Search results
Results from the WOW.Com Content Network
Tennessee-Tombigbee Waterway (red) The locks and dams (L&D) along the Tennessee-Tombigbee Waterway The Tennessee–Tombigbee Waterway (popularly known as the Tenn-Tom) is a 234-mile (377 km) artificial U.S. waterway built in the 20th century from the Tennessee River to the junction of the Black Warrior-Tombigbee River system near Demopolis, Alabama.
The Unified Soil Classification System (USCS) is a soil classification system used in engineering and geology to describe the texture and grain size of a soil. The classification system can be applied to most unconsolidated materials, and is represented by a two-letter symbol. Each letter is described below (with the exception of Pt): If the ...
Cation-exchange capacity is defined as the amount of positive charge that can be exchanged per mass of soil, usually measured in cmol c /kg. Some texts use the older, equivalent units me/100g or meq/100g. CEC is measured in moles of electric charge, so a cation-exchange capacity of 10 cmol c /kg could hold 10 cmol of Na + cations (with 1 unit ...
A taxonomy is an arrangement in a systematic manner; the USDA soil taxonomy has six levels of classification. They are, from most general to specific: order, suborder, great group, subgroup, family and series. Soil properties that can be measured quantitatively are used in this classification system – they include: depth, moisture ...
Topsoil is composed of mineral particles and organic matter and usually extends to a depth of 5-10 inches (13–25 cm). Together these make a substrate capable of holding water and air which encourages biological activity. There are generally a high concentration of roots in topsoil since this is where plants obtain most of their vital nutrients.
The United States Merchant Marine [1] [2] is an organization composed of United States civilian mariners and U.S. civilian and federally owned merchant vessels.Both the civilian mariners and the merchant vessels are managed by a combination of the government and private sectors, and engage in commerce or transportation of goods and services in and out of the navigable waters of the United ...
Map of the United States showing what percentage of the soil in a given area is classified as an Ultisol-type soil. The great majority of the land area classified in the highest category (75%-or-greater Ultisol) lies in the South and overlays with the Piedmont Plateau, which runs as a diagonal line through the South from southeast (in Alabama) to northwest (up into parts of Maryland).
A bathymetric chart is a type of isarithmic map that depicts the submerged bathymetry and physiographic features of ocean and sea bottoms. [1] Their primary purpose is to provide detailed depth contours of ocean topography as well as provide the size, shape and distribution of underwater features. Topographic maps display elevation above ground ...