Introduction

The report provides a state-of-the-art of methodologies and guidelines related to quality assurance in water resources modelling. The conclusions from the present report will form the basis for the further HarmoniQuA work on establishment of a common glossary and a generic set of guidelines and methodologies. HarmoniQuA aims to be a component of a future infrastructure for model based water management at catchment and river basin scal

Uncertainty in geological and hydrogeological data

Uncertainty in conceptual model structure and in environmental data is of essential interest when dealing with uncertainty in water resources management. To make quantification of uncertainty possible is it necessary to identify and characterise the uncertainty in geological and hydrogeological data. This paper discusses a range of available techniques to describe the uncertainty related to geological model structure and scale of support. Literature examples on uncertainty in hydrogeological variables such as saturated hydraulic conductivity, specific yield, specific storage, effective porosity and dispersivity are given. Field data usually have a spatial and temporal scale of support that is different from the one on which numerical models for water resources management operate. Uncertainty in hydrogeological data variables is characterised and assessed within the methodological framework of the HarmoniRiB classification

Modelling the hydrological impacts of climate change on UK lowland wet grassland

Hydrological impacts of climate change upon the Elmley Marshes, southeast England, are simulated using a coupled hydrological/hydraulic model developed using MIKE SHE/MIKE 11 and calibrated to contemporary conditions. Predicted changes in precipitation, temperature, radiation and wind speed from the UK Climate Impacts Programme associated with four emissions scenarios for the 2050s are used to modify precipitation and potential evapotranspiration data. For each emissions scenario two sets of potential evapotranspiration data are derived, one using changes in temperature (PETtemp), the other incorporating changes in temperature, radiation and wind speed (PETtrws). Results indicate drier conditions through the progressively higher emissions scenarios when compared to contemporary conditions. Changes are particularly pronounced when using PETtrws. Summer water tables are lower (PETtemp 0.01�0.08 m; PETtrws 0.07�0.27 m) and the duration of high winter water tables is reduced. Although water tables still intercept the surface in winter when using PETtemp, this ceases when PETtrws is employed. Summer ditch water levels for the PETtemp scenarios are lower (0.01�0.21 m) and in dry winters they do not reach mean field level. Under the PETtrws scenarios summer and winter ditch water levels are lower by on average 0.21 and 0.30 m, respectively. Levels never reach the elevation of the marsh surface. Lower groundwater and ditch water levels result in declines in the magnitude and duration of surface inundation which is virtually eliminated with the PETtrws scenarios. The changes in hydrological conditions simulated by the model are of sufficiently fine resolution to infer ecological impacts which are likely to include the loss of some grassland species adapted to high water tables. Reductions in the extent of surface water in spring, especially for the PETtrws scenarios, are likely to reduce suitability for wading birds including lapwing (Vanellus vanellus) and redshank (Tringa totanus) for which the marshes are internationally renowned

Uncertainties in river basin data at various support scales ? Example from Odense Pilot River Basin

International audienceIn environmental modelling studies field data usually have a spatial and temporal scale of support that is different from the one at which models operate. This calls for a methodology for rescaling data uncertainty from one support scale to another. In this paper data uncertainty is assessed for various environmental data types collected for monitoring purposes from the Odense river basin in Denmark by use of literature information, expert judgement and simple data analyses. It is demonstrated how such methodologies can be applied to data that vary in space or time such as precipitation, climate variables, discharge, surface water quality, soil parameters, groundwater abstraction, heads and groundwater quality variables. Data uncertainty is categorised and assessed in terms of probability density functions and temporal or spatial autocorrelation functions. The autocorrelation length scales are crucial when support scale is changing and it is demonstrated how the assumption used when estimating the autocorrelation parameters may limit the applicability of these autocorrelation functions

Current Results of the EC-sponsored Catchment Modelling (CatchMod) Cluster

To support the Water Framework Directive implementation, much research has been commissioned at both national and European levels. CatchMod is a cluster of these projects, which is focusing on the development of computational catchment models and related tools. This paper presents an overview of the results of the CatchMod cluster to dat

Measurement of the branching ratio for beta-delayed alpha decay of 16N

While the 12C(a,g)16O reaction plays a central role in nuclear astrophysics, the cross section at energies relevant to hydrostatic helium burning is too small to be directly measured in the laboratory. The beta-delayed alpha spectrum of 16N can be used to constrain the extrapolation of the E1 component of the S-factor; however, with this approach the resulting S-factor becomes strongly correlated with the assumed beta-alpha branching ratio. We have remeasured the beta-alpha branching ratio by implanting 16N ions in a segmented Si detector and counting the number of beta-alpha decays relative to the number of implantations. Our result, 1.49(5)e-5, represents a 24% increase compared to the accepted value and implies an increase of 14% in the extrapolated S-factor

Integrated hydrological modeling of the North China Plain and implications for sustainable water management

Groundwater overdraft has caused fast water level decline in the North China Plain (NCP) since the 1980s. Although many hydrological models have been developed for the NCP in the past few decades, most of them deal only with the groundwater component or only at local scales. In the present study, a coupled surface water–groundwater model using the MIKE SHE code has been developed for the entire alluvial plain of the NCP. All the major processes in the land phase of the hydrological cycle are considered in the integrated modeling approach. The most important parameters of the model are first identified by a sensitivity analysis process and then calibrated for the period 2000–2005. The calibrated model is validated for the period 2006–2008 against daily observations of groundwater heads. The simulation results compare well with the observations where acceptable values of root mean square error (RMSE) (most values lie below 4 m) and correlation coefficient (<i>R</i>) (0.36–0.97) are obtained. The simulated evapotranspiration (ET) is then compared with the remote sensing (RS)-based ET data to further validate the model simulation. The comparison result with a <i>R</i>² value of 0.93 between the monthly averaged values of simulated actual evapotranspiration (AET) and RS AET for the entire NCP shows a good performance of the model. The water balance results indicate that more than 70% of water leaving the flow system is attributed to the ET component, of which about 0.25% is taken from the saturated zone (SZ); about 29% comes from pumping, including irrigation pumping and non-irrigation pumping (net pumping). Sustainable water management analysis of the NCP is conducted using the simulation results obtained from the integrated model. An effective approach to improve water use efficiency in the NCP is by reducing the actual ET, e.g. by introducing water-saving technologies and changes in cropping