We developed a GRASS GIS tool for modelling riverine fish dispersal (FIDIMO).
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Empirical leptokurtic fish dispersal kernels are used to model movement distances.
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Kernels are applied to rasterized river networks, considering movement barriers.
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FIDIMO allows predicting and simulating spatio-temporal patterns of fish dispersal.
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The tool builds on free and open source software and allows manifold adaptations.
Abstract
Dispersal is a key process in community ecology and dynamics that comprise not only various movement processes, but also behavioural components and large-scale spatio-temporal patterns. Modelling fish dispersal further has to consider the species-specific dispersal abilities and the branching, dendritic nature of river networks.
With FIDIMO (fish dispersal model) a tool is provided for predicting and simulating spatio-temporal patterns of fish dispersal in river networks with a real integration of GIS for the first time. The model has been written in Python programming language as open source add-on for GRASS GIS. The model has been developed to apply the characteristics of heterogeneous, species and size class specific fish movement on a rasterized river network including migration barriers. Fish dispersal is modelled as a leptokurtic diffusion process spreading from spatially predefined source populations consisting of stationary and mobile components each. The fish dispersal model FIDIMO links conceptual considerations on dispersal modelling with empirically observed fish movement patterns and the strengths of geographically explicit modelling in FOSS GIS. It can be used for different species and any river network meeting the input requirements.
As main results FIDIMO yields probabilities of occurrence of fish species in river raster cells based on empirically derived dispersal kernels after the time step of interest modelled.
The model output serves to understand and predict time lags and spatio-temporal patterns of recolonization events, the related success of river rehabilitation and also the spread of invasive species. The consequent use of open source programmes allows free access to the code and facilitates easy modifications, adoptions and improvements of the model.
Abbreviations
GIS
Geographic Information Systems
FOSS
Free and Open Source Software
FIDIMO
Fish Dispersal Model
GRASS
Geographic Resources Analysis Support System
WGS84
World Geodetic System 1984
ETRS89
European Terrestrial Reference System 1989
UTM
Universal Transverse Mercator Projection
EPSG
European Petroleum Survey Group Geodesy
GUI
Graphical User Interface
GNU
GNU's Not Unix
WFD
Water Framework Directive
IWRM-net
Regional and National Research Programmes Network on Integrated Water Resource Management
IMPACT
Developing an Integrated Model to Predict Abiotic Habitat Conditions and Biota of Rivers for Application in Climate Change Research and Water Management