.717
KW  - Vulnerability
KW  -watershed
KW  -ecosystem
KW  -impacts
KW  -activities
KW  -consideration
AB  - The impact of human activities on sensitive watershed terrains is a critical consideration in the
management of urban ecosystems. Degradation of sensitive ecosystem features such as watershed land areas
is often irreversible due to the extent and intensity. The vulnerability of 150 m watershed management zone of
Otamiri river Owerri Imo State, Nigeria was studied by topographic analysis using 1977 Digital Elevation
Model (DEM), 1977 aerial photos, shuttle radar topographic mission DEM of 2000, 2006 satellite imagery
and the master plan of the study area. The impact of human activities in elevation change was
observed in the parts of substantial human activities while topographical stability was recorded for areas of
very low human activities. At the East banks of Otamiri and Nworie rivers where heavy human
activities take place, average changes in elevation were -7.138 and -4.454 m, respectively, indicating
eroded banks. While the West banks of Otamiri and Nworie rivers with sparse human activities
measured +0.048 and +0.000 m in average changes in elevation. Along Otamiri and Nworie water courses
from source to confluence, an average elevation increase of +3.616 and +5.159 m, respectively were
recorded, indicating sedimentation and siltation. And a reduction (-7.028 m) in average elevation change,
suggestive of erosive action was measured from Otamiri/Nworie confluence to the South, an area of
intensive sand excavation. The study recommends enforcement of the watershed management edict
that seeks to create a buffer zone around the river banks, so, as to protect the valuable
ecosystem.
ER  -