Integrated hydrological modelling of a managed coastal Mediterranean wetland (Rhone delta, France): initial calibration

This paper presents a model of a heavily managed coastal Mediterranean wetland. The hydrosystem studied , called ``Ile de Camargue', is the central part of the Rhone river delta. It comprises flat agricultural drainage basins, marshes, and shallow brackish lagoons whose connection to the sea is managed. This hydrosystem is subject to strong natural hydrological variability due to the combination of a Mediterranean climate and the artificial hydrological regime imposed by flooded rice cultivation. To quantify the hydrological balance at different spatial and temporal scales, a simplified model is developed — including the basin and the lagoons — using a time step that enables the temporal dynamic to be reproduced that is adapted to data availability. This modelling task takes into account the functioning of the natural and anthropogenic components of the hydrosystem. A conceptual approach is used for modelling drainage from the catchment, using a GIS to estimate water input for rice irrigation. The lagoon system is modelled using a two-dimensional finite element hydrodynamic model. Simulated results from the hydrodynamic model run under various hydro-climatic forcing conditions (water level, wind speed and direction, sea connection) are used to calculate hydraulic exchanges between lagoon sub units considered as boxes. Finally, the HIC ('Hydrologie de l’Ile de Camargue') conceptual model is applied to simulate the water inputs and exchanges between the different units, together with the salt balance in the hydrosystem during a calibration period.</p> <p style='line-height: 20px;'><b>Keywords: </b>water management,conceptual hydrological model, hydrodynamic model, box model, GIS, Rhone delta, Camargue

Influence of the setting process and the formulation on the drying of hemp concrete

International audienceHempconcrete is a sustainable material that becomes successful in the field of building construction. It is made out of hemp shivs mixed with a lime based binder and water and manufactured through three processes: spraying, moulding or mechanical mixing and tamping. Experiments were performed under natural and forced convection on several instrumented blocks during the curing time. The instrumentation (thermocouples, humidity sensors, weight-scales) allows investigating the drying kinetics and the moisture diffusivity and apprehending the hygrothermal behaviour of the material. It is observed that manufacturing processinfluences the initial water content and the final density whereas the hygrothermal behaviour depends on the material formulation

Satellite images and relief delineation following wetland spatial evolution

[Notes_IRSTEA]SRef-ID: 1607-7962/gra/EGU04-A-06834 [Departement_IRSTEA]DS [TR1_IRSTEA]METHODO / SYNERGIERemote sensing provide a good opportunity to monitor the rapid Hydro-Geomorphologic units i.e., Wetland and floods. The spatial coverage of these units is related to micro relief of the region. Therefore a good knowledge of micro relief has a prime importance in understanding the land -water interaction in such areas. In present study, the micro relief in Rhone delta river (in South of France) have been derived using fine resolution DEM (Digital Elevation Model) and multi-temporal SPOT data. The DEM (Digital Elevation Model) results showed wetland sites in the region and its spatial relation with terrain. Since the micro relief play important role in spatial coverage of wetland in rapid response to hydrological season. Therefore, this parameter is also derived by extracting the surface area of wetland in various seasons. The comparative analysis show that combination of these two methods can be use efficiently to monitor the wetland dynamics

Integrated hydrological modelling of a managed coastal Mediterranean wetland (Rhone delta, France): initial calibration

International audienceThis paper presents a model of a heavily managed coastal Mediterranean wetland. The hydrosystem studied , called ``Ile de Camargue", is the central part of the Rhone river delta. It comprises flat agricultural drainage basins, marshes, and shallow brackish lagoons whose connection to the sea is managed. This hydrosystem is subject to strong natural hydrological variability due to the combination of a Mediterranean climate and the artificial hydrological regime imposed by flooded rice cultivation. To quantify the hydrological balance at different spatial and temporal scales, a simplified model is developed — including the basin and the lagoons — using a time step that enables the temporal dynamic to be reproduced that is adapted to data availability. This modelling task takes into account the functioning of the natural and anthropogenic components of the hydrosystem. A conceptual approach is used for modelling drainage from the catchment, using a GIS to estimate water input for rice irrigation. The lagoon system is modelled using a two-dimensional finite element hydrodynamic model. Simulated results from the hydrodynamic model run under various hydro-climatic forcing conditions (water level, wind speed and direction, sea connection) are used to calculate hydraulic exchanges between lagoon sub units considered as boxes. Finally, the HIC ("Hydrologie de l'Ile de Camargue") conceptual model is applied to simulate the water inputs and exchanges between the different units, together with the salt balance in the hydrosystem during a calibration period. Keywords: water management,conceptual hydrological model, hydrodynamic model, box model, GIS, Rhone delta, Camargue