A wetland is a distinct ecosystem, flooded by water, either permanently or seasonally, where oxygen-free processes prevail. The primary factor that distinguishes wetlands from other land forms or water bodies is the characteristic vegetation of aquatic plants, adapted to the unique hydric soil. Wetlands play a number of functions, including water purification, water storage, processing of carbon and other nutrients, stabilization of shorelines, support of plants and animals. Wetlands are considered the most biologically diverse of all ecosystems, serving as home to a wide range of plant and animal life. Whether any individual wetland performs these functions, the degree to which it performs them, depends on characteristics of that wetland and the lands and waters near it. Methods for assessing these functions, wetland ecological health, general wetland condition have been developed in many regions and have contributed to wetland conservation by raising public awareness of the functions and the ecosystem services some wetlands provide.
Wetlands occur on every continent. The main wetland types are swamp, marsh and fen. Many peatlands are wetlands; the water in wetlands is either brackish, or saltwater. Wetlands can be non-tidal; the largest wetlands include the Amazon River basin, the West Siberian Plain, the Pantanal in South America, the Sundarbans in the Ganges-Brahmaputra delta. The UN Millennium Ecosystem Assessment determined that environmental degradation is more prominent within wetland systems than any other ecosystem on Earth. Constructed wetlands are used to treat municipal and industrial wastewater as well as stormwater runoff, they may play a role in water-sensitive urban design. A patch of land that develops pools of water after a rain storm would not be considered a "wetland" though the land is wet. Wetlands have unique characteristics: they are distinguished from other water bodies or landforms based on their water level and on the types of plants that live within them. Wetlands are characterized as having a water table that stands at or near the land surface for a long enough period each year to support aquatic plants.
A more concise definition is a community composed of hydric soil and hydrophytes. Wetlands have been described as ecotones, providing a transition between dry land and water bodies. Mitsch and Gosselink write that wetlands exist "...at the interface between terrestrial ecosystems and aquatic systems, making them inherently different from each other, yet dependent on both."In environmental decision-making, there are subsets of definitions that are agreed upon to make regulatory and policy decisions. A wetland is "an ecosystem that arises when inundation by water produces soils dominated by anaerobic and aerobic processes, which, in turn, forces the biota rooted plants, to adapt to flooding." There are four main kinds of wetlands – marsh, swamp and fen. Some experts recognize wet meadows and aquatic ecosystems as additional wetland types; the largest wetlands in the world include the swamp forests of the Amazon and the peatlands of Siberia. Under the Ramsar international wetland conservation treaty, wetlands are defined as follows: Article 1.1: "...wetlands are areas of marsh, peatland or water, whether natural or artificial, permanent or temporary, with water, static or flowing, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six metres."
Article 2.1: " may incorporate riparian and coastal zones adjacent to the wetlands, islands or bodies of marine water deeper than six metres at low tide lying within the wetlands." Although the general definition given above applies around the world, each county and region tends to have its own definition for legal purposes. In the United States, wetlands are defined as "those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, that under normal circumstances do support, a prevalence of vegetation adapted for life in saturated soil conditions. Wetlands include swamps, marshes and similar areas"; this definition has been used in the enforcement of the Clean Water Act. Some US states, such as Massachusetts and New York, have separate definitions that may differ from the federal government's. In the United States Code, the term wetland is defined "as land that has a predominance of hydric soils, is inundated or saturated by surface or groundwater at a frequency and duration sufficient to support a prevalence of hydrophytic vegetation adapted for life in saturated soil conditions and under normal circumstances supports a prevalence of such vegetation."
Related to this legal definitions, the term "normal circumstances" are conditions expected to occur during the wet portion of the growing season under normal climatic conditions, in the absence of significant disturbance. It is not uncommon for a wetland to be dry for long portions of the growing season. Wetlands can be dry during the dry season and abnormally dry periods during the wet season, but under normal environmental conditions the soils in a wetland will be saturated to the surface or inundated such that the soils become anaerobic, those conditions will persist through the wet portion of the growing season; the most important factor producing wetlands is flooding. The duration of flooding or prolonged soil saturation by groundwater determines whether the resulting wetland has aquatic, marsh or swamp vegetation. O
Scolty Hill is a small hill south of the Deeside town, Banchory. Its best known feature is the 20m tall tower monument, built in 1840 as a memorial to General William Burnett who fought alongside Wellington; the tower was restored in 1992 and a viewing platform added by the Rotary Club of Banchory-Ternan. It enjoys splendid views over Banchory, the Dee Valley and the Grampian Mountains, which surround the hill; this encourages thousands of visitors each year. It is popular for tourists and mountain bikers. Part of the hill is owned by the Forestry Commission, the other part is owned by local landowner Ron Middleton. Recent forestry work has meant. However, once this is completed the Scolty Woodland Park Association plan on recreating some of the paths on the hill and local mountain bikers plan on creating a downhill mountain bike track, similar to the one at Pitfichie. Forestry Commission website Walking Scotland - Scolty Hill Banchory Community Website Visit Banchory -Gateway to Royal Deeside Banchory Biking Rotary Club of Banchory-Ternan
Vehicle infrastructure integration is an initiative fostering research and applications development for a series of technologies directly linking road vehicles to their physical surroundings and foremost in order to improve road safety. The technology draws on several disciplines, including transport engineering, electrical engineering, automotive engineering, computer science. VII covers road transport although similar technologies are in place or under development for other modes of transport. Planes, for example, use ground-based beacons for automated guidance, allowing the autopilot to fly the plane without human intervention. In highway engineering, improving the safety of a roadway can enhance overall efficiency. VII targets improvements in both efficiency. Vehicle infrastructure integration is that branch of engineering, which deals with the study and application of a series of techniques directly linking road vehicles to their physical surroundings in order to improve road safety; the goal of VII is to provide a communications link between vehicles on the road, between vehicles and the roadside infrastructure, in order to increase the safety and convenience of the transportation system.
It is based on widespread deployment of a dedicated short-range communications link, incorporating IEEE 802.11p. VII's development relies on a business model supporting the interests of all parties concerned: industry, transportation authorities and professional organisations; the initiative has three priorities: evaluation of the business model and acceptance by the stakeholders. Current active safety technology relies on vehicle-based vision systems. For example, this technology can reduce rear-end collisions by tracking obstructions in front or behind the vehicle, automatically applying brakes when needed; this technology is somewhat limited in that it senses only the distance and speed of vehicles within the direct line of sight of cameras and the sensing range of radars. It is completely ineffective for angled and left-turn collisions, it may cause a motorist to lose control of the vehicle in the event of an impending head-on collision. The rear-end collisions covered by today's technology are less severe than angle, left-turn, or head-on collisions.
Existing technology is therefore inadequate for the overall needs of the roadway system. VII would provide a direct link between a vehicle on the road and all vehicles within a defined vicinity; the vehicles would be able to communicate with each other, exchanging data on speed, orientation even on driver awareness and intent. This could increase safety for nearby vehicles, while enhancing the overall sensitivity of the VII system, for example, by performing an automated emergency maneuver more effectively. In addition, the system is designed to communicate with the roadway infrastructure, allowing for complete, real-time traffic information for the entire network, as well as better queue management and feedback to vehicles, it would close the feedback loops on what is now an open-loop transportation system. Through VII, roadway markings and road signs could become obsolete. Existing VII applications use sensors within vehicles which can identify markings on the roadway or signing along the side of the road, automatically adjusting vehicle parameters as necessary.
VII aims to treat such signs and markings as little more than stored data within the system. This could be in the form of data acquired via beacons along a roadway or stored at a centralised database and distributed to all VII-equipped vehicles. All the above factors are in response to safety but VII could lead to noticeable gains in the operational efficiency of a transportation network; as vehicles will be linked together with a resulting decrease in reaction times, the headway between vehicles could be reduced so that there is less empty space on the road. Available capacity for traffic would therefore be increased. More capacity per lane will in turn mean fewer lanes in general satisfying the community's concerns about the impact of roadway widening. VII will enable precise traffic-signal coordination by tracking vehicle platoons and will benefit from accurate timing by drawing on real-time traffic data covering volume and turning movements. Real-time traffic data can be used in the design of new roadways or modification of existing systems as the data could be used to provide accurate origin-destination studies and turning-movement counts for uses in transportation forecasting and traffic operations.
Such technology would lead to improvements for transport engineers to address problems whilst reducing the cost of obtaining and compiling data. Tolling is another prospect for VII technology as it could enable roadways to be automatically tolled. Data could be collectively transmitted to road users for in-vehicle display, outlining the lowest cost, shortest distance, and/or fastest route to a destination on the basis of real-time conditions. To some extent, results along these lines have been achieved in trials performed around the globe, making use of GPS, mobile phone signals, vehicle registration plates. GPS is becoming standard in many new high-end vehicles and is an option on most new low- and mid-range vehicles. In addition, many users have mobile phones which transmit trackable signals (and may be GPS-