GIS-Hydro Database GIS-Hydro Database for Tres Palacios Bayfor Tres Palacios Bay
Stephanie JohnsonStephanie Johnson
GIS in Water ResourcesGIS in Water ResourcesClass PresentationClass PresentationNovember 21, 2006November 21, 2006
Dr. David Maidment – AdvisorDr. David Maidment – AdvisorUT - Center for Research in Water Resources (CRWR)UT - Center for Research in Water Resources (CRWR)
Study AreaStudy Area
Tres Palacios Bay
Matagorda Bay
/0 10 205 Miles
Tres Palacios BayPalacios, Texas
Tres Palacios BayTres Palacios Bay
Determined to Determined to not meet dissolved oxygen not meet dissolved oxygen standardsstandards of 5 mg/L of 5 mg/L
TCEQ begins a TCEQ begins a dissolved oxygen TMDL dissolved oxygen TMDL study study Overseen by Dr. Paul Montagna, Texas A&M Overseen by Dr. Paul Montagna, Texas A&M
Corpus ChristiCorpus Christi Water quality monitoring for the past 2 yearsWater quality monitoring for the past 2 years
UT-CRWR asked to help with water quality UT-CRWR asked to help with water quality modelingmodeling
Objective of ProjectObjective of Project
Develop a Develop a GIS-based datasetGIS-based dataset for future water for future water quality modelingquality modeling
Introductory qualitative analysis of monitoring Introductory qualitative analysis of monitoring datadata
Use as a test for webscraper tool that Use as a test for webscraper tool that calculates calculates duration curvesduration curves
DatasetDataset
Base mapBase map – used as a guide – used as a guide Developed by Sally Morehead, M.S. at UT-Austin Marine Science Developed by Sally Morehead, M.S. at UT-Austin Marine Science
Institute for initial efforts in studyInstitute for initial efforts in study HydrographyHydrography
Tyler Jantzen at CRWR - Tyler Jantzen at CRWR - NHDPlusNHDPlus data data Jantzen is supported by TNRIS to develop TX NHDPlus Data for his Jantzen is supported by TNRIS to develop TX NHDPlus Data for his
M.S. thesisM.S. thesis General dataGeneral data
Texas General Land Office (GLO) – Political boundaries, roads, etc.Texas General Land Office (GLO) – Political boundaries, roads, etc. Federal agencies – NRCS soil and landuse, etc.Federal agencies – NRCS soil and landuse, etc.
Local data sourcesLocal data sources TCEQ – Water quality monitoring stationsTCEQ – Water quality monitoring stations Dr. Paul Montagna – water quality monitoring points in Tres Palacios Dr. Paul Montagna – water quality monitoring points in Tres Palacios
BayBay
SoilsRoads/Cities
Tres Palacios Bay Tres Palacios Bay WatershedWatershed
Matagorda Bay
Tres Palacios Bay
Monitoring PointsMonitoring Points
1 USGS flow gage1 USGS flow gage on the Tres Palacios on the Tres Palacios RiverRiver
27 TCEQ TRACS 27 TCEQ TRACS river monitoring river monitoring pointspoints
4 monitoring points4 monitoring points in Tres Palacios Bayin Tres Palacios Bay
17 TCEQ TRACS 17 TCEQ TRACS monitoring points in monitoring points in Tres Palacios BayTres Palacios Bay
Qualitative AnalysisQualitative Analysis
PatternsPatterns in low D.O. levels in low D.O. levels LocationLocation Time of yearTime of year Natural events (flow regime)Natural events (flow regime)
Theorize Theorize potential sourcespotential sources of pollution of pollution Non-point vs. pointNon-point vs. point Municipal vs. ruralMunicipal vs. rural
(Yet to be completed)
Load Duration CurveLoad Duration Curve
Basically a Basically a cumulative frequency distributioncumulative frequency distribution Derived from a flow duration curveDerived from a flow duration curve
MultiplyMultiply flow duration curve by the flow duration curve by the desired desired pollutant concentrationpollutant concentration and a conversion and a conversion factorfactor
Outcome: allowable Outcome: allowable load/dayload/day
Source: White Paper (1): Advantages and Disadvantages of Using Load Duration Curves to Estimate Existing and Allowable Loads for the Development of Nutrient TMDLs
Applying the water quality standard of 0.05 mg/L TP:
Low FlowHigh Flow
ExampleExample
Webscraper for Duration Webscraper for Duration Curve CreationCurve Creation
Raw DataRaw Data
CalculationsCalculations
Flow %
RangeFlow Regime
Number of
Samples
Avg FC Loading
(CFU/100mL)
Avg Single Sample Target
(CFU/100mL)
% Load Reductio
n
Avg Geometric
Mean Target (CFU/100mL)
% Load Reducti
on
0-10 High Flow 48 1.11E+14 1.39E+13 87.6% 6.93E+12 93.8%
10-30Moist
Conditions 113 1.45E+12 1.32E+12 8.6% 6.61E+11 54.3%
30-70 Normal Flow 179 4.70E+11 2.47E+11 47.6% 1.23E+11 73.8%
70-90Dry
Conditions 69 7.39E+10 8.59E+10 -16.2% 4.29E+10 41.9%
90-100 Low Flow 2 2.22E+09 3.84E+10 -1629.1% 1.92E+10 -764.6%
Overall Average 82 2.27E+13 3.11E+12 -300.3% 1.56E+12 -100.2%
Calculations (cont.)Calculations (cont.)
Future WorkFuture Work
For GIS ProjectFor GIS Project Qualitative analysis of monitoring dataQualitative analysis of monitoring data Create more duration curves for Tres Palacios RiverCreate more duration curves for Tres Palacios River
Future ModelingFuture Modeling Use data to Use data to developdevelop a dissolved oxygen water a dissolved oxygen water
quality quality modelmodel Use Use runoffrunoff and and land useland use data to determine the data to determine the
nutrient load from each catchmentnutrient load from each catchment Create duration curves for non-point source nutrient Create duration curves for non-point source nutrient
loadsloads
CreditsCredits
Thanks to:Thanks to:Dr. David Maidment, Tyler Jantzen, Dr. Paul Dr. David Maidment, Tyler Jantzen, Dr. Paul Montagna, Ernest To, Sally Morehead, Montagna, Ernest To, Sally Morehead, CRWR staffCRWR staff
Photos from: http://www.portofpalacios.com
Questions?Questions?