Introduction Welcome to the Belgium Study Abroad Program Courses: AGSM 335: Soil and Water Management BAEN 460: Principals of Environmental Hydrology
BAEN 460 / AGSM 335 Combined lecture and HW sessions for both classes Lecture 8:30 10:00 Problems 13:30 15:00 Same basic HW problems But BAEN 460 will have engineering design problems included HW problems = 20% of grade All HW problems are due the next class day Same tests Midterm (to be scheduled) Final exam the last week of class 2 tests = 40% of grade
Field Trip Reports (4) Field trip reports = 30% of grade See web page for field trip report requirements http://munster.tamu.edu Must be type-written At least 4 pages in length (double spaced) Due next class day Must have a 1 page write-up for hydrology Must have a 1 page write-up for technology 2 reports will apply to AGSM 335 / BAEN 460 2 reports will apply to AGSM 337 / BAEN 465
Seminar Reports (4) Seminar reports = 10% of grade See class webpage for seminar report guidelines Due next class day 2 will apply to AGSM 335 / BAEN 460 2 will apply to AGSM 337 / BAEN 465 At least 1 page write-up (double spaced) Summary of topics presented in the seminar Comparison of U.S. vs. European procedures Any questions?
The Hydrologic Cycle An Overview Assignments: - HW 1
What Is Hydrology? Hydrology is the scientific study of the movement, distribution, and quality of water on Earth, including the hydrologic cycle, water resources and environmental watershed sustainability
Why Study Hydrology? Water supply Flooding Drought Agriculture Climate change Etc.
U.S. Water Withdrawals
U.S. Water Withdrawals
U.S. Water Use
U.S. Water Use
U.S. Groundwater Use
U.S. Irrigation Water Use
California Drought Map July 7, 2015
Texas Drought Map Oct 4, 2011
Texas Drought Map July 7, 2015
Water Withdrawals in Belgium
The Global Hydrologic Cycle Global hydrologic cycle is the circulation of water around the globe Closed system Estimated 300,000,000 mi 3 of water On the land surface (runoff, streamflow, storage) Beneath the surface (infiltration, groundwater flow, storage) In the atmosphere (precipitation, evaporation, transpiration)
The Hydrologic Cycle
Primary Components Precipitation Interception Evaporation/Transpiration (Evapotranspiration) Infiltration Groundwater Flow and Storage Surface Runoff, Interflow and Storage Streamflow and Storage The sun!
The Hydrologic Cycle The sun drives the process Energy source for: Evaporation and transpiration Aka evapotranspiration (ET) Evaporation from: Soil surface vegetation surfaces Surface water bodies lakes / rivers / oceans*** Clouds are transported from the oceans to the land masses Clouds are water vapor Transpiration roots mine water from the soil Snow melt
Evaporated water from Earth s surface is stored as water vapor in the atmosphere. Water vapor and small water droplets form clouds. As the atmosphere becomes saturated, water is released back to the Earth s surface as some form of precipitation (rain, snow, sleet or hail). Precipitation
Water intercepted by vegetation before it hits the ground. Varies with Type, Density and Stage of Growth of Vegetation Rainfall Intensity Wind Speed May be a significant % of total annual rainfall. Interception
Evaporation and Transpiration Evaporation Phase change from liquid to vapor. Transpiration Evaporation from plant surfaces of water that has traversed from the soil, through the plant to the plant surface. Evapotranspiration
Evaporation and Transpiration ET Small daily amounts College Station in August approximately 8 mm per day College Station in January approximately 2 mm per day But, over large areas Occurs every day (mostly during the day) More than half of the water that enters the soil is returned to the atmosphere through ET
Evaporation and Transpiration Increases with increasing: Air temp. / wind speed / solar radiation Decreases with increasing relative humidity Lots of moisture already in the air no room for more
Evaporation and Transpiration Transpiration Natural by-product of photosynthesis
Movement of water through the soil surface. Major abstraction during significant runoff producing storms. Dependent on: Soil physical properties % sand / silt / clay Vegetative cover Antecedent moisture condition Rainfall intensity Slope of the infiltrating surface Compaction Human activity Urban development Impervious surfaces Infiltration
Soil Classification Systems
Infiltration Porosity = the amount of open space in soil
Elements in the Soil Matrix - unsaturated zone
Porosity V v V s n 1 V t V t
Range of Porosity Values for Unconsolidated Materials Material Porosity (%) Clay 40 70 Silt 35 50 Fine Sand 40 50 Medium Sand 35 40 Coarse Sand 25 40 Gravel 20 40 Sand and Gravel mix 10 30 Limestone 0 50 Sandstone 5 30 Shale 0 10 Crystalline Rock 0 10
Volumetric Soil Water Content θ v V V w t
Gravimetric Soil Water Content θ g m m w s
Bulk Density ρ b m V t s
Impervious surfaces are resistant to the movement of water through them. i.e. paved surfaces, hard packed surfaces, roofs etc. Pervious vs. Impervious Surfaces Pervious surfaces let water pass through them, i.e. soil, vegetation, fissures.
Bank Storage Loss from streamflow during periods of rising stage when water seeps into the banks of the stream. Usually more of a temporary storage than an abstraction.
Surface Storage and Detention Surface storage- Volume of water required to fill depressions and other storages before surface runoff begins Detention storage- Buildup of small depths of water required to support the runoff process.
Groundwater Groundwater recharged by: Water that infiltrates past the root zone Losing streams (in arid regions generally) Groundwater is deeper than the stream This is generally a vertical downward flow path
Groundwater Groundwater discharges into: Gaining streams (in humid regions generally) Groundwater is higher than the stream Provides base flow for perennial streams
Groundwater Groundwater discharges into: Springs (for example: Comal / San Marcos) Lakes and the sea This is generally a lateral flow process
Abstractions Losses from rainfall that do not show up as runoff Abstractions may include: Interception Infiltration Surface depressions Etc.
Water that is not abstracted generally becomes surface runoff Typically conveyed to ditches, small streams, larger streams and eventually to a river Rivers generally flow to the sea Surface Runoff
Interflow Lateral runoff that quickly moves to a surface water body In forested areas, it is flow that is below the surface but above the soil layer Typical in or under a large litter layer Can occur in soil with a clay layer or bedrock close to the surface Flow along the top of the clay or bedrock
Tennessee River Basin
Ohio River Basin
Rivers in Belgium
Manneken Pis