There are several GIS based tools for gathering data on alluvial soils and flood plains:
USGS Soil Survey tool: https://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx
Due to the amount of data provided by the USGS, I chose to demonstrate a small part of the watershed near the town of Marshall. The map shows how susceptible soils are to fire damage, due to the amount of organic matter within. Red indicates high potential for damage, to Green for low potential for damage.
The second from FEMA's National Flood Hazard Layer database, shows flood hazard areas in precise locations. This one shows the town of Marshall; notice Blanahassett Island in the middle. The island flooded twice in 2020, video can be seen my prior post on flooding.
