Comparative Analysis of Daily Flow Pattern Hydrographs Used to Disaggregate Monthly Naturalized Flows to Daily
Abstract
Observed and synthesized sequences of stream flow data are explored from the perspective of improving capabilities for disaggregating monthly naturalized flow volumes, representing natural undeveloped conditions, to daily volumes. The research investigates 1) characteristics of river flows and impacts of water resources development on flows, 2) capabilities for disaggregating monthly naturalized flows to daily, and 3) the sensitivity of water availability modeling results to the daily flow pattern hydrographs adopted in monthly-to-daily naturalized flow disaggregation.
The Texas Commission on Environmental Quality (TCEQ) Water Availability Modeling (WAM) System consists of the Water Rights Analyses Package (WRAP) and input datasets for all the river basins of Texas. TCEQ sponsored research at Texas A&M University over the past several years has included development of a daily version of the monthly WRAP/WAM modeling system. The thesis research focuses on improving capabilities for developing daily pattern hydrographs for use in disaggregating monthly WAM naturalized flow sequences to daily within the daily WRAP modeling system.
Comparative statistical analyses are performed for observed and synthesized river flows at numerous gage sites in the Brazos, Trinity, Neches, and Sabine River Basins. The datasets of monthly and daily flows investigated in the thesis include observed flows at U.S. Geological Survey (USGS) gages, TCEQ WAM System naturalized flows, unregulated flows from a U.S. Army Corps of Engineers (USACE) reservoir operations modeling system, and flows generated with the Soil and Water Assessment Tool (SWAT) and Hydrologic and Water Quality System (HAWQS) watershed rainfall-runoff modeling systems. Daily WRAP simulations of the four case study river basins for a 1940-2015 hydrologic period-of-analysis are performed with alternative flow disaggregation schemes. The USACE Hydrologic Engineering Center (HEC) Data Storage System (DSS) and HEC-DSSVue are employed in the compilation and comparative analyses of datasets.
Stream flow throughout Texas is extremely variable temporally with the extremes of floods and droughts as well as seasonal and continuous variability. The impacts of water resources development on river flows vary greatly between different locations. Impacts of upstream development are very different across the range of low to median to high flows. The HEC-DSSVue based approach for compiling, analyzing, comparing, selecting, and combining datasets significantly enhances the WRAP/WAM modeling system.
Subject
comparative analysisWRAP
WAM
flow pattern
hydrograph
disaggregation
naturalized flows
monthly to daily
river flow characteristics
water resources development
sensitivity analysis
statistical analysis
HAWQS
SWAT
HEC DSS
HEC-DSSVue
flow regime
spatial and temporal variation
floods
droughts
seasonal variation
senate bill 3
environmental flows Brazos
Trinity
Neches
Sabine
WRAP simulations
daily version
flow volumes
Citation
Verma, Vivek (2017). Comparative Analysis of Daily Flow Pattern Hydrographs Used to Disaggregate Monthly Naturalized Flows to Daily. Master's thesis, Texas A & M University. Available electronically from https : / /hdl .handle .net /1969 .1 /165882.