The HiWet project aims to provide a framework for efficient freshwater wetland ecosystem monitoring and evaluation of ecosystem health, using novel techniques to estimate evapotranspiration (ET) and to derive evaporative stress as an indicator for the health state of the wetland vegetation. The project targets consistent ET retrieval across scales, from the local field scale (fine spatial resolution) to the regional catchment scale (coarse spatial resolution) derived from combined use of hydrological models and remote sensed energy balances. In addition the project aims to contribute greatly to an increased understanding of the functioning of freshwater wetland ecosystems.
By combining surface energy balance methods with hydrological models, a new method of multi-scale hydrological water balance modelling (for wetlands) will be developed that is innovative at two levels:
This new approach is especially relevant for wetland management, where evapotranspiration varies dynamically in space and time. A suitable indicator of wetland ecosystem health will be developed based on both classical vegetation analyses and analysis of plant functional traits and types. In order to validate the hypothesis that evapotranspiration estimates are indeed a good indicator of fresh water ecosystem health, these results are evaluated with ground truth data.
The project will contribute to the monitoring of wetland health status and associated changes in freshwater wetland ecosystem functioning. An output of the project will be the identification of health status indicators that are specific for the main wetland typologies. A better understanding of the reciprocal interactions between hydrology and vegetation also allows making recommendations for wetland management and restoration, especially related to desiccation and eutrophication problems.