Hydrologic Related Activities Hydrologic Related Activities within the Joint Institute for within the Joint Institute for

Caribbean Climate StudiesCaribbean Climate Studies

Eric Harmsen, Ph.D., P.E.Eric Harmsen, Ph.D., P.E.

Dept. of Agricultural and Biosystems EngineeringDept. of Agricultural and Biosystems Engineering

University of Puerto Rico – Mayagüez CampusUniversity of Puerto Rico – Mayagüez Campus

Countries within the humid tropics contain Countries within the humid tropics contain almost one-third of the total world almost one-third of the total world population.  population. 

Within this region there are many small Within this region there are many small islands whose water resources are subject islands whose water resources are subject to an ever-increasing risk. to an ever-increasing risk.

The threat to water resources include: The threat to water resources include: population pressure, urban development, population pressure, urban development, pollution, and potentially adverse changes pollution, and potentially adverse changes in the climate in the climate

Background

A Small-Scale View of theA Small-Scale View of theHydrologic CycleHydrologic Cycle

ObjectiveObjective

• Develop tools for estimating and Develop tools for estimating and predicting components of the hydrologic predicting components of the hydrologic cycle. (e.g., soil moisture)cycle. (e.g., soil moisture)

• Construct island-wide groundwater flow Construct island-wide groundwater flow and surface hydrologic models to be and surface hydrologic models to be coupled with the Regional Atmospheric coupled with the Regional Atmospheric Modeling System (RAMS)Modeling System (RAMS)

“Soil Moisture Retrieval Algorithm and its Implementation

Applied to a Selected Area in Puerto Rico”

““Inverse procedure for estimating vertically Inverse procedure for estimating vertically distributed soil hydraulic parameters using GPR”distributed soil hydraulic parameters using GPR”

“Validation of an inverse procedure for“Validation of an inverse procedure forestimating soil moisture content using GPR”estimating soil moisture content using GPR”

“Estimating long-term average monthly evapotranspiration from pan evaporation data at

seven locations in Puerto Rico”

ATLAS MissionATLAS Mission

Initial Hydrologic ModelingEffortsInitial Hydrologic ModelingEfforts

1. Development Conceptual Groundwater Model for Puerto Rico• Literature Study• Use of Numerical Tools

GMS GIS Remote Sensing

2. Model Configuration (MODFLOW)3. Calibration and validation efforts4. Model Coupling5. Predictive Simulations

Locations of USGS Groundwater Locations of USGS Groundwater Resource and Modeling Studies in Puerto Resource and Modeling Studies in Puerto

RicoRico

Groundwater Finite Groundwater Finite Difference GridDifference Grid

Characterization of Aquifer Units

Geological CharacterizationGeological CharacterizationBoreholes Solid TINS

Cross Sections3-D Visualization

Surface Hydrologic ModelSurface Hydrologic Model1. Development of a Surface Hydrologic Conceptual

Model• Literature Study• Use of Numerical Tools

WMS GMS Remote Sensing

2. Model Selection• LEAF-2• TOPMODEL• HSPF

3. Calibration and validation efforts4. Model Coupling5. Predictive Simulations

HSPFHSPF

HSPF is capable of simulating the balance of moisture within the first few meters of the ground surface.

Groundwater/Surface WaterGroundwater/Surface Water

ProposalsProposals– NSF-WEAVE (PR Hydrologic Model)NSF-WEAVE (PR Hydrologic Model)– Sea Grant (Submarine Groundwater Sea Grant (Submarine Groundwater

Discharge)Discharge)– EQSERC (Air and Watershed Modeling)EQSERC (Air and Watershed Modeling)– NASA (El Yunque Climate/Hydrologic NASA (El Yunque Climate/Hydrologic

Modeling)Modeling)

PR Climate/Hydrologic ModelPR Climate/Hydrologic Model

RAMS

LEAF-2

TOPMODEL

AquiferRechargeCalculation

MODFLOW

Grid cell is located withinInterior Mountain area

Grid cell islocated withingcoastal or karsticlimestone area

Water thatdischarges tosurface waterbodies

Water thatdischarges tosurface waterbodies Water and

energy fluxes

Water andenergy fluxes

Re-optimize modelparameters

extrapolate boundaryconditions into future

Predict short andlong-term conditions

For example,- Aquifer recharge- Surface Water Elevations- Contaminant Loading

Update boundarycondition data

Evaluate keysimulated variables

For example,- Groundwater elevations- Drawdown at muncipal wells- Contaminant concentrations at receptor locations- Discharge rates into sensitive ecosystems

Evaluate correctivemeasures - makerecommendations

Real-Time Hydrologic Modeling System Real-Time Hydrologic Modeling System FlowchartFlowchart

Potential ChallengesPotential Challenges

Puerto Rico has extreme Puerto Rico has extreme variations invariations in– TopographyTopography– GeologyGeology– SoilsSoils– WeatherWeather