IGG is pleased to invite you to a scientific seminar, which will be held in remote form on the Zoom platform. The presentation titled "Land Movement Due to Aquifer System Drainage: A Global Threat" will be given by Dr Artur Guzy from the AGH University of Science and Technology in Krakow.
The seminar will begin on Thursday, April 13, 2023 at 09:00 AM (CEST).
Join the Zoom meeting: ZOOM LINK
Meeting ID: 811 427 0260
Access code: igig
Land Movement Due to Aquifer System Drainage: A Global Threat
Dr Artur Guzy, AGH University of Science and Technology, Cracow, Poland
Land subsidence is a widespread phenomenon worldwide, resulting from both natural and anthropogenic processes. Overexploitation of groundwater resources, driven by the growing demand for potable water due to rapid population growth, has emerged as the primary cause.
Significant aquifer system compaction is observed mainly in densely populated metropolitan areas, particularly in Southeast Asia large coastal cities located in river deltas. In extreme cases, overexploitation of groundwater resources can cause several meters of land subsidence, leading to socioeconomic consequences and high repair costs for damaged infrastructure. As a result, land subsidence caused by alluvial deposit compression has been extensively monitored, documented, and acknowledged, prompting the development of long-term land subsidence management plans in vulnerable areas.
In contrast, drainage of deeper rock layers remains a poorly understood research topic. Such drainage typically results from the underground exploitation of mineral resources, including coal. Mining necessitates significant lowering of the aquifer pressure head in the surrounding area, and addressing the geological, hydrogeological context, and disturbances caused by mining presents a challenging research topic.
Mining-induced drainage is crucial due to the lack of effective modelling possibilities for these phenomena, especially regarding observed land subsidence separation, which is a superposition of direct (post-mining void migration) and indirect effects (rock mass drainage) of mining exploitation. In rock mass deformation and land subsidence forecasts, indirect influences are often overlooked or misinterpreted, resulting in underestimation of actual damages. Mining drainage has broad negative economic and social implications that remain incompletely understood.
Freshwater and water management are critical issues that will likely become even more pressing with climate change. Given global efforts to meet the Paris Agreement targets, which primarily focus on reducing greenhouse gas emissions from coal combustion, the outcome of coal next chapter is crucial for climate change mitigation. Unsustainable mine closures through flooding increase pore pressure within the rock medium, causing land uplifts and infrastructure damages. Furthermore, rapid piezometric rebound may result in unfavourable stress distribution, suffocating the rock mass and forming sinkholes. If not properly managed, these phenomena pose dangers to residents in affected areas.
The presentation aims to introduce land subsidence due to groundwater pumping through selected global examples. Specifically, it will address land subsidence resulting from overexploitation of groundwater resources in unconsolidated Quaternary sediments; land subsidence due to groundwater dewatering of deep aquifer systems related to mining; and land uplift and sinkhole occurrence due to mine closure and groundwater rebound.