CEE 3430, Engineering Hydrology David Tarboton

Overview Handouts Web: http://www.engineering.usu.edu/dtarb/cee3430 Syllabus Schedule Student Information Sheet Homework 1 Web: http://www.engineering.usu.edu/dtarb/cee3430 Outline for today Review Syllabus and Schedule Introduce the Hydrologic Cycle and Water Balance Concepts CEE 3430 – Spring 2011

Texts CEE 3430 – Spring 2011

Course Learning Objective Upon successful completion of the course you should be able to apply the principles of hydrology to solve engineering hydrology design problems involving hydrologic modeling and analysis. CEE 3430 – Spring 2011

Specifically (1) Identify and describe the processes and quantities involved in the hydrologic cycle. (Bedient Ch 1) Quantify the components of the water balance of a watershed. (Bedient, Ch 1) Calculate hydrologic losses due to evaporation and infiltration. (Bedient, Ch 1) Calculate hydrographs based on streamflow and precipitation measurements, watershed attributes and unit hydrograph theory. (Bedient, Ch 2) CEE 3430 – Spring 2011

Specifically (2) Assemble the data and parameters specific to a given problem and location. Demonstrate skill in the selection of appropriate parameters and the ability to evaluate the sensitivity and uncertainty in parameters and the implication for selection of design alternatives. (Bedient, Ch 5) Formulate problems and prepare inputs to use hydrologic engineering software (computer models) for analysis and design. Summarize and synthesize outputs from these computer models. (Bedient, Ch 5) CEE 3430 – Spring 2011

Specifically (3) Quantify the probability associated with extreme hydrologic events and the magnitude of hydrologic events of specified recurrence interval and frequency. (Bedient, Ch 3) Identify and describe the physical factors, mechanisms and processes involved in the transformation from rainfall to runoff. (Tarboton module Ch 1-3) Quantify the hydrologic properties of water in soils (Tarboton module Ch 4) Calculate infiltration and surface runoff from precipitation on a watershed soil surface. (Tarboton module Ch 5-6) Quantify the flow of groundwater and evaluate the impacts of well pumping on groundwater flow and properties. (Bedient, Ch 8) Design hydrologic solutions to drainage, culvert and flooding problems. (Bedient, Ch 9) CEE 3430 – Spring 2011

Learning Objective for Today Be able to identify and describe the processes and quantities involved in the hydrologic cycle Be able to apply the concept of mass balance to determine certain hydrologic quantities Reading Preface Bedient Pages 1-15 Next time Bedient Pages 15-43 CEE 3430 – Spring 2011

Great Salt Lake Evaporation The Great Salt Lake has an average inflow from streamflow of 2316220 acre ft / year The area is about 1 million acres Average annual precipitation on the lake is about 10 inches/year What is the average annual evaporation ? CEE 3430 – Spring 2011

Water Balance Atmospheric Water Soil Water Surface Water Groundwater Change of Storage Inflow – Outflow =

Watershed delineated on a topographic map

Watershed water balance P E+T Q S G

Streamstats http://water.usgs.gov/osw/streamstats/utah.html CEE 3430 – Spring 2011

Figure 1-1 from Bedient: http://hydrology.rice.edu/bedient/ The Hydrologic Cycle Atmospheric Moisture 100 Precipitation on land Infiltration W a t e r b l Groundwater flow 1 Groundwater discharge 38 Surface discharge 61 Evaporation from land 39 Moisture over land 385 Precipitation on ocean 424 Evaporation from ocean Surface runoff Impervious strata Groundwater Recharge P Snow melt Runoff Evap ET Evap Streams Runoff Lake GW Reservoir Figure 1-1 from Bedient: http://hydrology.rice.edu/bedient/

Water Resources Management Hydrologic Science in the hierarchy from basic sciences to water resources management Basic Sciences Mathematics Statistics Physics Chemistry Biology Geosciences Geology Soil Science Atmospheric Science Ocean Science Glaciology Geochemistry Economics Law Sociology Political Science Engineering Hydrology Agriculture Forestry Fluid Mechanics Hydraulic Engineering Meteorology Hydrologic Science Water Resources Management Modified From: National Research Council Committee on Opportunities in the Hydrologic Sciences (COHS), (1991), Opportunities in the Hydrologic Sciences, Editor, P. S. Eagleson, National Academy Press, Washington, D.C.

Summary The engineering hydrologist must be able to calculate or estimate various components of the hydrologic cycle to solve hydrologic problems Drainage design, flood protection, water supply The concept of the water balance is fundamental to much hydrologic analysis Become comfortable converting units and working with “incompatible” units, it is an unfortunate fact of life CEE 3430 – Spring 2011