Modelling ditch water levels on the Pevensey Levels wetland, a lowland wet grassland wetland in East Sussex, UK

The paper describes a user-friendly, physically-based model for the estimation of ditch water levels in wet grassland drainage ditches. Data requirements are standard climatic data and basic hydrological parameters, such as hydraulic conductivity, The model also requires information describing the form and dimensions of the ditch system, as it is based on a level-volume-surface area relationship, At each time step the model calculates the level change associated with volumetric changes in storage in the system due to rainfall, evaporation, runoff, seepage and discharge through water level control structures. Application of the model to a ditch system on a National Nature Reserve on the Pevensey Levels, East Sussex provided a close replication of measured ditch water levels (R(2) = 0.82). Model output data can potentially be used to provide a rapid assessment procedure to assess the impacts of different water level management strategies on ecological communities and agricultural practices in wet grassland areas. (C) 2000 Elsevier Science Ltd. All rights reserved.