D-Infinity Upslope Dependence

Title  D-Infinity Upslope Dependence

Summary

The D-Infinity Upslope Dependence tool quantifies the amount each grid cell in the domain contributes to a destination set of grid cells. D-Infinity flow directions proportion flow from each grid cell between multiple downslope grid cells. Following this flow field downslope the amount of flow originating at each grid cell that reaches the destination zone is defined. Upslope influence is evaluated using a downslope recursion, examining grid cells downslope from each grid cell, so that the map produced identifies the area upslope where flow through the destination zone originates, or the area it depends on, for its flow.


Usage

Command Prompt Syntax:

mpiexec -n <number of processes> DinfUpDependence -ang <angfile> -dg <dgfile> -dep <depfile>

angfile: Dinf flow direction input file

dgfile: disturbance grid input file

depfile: flow dependence output file


Syntax

DInfUpslopeDependence (Input_D-Infinity_Flow_Direction_Grid, Input_Destination_Grid, Input_Number_of_Processes, Output_Upslope_Dependence_Grid)

Parameter Explanation Data Type
Input_D-Infinity_Flow_Direction_Grid Dialog Reference

A grid giving flow direction by the D-Infinity method where the flow direction angle is determined as the direction of the steepest downward slope on the eight triangular facets formed in a 3 x 3 grid cell window centered on the grid cell of interest. Flow direction is measured in radians, counter-clockwise from east as a continuous (floating point) quantity between 0 and 2 pi. The algorithm is described in Tarboton, D. G., (1997), "A New Method for the Determination of Flow Directions and Contributing Areas in Grid Digital Elevation Models," Water Resources Research, 33(2): 309-319. This grid can be produced using the D-Infinity Flow Direction tool.

 Raster Layer
Input_Destination_Grid Dialog Reference

A grid that encodes the destination zone that may receive flow from upslope. This grid must be 1 inside the zone y and 0 over the rest of the domain.

 Raster Layer
Input_Number_of_Processes Dialog Reference

This input indicates the number of stripes that the domain will be divided into and the number of MPI parallel processes that will be spawned to evaluate each piece of the domain.

 Long
Output_Upslope_Dependence_Grid Dialog Reference

A grid quantifing the amount each source point in the domain contributes to the zone defined by the destination grid.

 Raster Dataset

Code Samples

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Credits

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