China
Africa
Explore chapters and articles related to this topic
Water Hydraulics
Published in Frank R. Spellman, The Science of Water, 2020
Discharge (or flow) is the quantity of water passing a given point in a pipe or channel during a given period. This may be stated another way for open channels: The flow rate through an open channel is directly related to the velocity of the liquid and the cross-sectional area of the liquid in the channel: Q=A×V
Water Hydraulics
Published in Frank R. Spellman, Handbook of Water and Wastewater Treatment Plant Operations, 2020
Discharge (or flow) is the quantity of water passing a given point in a pipe or channel during a given period. Stated another way for open channels, the flow rate through an open channel is directly related to the velocity of the liquid and the cross-sectional area of the liquid in the channel. Q=A×V
The Flood Hydrograph
Published in Richard J. Chorley, Introduction to Physical Hydrology, 2019
Thus the discharge hydrograph consists of a series of irregular saw-tooth-shaped fluctuations superimposed on a gently undulating section. These two components are usually defined as storm runoff (or the flood hydrograph) and base flow, the latter being attributed to ground-water discharge. A further analysis of the hydrograph has been made by separating storm runoff according to the path to the river. The initial rise in the hydrograph is attributed to channel precipitation – water falling directly on to the connected water surfaces of a basin- while the bulk of the increase in discharge is said to be caused by surface runoff. Interflow is the third component, and this water, which moves laterally through the upper soil horizons until it is intercepted by a stream channel, is particularly important during recession.
Towards an AI-based early warning system for bridge scour
Published in Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, 2023
Negin Yousefpour, Oscar Correa
In order to explore whether velocity is a critical feature in presence of stage time-series, we incorporated the discharge measurements (discharge), obtained from the USGS website, into the LSTM models for bridge 742 as an input feature and compared the performance among three different feature combinations: ssd:[sonar, stage, discharge], sd:[sonar, discharge] and ss:[sonar, stage]. The USGS measurements at gaging stations are fully explained in Sauer and Turnipseed (2010). The most practical method of measuring the discharge of a stream is the velocity-area method. Discharge is computed as the product of the area and velocity. The measurement is made by subdividing a channel cross section into segments and by measuring the depth and velocity in a vertical within each segment. The velocity is measured through various methods such as current-meter, ADV (Acoustic Doppler Velocimeter) and ADCP (Acoustic Doppler Current Profiler).
GIS-based risk assessment of tropical surface water pollution by integrating hydrogeological and anthropogenic parameters
Published in Human and Ecological Risk Assessment: An International Journal, 2023
Muhammad Firdaus Umar Saifuddin, Zulfa Hanan Ash’aari, Ahmad Zaharin Aris, Zed Diyana
Watershed size is also an important factor because it determines the likelihood and influence of different land use establishment such as residential, recreational, and industrial land use on water quality (Azyana et al. 2012; Alavipoor et al. 2016). Generally, a larger watershed is more susceptible to water pollution because there is usually more establishment and higher discharge. Table 5 contains the area of each sub-basin in the Selangor River Basin. Based on Table 5, Rawang has the largest sub-basin area, followed by Tanjung Karang, Kerling, Batang Kali and Hulu Selangor. There is an interaction between river discharge and land use on how it affects the water quality. Agricultural activities and high discharge cause the mobilization of high concentrations of sediment, total nitrogen, and total phosphorus (Uwimana et al. 2017). However, there is a variation in this interaction as “buildup, washout and dilution mechanism” and seasonal variation affects the transport and concentration of the nutrients (Uwimana et al. 2017). In addition, river discharge is also dependent on factors like precipitation, infiltration, evaporation, and evapotranspiration. In fact, watersheds with high runoff but small area can have the same amount of discharge as rivers with a larger watershed area but low runoff (Milliman and Giosan 2019). Thus, there is still an ongoing debate regarding the impact of watershed size on water quality because each watershed has unique features that can influence the water quality (Azyana et al. 2012).
Assessing the impacts of vehicle wash wastewater on surface water quality through physico-chemical and benthic macroinvertebrates analyses
Published in Water Science, 2020
Reeta Rai, Subodh Sharma, D.B. Gurung, Bishal K. Sitaula, Ram Devi Tachamo Shah
Vehicle washing consumes large quantity of water, involves the use of chemicals, and generates potentially toxic wastewater effluents (Zaneti, Etchepare, & Rubio, 2012). VWW contains a wide range of contaminants such as petroleum hydrocarbon wastes (petrol, diesel, and motor oil), nutrients (phosphorous and nitrogen), surfactants, asphalt, salts, organic matter, and heavy metals (Boluarte et al., 2016; Hamada & Miyazaki, 2004; Smith & Shilley, 2009). Discharge of such contaminants into the surface water bodies degrade water quality which in turn affect aquatic ecosystems and also impair the use of water for household, industrial, agricultural, and recreational purposes. The surface water pollution due to untreated VWW has been mostly reported from developing countries like Ghana (Aikins & Boakye, 2015), India (Mazumber & Mukherjee, 2011), Pakistan (Yasin, Iqbal, Arshad, Rustam, & Zafar, 2012), and Zimbabwe (Danha, Utete, Soropa, & Rufasha, 2014). Corresponding to these studies, Sato, Qadir, Yamamoto, Endo, and Zahoor (2013) have also reported that in low-income countries, only 8% of industrial and municipal wastewaters are treated. Such practices in developing countries could be due to lack of awareness on impacts, unaffordable establishments and operating costs of treatment plants, and less attention from the policy makers.