Erosion control functions

Some coastal environments may be regarded as rather stable (rock and reef coasts) while others are more vulnerable (sand and mud coasts, soft cliffs). In this last case, coastal users and managers aU over the world are frequently faced with serious erosion of their sandy coasts. Possible causes of erosion include natural processes (i.e., action of waves, tides, currents, sea level rise, etc.) and sediment deficit due to human impact (i.e., river regulations, sand mining, and coastal engineering works). Countermeasmes for beach erosion control function depend on local conditions of shore and beach, coastal chmate, and sediment transport. Continuous maintenance and improvement of the coasthnes, together with monitoring and studies of coastal processes have yielded considerable experience on various coastal protection measures all over the world. 

In more recent applications, several types of ET cover designs also have incorporated synthetic materials, such as geomembranes, which are used to enhance the function of minimizing water into the waste. For example, the Operating Industries Inc. Landfill in California has incorporated a soil layer with a geosynthetic clay liner in the design. The cover system for this site will reduce surface gas emissions, prevent oxygen intrusion and percolation, and provide for erosion control.68... 

Thus, the amount of drug released is proportional to the square root oftjiBe ndCs. In some cases, diffusion is not the only pathway by which a drug is released from the delivery system. The erosion of the delivery matrix following relaxation of the polymer and other functional excipient(s) contributes to the overall drug release as well. Discussed below are examples of the diffusion- and erosion-controlled matrix delivery systems. 

Wetland values are dependent on social perceptions. The valued functions have historically included water storage, flood control, erosion control, sediment control, nutrient removal, protection of general water quality, habitat for crops and fisheries, recreation, and wildlife... 

Erosion control fabrics n. Fabrics used in the stabilization of embankments and the containment of silt run-off from erodible slopes. In embankment stabilization, the fabric functions as a filter medium behind stabilizing rip-rap revetments. In siltation control, the fabric acts as a filter to contain silt while allowing excess water to drain freely. In turf reinforcement, the mat is used to retain soil while allowing roots and stems to grow through. In fabric-forming systems for the construction of revetments, a double-layer, water-permeable fabric is positioned, then pumped full of structural grout. These systems are alternatives to rip-rap. 

Coir-based geotextiles have both the benefits of biodegradabihty and durability required for the slow establishment of vegetative cover. Various open-weave coir geotextiles are employed in erosion control for reinforcement and embankment applications. Typical functional specifications for a woven coir geotextile are ... 

In aU of these functions, the geosynthetic is acting in one of two unique ways either it is actively controlling the dislodgement of soil, called erosion control, or it is intercepting and filtering the dislodged soil, called sediment, out of suspension once it has been transported by mnoff, called sediment control or sediment retention. 

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