Sediments erosion

The use of conservation tillage, made possible by triazine and other herbicides, has dramatically reduced soil erosion and its on- and off-site impacts. Significant benefits from the use of herbicides such as the triazines can be realized because conservation tillage reduces erosion, sedimentation, and flooding. By creating a crop field with many features comparable to those in natural areas, conservation tillage also provides other benefits to the environment and to wildlife. 

Cs 30 y Watershed erosion, sedimentation, and mixing Ritchie et al. (1974) Baskaran and Naidu (1995)... 

Rijsdijk, A., and Bniijnzeel, L. A. 1990 Erosion, sediment yield and land-use patterns in the Konto watershed, East Java, Indonesia. Konto River Project Communication no. 18, 2 Volumes. Konto River Project, Malang, Indonesia. 

Hillier, S., 1995. Erosion, sedimentation and sedimentary origin of clays. In Velde, B. (ed) Origin and mineralogy of clays. Springer Verlag, Berlin, Heidelberg, New York, pp 162-219. 

According to Whitt (1968), more than 3 million acres of land in the United States have been subjected to surface mining, and about two-thirds of this has left problems of soil erosion, sedimentation, and water pollution. Most of the affected land is privately owned and can be reclaimed and returned to productive use. 

VA Administrative Code Agency 25 Chapter 150 Virginia Gas and Oil Regulation Section 100 Operations plans Section 260 Erosion, sediment control and reclamation Section 270 Stormwater management... 

Physical and chemical processes that affect the transit of metals are taken into account in the model including advection, dispersion, erosion, sedimentation, and chemical reaction (spedation, adsorption, desorption, precipitation, and dissolution). Algorithms for the simulation of crucial metal transformation processes are thoroughly described in the User Manual (2). The modeling procedure is illustrated in Figure 1. 

Solids materials that are insoluble in hydrocarbon or water can be entrained in the crude. These are called bottom sediments and comprise fine particles of sand, drilling mud, rock such as feldspar and gypsum, metals in the form of minerals or in their free state such as iron, copper, lead, nickel, and vanadium. The latter can come from pipeline erosion, storage tanks, valves and piping systems, etc. whatever comes in contact with the crude oil. 

Physiographic development of the surface of the earth refers to the landforms and shapes of the landscape. These surface features are subject to continuous change from constructive (e.g., uplift, volcanic activity, and deposition of sediments) and destructive (e.g., erosion) processes. Landform modifications are continuous and sequential. These modifications establish a predictable continuity that can be helpful in determining certain aspects of relative geologic ages. 

Rivers transport suspended sediments derived from the disintegration of basin surface layers. With reduced velocity, sediment is deposited in the river channel. The finest material is carried to the sea. It has been estimated that the average mechanical denudation rate for continents is 0.056 mm year (35). This is based on a total suspended load of 13.5 x 10 metric tons year (S). Presently, about two-thirds of the world s total suspended sediment load derives from Southern Asia and large Pacific Islands. Berner has estimated the increase in sediment loss in the U.S. and world since prehuman times to be approximately 200% (35). Current estimated erosion rate from the major land forms is provided in Table I. The relatively recent construction of large sediment trapping dams that normally caused sediment to be deposited in river valleys or transported to the ocean has drastically reduced sediment yields in great rivers. 

The material transported by rivers consists of dissolved ions (dissolved load), sediment suspended in the flow (suspended load), and sediment transported along the bed of the river (bedload). The total load and the proportion of the load represented by these phases varies widely among rivers in different environments. In particular, climate, topography, and erosion influence the amount and composition of riverine sediment loads. 

Hallet, B., Hunter, L., and Bogen, J. (1996). Rates of erosion and sediment yield by glaciers A review of... 

The ocean surface represents the master base level for continental erosion and sedimentation. 

---