Hydrology can be defined as the study of the movement of the Earth’s water in
relation to the land or soil. This study tells us a lot about the soil of an
area, but first one must have a simple understanding of the important factors in hydrology. Among the most important parts of hydrology, groundwater sits close to the top of the list. The name “groundwater” comes
from the fact that the water resides below the surface, in an area of the
ground known as the zone of saturation. (Source: Casey Allen Lecture Notes)
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| The blue section of this diagram is the Zone of Saturation where groundwater sits. Here, rather than air and water filling in the porous spaces of the ground, water saturates the area. Source: Casey Allen Lecture Notes |
Most natural wells tap into this
phenomenon. However, by pumping this ground water out of these aquifers for
drinking water or for growing crops, compaction occurs where the water no
longer supports the spaces between sediment. This process, known as subsidence,
appears in a dramatic case in the San Joaquin Valley south of
Charming. (Source: Casey
Allen Lecture Notes)
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| The San Joaquin Valley has experienced so much groundwater subsidence since 1925 that by 1977 the elevation of the land had decreased by roughly 9 meters (or about 30 feet)! This is the result of groundwater subsidence: the compaction of the ground after the removal of groundwater. Credit: (Casey Allen Lecture Notes) |
The
hydrology and climate of an area define its soil. Based on the climate and
hydrology of the San Joaquin Valley, one can safely assume that Charming has an Alfisol soil type. Alfisol soil types generally thrive in warm, wet/dry climates with some amount of noticeable humidity (Source: Online Text)
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| As seen in this map, the area of Charming appears to be mostly Alfisol soil. (Credit: Casey Allen Lecture Notes) |
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Soil Profile from San Joaquin Valley.
Top to bottom: O Horizon, A Horizon,
B Horizon, C Horizon, R Horizon
Photo Credit: pssac.org
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