18/11/2010

ExtendSim-PCRaster

A generic platform for spatial-dynamic modelling of

nutrient transport and policy options

Jean-Luc de Kok

Hans van der Kwast

Steven Broekx

Guy Engelen

18/11/2010 2© 2010, VITO NV

@2005..2007, PES PCRaster Environmental Software

Extending Systems Analysis with a

spatial component

» SA and system dynamics: Simulation of processes and

interactions

» GIS and spatial modeling: Describe locations and

patterns in the landscape

» Adding pattern to process

» Space is an important aspect of the processes in the landscape

» Describing development of processes and patterns

» PCRaster: a tool for developing spatial simulation

models

» WP 8.2: Link PCRaster to Extend

18/11/2010 3© 2010, VITO NV

WATER QUALITY

HYDROLOGY

AGRO

ECONOMICS

POLICY

PCRaster – PolFlow

Scheldt basin F-B-NL (1 km2)

ExtendSim

simulation 2008 -2038

(time step 1 year)

GIS

Integration ExtendSim- PCRaster

18/11/2010 4© 2010, VITO NV

Approach:

1. ExtendSim writes ASCII file for PCRaster

2. ExtendSim interface block starts PCRaster

3. PCRaster performs map-based calculation

4. PCRaster stores maps for ExtendSim

5. PCRaster deletes lock file, ExtendSim takes

over

18/11/2010 5© 2010, VITO NV

PCRaster: generic platform spatial modelling

• Raster-based GIS, suitable for distributed dynamic

modelling

• High-level scripting language

• Compatible with other systems due to use of door

ASCII script files and implementation in GDAL

• Simple to update/replace model and data

• Maps + map series

• Tables with temporal data

• Free of charge

• PCRaster Python library for advancrd GIS

functionalities and couping with other models / GIS

systems

18/11/2010 6© 2010, VITO NV

PCRaster model Scheldt (PolFlow)

after De Wit (1999)

Industry Households Agriculture Atm. Deposition Other

Direct sources (Dix) Soil surface surplus (SSSx)

Soil/Groundwater system

Indirect sources (IEx)

Rivir network

N load at location x (Lx)

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Extendsim – generic platform for dynamic simulation

• completely graphical design environment based on

hierarchical simulation models

• extendable, generic libraries of reusable model building

components (graphical or in C++ like language)

• large number of tools for “on-the-fly” visualisation,

calibration, data management etc.

• integration of internal and external databases

• coupling PCRaster (new SPICOSA deliverable)

• online support and low entry and maintenance costs

18/11/2010 12© 2010, VITO NV

transport &

processing of manure

manure

production

cattle farming

income effect

farm closures

distribution of free

area over sectors

change of cattle

stock and crop area

6 regions

8 farm types

5 animal types

10 crop types

(Sources: FADN- VLM-ILVO)

PCRaster

N concentration

Hemiksem

N deposition

norm (kg/ha/jr)

Farming module ExtendSim

manure norm

area

reference income

18/11/2010 13© 2010, VITO NV

Estuarine/marine module

18/11/2010 14© 2010, VITO NV

18/11/2010 15© 2010, VITO NV

animation of concentration via model building components

which can be place on map and communicate with PCRaster

18/11/2010 16© 2010, VITO NV

Input data PCRaster

Main data:• Environment: soil use, relief, precipitation – temperature, soil type, N-

deposition, hydrogeology, land use

• Emissions:

• Domestic: IE (not) connected per WWTP

• WWTP: purification efficiency – year of construction

• Industry: individual discharges

• Agriculture: number of animals – crops per province, fertilizer use –

manure processing per province

• Calibration: water quantity and water quality samples

• General trends 1940- 2000 (evolution cattle stocks, crops, industrial

discharges, WWTP efficiency, population size ...)

Sources: FEA, DGRNE, Agence de l’eau Artois Picardie, EUROSTAT,

HIC, VLM – manure database, KNMI, EMEP, ...

18/11/2010 17© 2010, VITO NV

Nitrogen concentration

0

5

10

15

20

25

30

0 5 10 15 20 25 30

Mo

de

lle

d c

on

ce

ntr

ati

on

(m

g/L)

Observed concentration (mg/l)

Dendermonde (Dender)

Zwijngaarde (Bovenschelde)

Gent (Leie)

Deinze (Leie)

Mechelen (Zenne)

Willebroek (Dijle)

Grobbendonk (Kleine Nete)

Lier (Grote + Kleine Nete)

Hemiksen (Benedenschelde)

Nederzwalm (Bovenschelde)

Linear (lijn)

18/11/2010 18© 2010, VITO NV

Initial state 2008:

18/11/2010 19© 2010, VITO NV

State 2038 with cattle stock reduction (2 % per year)

N concentration outflow (mg/l)

2008 - 2038

18/11/2010 20© 2010, VITO NV