Use of Semivariograms to Identify Earthquake Damage in an Urban Area

The 1999 Izmit earthquake (Mw 7.4) on the North Anatolian Fault Zone resulted in severe damage to the urban areas of Izmit, Adapazari (Sakarya), Golcuk, and Yalova. A semivariogram approach was used to quantify earthquake-induced spatial variation and thereby the degree of damage in the Adapazari inner city. Semivariograms were calculated for 24 transects on SPOT high resolution visible infrared (HRVIR) panchromatic images obtained before and after the earthquake. The differences between the pre- and postearthquake semivariogram shape and measures of shape, range, nugget, and sill were related to the severity of earthquake damage