Long-term gas migration through clays cannot be simulated by conventional two-phase flow models alone owing to the presence of material deformation. In this article, an extended twophase flow model that incorporates mechanical effects is proposed. The model allows the formation of preferential pathway and considers the relation between pore moisture and pore deformation. It was carried out with the intention of avoiding the complexity of a fully coupled thermal, hydraulic and mechanical modelling. In the new model, porosity, permeability, swelling pressure and pathways formation threshold depend on the water saturation. The model is validated on different gas injection experiments with controlled flow rate and controlled pressure. Some experiments are well known in the literature; some are new. In each case, an inverse approach is used to identify the model parameters. The results confirm that, depending on the type of bentonite (MX80, Avonlea, KunigelV1), modelling the gas migration could require the existence of a pressureinduced saturation-depending preferential pathway. In laboratory-scale experiments, the model leads to an accurate evaluation of the long-term gas migration trends, including not just the gas migration stage but also the water re-saturation level. In a field-scale experiment, the behaviour of the model in a realistic context is revealed.

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A water resources management considering not only water but also heat has become a crucial issue due to limited availability of water resources, increasing water contaminations and ground source heat utilizations. Indicators are useful to manage water resources. Water budget and Heat budget can be one of the major indicators for sustainable water resources management because detecting the disequilibrium of these budgets at an early stage makes it possible to implement effective measures. However, many components required to estimate these budgets in a domain that include the surface and the subsurface are difficult to measure directly, for instance, the water and heat transported by recharge, and the groundwater discharge in a regional watershed scale. An integrated watershed modeling technique allows to represent seamlessly the mass and heat transport behaviors from the surface to the underground in arbitrary temporal and spatial scales. Moreover, a spatiotemporal water flow behavior can be expressed without any explicit conditions for routing the paths of water movement. Therefore, this kind of modeling technique becomes efficient tool to estimate the components of these budgets.