Lekan is a free and open source tool that can be used without constraint

Available version

Due to important changes of file structure, be aware that all files (rainfall file, runoff file and project file) saved with version 2.2 or later can not be open with version before 2.2.

Files created with version between 2.0 and 2.1 can be open with version 2.2 or later.

An example of use can be found here.

Release notes

Version 2.3

New feature:

  • 2D flow modelling
  • gridded precipitation

Releases history here: https://github.com/vcloarec/ReosProject/releases

Version 2.2

New features:

  • Import data from external sources: it is now possible to import data from Delft-FEWS files (rainfall and flow rate) and from remote server Hubeau (real-time flow rate). Infrastructure is ready to add more data providers.
  • Add spatial position capability to rainfall station in the rainfall manager
  • Improve the user interface for plots: customize legends (position, column count), activate/deactivate curves, change the color associated with time series
  • Add the possibility to associate gauged hydrograph to a watershed, hydrograph is entered in a table or imported from external sources
  • Overlay gauged hydrograph or result from another meteorological model in the runoff hydrograph calculation plot
  • Introducing the Hydraulic Network module: node/link to simulate flow propagation. Following elements can be added to the network:
    • Simple junction nodes that sum hydrographs from upstream links and eventually a produced gauged hydrograph
    • Watershed nodes that produce calculated runoff hydrograph or a gauged hydrograph that are summed to hydrographs from upstream links
    • Routing links that can transform an input hydrograph to an output hydrograph with a specified flow routing to simulate the propagation
  • Improve the displaying of the description of formulation/method
  • Date/Time in locale format

Version 2.1.4

The following issue has been fixed:

  • The Generalized Rational Method Unit Hydrograph gave some bad results especially when the concentration time was greater than the rainfall duration.

Version 2.1.3

  • Italian language added
  • Nash Unit Hydrograph

The following issues have been fixed:

  • some issues related to the decimal separator depending of the regional settings
  • it cold be impossible to check some formulas in the time concentration board

Version 2.1.2

The following issues have been fixed:

  • output hydrograph had a variable time step, that was not convenient when exporting values to other tools that does not support variable time step. In this new corrective release, the user can choose to have a constant time step.
  • when creating a new rainfall, a time offset could appear in the output hydrograph table equal to the difference from UTC and local time.

Version 2.1.1

The following issues have been fixed:

  • raster with int value was not recognized anymore as DEM, leading that SRTM was not recognized as DEM
  • removing burning lines tool could crash Lekan (when clicking where there was not burning line)
  • rainfall importer didn’t recognize end of line for some files (CSV Windows)
  • header text of rainfall table was cut

Nepali translation added

Version 2.1.0

Following features were added since version 2.0:

  • average elevation parameters for watershed
  • Giandotti concentration time formula
  • new button in the delineate watershed widget to load raster DEM file
  • detects raster DEM file and suggest to register as DEM layer
  • detects project has changed and ask to save before quit
  • warning when DEM raster layer coordinate system is invalid
  • improves the calculation of elevation on polyline
  • allows not selected watershed

Following issues were fixed since version 2.0.2:

  • DEM indicator disappears when layer move in the GIS layer tree
  • translation of parameter when language change for the same project

Version 2.0.2

The following issues have been fixed:

  • double check if file exists when exporting watershed delineating and stream path
  • invalid coordinate reference system when loading some layers

Version 2.0.1

The following issues have been fixed:

  • “Remove burning line button” is enabled when any burning lines is present.
  • New default meteorological model is created each time a project is loaded, leading to multiple meteorological model with same name.
  • Rounding error with the filling DEM process can lead to error when delineating watershed, happens with long/lat coordinate reference system.