Research Article
A GIS-Enabled Approach for Assessing Damage Potential of Levee Systems Based on Underlying Geology and River Morphology
Table 3
Underlying geology classification for the Sacramento River basin.
| Deposit classification | Code | Short description | Geological epoch | Maximum thickness (m) |
| Alluvial deposits | Qa | Alluvium-unweathered gravel, sand, and silt | Holocene | 10 | Basin deposits | Qb | Basin deposits, undivided-Fine grained silt and clay | Holocene | 60 | Alluvial deposits | Qsc | Stream channel deposits of open, active stream channels (morphology constantly changing) | Holocene | 25 | Alluvial deposits | Qmu | Modesto formation—upper Member—unconsolidated, unweathered mix of gravel, sand, silt and clay | Pleistocene | 120 | Alluvial deposits | Qml | Modesto formation—lower Member—unconsolidated, slightly weathered gravel, sand, silt, and clay | Pleistocene | 120 | Alluvial deposits | Qru | Riverbank formation—upper Member—unconsolidated alluvium composed of gravel, sand, and silt | Pleistocene | 120 | Alluvial deposits | Qrl | Riverbank formation—lower Member—semiconsolidated gravel, sand, and silt | Pleistocene | 120 | Alluvial deposits | Qsc | Stream channel deposits of open, active stream channels (morphology constantly changing) | Holocene | 250 |
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