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Urban Stream
An urban stream is a formerly natural River, waterway that flows through a Urban area, heavily populated area. Often times, urban streams are low-lying points in the landscape that characterize catchment urbanization. Urban streams are often Water pollution, polluted by urban runoff and combined sewer outflows. Water scarcity makes flow management in the rehabilitation of urban streams problematic. Description Governments may alter the flow or course of an urban stream to prevent localized flooding by river engineering: lining stream beds with concrete or other hardscape materials, diverting the stream into culverts and storm sewers, or other means. Some urban streams, such as the subterranean rivers of London, run completely underground. These modifications have often reduced habitat for fish and other species, caused downstream flooding due to alterations of flood plains, and worsened water quality. Stressors Toxicants, ionic concentrations, nutrient pollution, available nutr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second River West Of High Jeh
The second (symbol: s) is a unit of Time in physics, time derived from the division of the day first into 24 hours, then to 60 minutes, and finally to 60 seconds each (24 × 60 × 60 = 86400). The current and formal definition in the International System of Units (SI) is more precise: The second [...] is defined by taking the fixed numerical value of the caesium frequency, Δ''ν''Cs, the unperturbed Ground state, ground-state hyperfine structure, hyperfine transition frequency of the caesium-133, caesium 133 atom, to be when expressed in the unit Hertz, Hz, which is equal to s−1. This current definition was adopted in 1967 when it became feasible to define the second based on fundamental properties of nature with caesium clocks. As the speed of Earth's rotation varies and is slowing ΔT (timekeeping), ever so slightly, a leap second is added at irregular intervals to civil time to keep clocks in sync with Earth's rotation. The definition that is based on of a Earth's rota ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flood Plain
A floodplain or flood plain or bottomlands is an area of land adjacent to a river. Floodplains stretch from the banks of a river channel to the base of the enclosing valley, and experience flooding during periods of high Discharge (hydrology), discharge.Goudie, A. S., 2004, ''Encyclopedia of Geomorphology'', vol. 1. Routledge, New York. The soils usually consist of clays, silts, sands, and gravels deposited during floods. Because of regular flooding, floodplains frequently have high soil fertility since nutrients are deposited with the flood waters. This can encourage farming; some important agricultural regions, such as the Nile and Mississippi Basin, Mississippi Drainage basin, river basins, heavily exploit floodplains. Agricultural and urban regions have developed near or on floodplains to take advantage of the rich soil and freshwater. However, the Flood risk, risk of inundation has led to increasing efforts to Flood control, control flooding. Formation Most floodplai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nonpoint Source Pollution
Nonpoint source (NPS) pollution refers to diffuse contamination (or pollution) of water or air that does not originate from a single discrete source. This type of pollution is often the cumulative effect of small amounts of contaminants gathered from a large area. It is in contrast to point source pollution which results from a single source. Nonpoint source pollution generally results from land runoff, precipitation, atmospheric deposition, drainage, seepage, or hydrological modification (rainfall and snowmelt) where tracing pollution back to a single source is difficult. Nonpoint source water pollution affects a water body from sources such as polluted runoff from agricultural areas draining into a river, or wind-borne debris blowing out to sea. Nonpoint source air pollution affects air quality, from sources such as smokestacks or car tailpipes. Although these pollutants have originated from a point source, the long-range transport ability and multiple sources of the pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nationwide Urban Runoff Program
The Nationwide Urban Runoff Program (NURP) was a research project conducted by the United States Environmental Protection Agency (EPA) between 1979 and 1983. It was the first comprehensive study of urban stormwater pollution across the United States. Study objectives The principal focus areas of the study consisted of: * Examine the water quality aspects of urban runoff, and a comparison of results across various urban sites * Assess the impact of urban runoff on overall water quality * Implement stormwater management best practices. A major component of the project was an analysis of water samples collected during 2,300 storms in 28 major metropolitan areas. Findings Among the conclusions of the report are the following: * "Heavy metals (especially copper, lead and zinc) are by far the most prevalent priority pollutant constituents found in urban runoff...Copper is suggested to be the most significant hreat/nowiki> of the three." * "Coliform bacteria are present at high leve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Runoff
Surface runoff (also known as overland flow or terrestrial runoff) is the unconfined flow of water over the ground surface, in contrast to ''channel runoff'' (or ''stream flow''). It occurs when excess rainwater, stormwater, meltwater, or other sources, can no longer sufficiently rapidly infiltrate in the soil. This can occur when the soil is #Saturation excess overland flow, saturated by water to its full capacity, and the rain arrives #Infiltration excess overland flow, more quickly than the soil can absorb it. Surface runoff often occurs because wikt:impervious#Adjective, impervious areas (such as roofs and Road surface, pavement) do not allow water to soak into the ground. Furthermore, runoff can occur either through natural or human-made processes. Surface runoff is a major component of the water cycle. It is the primary agent of Soil erosion#Rainfall and runoff, soil erosion by water. The land area producing runoff that drains to a common point is called a drainage basin. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Onondaga Lake
Onondaga Lake is located in Central New York, immediately northwest of and adjacent to Syracuse, New York. The southeastern end of the lake and the southwestern shore are industrial areas and expressways; the northeastern shore and northwestern end border a series of parks and museums. It is surrounded by Liverpool, New York, Liverpool. Although it is near the Finger Lakes region, it is not traditionally counted as one of the Finger Lakes. Onondaga Lake is a dimictic lake, meaning that the lake water completely mixes from top to bottom twice a year. The lake is long and wide making a surface area of . The maximum depth of the lake is with an average depth of . Its drainage basin has a surface area of , encompassing Syracuse, Onondaga County except the eastern and northern edges, the southeastern corner of Cayuga County and the Onondaga Nation, Onondaga Nation Territory, and supports approximately 450,000 people.() Onondaga Lake has two natural tributaries that contribute ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York Times
''The New York Times'' (''NYT'') is an American daily newspaper based in New York City. ''The New York Times'' covers domestic, national, and international news, and publishes opinion pieces, investigative reports, and reviews. As one of the longest-running newspapers in the United States, the ''Times'' serves as one of the country's Newspaper of record, newspapers of record. , ''The New York Times'' had 9.13 million total and 8.83 million online subscribers, both by significant margins the List of newspapers in the United States, highest numbers for any newspaper in the United States; the total also included 296,330 print subscribers, making the ''Times'' the second-largest newspaper by print circulation in the United States, following ''The Wall Street Journal'', also based in New York City. ''The New York Times'' is published by the New York Times Company; since 1896, the company has been chaired by the Ochs-Sulzberger family, whose current chairman and the paper's publ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stormwater
Stormwater, also written storm water, is water that originates from precipitation (storm), including heavy rain and meltwater from hail and snow. Stormwater can soak into the soil ( infiltrate) and become groundwater, be stored on depressed land surface in ponds and puddles, evaporate back into the atmosphere, or contribute to surface runoff. Most runoff is conveyed directly as surface water to nearby streams, rivers or other large water bodies (wetlands, lakes and oceans) without treatment. In natural landscapes, such as forests, soil absorbs much of the stormwater. Plants also reduce stormwater by improving infiltration, intercepting precipitation as it falls, and by taking up water through their roots. In developed environments, such as cities, unmanaged stormwater can create two major issues: one related to the volume and timing of runoff ( flooding) and the other related to potential contaminants the water is carrying (water pollution). In addition to the pollutants carr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erosion
Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, transports it to another location where it is deposit (geology), deposited. Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as ''physical'' or ''mechanical'' erosion; this contrasts with ''chemical'' erosion, where soil or rock material is removed from an area by Solvation, dissolution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Agents of erosion include rainfall; bedrock wear in rivers; coastal erosion by the sea and Wind wave, waves; glacier, glacial Plucking (glaciation), plucking, Abrasion (geology), abrasion, and scour; areal flooding; Aeolian processes, wind abrasion; groundwater processes; and Mass wastin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daylighting (streams)
Daylighting is the opening up and restoration of a previously buried watercourse, one which had at some point been diverted below ground. Typically, the rationale behind returning the riparian environment of a stream, wash, or river to a more natural above-ground state is to reduce runoff, create habitat for species in need of it, or improve an area's aesthetics. In the United Kingdom, the practice is also known as deculverting. In addition to its use in urban design and urban planning, planning the term also refers to the public process of advancing such projects. According to the Planning and Development Department of the City of Berkeley, "A general consensus has developed that protecting and restoring natural creeks' functions is achievable over time in an urban environment while recognizing the importance of property rights." Systems Natural drainage systems Natural drainage systems help Stormwater#Stormwater management, manage stormwater by Infiltration (hydrology), infil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stream Restoration
Stream restoration or river restoration, also sometimes referred to as river reclamation, is work conducted to improve the environmental health of a river or stream, in support of biodiversity, recreation, flood management and/or landscape development. Stream restoration approaches can be divided into two broad categories: form-based restoration, which relies on physical interventions in a stream to improve its conditions; and process-based restoration, which advocates the restoration of Hydrology, hydrological and Geomorphology, geomorphological processes (such as sediment transport or connectivity between the Channel (geography), channel and the floodplain) to ensure a stream's Ecological resilience, resilience and ecological health. Form-based restoration techniques include deflectors; cross-vanes; weirs, step-pools and other grade-control structures; engineered log jams; bank stabilization methods and other channel-reconfiguration efforts. These induce immediate change in a st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dissolved Oxygen
Oxygen saturation (symbol SO2) is a relative measure of the concentration of oxygen that is dissolved or carried in a given medium as a proportion of the maximal concentration that can be dissolved in that medium at the given temperature. It can be measured with a dissolved oxygen probe such as an oxygen sensor or an optode in liquid media, usually water. The standard unit of oxygen saturation is percent (%). Oxygen saturation can be measured regionally and noninvasively. Arterial oxygen saturation (SaO2) is commonly measured using pulse oximetry. Tissue saturation at peripheral scale can be measured using NIRS. This technique can be applied on both muscle and brain. In medicine In medicine, oxygen saturation refers to ''oxygenation'', or when oxygen molecules () enter the tissues of the body. In this case blood is oxygenated in the lungs, where oxygen molecules travel from the air into the blood. Oxygen saturation (() sats) measures the percentage of hemoglobin bindin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
