Automated Web Gis Based Hydrograph Analysis Tool, What

Abstract

The separation of the base flow component from a varying streamflow hydrograph is called "hydrograph analysis." In this study, two digital filter based separation modules, the BFLOW and Eckhardt filters, were incorporated into the Web based Hydrograph Analysis Tool (WHAT) system. A statistical component was also developed to provide fundamental information for flow frequency analysis and time series analysis. The Web Geographic Information System (GIS) version of the WHAT system accesses and uses U.S. Geological Survey (USGS) daily streamflow data from the USGS web server. The results from the Eckhardt filter method were compared with the results from the BFLOW filter method that was previously validated, since measured base flow data were not available for this study. Following validation, the two digital filter methods in the WHAT system were run for 50 Indiana gaging stations. The Nash-Sutcliffe coefficient values comparing the results of the two digital filter methods were over 0.91 for all 50 gaging stations, suggesting the filtered base flow using the Eckhardt filter method will typically match measured base flow. Manual separation of base flow from streamflow can lead to inconsistency in the results, while the WHAT system provides consistent results in less than a minute. Although base flow separation algorithms in the WHAT system cannot consider reservoir release and snowmelt that can affect stream hydrographs, the Web based WHAT system provides an efficient tool for hydrologic model calibration and validation. The base flow information from the WHAT system can also play an important role for sustainable ground water and surface water exploitation, including irrigation and industrial uses, and estimation of pollutant loading from both base flow and direct runoff. Thus, best management practices can be appropriately applied to reduce and intercept pollutant leaching if base flow contributes significant amounts of pollutants to the stream. This Web GIS based system also demonstrates how remote, distributed resources can be shared through the Internet using Web programming. (KEY TERMS: hydrograph analysis; base flow separation; digital filter; rivers/streams; WHAT; Web GIS.)

Annual baseflow variations as influenced by climate variability and agricultural land use change in the Missouri River Basin

“…For the MORB, Norton et al (2014) found that out of 227 stations, 45 indicated significant increasing trend and 56 showed significant decreasing trend in the annual streamflow. Because baseflow is a major contributor of streamflow (Lim et al, 2005), the streamflow increase in Norton et al (2014) was likely driven by the increased baseflow. In South Dakota, Kibria et al (2016) found increasing trends in streamflow and baseflow respectively for 39% and 50% of the 18 studied watersheds.…”

“…The Eckhardt filter method (Eckhardt, 2005(Eckhardt, , 2008 was used on daily streamflow for baseflow separation in this study. The Eckhardt filter has been validated and widely used in similar analyses (Eckhardt, 2008;Lim et al, 2005;Ahiablame et al, 2013). It is mathematically expressed as (Eckhardt, 2005(Eckhardt, , 2008:…”

“…The Web-based Hydrograph Analysis Tool (WHAT; Lim et al, 2005) was used to estimate baseflow from long-term streamflow records . WHAT has three methods for baseflow separation: local minimum (Sloto and Crouse, 1996), a one-parameter digital filter or BFLOW filter (Lyne and Hollick, 1979), and twoparameter filter or Eckhardt filter (Eckhardt, 2005).…”

Applicability Assessment of Estimation Methods for Baseflow Recession Constants in Small Forest Catchments

“…The baseflow was separated from the streamflow hydrograph with the recession constant. In order to separate the baseflow from the long-term streamflow data, with about 30 years of records, digital filtering, which separated the baseflow with an automated algorithm, was used [3,20,28]. In many digital filtering methods, the filter introduced by Eckhardt [28] was selected, as it describes forest catchment characteristics well.…”

“…Increasing demand for fresh water, due to the continued population and economy growth, has necessitated the management of forests and mountain streams [1]; this has been exacerbated by the expanding environmental variations caused by climate change, which have complicated the runoff characteristics of forest catchments [2]. As such, the need for rational interpretations of streamflow hydrograph characteristics is increasing for clean water supplies [3]. Baseflow recession analysis is an essential element for reasonable hydrograph analysis [4].…”