Earth Surface Hydrology is concerned with the study of hydrological processes near and on the earth surface. It focuses on the flow of water, nutrients and energy between the earth surface and the subsoil and between the earth surface and the atmosphere. It aims to quantify how rainfall is portioned into infiltration, evaporation and runoff, and how nutrients in the soil and the earth surface are distributed through the landscape through surface runoff and groundwater flow.

Our research focuses on three major themes:

1) Large-scale hydrology
Research in this theme concentrates on the role of the terrestrial hydrological cycle in System Earth. In particular it focuses on the role of climate variability on continental hydrology, on land-surface atmosphere feedbacks and the modelling of global water scarcity and groundwater depletion. To this purpose we have built a next-generation global hydrological model PCR-GLOBWB. The model is already widely used in various global or continental change analyses, such as the assessment of global nutrient dynamics, methane emissions, global water stress assessment and real-time global flood forecasting. Additionally, we are focusing on large-scale coupled surface water-groundwater modeling such as for the Rhine and Danube basin and moelling the fate of the Himalayan glaciers and their effect on water scarcity.

2) Ecohydrology and eco-geomorphology
Ecohydrology is concerned with the spatio-temporal dynamics of soil moisture in relation to vegetation and its interaction with the atmosphere. Our niche is looking at groundwater dependent ecosystems at the catchment-scale in relation to climate change and climate variability. In cooperation with the Environmental Science group (Prof. Wassen) we have worked on spatial pattern formation and the relation between local vegetation-hydrology feedbacks and regional land-atmosphere feedbacks.  Also, we have developed a fully biophysical forest-growth model including light and water competition which is fully coupled to a landscape-scale hydrological model, including groundwater flow. Related to the functioning of ecosystems in particular and environmental quality in general is the assessment and modeling of groundwater and surface water quality.  Recently, we have been developing models to describe the co-evolution of soils, landforms and hydrology including soil genesis, erosion, landslides, vegetation dynamics, human impacts through agriculture and hydrologic response (the model Caleros). Within this new theme of eco-geomorphology we are also investigating critical shifts.

3) Geocomputation (in cooperation with Prof. dr. S.M. de Jong)
This research theme focuses on the development of spatio-temporal, numerical models of geoprocesses and the development of geostatistical data analysis and interpolation and visualisation methods. Emphasis is put on complexity in spatio-temporal modelling, issues of scale, spatio-temporal statistics and stochastic modelling. Our research on geocomputation is internationally recognised through the PCRaster modelling software. ESRI (CA), the world leader in GIS modelling and mapping software, is collaborating with the LGH group to further develop algorithms and methods for spatio-temporal modelling in the ArcGIS software. Geocomputation research provides strong support to LGH staff, but also to research of the CFG staff and of other departments in the Faculty of Geosciences. Recently, geocomputation research has extended to the development and application of data-assimilation and real-time forecasting methods using hydrological models and remote sensing information.

Note: these research themes are part of the research strategy of the department of Physical Geography.