TITLE:
Spatial Variability of Shear Wave Velocity Using Geostatistical Analysis in Mashhad City, NE Iran
AUTHORS:
Azam Ghazi, Naser Hafezi Moghadas, Hossein Sadeghi, Mohammad Ghafoori, Gholam Reza Lashkaripour
KEYWORDS:
Kriging, Interpolation Accuracy, Vs Interface, Mashhad City
JOURNAL NAME:
Open Journal of Geology,
Vol.4 No.8,
August
6,
2014
ABSTRACT: Shear wave velocity (Vs)
is one of the most important parameters of a geological model to assess the
site effect and the ground response. In this paper the spatial variability of
shear wave velocity in Mashhad capital city are investigated. For this purpose,
243 Vs profiles of different projects throughout the city were used. Based on
the Vs profiles the iso-level maps of the Vs interfaces 300, 500, 750, 950 and
1200 m/s were obtained by kriging interpolation method. The best semivariogram
models were obtained with changing the effective parameters and assessing the
components of the models and spatial dependence. The best models for the entire
interfaces were exponential. Based on these models, the spatial dependence of
depth data was moderate to strong. The performance of interpolations was
checked by cross-validation and its indicesi.e.
mean standardized prediction errors (MSPR), root mean square prediction errors
(RMSPE), average kriging standard error (AKSE), and root mean square
standardized prediction errors (RMSSPE) were assessed. A trend of depth
increasing towards the northeast was observed at all of the interfaces.