Fault-induced wetland loss at Matagorda, Texas, USA: land cover changes from 1943 to 2008

Abstract

Movement of growth faults, a type of normal fault which is formed during sedimentation and is characterized by having greater vertical thickness on the downthrown fault side, on barrier islands contributes to wetland losses. This study sought to quantify land cover changes in response to vertical fault movement on the East Matagorda Peninsula barrier feature, Texas, USA. A time series of aerial images was classified using automated unsupervised classification and hand digitization. After classification, total wetland losses on both the upthrown and downthrown sides of the fault were evaluated as a function of spatial distance from the fault plane. Results show that while wetland loss occurred on both sides of the fault, losses were far more extensive on the downthrown side. It was concluded that this vertical fault movement impacts wetland losses, especially on the downthrown side.