Hydrologic Model of the Hydrologic Model of the MayagMayagüeüez Bay Watersheds: z Bay Watersheds:
Progress ReportProgress Report
Eric Harmsen, Associate ProfessorEric Harmsen, Associate ProfessorDept. of Agricultural and Biosystems EngineeringDept. of Agricultural and Biosystems Engineering
Marcel Giovanni Prieto, Graduate StudentMarcel Giovanni Prieto, Graduate StudentDept. of Civil Engineering and Surveying Dept. of Civil Engineering and Surveying
AcknowledgementsAcknowledgements NASA-EPSCoRNASA-EPSCoR US Geologic SurveyUS Geologic Survey Sea GrantSea Grant U.S. Army Corps of Engineers (ERDC)U.S. Army Corps of Engineers (ERDC) LARSIP LaboratoryLARSIP Laboratory Puerto Rico Water Resources and Puerto Rico Water Resources and
Environmental Research InstituteEnvironmental Research Institute Professor Nazario Ramirez, UPRMProfessor Nazario Ramirez, UPRM Students: Sandra Ortiz, Richard Diaz, Students: Sandra Ortiz, Richard Diaz,
Moises Angeles Malaspina, Christian Moises Angeles Malaspina, Christian CalderonCalderon
Some Water Issues in Puerto RicoSome Water Issues in Puerto Rico
Water conflicts between agricultural and non-agricultural Water conflicts between agricultural and non-agricultural community (Lajas, PR)community (Lajas, PR)
Sediment transport is contaminating marine resources Sediment transport is contaminating marine resources at numerous coastal areas in PRat numerous coastal areas in PR
Saltwater intrusion is threatening groundwater Saltwater intrusion is threatening groundwater resources in the north and south coast of PRresources in the north and south coast of PR
Dropping groundwater elevations occurring in the South Dropping groundwater elevations occurring in the South Coast.Coast.
Many of the principal reservoirs have become partially filled Many of the principal reservoirs have become partially filled with sediment since their construction, reducing their with sediment since their construction, reducing their effectiveness in providing water supplies and mitigating flood effectiveness in providing water supplies and mitigating flood peaks.peaks. (e.g., Carra(e.g., Carraízo Reservoir which supplies San Juan)ízo Reservoir which supplies San Juan)
Problems with the water supply service of 700,000 Problems with the water supply service of 700,000 families at the present time in the island (families at the present time in the island (Nuevo Nuevo DíaDía 05 Feb. 05 Feb. 2005)2005)
Sediment Discharge to the Sediment Discharge to the MayagMayagüüez Bayez Bay
Rio Grande de Anasco Outlet
Water related issues will become Water related issues will become even more serious in the future even more serious in the future
Potential climate changePotential climate change Urban growthUrban growth Increasing populationIncreasing population Increasing cost of water and energyIncreasing cost of water and energy Contamination of water suppliesContamination of water supplies Environmental impacts from Environmental impacts from
changing flowschanging flows
ObjectiveObjective
• To develop an integrated hydrologic model for the To develop an integrated hydrologic model for the Mayaguez Bay Watersheds for the purpose of Mayaguez Bay Watersheds for the purpose of
• Estimating the components of the hydrologic cycleEstimating the components of the hydrologic cycle
• Evaluate the water balance under climate change Evaluate the water balance under climate change conditions (uncoupled)conditions (uncoupled)
Longer-term objectives:Longer-term objectives:
• Apply an integrated hydrologic model coupled with a Apply an integrated hydrologic model coupled with a regional atmospheric model (e.g., RAMS/TOPMODEL)regional atmospheric model (e.g., RAMS/TOPMODEL)
• Evaluate the water balance for the entire islandEvaluate the water balance for the entire island
Integrated Hydrologic ModelingIntegrated Hydrologic Modeling
MOTIVATIONMOTIVATION We will be able to address scientific and We will be able to address scientific and
practical questions related to the practical questions related to the hydro/atmospheric systemhydro/atmospheric system
How might changes in global/local weather affect How might changes in global/local weather affect our water supplyour water supply
How will urban growth effect the hydrology (land How will urban growth effect the hydrology (land use change, Urban Head Island effect)use change, Urban Head Island effect)
Evaluate the effect of specific types of storms on Evaluate the effect of specific types of storms on
FloodingFlooding
Landslide potentialLandslide potential
Modeling StrategyModeling Strategy
1.1. Multi-watershed model (short-term)Multi-watershed model (short-term)• Develop and calibrate hydrologic modelDevelop and calibrate hydrologic model• Use output from climate change simulations Use output from climate change simulations
from an atmospheric simulation model as from an atmospheric simulation model as input to the hydrologic modelinput to the hydrologic model
2.2. Island-wide model (long-term)Island-wide model (long-term)• Develop and calibrate hydrologic modelDevelop and calibrate hydrologic model• Hydrologic model coupled with RAMSHydrologic model coupled with RAMS
QualificationQualification
Model will be developed based on a Model will be developed based on a roughrough calibrationcalibration
• Available groundwater elevationsAvailable groundwater elevations• USGS gauging station – Total daily volume USGS gauging station – Total daily volume
(not hydrographs)(not hydrographs)• Overland flow only (no channel flow)Overland flow only (no channel flow)
Model SelectionModel Selection
RequirementsRequirements Should simulate Should simulate
• Overland flowOverland flow• Vadose zone flowVadose zone flow• Groundwater flow (preferably in 3-D)Groundwater flow (preferably in 3-D)• 1-D channel flow1-D channel flow
Should run on a supercomputerShould run on a supercomputer Source code should be freely available Source code should be freely available
Models we evaluated:Models we evaluated: Mike SheMike She, WASH123D, IHM, GHSSA, WASH123D, IHM, GHSSA
• Conceptual model developmentConceptual model development Identification of data sourcesIdentification of data sources Delineation of study areaDelineation of study area Conceptualize surface, soil and subsurface Conceptualize surface, soil and subsurface
systemssystems Development of GIS mapDevelopment of GIS map Perform simplified GIS water balancePerform simplified GIS water balance
Study AreaStudy Area
Requirements Requirements • Two or more watershedsTwo or more watersheds• Boundary along coastBoundary along coast• Large topographic reliefLarge topographic relief• Include alluvial and bedrock aquifersInclude alluvial and bedrock aquifers• Various land use categoriesVarious land use categories
GIS Water Balance of the GIS Water Balance of the Mayaguez Drainage BasinMayaguez Drainage Basin
Precip = ET + RO + Rch +ΔS
Precip = PrecipitationET = EvapotranspirationRO = Surface RunoffRch = Aquifer RechargeΔS = Change in soil moisture storage
Soil Moisture ContentSoil Moisture Content
UPR-Mayaguez Campus - September 2005
0
10
20
30
40
50
0 5 10 15 20 25 30 35
Days
Per
cen
t S
oil
Mo
istu
re
Sensor 1
Sensor 2
Soil Moisture ContentSoil Moisture ContentUPR - Mayaguez Campus January 2005
0
5
10
15
20
25
5 10 15 20 25 30
Days
Per
cen
t M
ois
ture
C
on
ten
t
Sensor 1
Sensor 2
Potential EvapotranspirationPotential Evapotranspiration Hargreaves-Samani MethodHargreaves-Samani Method
PET = 0.0023 x RPET = 0.0023 x Raa x (T +17.8) x x (T +17.8) x (T(Tmaxmax – T – Tminmin))0.50.5
PET = potential or reference ETPET = potential or reference ETRRaa = extraterrestrial evapotranspiration = extraterrestrial evapotranspirationT = average daily air temperatureT = average daily air temperatureTTminmin = average daily minimum temperature = average daily minimum temperatureTTmaxmax = average daily maximum temperature = average daily maximum temperature
Hydrologic Model - EvapotranspirationHydrologic Model - Evapotranspiration
2
3
4
5
6
7
2 3 4 5 6 7
ETo Penman-Monteith (mm/day)
ET
o H
arg
reav
es-S
aman
i (m
m/d
ay)
Surface ElevationEvaluation of Simplified Method
Air Temperature Reference Evapotranspiration
Hydrologic Model - EvapotranspirationHydrologic Model - Evapotranspiration
Kc Literature
Reference ET X
Actual ET September
NDVI
Actual ET January
Hydrologic Model – Surface RunoffHydrologic Model – Surface RunoffMONTHLY RUNOFF
COEFFICIENT
MONTHLY RAINFALL
LAND COVER
MONTHLY RUNOFF
Aquifer RechargeAquifer Recharge
January
Aquifer Rechargewas zeroat all locations
September
59.7 mm Average
Mayaguez Bay Drainage Area Water Balance
050
100150200250300
Rain Runoff Recharge ET
Water Balance Component
De
pth
of
Wa
ter
(m
m)
September
January
Mayaguez Bay Drainage Area Water Balance
0%
20%
40%
60%
80%
Runoff Recharge ET
Water Balance Component
Per
cen
t o
f R
ain
fall
September
January
Global WarmingGlobal Warming
http://www.gfdl.noaa.gov/~tk/climate_dynamics/fig1.gif
PET = 0.0023 x RPET = 0.0023 x Raa x (T +17.8) x x (T +17.8) x (T(Tmaxmax – T – Tminmin))0.50.5
“ “ There has also been a general trend There has also been a general trend toward reduced diurnal temperature toward reduced diurnal temperature range, mostly because nights have range, mostly because nights have warmed more than days.”warmed more than days.”
- Union of Concerned Scientists- Union of Concerned Scientistshttp://www.ucsusa.org/global_warming/science/early-warning-signs-of-global-http://www.ucsusa.org/global_warming/science/early-warning-signs-of-global-
warming-heat-waves.htmlwarming-heat-waves.html
Annual Rainfall
600
650
700
750
800
850
900
950
1000
1050
1100
1980 2000 2020 2040 2060 2080 2100 2120
Year
Rai
nfa
ll (
mm
/yea
r)
Air Temperature
25.2
25.4
25.6
25.8
26
26.2
26.4
26.6
26.8
27
27.2
1980 2000 2020 2040 2060 2080 2100 2120
Year
Air
Tem
per
atu
re (
C)
Relative Humidity
67
68
69
70
71
72
73
74
75
76
1980 2000 2020 2040 2060 2080 2100 2120
Year
RH
(%
)
Net Radiation
608
610
612
614
616
618
620
622
624
626
628
1980 2000 2020 2040 2060 2080 2100 2120
Year
Rn
et (
W/m
2)
Global Climate Circulation Model – Caribbean AreaDOE - Accelerated Climate Prediction Initiative
Some Climate Change ResultsSome Climate Change Results
mm/monthMillion Gallons
per month2050 2.7 5842100 5.4 1168
Increase in ET relative to Year 2000
Drop in the Groundwater
Elevation relative to Year 2000
mm2050 13.52100 27.0
Reduction in Aquifer Recharge During the Month of September
40
45
50
55
60
65
70
75
80
1980 2000 2020 2040 2060 2080 2100 2120
Year
Rec
har
ge
(mm
/mo
nth
)
Conclusions from GIS Water Conclusions from GIS Water Balance AnalysisBalance Analysis
During the next 50 to 100 years:During the next 50 to 100 years: ET can be expected to increase by 3 to 5 ET can be expected to increase by 3 to 5
mm/month mm/month In the worse case the aquifer recharge will In the worse case the aquifer recharge will
also drop by this amountalso drop by this amount The expected drop in the water table is The expected drop in the water table is
between 13 to 27 mm.between 13 to 27 mm. Increase urban development may Increase urban development may
decrease aquifer recharge and increase decrease aquifer recharge and increase surface runoff.surface runoff.
Numerical ModelNumerical Model MIKE SHEMIKE SHE
• AdvantagesAdvantages Easy to useEasy to use 3-D groundwater3-D groundwater Water balance analysis Water balance analysis
tools are excellenttools are excellent Can simulate other Can simulate other
processes: sediment and processes: sediment and solute transportsolute transport
• DisadvantagesDisadvantages Only runs on a PCOnly runs on a PC Documentation is not Documentation is not
completecomplete
OLF – Diffuse wave approximation of the Saint Venant equationsUZ – Richards Equation, gravity method, 2 layer water balanceSZ – standard groundwater equation (MODFLOW)
Simulation of average conditions Simulation of average conditions for Mayaguez Bay Areafor Mayaguez Bay Area
Rainfall – Time series for Hacienda Constanza Rainfall – Time series for Hacienda Constanza weather stationweather station
Manning’s n: 0.07Manning’s n: 0.07 Soil: Loamy ClaySoil: Loamy Clay Potential ET: 4.4 mm/dayPotential ET: 4.4 mm/day Aquifer Aquifer
• type: unconfinedtype: unconfined• thickness: 33 mthickness: 33 m• conductivity: 0.33 m/dayconductivity: 0.33 m/day
Initial groundwater elevation: 0 m below Initial groundwater elevation: 0 m below surfacesurface
September Mayaguez Bay Drainage Area Water BalanceComparison of GIS and MIKE SHE Water Balance
050
100150200250300350400450
Rain Runoff Recharge ET Delt S
Water Balance Component
Dep
th o
f W
ater
(m
m)
GIS
MIKE SHE
Future WorkFuture Work
Model CalibrationModel Calibration• Groundwater elevationsGroundwater elevations• Daily Surface water VolumesDaily Surface water Volumes
Climate Change scenariosClimate Change scenarios• Decide which climate parameters to Decide which climate parameters to
varyvary Write Proposals for more funding Write Proposals for more funding
(NASA-NEWS)(NASA-NEWS)