Thomas Baumgartl | The University of Queensland, Australia (original) (raw)

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Papers by Thomas Baumgartl

Journal of Cleaner Production, Mar 1, 2022

SPE Economics & Management, 2014

Summary The rapid expansion of the coal-seam-gas (CSG) sector in Queensland has fueled debate on ... more Summary The rapid expansion of the coal-seam-gas (CSG) sector in Queensland has fueled debate on the sector's contributions to community sustainability in a rural economy dominated by the farming of food and cotton, cattle grazing, coal mining, and a modest level of tourism. For example, will the impacts of CSG extraction on surface and groundwater have sustained negative impacts on the growing of grain, and if so, what should one expect of the CSG industry today? The intensity of debate is accompanied by an array of operating conditions placed on CSG projects by the state government, extensive media coverage, and a focus on what it takes to maintain a “social license to operate.” Such a context is a challenge for resource companies committed to sustainability principles and to contributing to the social, economic, and institutional development of the communities in which they operate as well as to the conservation of biodiversity and integrated approaches to land-use planning. ...

Land Degradation & Development, Mar 8, 2018

Extensive disturbances during the mining and rehabilitation process can include removal of vegeta... more Extensive disturbances during the mining and rehabilitation process can include removal of vegetation, removal and storage of soils hence their modification, changes in topography, and planting of new vegetation. A main goal of mine rehabilitation is to produce a post-mining landscape that is resistant to geotechnical failure and to surface erosion processes. To achieve this, hydrology and erosion models are required to determine erosion rates under alternative landscape designs, including landscape form and cover options. By critical review of the relevant literature, it was found that most previous erosion modelling studies have concentrated on surface hydrology in agricultural, forestry, and other natural systems, while disturbed ecosystems like mining regions have received little attention. Landscape evolution models have been developed for mined landform applications but modelling over long time-scales compromises the temporal and spatial resolution. The main objectives of this research therefore were: Extend an existing plot-scale hydrological model to plot-scale erosion model. To improve knowledge of the errors and uncertainty in applying a high-resolution erosion model to mined landforms and to conclude on the potential applicability and limitations of EroCA. The experimental data used in the research were from a 30 m × 30 m field plot on a mine waste rock dump in the wet tropical environment of the Ranger mine (north-east Australia) from the period 2009 to 2014. The new EroCA model is an extension to the RunCA model, which was developed to provide high resolution simulation of runoff and infiltration in constructed landforms. The extended model uses mass balance principles and established erosion and sediment transport models, covering both suspended and bedload, and solves the equations using the cellular automata approach. Code verification against analytical solutions of runoff and sediment illustrated small errors, which were partly due to approximations used in the analytical solutions. The EroCA model was then applied to the Ranger experimental plot data to assess the suspended and bedload erosion performance. EroCA was able to reasonably represent the observed flows and turbidity profiles. Although an arbitrary reduction in the erodibility parameter value of 20% per year was needed to simulate the bedload depletion.

Rehabilitation in the mining context refers to restoring the natural characteristics such as land... more Rehabilitation in the mining context refers to restoring the natural characteristics such as land stability, vegetation, soil functions, biodiversity and hydrological cycle. The main aim of mine rehabilitation is to construct environmentally sustainable landforms and to restore their ecosystem services, either to a site specific stable equilibrium or ideally to its previous state. The objective of this work is to build a predictive and decision making tool using hypothetical modelling to simulate water fluxes for two different scenarios in terms of different soil cover depth including vegetation (grass). Hypothetical hydrological modelling was performed using the HYDRUS-1D with one-dimension water flow modelling based on the Richards equation and hydraulic functions of van Genuchten-Mualem model. The soil and coal hydraulic parameters were derived from laboratory tests using the extended evaporation method. Water flux modelling was performed for 2021 using the climatic data from Latrobe Valley (Victoria, Australia) meteorological station, where the coal and soil samples were collected. Two scenarios were selected which varied in the depth of soil cover and coal layer, both with grass vegetation on top of the soil columns. The first scenario (S1) had 50 cm of soil cover, while the second scenario (S2) had 100 cm of soil cover on top of coal material, respectively. Modelling results revealed that soil water content and fluxes were directly reflecting the precipitation pattern and the most limiting factor in downward water flow was the low permeability of the coal layer. The hydraulic parameters for coal show large water retention capacity at very low hydraulic conductivity. The shallower soil cover in the S1 scenario resulted in higher soil water content during the period of intense rainfall and resulted in larger and faster initiation of surface runoff. The thicker soil cover layer resulted in larger infiltration rate and root water uptake which was however limited when the soil was fully saturated in both scenarios. Interestingly, very similar bottom flux in both scenarios even with two different coal layer depth (i.e., 30 cm vs 80 cm) were recorded. Water balance results indicate increase in potential of storing water in the S1 scenario which has a thicker coal layer due to its high water retention capacity. However, at this point it is not clear to what extent stored water from coal can be available for plants. Beside valuable research insights in terms of soil cover design, hypothetical modelling will assist in preventing experimental design flaws and providing a more efficient, robust controlled experiment performed in a next study phase.

&lt;p&gt;Temperate Highland Peat Swamps on Sandstone (THPSS) are ecological commu... more &lt;p&gt;Temperate Highland Peat Swamps on Sandstone (THPSS) are ecological communities that consist of either ephemeral or permanent swamps developed in peat overlying Triassic sandstone formations in the Sydney Basin Bioregion of eastern Australia. THPSS with distinctive vegetation play an important role in biodiversity, carbon capture and storage, and the regional hydrological cycle. Some THPSS of Sydney Basin have underlying sandstone with cracks potentially formed over the past decades by human intervention. These cracks may create preferential flow paths that may accelerate the drainage process at the bottom of the swamps and may affect the soil moisture conditions of the swamps with ecological consequences. In order to understand and predict the impact of cracks on the swamps&amp;#8217; soil moisture and provide information to guide the management and restoration of the THPSS, 2D numerical simulations have been carried out using dual-porosity hydraulic models or explicit fast flow paths to represent the preferential flow paths. The models are calibrated and validated against historical soil moisture data and then used to evaluate the effect of cracks on soil moisture.&lt;/p&gt;

Proceedings of the International Conference on Mine Closure, 2021

Soil Science Society of America Journal, Jul 1, 2017

International Journal of Sustainable Development and World Ecology, Jan 4, 2017

Ecological Engineering, May 1, 2017

Agricultural hillslopes present particular challenges for estimating vadose zone dynamics due to ... more Agricultural hillslopes present particular challenges for estimating vadose zone dynamics due to a variety of processes, such as surface runoff, vertical flow, erosion, subsurface preferential flow affected by soil structure and layering, non-linear chemical behaviour, evapotranspiration, etc. To investigate these processes and complexity, the SUPREHILL critical zone observatory (CZO) was started in 2020, at vineyard hillslope site in Croatia. The observatory is extensively equipped for the soil-water regime and agrochemical fluxes monitoring, and includes an extensive sensor network, lysimeters (weighing and passive wick), suction probes, surface and subsurface flow and precipitation collection instruments. The main objective of the SUPREHILL observatory is to quantify subsurface lateral and local scale preferential flow processes. Local-scale nonlinear processes in eroded agricultural hillslope sites have large significance on water and solute behaviour within the critical zone and thus need to be researched in depth using combined methods and various approaches. First results from the sensor and lysimeter network, soil-water regime monitoring, isotope analysis, and agrochemical concentrations in 2021 supported the hypothesis of the observatory, that the subsurface flow plays a relevant part in the hillslope soil-water dynamics. In the wick lysimeter network, although the highest cumulative outflow values were found at the hilltop, the highest individual measurements were found at the footslope. During high-intensity rainfall events, there were differences in weighing lysimeters, possibly related to subsurface lateral flow. Based on the isotope analysis, wick lysimeters exhibit a greater variation of d-excess values than suction probes. Agrochemical fluxes confirmed the sloping effect on their transport in soil and demonstrated the favourability of Cu transport by subsurface flow. Using the comprehensive database presented herein, future analyses of this hypothesis will be carried out in more detail using model-based analyses.

Open-cast or surface mining present a site-specific and a temporary use of land that unavoidably ... more Open-cast or surface mining present a site-specific and a temporary use of land that unavoidably involves the displacement of the fertile topsoil layer and overall environmental change. Following mine closure, rehabilitation of mining areas is essential to build sustainable and stable landforms. Reclamation of soils is particularly challenging as their construction needs to take into account broader land reclamation analysis including soils, water, vegetation, stability and biodiversity effects. The objective of this study was to assess development in soil properties of rehabilitated soils since construction (1980, 1998, 2009, 2016, 2017) focusing on hydraulic and mechanical soil properties. The study was performed at an open-cast lignite coal mine site in south-east Australia (Victoria) in 2021. Soil hydraulic properties (SHP) were determined using the extended evaporation method while the mechanical properties were assessed using in-situ vane shear tests. The study indicated the relevance of a consistent soil cover design and construction. The soil hydraulic properties results showed a shift in soil water retention curve characteristic (1980 vs 2017 site), together with a decrease in saturated hydraulic conductivity (Ks), which can certainly influence soil water dynamics and increase surface runoff. The vane shear test showed large heterogeneity among the sites with rehabilitated sites indicating large internal variation compared to the reference site and generally higher shear resistance. Differences in soil hydraulic conductivity and higher SOC storage over time revealed developments in soil recovery, but the improvement in soil mechanical strength did not show any relation to soil properties affecting soil structural stability. Rather, the change was driven by the large variability in texturally affected pore size distribution among the sites. The observed small-scale heterogeneity of the rehabilitated soils is most likely explained by disturbance due to excavation activities and used rehabilitation methods as well as availability of the soil material. Closer monitoring of rehabilitated areas temporally and spatially as well as in improvement in topsoil cover design is recommended, as such heterogeneity leads to uncertainty in long-term sustainable landscape formation.

Proceedings of the International Conference on Mine Closure, 2022