The global gradient-based groundwater model framework G³M Documentation

Indices and tables

Quickstart: The model framework

The global gradient-based groundwater model framework G³M-f is an extesible model framework. Its main purpose is to be used as a main bilding block for the global groundwater mode G³M. G³M is a newly developed gradient-based groundwater model which adapts MODFLOW [@harbaugh2005modflow] principles for the globalscale. It is written in C++ and intended to be coupled to the global hydraulic model WaterGAP (, but can also be used for regional groundwater models and coupling to other hydraulic models. While it is intended to be used as a in memory coupled model it is also capable of running a standard standalone groundwater model.

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes.


clang >= 3.8 with openMP (currently gcc is not supported)
libboost >= 1.56


mkdir build
cd build
cmake ../

How to use

Center building stone for the framework is the GW_interface connecting any model with the groundwater code. Implement this interface if you want to couple your model to G³M-f or build a custom standalone application.

class GW_Interface {
        virtual ~GW_Interface() {}

        virtual void
        loadSettings() = 0;

        virtual void
        setupSimulation() = 0;

        virtual void
        writeData() = 0;

        virtual void
        simulate() = 0;

Write out data

Writeout of data is specified by a JSON file called out.json. If you want to add custom fields you can do so in src/DataProcessing/DataOutput.

  "output": {
    "StaticResult": [
        "name": "wtd",
        "type": "csv",
        "field": "DepthToWaterTable",
        "ID": "false",
        "position": "true"
    "InnerIteration": {
    "OuterIteration": {

Config model

In order to configure the model variables you can simply change the .json file. Allowing you to change the convergence criteria and the location for your input files.

  "config": {
    "model_config": {
      "nodes": "grid_simple.csv",
      "row_cols": "true",
      "stadystate": "true",
      "numberofnodes": 100,
      "threads": 1,
      "layers": 2,
      "confinement": [
      "cache": "false",
      "adaptivestepsize": "false",
      "boundarycondition": "SeaLevel",
      "sensitivity": "false"
    "numerics": {
      "solver": "PCG",
      "iterations": 500,
      "inner_itter": 10,
      "closingcrit": 1e-8,
      "headchange": 0.0001,
      "damping": "false",
      "min_damp": 0.01,
      "max_damp": 0.5,
      "stepsize": "daily"
  "input": {
    "data_config": {
      "k_from_lith": "true",
      "k_ocean_from_file": "false",
      "specificstorage_from_file": "false",
      "specificyield_from_file": "false",
      "k_river_from_file": "true",
      "aquifer_depth_from_file": "false",
      "initial_head_from_file": "true",
      "data_as_array": "false"
    "default_data": {
      "initial_head": 5,
      "K": 0.008,
      "oceanK": 800,
      "aquifer_thickness": [
      "anisotropy": 10,
      "specificyield": 0.15,
      "specificstorage": 0.000015
    "data": {
      "recharge": "recharge_simple.csv",
      "elevation": "elevation_simple.csv",
      "rivers": "rivers_simple.csv",
      "lithologie": "lithology_simple.csv",
      "river_conductance": "rivers_simple.csv",
      "initial_head": "heads_simple.csv"

Building a simple model

The following shows the code for a simple model loop running a steady-state model with daily timesteps.

void StandaloneRunner::simulate() {
    Simulation::Stepper stepper = Simulation::Stepper(_eq, Simulation::DAY, 1);
    for (Simulation::step step : stepper) {
        LOG(userinfo) << "Running a steady state step";
    DataProcessing::DataOutput::OutputManager("data/out_simple.json", sim).write();

Deployment in other models

Just implement the GW_interface and provide a DataReader.

Running the tests

Automated tests consits of gunit test which are compiled automatically with the attached cmake file. You can run them by executing the test executable.


Running a simple model

The following picture shows the conceptual example model: image0

After compilation run:


It will yield a depth to water table CSV file called wtd.csv for a simple model.

Built With


Please read for details on our code of conduct, and the process for submitting pull requests to us.


We use SemVer for versioning. For the versions available, see the tags on this repository.

Authors and Contributors

  • Robert Reinecke - Initial work


This project is licensed under the GNU General Public License - see the LICENSE file for details. Please note that the code contains a modified version of the Eigen3 library which is published under the MPL 2.0.


G³M framework

The following describes the classes and modules that G³M provides for building a groundwater model. The framework is separated into 6 packages:

  • DataProcessing
  • Logging
  • Misc
  • Model
  • Simulation
  • Solver

In order to implement any model the following interface has to be implemented:

class GlobalFlow::GW_Interface

Main interface to the groundwater model.

Interface to the groundwater simulation Implement me!

Subclassed by GlobalFlow::GlobalStandaloneRunner, GlobalFlow::StandaloneRunner

Public Functions

virtual GlobalFlow::GW_Interface~GW_Interface()
virtual void GlobalFlow::GW_InterfaceloadSettings() = 0

Read general simulation settings e.g. Options

virtual void GlobalFlow::GW_InterfacesetupSimulation() = 0

Do additional work required for a running simulation

virtual void GlobalFlow::GW_InterfacewriteData() = 0

How should the data be written out

void GlobalFlow::GW_InterfacesetupCallBack(Callback callback)

Set up the calback for model coupling Could be inefficient

  • callback: a callback function

virtual void GlobalFlow::GW_Interfacesimulate() = 0

Simulate/Run the model


Data processing is mainly concerned with providing utilities for reading in data (DataReader) or writing out data. New types of outputs can be implemented in the OutputFactory.

class GlobalFlow::DataReader

Interface that needs to be implemented for reading in required data for the model.

Subclassed by GlobalFlow::DataProcessing::GlobalDataReader, GlobalFlow::DataProcessing::SimpleDataReader

Public Functions

virtual GlobalFlow::DataReader~DataReader()

Virt destructor -> interface

void GlobalFlow::DataReaderinitNodes(NodeVector nodes)

Initialize internal ref to node vetor.

  • nodes: The vector of nodes

virtual void GlobalFlow::DataReaderreadData(Simulation::Options op) = 0

Entry point for reading simulation data.

This method needs to be implemented!
readData() is called by simulation at startup
  • op: Options object

template <class Fun>
void GlobalFlow::DataReaderloopFiles(std::string path, std::vector<std::string> files, Fun fun)

Generic method for looping through files inside a directory and applying a generic function.

  • path: the directory
  • files: a vector of files
  • fun: a function that is applied e.g. reading the data

int GlobalFlow::DataReadercheck(int globid)

Check weather id exists in the simulation.

i the position in the node vector
  • globid: Global identifier, can be different from position in node vector

template <class ProcessDataFunction>
void GlobalFlow::DataReaderreadTwoColumns(std::string path, ProcessDataFunction processData)

Read data from a two-column csv file and apply function to data.

  • path: to the csv file
  • processData: A processing function e.g. upscaling of data

void GlobalFlow::DataReaderreadZeroPointFiveToFiveMin(std::string path)

Creates a mapping of 0.5° ArcIDs to a list of contained 5’ GlobIDs.

  • path: to file

const std::unordered_map<int, std::vector<int>> &GlobalFlow::DataReadergetArcIDMapping()

provides acccess to mapping of different resolutions

<ARCID(0.5°), vector<GlobalID(5’)>>

const std::unordered_map<int, int> &GlobalFlow::DataReadergetGlobIDMapping()

provides access to mapping of data ids to position in node vector

<GlobalID, ID>

std::string GlobalFlow::DataReaderbuildDir(std::string path)

Builds a corect path from the base dir.

A path based on the base dir
  • path: The relative path from the config



enum GlobalFlow::DataProcessing::DataOutput::FieldType

What kind of data is collected Internal data fields that can be written out.



Internal position


Data ID


Area of the node


Hydraulic conductivity of the node


Elevation of the node


Slope in the node


Postion of the node in X and Y


Hydraulic head


The equilibrium head -> inital head


All in and outflows


Lateral flows based on the equilibrium head


Sum of all lateral flows of node


Only lateral out flows


Is there a wetland?


Is there a lake?


Surface water body head


GW recharge rate


Is there a dynamic river?


Velocity of lateral gw flow


Outflow to river


Inflow from river


Depth to groundwater table based on elevation


Conductance of riverbed


Conductance of drainbed


Conductance of wetland


Conductance of global wetland


Conductance of lake


Boundary condition outflow


Global wetland outflow


Wetland outflow


Lake outflow


Global wetland inflow


Wetland inflow


Lake inflow

class GlobalFlow::DataProcessing::DataOutput::FieldCollector

Iterates over internal fields and searches for data to be written out This is currently relatively inefficient

Public Types

using GlobalFlow::DataProcessing::DataOutput::FieldCollectorpos_v = std::vector<std::pair<double, double>>

Public Functions

GlobalFlow::DataProcessing::DataOutput::FieldCollectorFieldCollector(FieldType enumField)

The constructor

  • enumField: What data should be collected


Should not be used

pos_v GlobalFlow::DataProcessing::DataOutput::FieldCollectorgetPositions(Simulation::Simulation const &simulation)

get the positions of the nodes

A vector of positions
  • simulation: The simulation

std::vector<large_num> GlobalFlow::DataProcessing::DataOutput::FieldCollectorgetIds(Simulation::Simulation const &simulation)

Get the data ids of the nodes.

A vector of IDs
  • simulation: The simulation

template <typename T>
data_vector<T> GlobalFlow::DataProcessing::DataOutput::FieldCollectorget(Simulation::Simulation const &simulation)

Collects the data from simulation nodes

Relatively inefficient currently
The collected data
  • simulation: The simulation


template <typename T>
class GlobalFlow::DataProcessing::DataOutput::OutputInterface

Writes data to a file

Subclassed by GlobalFlow::DataProcessing::DataOutput::CSVOutput< T >, GlobalFlow::DataProcessing::DataOutput::GFS_JSONOutput< T >, GlobalFlow::DataProcessing::DataOutput::NETCDFOutput< T >

Public Functions

virtual GlobalFlow::DataProcessing::DataOutput::OutputInterface~OutputInterface()
virtual void GlobalFlow::DataProcessing::DataOutput::OutputInterfacewrite(path filePath, bool printID, bool printXY, std::vector<T> data, pos_v p, a_vector ids) = 0

Needs to be implemented

  • filePath:
  • printID: Bool
  • printXY: Bool
  • data: Data vector
  • p: Position vector

template <typename T>
class GlobalFlow::DataProcessing::DataOutput::CSVOutput

Writes data to a CSV file

Inherits from GlobalFlow::DataProcessing::DataOutput::OutputInterface< T >

Public Functions

void GlobalFlow::DataProcessing::DataOutput::CSVOutputwrite(path filePath, bool printID, bool printXY, std::vector<std::pair<double, double>> data, pos_v p, a_vector ids)
void GlobalFlow::DataProcessing::DataOutput::CSVOutputwrite(path filePath, bool printID, bool printXY, std::vector<bool> data, pos_v p, a_vector ids)
void GlobalFlow::DataProcessing::DataOutput::CSVOutputwrite(path filePath, bool printID, bool printXY, std::vector<double> data, pos_v p, a_vector ids)
void GlobalFlow::DataProcessing::DataOutput::CSVOutputwrite(path filePath, bool printID, bool printXY, std::vector<std::string> data, pos_v p, a_vector ids)
template <typename T>
class GlobalFlow::DataProcessing::DataOutput::NETCDFOutput

Writes data to a NETCDF file

Inherits from GlobalFlow::DataProcessing::DataOutput::OutputInterface< T >

Public Functions

void GlobalFlow::DataProcessing::DataOutput::NETCDFOutputwrite(path filePath, bool printID, bool printXY, std::vector<T> data, pos_v p, a_vector ids)

Needs to be implemented

  • filePath:
  • printID: Bool
  • printXY: Bool
  • data: Data vector
  • p: Position vector

template <typename T>
class GlobalFlow::DataProcessing::DataOutput::GFS_JSONOutput

Inherits from GlobalFlow::DataProcessing::DataOutput::OutputInterface< T >

Public Functions

void GlobalFlow::DataProcessing::DataOutput::GFS_JSONOutputwrite(path filePath, bool printID, bool printXY, std::vector<T> data, pos_v p, a_vector ids)

Needs to be implemented

  • filePath:
  • printID: Bool
  • printXY: Bool
  • data: Data vector
  • p: Position vector

template <typename T>
class GlobalFlow::DataProcessing::DataOutput::OutputFactory

Public Static Functions

static OutputInterface<T> *GlobalFlow::DataProcessing::DataOutput::OutputFactorygetOutput(OutputType type)


class GlobalFlow::DataProcessing::DataOutput::OutputManager

Public Functions

GlobalFlow::DataProcessing::DataOutput::OutputManagerOutputManager(path output_spec_path, Simulation::Simulation const &sim)
void GlobalFlow::DataProcessing::DataOutput::OutputManagerwrite()

Visits all registered output options and triggers write.


Provides readable logging facilities

class GlobalFlow::Logging::Logger

Inherits from GlobalFlow::Logging::LoggerInterface

Public Functions



Contains some deprecated helpers for iterating different grid solutions not documented here.


void NANChecker(const double &value, std::string message)
double roundValue(double valueToRound)
template <typename T, typename… Args>
std::unique_ptr<T> make_unique(Args&&... args)
template <class T>
Is<T> is(T d)
class NANInSolutionException

Inherits from exception

Private Functions

virtual const char *NANInSolutionExceptionwhat() const
class InfInSolutionException

Inherits from exception

Private Functions

virtual const char *InfInSolutionExceptionwhat() const
template <class T>
struct Is
#include <Helpers.hpp>

Public Functions

bool Isin(T a)
template <class Arg, class… Args>
bool Isin(Arg a, Args... args)

Public Members

T Isd_
class Position

Public Functions

PositionPosition(double lat, double lon)

Public Members

const double Positionlat = {0}
const double Positionlon = {0}



class GlobalFlow::Model::ExternalFlow

TODO add flow equation here

Public Functions

GlobalFlow::Model::ExternalFlowExternalFlow(int id, FlowType type, t_meter flowHead, t_s_meter_t cond, t_meter bottom)
GlobalFlow::Model::ExternalFlowExternalFlow(int id, t_vol_t recharge, FlowType type)


GlobalFlow::Model::ExternalFlowExternalFlow(int id, t_meter flowHead, t_meter bottom, t_vol_t evapotrans)

Constructor for Evapotranspiration.

  • id:
  • flowHead:
  • bottom:
  • evapotrans:

bool GlobalFlow::Model::ExternalFlowflowIsHeadDependant(t_meter head) const

Check if flow can be calculated on the right hand side

  • head: The current hydraulic head

t_s_meter_t GlobalFlow::Model::ExternalFlowgetP(t_meter head, t_meter eq_head, t_vol_t recharge, t_dim slope, t_vol_t eqFlow) const

The head dependant part of the external flow equation

  • head: The current hydraulic head
  • eq_head: The equilibrium head
  • recharge: The current recharge
  • slope:
  • eqFlow:

t_vol_t GlobalFlow::Model::ExternalFlowgetQ(t_meter head, t_meter eq_head, t_vol_t recharge, t_dim slope, t_vol_t eqFlow) const

The head independant part of the external flow equation

  • head:
  • eq_head:
  • recharge:
  • slope:
  • eqFlow:

FlowType GlobalFlow::Model::ExternalFlowgetType() const
t_meter GlobalFlow::Model::ExternalFlowgetBottom() const
t_vol_t GlobalFlow::Model::ExternalFlowgetRecharge() const
t_meter GlobalFlow::Model::ExternalFlowgetFlowHead() const
t_s_meter_t GlobalFlow::Model::ExternalFlowgetDyn(t_vol_t current_recharge, t_meter eq_head, t_meter head, t_vol_t eq_flow) const
t_meter GlobalFlow::Model::ExternalFlowgetRiverDiff(t_meter eqHead) const
t_s_meter_t GlobalFlow::Model::ExternalFlowgetConductance() const
int GlobalFlow::Model::ExternalFlowgetID() const
void GlobalFlow::Model::ExternalFlowsetMult(double mult)


class GlobalFlow::Model::FluidMechanics

Provides helper functions for conductance calulcations

Public Functions

t_meter GlobalFlow::Model::FluidMechanicscalcDeltaV(t_meter head, t_meter elevation, t_meter depth)

Used to calculate if a cell is dry

quantity<MeterSquaredPerTime> GlobalFlow::Model::FluidMechanicscalculateHarmonicMeanConductance(FlowInputHor flow)

Calculates the horizontal flow between two nodes.

A weighted conductance value for the flow between two nodes Calculates the harmonic mean conductance between two nodes. $C = 2 EdgeLenght_1 { (TR_1 TR_2)}{(TR_1 EdgeLenght_1 + TR_2 EdgeLenght_2)}$
  • flow: a touple of inputs about the aquifer

double GlobalFlow::Model::FluidMechanicssmoothFunction__NWT(t_meter elevation, t_meter verticalSize, t_meter head)

Simple smoother function to buffer iteration steps in NWT approach

smoothed head
  • elevation:
  • verticalSize:
  • head:

quantity<MeterSquaredPerTime> GlobalFlow::Model::FluidMechanicsgetHCOF(bool steadyState, quantity<Dimensionless> stepModifier, t_s_meter storageCapacity, t_s_meter_t P)

Get the coeffiecients for storage and P components

  • steadyState:
  • stepModifier:
  • storageCapacity:
  • P:

quantity<MeterSquaredPerTime> GlobalFlow::Model::FluidMechanicscalculateVerticalConductance(FlowInputVert flow)

Calculates the vertical flow between two nodes

the vertical conductance
  • flow: a touple of inputs about the aquifer

double GlobalFlow::Model::FluidMechanicsgetDerivate__NWT(t_meter elevation, t_meter verticalSize, t_meter head)

Calculate derivates for NWT approach

  • elevation:
  • verticalSize:
  • head:


class GlobalFlow::Model::NodeInterface

Interface defining required fields for a node. A node is the central comutational and spatial unit. A simulated area is seperated into a discrete raster of cells or nodes (seperate computational units which stay in contact to ech other). Is equal to ‘cell’.

Nodes can be of different physical property e.g. different size.

Subclassed by GlobalFlow::Model::StandardNode, GlobalFlow::Model::StaticHeadNode

Public Functions

GlobalFlow::Model::NodeInterfaceNodeInterface(NodeVector nodes, double lat, double lon, t_s_meter area, large_num ArcID, large_num ID, t_vel K, int stepModifier, double aquiferDepth, double anisotropy, double specificYield, double specificStorage, bool confined)

Constructor of abstract class NodeInterface.

  • nodes: Vector of all other existing nodes
  • lat: The latitude
  • lon: The Longitude
  • area: Area in m²
  • ArcID: Unique ARC-ID specified by Kassel
  • ID: Internal ID = Position in vector
  • K: Hydraulic conductivity in meter/day (default)
  • stepModifier: Modfies default step size of day (default=1)
  • aquiferDepth: Vertical size of the cell
  • anisotropy: Modifier for vertical conductivity based on horizontal
  • specificYield: Yield of storage for dewatered conditions
  • specificStorage: Specific storage - currently for confined and unconfined
  • confined: Is node in a confined layer

virtual GlobalFlow::Model::NodeInterface~NodeInterface()
large_num GlobalFlow::Model::NodeInterfacegetID()
void GlobalFlow::Model::NodeInterfacesetElevation(t_meter elevation)

Set elevation on top layer and propagate to lower layers.

  • elevation: The top elevation (e.g. from DEM)

void GlobalFlow::Model::NodeInterfacesetSlope(double slope_percent)

Set slope from data on all layers Slope input is in % but is required as absolut thus: slope = sloper_percent / 100.

  • slope:

void GlobalFlow::Model::NodeInterfacesetEfold(double efold)

Set e-folding factor from data on all layers.

  • e-fold:

void GlobalFlow::Model::NodeInterfacesetEqHead(t_meter wtd)

Calculated equilibrium groundwater-head from eq_wtd Assumes that if initialhead = false that the eq_head is also used as initial head.

  • head:

template <class HeadType>
FlowInputHor GlobalFlow::Model::NodeInterfacecreateDataTuple(map_itter got)
FlowInputVert GlobalFlow::Model::NodeInterfacecreateDataTuple(map_itter got)
template <class HeadType>
t_vol_t GlobalFlow::Model::NodeInterfacecalcLateralFlows(bool onlyOut)

Calculate the lateral groundwater flow to the neighbouring nodes Generic function used for calulating equlibrium and current step flow


t_vol_t GlobalFlow::Model::NodeInterfacegetEqFlow()

Calculate the equlibrium lateral flows

eq lateral flow

t_vol_t GlobalFlow::Model::NodeInterfacegetLateralFlows()

Get the current lateral flow


t_vol_t GlobalFlow::Model::NodeInterfacegetLateralOutFlows()

Get the current lateral out flows


bool GlobalFlow::Model::NodeInterfaceresetFloodingHead()

Cuts off all heads above surface elevation.

Should only be used in spinn up phase!
Bool if node was reset

void GlobalFlow::Model::NodeInterfacescaleRiverConduct()

Scales river conduct by 50%.

Should only be used in spinn up phase

void GlobalFlow::Model::NodeInterfaceupdateHeadChange()

Update the current head change (in comparison to last time step)

Should only be caled at end of timestep

void GlobalFlow::Model::NodeInterfaceinitHead_t0()
void GlobalFlow::Model::NodeInterfacesetHead_direct(double head)
t_vel GlobalFlow::Model::NodeInterfacegetK__pure()
t_vel GlobalFlow::Model::NodeInterfacegetK()

Get hydraulic conductivity.

hydraulic conductivity (scaled by e-folding)

t_vel GlobalFlow::Model::NodeInterfacegetK_vertical()

Get hydraulic vertical conductivity.

hydraulic conductivity scaled by anisotropy (scaled by e-folding)

void GlobalFlow::Model::NodeInterfacesetK(t_vel conduct)

Modify hydraulic conductivity (applied to all layers below)

  • New: conductivity (if e-folding enabled scaled on layers)

void GlobalFlow::Model::NodeInterfacesetK_direct(t_vel conduct)

Modify hydraulic conductivity (no e-folding, no layers)

  • New: conductivity

t_c_meter GlobalFlow::Model::NodeInterfacegetOUT()

Get all outflow since simulation start.

t_c_meter GlobalFlow::Model::NodeInterfacegetIN()

Get all inflow since simulation start.

void GlobalFlow::Model::NodeInterfacetoogleStadyState(bool onOFF)

Toogle steady state simulation.

  • onOFF: true=on Turns all storage equations to zero with no timesteps

void GlobalFlow::Model::NodeInterfaceupdateStepSize(double mod)
t_s_meter GlobalFlow::Model::NodeInterfacegetStorageCapacity()

Storage capacity based on yield or specific storage.

Potential flow budget when multiplied by head change Uses an 0.001m epsilon to determine if a water-table condition is present. If the layer is confined or not in water-table condition returns primary capacity.

ExternalFlow &GlobalFlow::Model::NodeInterfacegetExternalFlowByName(FlowType type)

Get and external flow by its FlowType.

Ref to external flow
  • type: The flow type
  • OutOfRangeException:

t_vol_t GlobalFlow::Model::NodeInterfacegetExternalFlowVolumeByName(FlowType type)

Get and external flow volume by its FlowType.

Flow volume
  • type: The flow type

t_vol_t GlobalFlow::Model::NodeInterfacegetTotalStorageFlow()

Get flow budget based on head change.

Flow volume Note: Water entering storage is treated as an outflow (-), that is a loss of water from the flow system while water released from storage is treated as inflow (+), that is a source of water to the flow system

t_vol_t GlobalFlow::Model::NodeInterfacecalculateExternalFlowVolume(const ExternalFlow &flow)

Get flow budget of a specific external flows.

Flow volume Note: Water entering storage is treated as an outflow (-), that is a loss of water from the flow system while water released from storage is treated as inflow (+), that is a source of water to the flow system
  • &flow: A external flow

t_vol_t GlobalFlow::Model::NodeInterfacecalculateDewateredFlow()

Caluclate dewatered flow.

Flow volume per time If a cell is dewatered but below a saturated or partly saturated cell: this calculates the needed additional exchange volume

t_vol_t GlobalFlow::Model::NodeInterfacegetCurrentIN()

Get all current IN flow.

Flow volume

t_vol_t GlobalFlow::Model::NodeInterfacegetCurrentOUT()

Get all current OUT flow.

Flow volume

void GlobalFlow::Model::NodeInterfacesaveMassBalance()

Tell cell to save its flow budget.

void GlobalFlow::Model::NodeInterfacesetNeighbour(large_num ID, NeighbourPosition neighbour)

Add a neighbour.

  • ID: The internal ID and position in vector
  • neighbour: The position relative to the cell

int GlobalFlow::Model::NodeInterfacegetNumofNeighbours()
NodeInterface *GlobalFlow::Model::NodeInterfacegetNeighbour(NeighbourPosition neighbour)

Get a neighbour by position.

Pointer to cell object
  • neighbour: The position relative to the cell

int GlobalFlow::Model::NodeInterfaceaddExternalFlow(FlowType type, t_meter flowHead, double cond, t_meter bottom)

At an external flow to the cell.

Number assigned by cell to flow
  • type: The flow type
  • flowHead: The flow head
  • cond: The conductance
  • bottom: The bottom of the flow (e.g river bottom)

void GlobalFlow::Model::NodeInterfaceremoveExternalFlow(FlowType type)

Remove an external flow to the cell by id.

  • ID: The flow id

bool GlobalFlow::Model::NodeInterfacehasTypeOfExternalFlow(FlowType type)

Check for an external flow by type.

  • type: The flow type

void GlobalFlow::Model::NodeInterfaceupdateUniqueFlow(double amount, FlowType flow = RECHARGE)

Updates GW recharge Curently assumes only one recharge as external flow!

  • amount: The new flow amount

void GlobalFlow::Model::NodeInterfacescaleDynamicRivers(double mult)

Scale dyn rivers for sensitivity

  • mult:

void GlobalFlow::Model::NodeInterfaceupdateExternalFlowConduct(double amount, FlowType type)

Update wetlands, lakes.

  • amount:
  • type:

void GlobalFlow::Model::NodeInterfaceupdateExternalFlowFlowHead(double amount, FlowType type)

Multiplies flow head for Sensitivity An. wetlands, lakes, rivers.

  • amount:
  • type:

void GlobalFlow::Model::NodeInterfaceupdateLakeBottoms(double amount)

Update lake bottoms Used for sensitivity.

  • amount:

bool GlobalFlow::Model::NodeInterfacehasRiver()

Check for type river.


bool GlobalFlow::Model::NodeInterfacehasOcean()

Check for type ocean.


t_vol_t GlobalFlow::Model::NodeInterfacegetQ()

Get Q part of flow equations.

volume over time

t_s_meter_t GlobalFlow::Model::NodeInterfacegetP()

Get P part of flow equations.

volume over time

t_vol_t GlobalFlow::Model::NodeInterfacecalculateNotHeadDependandFlows()

Get flow which is not groundwater head dependent.

volume over time Flow can be added to constant flows on right side of the equations If head is above river bottom for example

std::unordered_map<large_num, t_s_meter_t> GlobalFlow::Model::NodeInterfacegetJacobian()

The jacobian entry for the cell (NWT approach)

map <CellID,Conductance>

std::unordered_map<large_num, t_s_meter_t> GlobalFlow::Model::NodeInterfacegetConductance()

The matrix entry for the cell.

map <CellID,Conductance> The left hand side of the equation

t_vol_t GlobalFlow::Model::NodeInterfacegetRHS()

The right hand side of the equation.

volume per time

double GlobalFlow::Model::NodeInterfacegetRHS__NWT()

The right hand side of the equation (NWT)

volume per time

void GlobalFlow::Model::NodeInterfacesetHead(t_meter head)
t_meter GlobalFlow::Model::NodeInterfacecalcInitialHead(t_meter initialParam)
bool GlobalFlow::Model::NodeInterfaceisStaticNode()
PhysicalProperties &GlobalFlow::Model::NodeInterfacegetProperties()
void GlobalFlow::Model::NodeInterfaceenableNWT()
template <typename CompareFunction>
t_vol_t GlobalFlow::Model::NodeInterfacegetNonStorageFlow(CompareFunction compare)

Caluclate non storage related in and out flow.

Flow volume

quantity<Velocity> GlobalFlow::Model::NodeInterfacegetVelocity(map_itter pos)

Calculate the lateral flow velocity

  • pos:

std::pair<double, double> GlobalFlow::Model::NodeInterfacegetVelocityVector()

Calculate flow velocity for flow tracking Vx and Vy represent the flow velocity in x and y direction. A negative value represents a flow in the oposite direction.

Velocity vector (x,y)

Public Members

bool GlobalFlow::Model::NodeInterfacecached = {false}

Calculated equilibrium flow to neighbouring cells Static thus calculated only once.

Depends on: K in cell and eq_head in all 6 neighbours

t_vol_t GlobalFlow::Model::NodeInterfaceeq_flow = {0 * si::cubic_meter / day}
class GlobalFlow::Model::NodeInterfaceNodeNotFoundException

Inherits from exception



class GlobalFlow::Simulation::Options

Reads simulation options from a JSON file Defines getters and setters for options

Public Types

enum GlobalFlow::Simulation::OptionsBoundaryCondition



Public Functions

void GlobalFlow::Simulation::OptionssetClosingCrit(double crit)
void GlobalFlow::Simulation::OptionssetDamping(bool set)
bool GlobalFlow::Simulation::OptionsisDampingEnabled()
double GlobalFlow::Simulation::OptionsgetMinDamp()
double GlobalFlow::Simulation::OptionsgetMaxDamp()
double GlobalFlow::Simulation::OptionsgetMaxHeadChange()
bool GlobalFlow::Simulation::OptionsisConfined(int layer)
vector<bool> GlobalFlow::Simulation::OptionsgetConfinements()
BoundaryCondition GlobalFlow::Simulation::OptionsgetBoundaryCondition()
bool GlobalFlow::Simulation::OptionsisSensitivity()
bool GlobalFlow::Simulation::OptionsisKFromLith()
bool GlobalFlow::Simulation::OptionsisKOceanFile()
bool GlobalFlow::Simulation::OptionsisSpecificStorageFile()
bool GlobalFlow::Simulation::OptionsisSpecificYieldFile()
bool GlobalFlow::Simulation::OptionsisKRiverFile()
bool GlobalFlow::Simulation::OptionsisAquiferDepthDile()
string GlobalFlow::Simulation::OptionsgetKDir()
string GlobalFlow::Simulation::OptionsgetKRiverDir()
string GlobalFlow::Simulation::OptionsgetKOceanDir()
string GlobalFlow::Simulation::OptionsgetSSDir()
string GlobalFlow::Simulation::OptionsgetSYDir()
string GlobalFlow::Simulation::OptionsgetAQDepthDir()
bool GlobalFlow::Simulation::OptionsisRowCol()
int GlobalFlow::Simulation::OptionsgetInnerItter()
long GlobalFlow::Simulation::OptionsgetNumberOfNodes()
int GlobalFlow::Simulation::OptionsgetNumberOfLayers()
int GlobalFlow::Simulation::OptionsgetMaxIterations()
double GlobalFlow::Simulation::OptionsgetConverganceCriteria()
string GlobalFlow::Simulation::OptionsgetSolverName()
bool GlobalFlow::Simulation::OptionsdisableDryCells()
string GlobalFlow::Simulation::OptionsgetNodesDir()
string GlobalFlow::Simulation::OptionsgetElevation()
string GlobalFlow::Simulation::OptionsgetEfolding()
string GlobalFlow::Simulation::OptionsgetEqWTD()
string GlobalFlow::Simulation::OptionsgetSlope()
string GlobalFlow::Simulation::OptionsgetBlue()
vector<string> GlobalFlow::Simulation::OptionsgetElevation_A()
vector<string> GlobalFlow::Simulation::OptionsgetEfolding_a()
vector<string> GlobalFlow::Simulation::OptionsgetEqWTD_a()
vector<string> GlobalFlow::Simulation::OptionsgetSlope_a()
vector<string> GlobalFlow::Simulation::OptionsgetBlue_a()
string GlobalFlow::Simulation::OptionsgetRecharge()
string GlobalFlow::Simulation::OptionsgetLithology()
string GlobalFlow::Simulation::OptionsgetRivers()
string GlobalFlow::Simulation::OptionsgetGlobalLakes()
string GlobalFlow::Simulation::OptionsgetGlobalWetlands()
string GlobalFlow::Simulation::OptionsgetLocalLakes()
string GlobalFlow::Simulation::OptionsgetLocalWetlands()
string GlobalFlow::Simulation::OptionsgetMapping()
int GlobalFlow::Simulation::OptionsgetThreads()
const bool GlobalFlow::Simulation::OptionsadaptiveStepsizeEnabled()
const int GlobalFlow::Simulation::OptionsgetStepsizeModifier()
bool GlobalFlow::Simulation::OptionscacheEnabled()
int GlobalFlow::Simulation::OptionsgetInitialHead()
double GlobalFlow::Simulation::OptionsgetInitialK()
double GlobalFlow::Simulation::OptionsgetOceanConduct()
vector<int> GlobalFlow::Simulation::OptionsgetAquiferDepth()
double GlobalFlow::Simulation::OptionsgetAnisotropy()
double GlobalFlow::Simulation::OptionsgetSpecificYield()
double GlobalFlow::Simulation::OptionsgetSpecificStorage()
void GlobalFlow::Simulation::Optionsload(const std::string &filename)
void GlobalFlow::Simulation::Optionssave(const std::string &filename)


class GlobalFlow::Simulation::Simulation

The simulation class which holds the equation, options and data instance Further contains methods for calulating the mass balance and sensitivity methods TODO: Clean me up!

Public Types

enum GlobalFlow::Simulation::SimulationFlows


GlobalFlow::Simulation::SimulationRIVERS = 1

Public Functions

GlobalFlow::Simulation::SimulationSimulation(Options op, DataReader *reader)
Solver::Equation *GlobalFlow::Simulation::SimulationgetEquation()
void GlobalFlow::Simulation::Simulationsave()
std::string GlobalFlow::Simulation::SimulationNodeInfosByID(unsigned long nodeID)

Get basic node information by its id

A string of information
  • nodeID:

template <int FieldNum>
std::string GlobalFlow::Simulation::SimulationgetFlowSumByIDs(std::array<int, FieldNum> ids)

Get budget per node

  • ids:

std::string GlobalFlow::Simulation::SimulationNodeFlowsByID(unsigned long nodeID)

Return all external flows seperatly

template <class FunOut, class FunIn>
MassError GlobalFlow::Simulation::SimulationgetError(FunOut fun1, FunIn fun2)

Calulate the mass error

  • fun1: Function to get OutFlow
  • fun2: Function to get InFlow

MassError GlobalFlow::Simulation::SimulationgetMassError()

Get the total mass balance


MassError GlobalFlow::Simulation::SimulationgetCurrentMassError()

Get the mass balance for the current step


double GlobalFlow::Simulation::SimulationgetLossToRivers()

Get the flow lost to external flows


template <class Fun>
MassError GlobalFlow::Simulation::SimulationgetError(Fun fun)

Decide if its an In or Outflow

  • fun:

string GlobalFlow::Simulation::SimulationgetFlowByName(Flows flow)

Helper function for printing the mass balance for each flow

  • flow:

void GlobalFlow::Simulation::SimulationprintMassBalances()

Prints all mass balances

const double GlobalFlow::Simulation::SimulationcalcRecharge(const double recharge, const double &area)
DataReader *GlobalFlow::Simulation::SimulationgetDataReader()
NodeVector &GlobalFlow::Simulation::SimulationgetNodes()
void GlobalFlow::Simulation::SimulationscaleByIds(vector<int> ids, string field, double mult)
template <class Fun, class ChangeFunction>
void GlobalFlow::Simulation::SimulationscaleByFunction(Fun fun, ChangeFunction apply)
template <class Fun>
void GlobalFlow::Simulation::SimulationscaleByFunction(Fun fun, string field, double mult)

Helper function for sensitivity

  • fun:
  • field:
  • mult:

std::vector<int> GlobalFlow::Simulation::SimulationreadMultipliersPerID(string path)

Expects a file with global_ID, parameter, multiplier Multiplier is log scaled

a vector of node-ids (used to write out heads in correct order)
  • path: to csv file

void GlobalFlow::Simulation::SimulationreadMultipliers(string path)

Scale values for sensitivity analysis

  • path:

void GlobalFlow::Simulation::SimulationwriteResiduals(string path)

Get the residuals of the current iteration

  • path:

template <typename DataArray>
void GlobalFlow::Simulation::SimulationupdateGWRechargeFromWaterGAP(DataArray field, short month, int numberOfGridCells)

Coupling function for WaterGAP

Under development
  • field:
  • month:
  • numberOfGridCells:

Public Members

NodeVector GlobalFlow::Simulation::Simulationnodes


class GlobalFlow::Simulation::Stepper

holding the simulation iterator

Inherits from GlobalFlow::Simulation::AbstractStepper

Public Functions

GlobalFlow::Simulation::StepperStepper(Solver::Equation *eq, const TimeFrame time, const size_t steps)
virtual Solver::Equation *GlobalFlow::Simulation::Stepperget(int col) const
Iterator GlobalFlow::Simulation::Stepperbegin() const
Iterator GlobalFlow::Simulation::Stepperend() const
const TimeFrame GlobalFlow::Simulation::SteppergetStepSize()



class GlobalFlow::Solver::Equation

finite difference equation Should only be accessed through the stepper

Public Types

typedef Eigen::MatrixXd::Scalar GlobalFlow::Solver::EquationScalar
typedef Matrix<Scalar, Dynamic, 1> GlobalFlow::Solver::EquationVectorType

Public Functions

GlobalFlow::Solver::EquationEquation(large_num numberOfNodes, NodeVector nodes, Simulation::Options options)
void GlobalFlow::Solver::Equationsolve()

Solve the current iteration step

Solve Equation

int GlobalFlow::Solver::EquationgetItter()

The number of iterations

double GlobalFlow::Solver::EquationgetError()

The current residual error

GlobalFlow::Solver::EquationEquation(const Equation&)
Equation &GlobalFlow::Solver::Equationoperator=(const Equation&)
VectorXd GlobalFlow::Solver::EquationgetResults()
bool GlobalFlow::Solver::EquationtoogleSteadyState()

Toogle the steady-state in all nodes


void GlobalFlow::Solver::EquationupdateStepSize(size_t mod)

Set the correct stepsize (default is DAY)

  • mod:

VectorType GlobalFlow::Solver::EquationgetResiduals()
void GlobalFlow::Solver::EquationupdateClosingCrit(double crit)


std::ostream &operator<<(std::ostream &os, Equation &eq)

Helper to write out current residuals

  • os:
  • eq:

AdaptiveDamping .. doxygenclass:: GlobalFlow::Solver::AdaptiveDamping

G³M steady-state model

The implementation of the steady state-model along with the input data e.g. yearly average recharge, consists of two classes:
  1. The main class which implements the Groundwater Interface
  2. A data reader implementing the Data Reader Interface, which specifies how to read in the data


class GlobalFlow::GlobalStandaloneRunner

A standalone global steady-state groundwater model.

Inherits from GlobalFlow::GW_Interface

Public Functions


Default constructor.

void GlobalFlow::GlobalStandaloneRunnerloadSettings()

Read general simulation settings e.g. Options

void GlobalFlow::GlobalStandaloneRunnersetupSimulation()

Do additional work required for a running simulation

void GlobalFlow::GlobalStandaloneRunnersimulate()

Simulate/Run the model

void GlobalFlow::GlobalStandaloneRunnerwriteData()

How should the data be written out

Private Functions

set<int> GlobalFlow::GlobalStandaloneRunnergetMapping()

Helper function for arcID mappings.

a set of arcIDs

Private Members

Solver::Equation *GlobalFlow::GlobalStandaloneRunner_eq
Simulation::Options GlobalFlow::GlobalStandaloneRunnerop
Simulation::Simulation GlobalFlow::GlobalStandaloneRunnersim
DataProcessing::GlobalDataReader *GlobalFlow::GlobalStandaloneRunnerreader

Global Data Reader

class GlobalFlow::DataProcessing::GlobalDataReader

This class provides methods for loading large input data The paths are specified in the json file in in the data folder.

Inherits from GlobalFlow::DataReader

Public Types

using GlobalFlow::DataProcessing::GlobalDataReaderMatrix = std::vector<std::vector<T>>

Public Functions

GlobalFlow::DataProcessing::GlobalDataReaderGlobalDataReader(int step)


  • step: Daily, Monthly, …

void GlobalFlow::DataProcessing::GlobalDataReaderreadData(Simulation::Options op)

Entry point for reading simulation data.

This method needs to be implemented!
readData() is called by simulation at startup
  • op: Options object

Matrix<int> GlobalFlow::DataProcessing::GlobalDataReaderreadGrid(NodeVector nodes, std::string path, int numberOfNodes, double defaultK, double aquiferDepth, double anisotropy, double specificYield, double specificStorage, bool confined)

Method for already gridded defintions - that is structered in row and column.

Structured in row, col
A Matrix of computational nodes
  • nodes: Vector of nodes
  • path: Path to read definitions from
  • numberOfNodes: The number of expected computation nodes
  • defaultK: The default conductivity
  • aquiferDepth: The default depth per cell
  • anisotropy: The default relation of vertical and horizontal conductivity
  • specificYield: The default specific yield
  • specificStorage: The default specific storage
  • confined: If node is part of a confined layer?

int GlobalFlow::DataProcessing::GlobalDataReaderreadLandMask(NodeVector nodes, std::string path, int numberOfNodes, double defaultK, double aquiferDepth, double anisotropy, double specificYield, double specificStorage, bool confined)

Initial readin of node definitions - without col and row.

Without col and row Reads a csv file with x and y coordinates for predefined grid of cells
  • nodes: Vector of nodes
  • path: Path to read definitions from
  • numberOfNodes: The number of expected computation nodes
  • defaultK: The default conductivity
  • aquiferDepth: The default depth per cell
  • anisotropy: The default relation of vertical and horizontal conductivity
  • specificYield: The default specific yield
  • specificStorage: The default specific storage
  • confined: If node is part of a confined layer?

void GlobalFlow::DataProcessing::GlobalDataReaderreadOceanK(std::string path)

Read in a custom defintion for the ocean boundary.

  • path: Where to read from

void GlobalFlow::DataProcessing::GlobalDataReaderreadRiver(std::string path)

Read in a custom river defintion file Structured as: global_ID, Head, Bottom, Conduct.

  • path: Where to read the file from

void GlobalFlow::DataProcessing::GlobalDataReaderreadElevation(std::string path, std::vector<std::string> files)

Read elevation data from a specified path Used for multiple files.

!Uses setElevation() function. Should only be called after all layers are build as it affects layers below
  • path: Where to read the file from
  • files: If different files for different regions are given

void GlobalFlow::DataProcessing::GlobalDataReaderreadElevation(std::string path)

Read elevation data from a specified path.

!Uses setElevation() function. Should only be called after all layers are build as it affects layers below
  • path: Where to read the file from

void GlobalFlow::DataProcessing::GlobalDataReaderreadSlope(std::string path, std::vector<std::string> files)

Read slope data from a specified path.

  • path: Where to read the file from
  • files: If different files for different regions are given

void GlobalFlow::DataProcessing::GlobalDataReaderreadEfold(std::string path, std::vector<std::string> files)

Read e-folding data from a specified path.

  • path: Where to read the file from
  • files: If different files for different regions are given

void GlobalFlow::DataProcessing::GlobalDataReaderreadEqWTD(std::string path)

Read equilibrium water-table information used for the dynamic river computation.

  • path: Where to read the file from

void GlobalFlow::DataProcessing::GlobalDataReaderreadGWRecharge(std::string path)

Read difuse gw-recharge.

  • path: Where to read the file from

void GlobalFlow::DataProcessing::GlobalDataReaderreadConduct(std::string path)

Read cell conductance defintion.

currently does check if val > 10 m/day
  • path: Where to read the file from

template <typename ConversionFunction>
void GlobalFlow::DataProcessing::GlobalDataReaderreadGWRechargeMapping(std::string path, ConversionFunction convertToRate)

Read difuse groundwater recharge from a file and map the value using a conversion function.

Template Parameters
  • ConversionFunction: Allows the dynamic recalcualtion of recharge base don cell area
  • path: Where to read the file from
  • convertToRate: The conversion function

std::unordered_map<int, std::array<double, 3>> GlobalFlow::DataProcessing::GlobalDataReadercalulateRiverStage(std::string path)

Helper function for.

a map of bankfull depth, stream width, and lenght
  • path: Where to read the file from

void GlobalFlow::DataProcessing::GlobalDataReaderreadBlueCells(std::string file, std::unordered_map<int, std::array<double, 3>> bankfull_depth)

Reads in river defintions based on a specific elevation data-set.

  • file: to read from
  • bankfull_depth: A map with addition information

void GlobalFlow::DataProcessing::GlobalDataReaderreadLakesandWetlands(std::string pathGlobalLakes, std::string pathGlobalWetlands, std::string pathLokalLakes, std::string pathLokalWetlands)

Reads in lakes and wetlands defintions based on Lehner and Döll.

  • pathGlobalLakes:
  • pathGlobalWetlands:
  • pathLokalLakes:
  • pathLokalWetlands:

void GlobalFlow::DataProcessing::GlobalDataReaderaddEvapo()

Adds an evapotraspiration module to cells.

void GlobalFlow::DataProcessing::GlobalDataReaderaddDrainageHack()

A drainage component similar to de Graaf 2014.


Version 3, 29 June 2007

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e) Declining to grant rights under trademark law for use of some trade names, trademarks, or service marks; or

f) Requiring indemnification of licensors and authors of that material by anyone who conveys the material (or modified versions of it) with contractual assumptions of liability to the recipient, for any liability that these contractual assumptions directly impose on those licensors and authors.

All other non-permissive additional terms are considered “further restrictions” within the meaning of section 10. If the Program as you received it, or any part of it, contains a notice stating that it is governed by this License along with a term that is a further restriction, you may remove that term. If a license document contains a further restriction but permits relicensing or conveying under this License, you may add to a covered work material governed by the terms of that license document, provided that the further restriction does not survive such relicensing or conveying.

If you add terms to a covered work in accord with this section, you must place, in the relevant source files, a statement of the additional terms that apply to those files, or a notice indicating where to find the applicable terms.

Additional terms, permissive or non-permissive, may be stated in the form of a separately written license, or stated as exceptions; the above requirements apply either way.

  1. Termination.

You may not propagate or modify a covered work except as expressly provided under this License. Any attempt otherwise to propagate or modify it is void, and will automatically terminate your rights under this License (including any patent licenses granted under the third paragraph of section 11).

However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation.

Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice.

Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, you do not qualify to receive new licenses for the same material under section 10.

  1. Acceptance Not Required for Having Copies.

You are not required to accept this License in order to receive or run a copy of the Program. Ancillary propagation of a covered work occurring solely as a consequence of using peer-to-peer transmission to receive a copy likewise does not require acceptance. However, nothing other than this License grants you permission to propagate or modify any covered work. These actions infringe copyright if you do not accept this License. Therefore, by modifying or propagating a covered work, you indicate your acceptance of this License to do so.

  1. Automatic Licensing of Downstream Recipients.

Each time you convey a covered work, the recipient automatically receives a license from the original licensors, to run, modify and propagate that work, subject to this License. You are not responsible for enforcing compliance by third parties with this License.

An “entity transaction” is a transaction transferring control of an organization, or substantially all assets of one, or subdividing an organization, or merging organizations. If propagation of a covered work results from an entity transaction, each party to that transaction who receives a copy of the work also receives whatever licenses to the work the party’s predecessor in interest had or could give under the previous paragraph, plus a right to possession of the Corresponding Source of the work from the predecessor in interest, if the predecessor has it or can get it with reasonable efforts.

You may not impose any further restrictions on the exercise of the rights granted or affirmed under this License. For example, you may not impose a license fee, royalty, or other charge for exercise of rights granted under this License, and you may not initiate litigation (including a cross-claim or counterclaim in a lawsuit) alleging that any patent claim is infringed by making, using, selling, offering for sale, or importing the Program or any portion of it.

  1. Patents.

A “contributor” is a copyright holder who authorizes use under this License of the Program or a work on which the Program is based. The work thus licensed is called the contributor’s “contributor version”.

A contributor’s “essential patent claims” are all patent claims owned or controlled by the contributor, whether already acquired or hereafter acquired, that would be infringed by some manner, permitted by this License, of making, using, or selling its contributor version, but do not include claims that would be infringed only as a consequence of further modification of the contributor version. For purposes of this definition, “control” includes the right to grant patent sublicenses in a manner consistent with the requirements of this License.

Each contributor grants you a non-exclusive, worldwide, royalty-free patent license under the contributor’s essential patent claims, to make, use, sell, offer for sale, import and otherwise run, modify and propagate the contents of its contributor version.

In the following three paragraphs, a “patent license” is any express agreement or commitment, however denominated, not to enforce a patent (such as an express permission to practice a patent or covenant not to sue for patent infringement). To “grant” such a patent license to a party means to make such an agreement or commitment not to enforce a patent against the party.

If you convey a covered work, knowingly relying on a patent license, and the Corresponding Source of the work is not available for anyone to copy, free of charge and under the terms of this License, through a publicly available network server or other readily accessible means, then you must either (1) cause the Corresponding Source to be so available, or (2) arrange to deprive yourself of the benefit of the patent license for this particular work, or (3) arrange, in a manner consistent with the requirements of this License, to extend the patent license to downstream recipients. “Knowingly relying” means you have actual knowledge that, but for the patent license, your conveying the covered work in a country, or your recipient’s use of the covered work in a country, would infringe one or more identifiable patents in that country that you have reason to believe are valid.

If, pursuant to or in connection with a single transaction or arrangement, you convey, or propagate by procuring conveyance of, a covered work, and grant a patent license to some of the parties receiving the covered work authorizing them to use, propagate, modify or convey a specific copy of the covered work, then the patent license you grant is automatically extended to all recipients of the covered work and works based on it.

A patent license is “discriminatory” if it does not include within the scope of its coverage, prohibits the exercise of, or is conditioned on the non-exercise of one or more of the rights that are specifically granted under this License. You may not convey a covered work if you are a party to an arrangement with a third party that is in the business of distributing software, under which you make payment to the third party based on the extent of your activity of conveying the work, and under which the third party grants, to any of the parties who would receive the covered work from you, a discriminatory patent license (a) in connection with copies of the covered work conveyed by you (or copies made from those copies), or (b) primarily for and in connection with specific products or compilations that contain the covered work, unless you entered into that arrangement, or that patent license was granted, prior to 28 March 2007.

Nothing in this License shall be construed as excluding or limiting any implied license or other defenses to infringement that may otherwise be available to you under applicable patent law.

  1. No Surrender of Others’ Freedom.

If conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot convey a covered work so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not convey it at all. For example, if you agree to terms that obligate you to collect a royalty for further conveying from those to whom you convey the Program, the only way you could satisfy both those terms and this License would be to refrain entirely from conveying the Program.

  1. Use with the GNU Affero General Public License.

Notwithstanding any other provision of this License, you have permission to link or combine any covered work with a work licensed under version 3 of the GNU Affero General Public License into a single combined work, and to convey the resulting work. The terms of this License will continue to apply to the part which is the covered work, but the special requirements of the GNU Affero General Public License, section 13, concerning interaction through a network will apply to the combination as such.

  1. Revised Versions of this License.

The Free Software Foundation may publish revised and/or new versions of the GNU General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns.

Each version is given a distinguishing version number. If the Program specifies that a certain numbered version of the GNU General Public License “or any later version” applies to it, you have the option of following the terms and conditions either of that numbered version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of the GNU General Public License, you may choose any version ever published by the Free Software Foundation.

If the Program specifies that a proxy can decide which future versions of the GNU General Public License can be used, that proxy’s public statement of acceptance of a version permanently authorizes you to choose that version for the Program.

Later license versions may give you additional or different permissions. However, no additional obligations are imposed on any author or copyright holder as a result of your choosing to follow a later version.

  1. Disclaimer of Warranty.


  1. Limitation of Liability.


  1. Interpretation of Sections 15 and 16.

If the disclaimer of warranty and limitation of liability provided above cannot be given local legal effect according to their terms, reviewing courts shall apply local law that most closely approximates an absolute waiver of all civil liability in connection with the Program, unless a warranty or assumption of liability accompanies a copy of the Program in return for a fee.


How to Apply These Terms to Your New Programs

If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms.

To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively state the exclusion of warranty; and each file should have at least the “copyright” line and a pointer to where the full notice is found.

<one line to give the program’s name and a brief idea of what it does.> Copyright (C) <year> <name of author>

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see <>.

Also add information on how to contact you by electronic and paper mail.

If the program does terminal interaction, make it output a short notice like this when it starts in an interactive mode:

<program> Copyright (C) <year> <name of author> This program comes with ABSOLUTELY NO WARRANTY; for details type show w. This is free software, and you are welcome to redistribute it under certain conditions; type show c for details.

The hypothetical commands show w and show c should show the appropriate parts of the General Public License. Of course, your program’s commands might be different; for a GUI interface, you would use an “about box”.

You should also get your employer (if you work as a programmer) or school, if any, to sign a “copyright disclaimer” for the program, if necessary. For more information on this, and how to apply and follow the GNU GPL, see

The GNU General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License. But first, please read