HydroQGIS: Hydrological Geospatial Data Manipulation

Abstract:

Many aspects of hydrology are tightly coupled with geospatial data. For this reason, geospatial information systems (GIS) are often incorporated into work flows for analyzing hydrological data. These disjoint work flows, however, often require many steps and different applications to achieve the desired results.

Simplifying the workflow involved in regional flood peak scaling studies motivated the creation of the HydroQGIS plugin. Flood frequency analysis presents one of the largest hurdles in studying regional flood peak scaling. HydroQGIS aids these studies with a set of tools that reduce the time to perform flood frequency analsyis on USGS gauging stations. HydroQGIS is a framework for hydrological geospatial plugin development for Quantum GIS (QGIS). It uses the cross-platform nature of QGIS, QT, and Python to create a set of tools to help simplify the work flow of hydrological data searching, gathering, and analysis into a single application that can be used by users on any platform.

HydroQGIS combines the Quantum GIS plugin framework with various web-services to couple data and analysis in a uniform environment. QGIS provides a fully functioning GIS application on top of which plugins can be developed. The HydroQGIS plugin focuses on data acquisition and analysis from the geospatial domain. The design of HydroQGIS facilitates quick development of additional tools, used independently or in conjunction with other developed utilities, to streamline data acquisition and analysis.

HydroQGIS currently implements an Environmental Protection Agency (EPA) Watershed Delineation tool using the EPA Waters web service, as well as a United States Geological Survey (USGS) gauging station search using the USGS Instantaneous Values web service. These tools provide a unified GIS interface that allows users to locate and map gauging stations and watersheds using any base map of their choice. These tools, while useful by themselves, also support a flood frequency analysis (FFA) utility based on USGS Bulletin 17B guidelines. The FFA tool acquires and analyzes historical flood peak data for USGS gauging stations across the country. Combined with the USGS gauging station search tool, this provides a simple, easy to use work flow for developing flood frequency curves or for comparing flood behaviors at different sites.