Assessing Impacts of Land Subsidence in Victoria County, Texas, Using Geospatial Analysis

Land subsidence is an ongoing problem negatively affecting Victoria County along the Gulf Coast. Groundwater withdrawal and hydrocarbon extraction in the County are some of the known factors behind this geological hazard. In this study, we have used geospatial analysis and a conceptual model to evaluate land subsidence. A significant decline in the groundwater level in this area was noted from 2006 to 2016. The decline in the water level correlates with the major drought events along the Gulf Coast reported in earlier studies. These results are further corroborated by the emerging hotspot analysis performed on the groundwater data. This analysis divides the study area into intensifying, sporadic, and persistent hotspots in the northwest region and intensifying, persistent coldspots in the southeast region of Victoria County. Hydrocarbon production data show high oil and gas extraction from 2017 to 2021. There are a higher number of hydrocarbon production wells in the central and southern regions of the County than elsewhere. The conceptual models relate these events and suggest the existence of subsidence in the County, through which the water and hydrocarbon reservoirs in the study area may lose their reservoir characteristics due to sediment compaction.

Automated summary

Land subsidence is a persistent problem in Victoria County along the Gulf Coast, caused by groundwater withdrawal and hydrocarbon extraction. Geospatial analysis and a conceptual model are used in this study to assess the extent of land subsidence. The study finds a significant decrease in groundwater levels from 2006 to 2016, which is consistent with previous reports of major drought events along the Gulf Coast. The emerging hotspot analysis of groundwater data further supports these findings. Additionally, high oil and gas extraction is observed from 2017 to 2021, with a higher number of production wells in the central and southern regions of the County. The conceptual models suggest a link between these events and the occurrence of subsidence, leading to the potential loss of reservoir characteristics in the study area due to sediment compaction.