Jens Ammon
Hydrology BINGO
Card 1
Condensation
As warm, humid air rises and cools past the dew point, water vapor condenses around airborne particles such as dust.
Sandhills, NE, 2019
Air temperatures below the clouds is warm enough to hold more water vapor (water vapor pressure is not saturated). The air at and above the cloud level has reached the dew point (water vapor pressure is saturated) and water vapor must condense out into liquid droplets.
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Sandhills, NE, 2019
Fog occurs when humidity is high and surface temperatures fall below the dew point. It's a cloud, but the cooling of the air is happening at ground level.
Through Flow
Water that flows through the subsurface soil matrix above the water table.
Sandhills, NE, 2019
The left image shows the end of the throughflow path as the water returns to the surface as return flow. The flow resurfacing mid river bank is causing the above sand to collapse, creating the scalloped shapes.
Snow Accumulation
If surface temperatures are below freezing, snow will accumulate during a snow event. If temperatures remain below freezing, snow may be susceptible to redistribution by wind or other forces.
Logan, UT, 2021
This series of images shows snow accumulating on bikes that were unfortunately left outside during a snowstorm.
Rain (precipitation)
If temperatures are above freezing, precipitation will occur in the form of rain. Since rain is a liquid, if the precipitation rate exceeds the infiltration rate, surface runoff will occur.
Eureka County, NV, 2020
Afternoon mountain thunderstorm at the Barrick Gold Mine in Northern Nevada. Mining operations were halted due to lightning and crews discuss going home early.
Snow (precipitation)
If temperatures are below freezing, precipitation will occur in the form of snow. Since snow is a solid, a snowpack will develop if temperatures remain below freezing, and water will infiltrate the subsurface over a much longer time period than from rain precipitation.
Logan, UT, 2021
Logan Canyon, UT, 2021
The left video shows active snow precipitation. The right video shows an accumulated snowpack.
Baseflow
Baseflow is the "low flow" minimum stage of a river that is sustained year-round (for a perennial stream). This flow is sustained by a constant groundwater seepage and soil drainage, rather than storm and surface runoff.
Logan Canyon, UT, 2021
The river in this video is likely at or near baseflow conditions because in the days prior to the recording, there were no new storms and temperatures remained cold enough to prevent snowmelt/surface runoff.
Interception
Interception occurs when precipitation does not reach the soil it would otherwise infiltrate into. Interception can be caused by vegetation, ground debris, buildings, or any other objects that might collect precipitation. Once precipitation is stopped, some or all of it will evaporate rather than becoming part of the groundwater and surface hydrology for the system.
Logan, UT, 2021
The above pictures show rain interception by pine needles, a combination that is likely often overlooked.
Saturated Excess Overland Flow
Saturated excess overland flow occurs when the soil/ground material is fully saturated and any further incoming precipitation turns into runoff. Not to be confused with overland flow due to precipitation exceeding infiltration rates.
Logan Canyon, UT, 2021
Logan Canyon, UT, 2021
I am considering this to be Saturated excess overland flow rather than infiltration excess because the water is flowing over rock. The water is also from uphill snow melting at a rate that is probably slower than infiltration.
Stemflow
Stemflow is the water that runs down the truck/stems of a tree/plant after the precipitation is caught (intercepted) by the leaves.
Logan, UT, 2021
Here is an example of stemflow during rain precipitation. The dark areas of the tree trunk (also traced in blue) is the intercepted rain running down the tree.