The Use of Geodetic Leveling For Crustal Motion and Deformation Studies: A 30-Year Case Study in Ahmadu Bello University, Zaria

Abstract

This paper examines the stability of some benchmarks on the main campus of Ahmadu Bello University, Zaria, and reports the deformation studies of the area around the University dam. This dam serves as the main storage reservoir for the water supply to the University and surrounding communities. In order to study the deformation around the University dam and the stability of benchmarks, several surveys were carried out between 1976 and 2006. Within the period under review, it was revealed that the maximum downward displacement (settlement) of 96.44mm was recorded between 1976 and 2006 for a monitoring station (CP4) situated centrally along the embankment of the dam. The maximum upward displacement (uplift) of 8.03mm was recorded between 1976 and 2002 at a ground point (CP12) located in a roundabout in front of Faculty of Medicine of the University. The monitoring Station CP4 had the greatest average absolute displacement of 3.22mm per annum over the period of thirty years. Detailed results and analysis will be discussed in this paper.

Investigating the vertical displacement of Duhok embankment Dam: A 31- Years Case Study

“…The other reason for the vertical movement can be connected to the growth of the tree's roots that were located around 1.5 m near that point as shown in figure 6. The tree's roots can produce upward motion as the literature suggested Isioye and Musa (2007). From this comparison it can be understood that, the Duhok dam is not at risk because the actual settlement is less than predicted settlement.…”

Determination of Orthometric Height using GNSS and EGM Data: a Scenario of the Federal University of Technology Akure

“…The vertical location is the height above the reference ellipsoid which is also regarded as ellipsoidal height (Robert et al, 2016). However, for surveying and mapping purposes, orthometric height is preferred to the ellipsoidal height because of its relationship with the ocean (water body) and earth's gravity field which makes it to be considered as natural and physically meaningful for most applications (Isioye and Musa, 2007;Aleem et al, 2016, Olaleye, 2013Erenoğlu and Yüceses, 2019).…”