Unified Soil Classification System group symbol. For example, GW-GM corresponds to "well-graded gravel "with silt"." If the soil has more than 15% by weight retained on a #4 sieve (R > 15%), there is a significant amount of gravel, and the suffix "with gravel" may be added to the group name, but the group symbol does not change. For example, SP-SM could refer to "poorly graded SAND with silt" or "poorly graded SAND with silt and gravel." Unified Soil Classification System The Unified Soil Classification System (USCS) is a soil classification system used in engineering and geology to describe the texture and grain size
Gravel Ridge, Arkansas $44,318. Males had a median income of $31,553 versus $21,903 for females. The per capita income for the CDP was $16,932. About 7.9% of families and 8.5% of the population were below the poverty line, including 10.6% of those under age 18 and 12.9% of those age 65 or over. The climate in this area is characterized by hot, humid summers and generally mild to cool winters. According to the Köppen Climate Classification system, Gravel Ridge has a humid subtropical climate, abbreviated "Cfa" on climate maps. Gravel Ridge, Arkansas Gravel Ridge is a former census-designated place (CDP) in Pulaski County,