China
Africa
Explore chapters and articles related to this topic
Strong wind characteristics and turbulence
Published in John D. Holmes, Seifu A. Bekele, Wind Loading of Structures, 2020
John D. Holmes, Seifu A. Bekele
A well-documented and detailed description of the atmospheric boundary layers in temperate synoptic systems, for wind-loading purposes, is given in a series of data items published by the Engineering Sciences Data Unit (ESDU, 1974–1999). These include the effects of topographic and terrain changes. Teunissen (1970) and Counihan (1975) also provided a comprehensive review of adiabatic (i.e. neutrally stable) atmospheric boundary layer data. Cook (1985) described, for the designer, a structure of the atmospheric boundary layer, which is consistent with the ESDU models. Assessment of roughness parameters for terrains of various types (Wieringa, 1993), and the effects of terrain changes and topography on boundary-layer winds have been studied and reviewed extensively in journals such as Boundary-Layer Meteorology (Springer) and the Quarterly Journal of the Royal Meteorological Society (UK).
Siting
Published in Vaughn Nelson, Kenneth Starcher, Wind Energy, 2018
Vaughn Nelson, Kenneth Starcher
Wind maps, data compiled by meteorological towers, models, and other criteria are used to select wind farm locations. Other considerations for a wind farm developer are the type of terrain (complex to flat plain), wind shear, wind direction, and spacing of turbines based on predominant wind direction and availability, land cost, and requirements such as roads, turbine foundations, and substations. Terrain may be classified as complex, mesa, rolling, or plain. Passes may be classified as one type or a combination. Spacing is generally stated as diameter D of a wind turbine, so larger turbines will be farther apart.
Visualizing Terrain
Published in Terry A. Slocum, Robert B. McMaster, Fritz C. Kessler, Hugh H. Howard, Thematic Cartography and Geovisualization, 2022
Terry A. Slocum, Robert B. McMaster, Fritz C. Kessler, Hugh H. Howard
Whereas Section 17.7 dealt with approaches for symbolizing a broad range of smooth, continuous phenomena, in this chapter, we consider approaches for symbolizing a particular type of smooth, continuous phenomenon—Earth's terrain. By “terrain,” we mean Earth's elevation (both above and below sea level) and associated features found on Earth—its landscape. Specialized techniques have been developed for symbolizing terrain because of its importance in everyday life and in the burgeoning area of GIS.
Physically-based landslide susceptibility analysis using Monte Carlo simulation in a tropical mountain basin
Published in Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, 2020
Roberto J. Marin, Álvaro J. Mattos
Physically-based models (Montgomery and Dietrich 1994; Pack, Tarboton, and Goodwin 1998; Baum, Savage, and Godt 2002; Montrasio and Valentino 2008; Reid et al. 2015; Aristizábal et al. 2016) have been developed to describe these processes and the physical laws associated to the landslide occurrence in a simplified way to allow a spatially distributed slope stability analysis over large areas of terrain (Raia et al. 2014). They are very effective for landslide susceptibility assessment (Fell et al. 2005; Lee and Park 2016). Commonly, in those models the geomechanical and hydraulic soil parameters are defined deterministically even though the information to characterise the soil properties is scarce throughout the entire terrain, generating an unquantified uncertainty both in these input variables and in the factor of safety (FS) results (Zhang et al. 2018).
Selection of suitable site in Pakistan for wind power plant installation using analytic hierarchy process (AHP)
Published in Journal of Control and Decision, 2018
Yousaf Ali, Masab Butt, Muhammad sabir, Ubaidullah Mumtaz, Aneel Salman
Terrain type is also a very important factor to be taken into consideration before installing wind farm. Terrain is basically the type of landscape or ground. Different types of terrain for the wind farm yields different wind shear and resistance that ultimately effects the performance of the wind turbine and thus electricity generation. In order to mollify its effect we chose 50 metres height, as per the modern technology and advanced research, it is recommended to use this height as the optimum height because the terrain effect is almost negligible and below 50 metres.
Delineation and mapping of palaeochannels using remote sensing, geophysical, and sedimentological techniques: A comprehensive approach
Published in Water Science, 2021
Ritambhara K. Upadhyay, Naval Kishore, Mukta Sharma
For the analyses of terrain elevation, LiDAR data determine a common dataset which is the digital elevation model (DEM), and a raster dataset, specifically used for the modeling of hydrological surface flows such as flood estimation mapping (Charrier & Li., 2012; Jones, Poole, O’Daniel, Mertes, & Stanford, 2008). A 3D point-cloud dataset is used to calculate the DEM. It consists of the recorded points of terrain surface contact of the emitted and received laser pulses (Straatsma & Middelkoop, 2006). Using filter algorithms, DEMs can produce erroneous elevation data if ground points are not separated from vegetation canopy points, which may lead to the differentiation of bare ground point data from non-ground point data (Straatsma & Middelkoop, 2006). However, Hopkinson et al. (2005) stated that the reason for the underestimation of canopy surface DEM data and overestimation of bare ground DEM data can be found due to the penetration of lasers through canopy foliage, especially the low vegetation foliage. As a technique for correcting LiDAR height biases, the establishment of penetration measurements is recommended. It is, however, taken into account that only the penetration measurements which are dependent on vegetation class should be used. The use of airborne LiDAR data and LiDAR-derived DEMs in smooth and level, sparsely vegetated fluvial and alluvial floodplain studies, are used as tools for palaeochannel identification (Budja & Mlekuz, 2010; Challis, 2011; Chiverrell, Thomas, & Foster, 2008; Hohenthal, Alho, Hyyppä, & Hyyppä, 2011). Survey of the places where the study of terrain elevation is difficult or there is a lower ground access for the survey of the field, which is often expensive and time-consuming, Airborne LiDAR surveying techniques are often used to ease the process of the analysis of topography. Since there is a regular acquisition of the data obtained from this technology, there is scope to provide an additional tool to combine Landsat and GPR data for palaeochannel exploration.