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Wind Energy Resource
Published in D. Yogi Goswami, Frank Kreith, Energy Conversion, 2017
Ridges are elongated hills with a length-to-height ratio of at least 10 that have little or no flat area on the summit. As illustrated in Figure 7.12, the ideal prevailing wind direction for wind turbine siting should be perpendicular to the ridge axis. When the prevailing wind is not perpendicular to the axis, the ridge will not be as attractive a site. Concavity in the windward direction enhances speedup, and convexity reduces speedup by deflecting the wind flow around the ridge. The slope of a ridge is also an important parameter; steeper slopes give rise to stronger wind flow, but they also give rise to high turbulence in the lee of the ridge.
New City in Asia
Published in Spiro N. Pollalis, Planning Sustainable Cities, 2016
The main features of the DCK site’s natural topography are steep ridges and slopes. Extensive topographical analysis was done in order to provide the basis for deciding on the development of the city’s networks and constructions with the least intervention in these landscape features. The majority of the ridges were conserved and integrated with the landscape system, allowing large areas to contribute to the services and functions of the landscape infrastructure system.
Influence of Land Use, Soils, and Cultural Practices on Erosion, Eroded Carbon, and Soil Carbon Stocks at the Plot Scale in the Mediterranean Mountains of Northern Algeria
Published in Eric J. Roose, Rattan Lal, Christian Feller, Bernard Barthès, Bobby A. Stewart, Soil Erosion and Carbon Dynamics, 2005
Boutkhil Morsli, Mohamed Mazour, Mourad Arabi, Nadjia Mededjel, Eric Roose
Considering land management, the results indicate that continuous cultivation did not increase the erosion risks, even under traditional systems. However, bare and compacted soils, abandoned fields, overgrazed fallows, or degraded scrub lands can produce high runoff and increase risk of gully formation and landslides. Ridge cropping and protecting fallows and scrub land can reduce erosion risks and increase the SOC and the biomass production. Use of innovative and improved cultural practices (appropriate fertilizer rate, seed selection, ridging, and adapted cultural practices like crop rotations and intercropping) incorporated in the best traditional farming systems, as land husbandry, increased production (yield of cereals multiplied by 2 to 4 on improved plots), decreased erosion risk, and increased SOC (up to 28% increase) (Roose, 1993). Other antierosive techniques (gully management, stone walls, hedges, planting on the contour, etc.) are effective in trapping sediments and organic matters. The land husbandry approach has demonstrated that it is possible to improve crop production in the hilly regions (intensification and diversification) while enhancing the environment (Arabi and Roose, 1992; Roose, 1993; Mazour and Roose, 2002; Hamoudi and Morsli, 2003). In Algeria, where land use is rapidly changing, the national projects on rural development are based on the land husbandry strategy with the participatory approach (Morsli et al., 2004). Fruit tree plantations, improved cultural practices and water management, agroforestry, and grazing regulation are the most widely used strategies for the rural development. These improved practices have a positive effect on productivity, soil erosion control, and carbon sequestration. Nevertheless, Algeria needs additional research regarding the effects of conservation cultural practices (like no-till and mulch farming) on carbon sequestration and soil productivity.
Risk assessment of human exposure to radionuclides and heavy metals in oil-based mud samples used for drilling operation
Published in International Journal of Environmental Health Research, 2022
Emmanuel E. Okoro, Chidiebere Ochonma, Samuel E. Sanni, Omeje M., Kevin C. Igwilo, Olukunle C. Olawole
The study area is Field X located in Bayelsa State, Nigeria. A lowland state characterized by coastal beaches, beach ridge barriers, tidal flats, and flood plains. The climate for Bayelsa State can be classified as Tropical and the location is classified as Am under the Köppen and Geiger standard. The state experiences three weather conditions which are the humid rainy, warm and dry seasons. The state climate can be seen as an equatorial type towards the southern parts, and the northern parts experience tropical rain. They experience a heavy downpour of rain every month but it decreases from parts of the south down the north. The temperature is said to be uniform in the state, and it is between 26°C and 31°C. The height decreases downstream. It is bound by latitudes 4° 44ʹ 59.99” N and longitudes 6° 04ʹ 60.00” E; and the town where the oil and gas field is located is confidential and protected by Nigeria Law. The geology of Niger Delta covers about 256,000 km. Initially, it was the older transgressive Paleocene prodelta that transformed into discreet minibasins. These minibasins exhibit several tectonic configurations ranging from extensional, translational and the compressional toe-thrust region. The Niger Delta outcropping units comprise of the Imo Formation and the Ameki Group (Adebiyi 2015).
Quantifying blue carbon for the largest salt marsh in southern British Columbia: implications for regional coastal management
Published in Coastal Engineering Journal, 2021
Maija Gailis, Karen Elizabeth Kohfeld, Marlow G. Pellatt, Deborah Carlson
Despite historical modification of the marsh, the western portion of the Boundary Bay marsh is growing (Figure 5). Marsh expansion is a rare event in coastal marshes and is usually due to anthropogenic land changes and accumulation of debris from hydraulic mining (Watson 2008). Kellerhals and Murray (1969) hypothesized that western Boundary Bay marsh is prograding in response to tidal influence, sedimentation and vegetation growth, and ecological interactions that influence the growth of hummocks and eventual cohesion with the marsh. They surmised that the large quantities of eelgrass and algae are rafted onto hummocks and then covered with sand from strong winter storms. The new relief is then colonized with blue-green algal mats which then allow for typical sediment trapping and eventual halophyte propagation. The farthest western portion of the marsh contains a large beach ridge that was not present in the 1930s (Figure 5 and A6) (Engels and Roberts 2005). The area contained large logs and flotsam that blocked a large channel and has since been overgrown by vegetation (Kellerhalls and Murray 1969).
Geoheritage values of consanguineous wetland suites on the Swan Coastal Plain, Western Australia
Published in Australian Journal of Earth Sciences, 2019
The size and shape of wetland basins vary according to their geomorphic setting and the shape of the depressions that will become wetland basins. Thus, there are beach-ridge swale depressions, linear limestone-ridge depressions, karst depressions, ovoid depressions, inter-star-dune depressions and so on. The composition of surface sediments and the stratigraphy of the wetland fills also varies according to geological and geomorphic setting, climate, and host-water chemistry, and hence there is a pattern of stratigraphic sequences in relationship to geologic/geomorphic setting. For sediments and stratigraphy, variation can occur in an east–west transect, and from south to north on the Swan Coastal Plain. The east–west distribution can be related to consanguineous suites, and the south–north distribution is related to consanguineous suites and to climate.