AlterrAqua, a regional GIS based modelling system
Gerrit Hendriksen[1]
Frank van der Bolt1
Pim Dik1
Ab Veldhuizen1
In many issues of integrated water management an integrated model is needed that covers the whole (regional) system, including plant-atmosphere interactions, soil water, groundwater and surface water. SIMGRO (SIMulation of GROundwater) was developed for that purpose. AlterrAqua can be used as its processing tool.
AlterrAqua is a GIS toolbox that enables users to implement regional hydrological models using a mixture of standard databases (such as soil, land use and elevation maps) and local data, for instance derived from waterboards. It enables data consistency checks, model schematization, output presentation and contains several post-processing tools such as ‘Hoogwater Methodiek Commissie WB21’ (a method to verify regional standards on inundation and to estimate crop damage due to inundation), NATLES (NATure oriented Land Evaluation System) and BODEP (Soil Evaluation Program, a method to estimate crop damage).
Water flow in the unsatured zone is modelled with SIMGRO with data schematised by AlterrAqua using knowledge tables, soil and land use maps. The knowledge tables for instance provide information on root depth and are related to soil type and land use. The commonly used 1: 50 000 soil map is schematized into soil physical parameters using the Dutch ‘Staringreeks’.
The system is currently used by several waterboards and is applied in several projects in the Netherlands as well as abroad. The system can be applied to answer questions like:
- how does the water system react on extreme events or climate change;
- where can inundations be expected;
- how is crop damage caused by inundation geographically distributed;
- how do groundwater levels react on normal and extreme climatological events.
AlterrAqua is continuously being improved. Users and developers are organised in a user group which reviews change proposals and decide the priority for implementation. This construction ensures a certain quality level described by our quality management system.
In the near future AlterrAqua will be ready to process models including water quality like SWAP and ANIMO.
[1] Alterra, Wageningen, The Netherlands, E-mail: