Lekan is the application of the Reos Project. Its aim is to provide a software that assists the user doing hydrological and hydraulic studies for flood mapping and forecasting, hydraulic structure design, or other tasks linked to natural surface flow.

The user works in the GIS environment based on the QGIS software.

Hydrological Tools

  • Import, create, edit and manage rainfall data with station on map
  • Manually or automatically delineate watersheds and sub-watersheds based on a raster DEM
  • Manual or automatic main channel drawing: longest path or from a selected upstream point
  • Evaluate the mean slope base on the longitudinal profile
  • Concentration time calculation
  • Associate hyetograph to watersheds with rainfall scenarios
  • Runoff model
  • Calculate hydrographs with different transfer functions

Hydraulic Network

Connect from upstream to downstream watershed’s outlet, junctions and 2D flow model to simulate propagation of hydrographs.

Input hydrograph can be:

  • runoff hydrograps calculated with hydrologicals tools,
  • Entered manually or by copy/paste,
  • Imported from files or from a remote server.

Output can be extracted by copy/paste or used as an input boundary condition for a 2D flow model handled by Lekan.

Propagation in links are simulated by applying some transformation routing methods.


2D Flow Models


As elements of the hydraulic network, 2D structures are complete 2D flow models.

Without leaving the application, the user can build completely 2D models, launch them, and visualize results on a 2D map, a 3D view and profiles.

Today, the model is resolved thanks open TELEMAC solver, but there is a lot of room for other solver as the infrastructure is prepared to add other solver.

Each 2D structure is an independent model that can be linked to each other or to watershed by hydraulic links that propagate input/output hydrographs.