Skip to content

4. Model inputs

xilin xia edited this page Jun 10, 2020 · 2 revisions

Type of model inputs

The inputs of HiPIMS include three types of data: topography data to provide the range of model domain and the elevation value of each cell inside the domain, land cover data to setup friction and infiltration parameters, and water source data to drive the model.

Topography

  • DEM (Digital Elevation Model): a raster file (Gridded data set in ArcGrid ASCII format) representing surface height information of the model domain. It can be obtained from DigiMap.

  • Bathymetry data of rivers and lakes: raster files (Gridded data set in ArcGrid ASCII format) or vectors of 3D points or lines to provide bed elevation in rivers and lakes with water removed. Bathymetry data can be acquired either from Digimap or local authorities depends on study areas.

Land cover map

  • A raster file with the same range and format of DEM to indicate the physical land type such as grassland, forest, open water, urban area, etc. The types of land cover are used to set the friction and infiltration parameters that are essential in HiPIMS. Land cover maps are available in DigiMap.

Water sources

  • Initial conditions: a raster file (Gridded data set in ArcGrid ASCII format) representing initial water depth of rivers and lakes in the model domain. Initial conditions can be obtained from field survey or generated by running HiPIMS for a couple of days on a dry DEM with designed or observed rainfall data.

  • Rainfall: two files to provide the rainfall rate in each cell of the model domain. One file gives time series of rainfall rate values at different coverages (vectors in plain text files). The other file with the same format of DEM is to define the range and position of the rainfall coverages. Rainfall data can be obtained from surface station observations, radar rainfall, or numerical weather predictions.

  • Boundary conditions: vectors in plain text files to provide water depths or discharges on boundary cells, like inflows from upstream or water depths in the outlets of the model domain. The water depth or discharge can be got from river gauge stations and tide stations.

Description of Input files

The input folder includes two subfolders: mesh, field. A 'DEM.txt' file (Gridded data set in ArcGrid ASCII format) is stored in mesh folder. All the other input files are stored in field folder. A time setup file ('times_setup.dat') provides four numeric values representing model start time, model end time, output interval, and backup interval in seconds, respectively. 'times_setup.dat' is not compulsory as the four time-values can be type in manually when running HiPIMS. All these input files can be generated by using a Python package.

Mesh file:

DEM.txt spatial reference of the DEM raster of the model domain in ArcGrid data format

Field files:

There are typically 15 field files if one boundary condition was given for depth and velocity. More field files would be created if there were more boundary conditions. The fundamental files are introduced in Table 1*.

Table 1. List of field files

File name File type Notes
z.dat Basic terrain ID, type, and elevation values
h.dat/eta.dat Initial conditions initial water depth/elevation (m)
hU.dat initial water velocities (m/s)
precipitation.dat initial rainfall rate (m/s)
manning.dat Friction parameter friction coefficient
hydraulic_conductivity.dat Green-Ampt infiltration parameters hydraulic conductivity
cumulative_depth.dat cumulative depth
capillary_head.dat capillary head
water_content_diff.dat water content difference
sewer_sink.dat Drainage parameter sewer sink rate
h_BC_N.dat Boundary conditions water depth on the N^th^ boundary
hU_BC_N.dat water velocities on the N^th^ boundary
precipitation_mask.dat Rainfall sources rainfall source ID
precipitation_source_all.dat time series of all rainfall sources
gauges_pos.dat Gauge monitoring Coordinates of monitoring points
Other files:
times_setup.dat Four values respectively indicate model start time, total time, output interval, and backup interval in seconds
device_setup.dat Values to define the ID of GPU devices that used to run model in each subdomain.

*The landslide solver currently does not consider spatially varying friction coefficient and infiltration, therefore it only takes the first three files as inputs.

Clone this wiki locally