Time of concentration (TOC) is an important hydrology parameter which represents the time required for surface runoff to travel from the most hydraulically remote point (normally divide or ridge) in…
Time of concentration (TOC) is an important hydrology parameter which represents the time required for surface runoff to travel from the most hydraulically remote point (normally divide or ridge) in…
Whitebox Tools (WBT) is an advanced geospatial data analysis platform developed by Whitebox Geospatial, Inc. WBT contains plenty of tools to process various types of geospatial data for H&H analysis. WBT can…
To model infiltration loss within 2D domain for a Rain-on-Grid (RoG) HEC-RAS model, a land cover layer and a soils layer needs to be generated first and then an infiltration…
In HEC-RAS 6.0, users have the option to import either raster landcover files or vector landcover files to create a land cover layer which will then be used to associate…
This post (3 of 3) is an instruction of combining Land Cover Raster file and HSG Raster file to create a CN raster file for calculating an area-weighted average CN…
Hydrologic Soil Group Data (A, B, C, and D) is an important soil property which impacts the soil infiltration rates and runoff potential. Soils were originally assigned to hydrologic soil…
The SCS (NRCS) Curve Number is used to quantify infiltration loss during runoff calculation. As illustrated in Figure 1, the CN is determined by both soil types (Hydrologic Soil Groups,…
File geodatabase is a collection of files in a folder to store and manage both spatial and nonspatial data. File geodatabase originally came from ESRI ArcGIS and the QGIS has…
QGIS in an open source and free GIS software which can be installed by downloading the installation file at https://www.qgis.org. There are two ways to install QGIS: one is to…
Earth is not a perfect globe and its surface is irregular. GIS needs to use coordinates values (X/Y, or Longitude/Latitude) to describe an actual position/feature on earth in software system.…