scholarly journals Regime equations development for the design of Egyptian sandy canals

2020 ◽  
Vol 15 (4) ◽  
pp. 999-1010
Author(s):  
Ahmed A. Arafa ◽  
Nahla M. AboulAtta ◽  
Tarek A. El-Samman ◽  
Neveen Y. Saad
Keyword(s):  
Sensitivity Analysis ◽  
Carrying Capacity ◽  
Sandy Soils ◽  
Field Measurements ◽  
Irrigation Canals ◽  
High Aswan Dam ◽  
Extensive Field ◽  
Aswan Dam ◽  
Solids Suspension

Abstract The construction of the High Aswan Dam in Egypt led to reducing the solids suspension in water from more than 3,500 p.p.m. to less than 100 p.p.m. As the regime of Egyptian canals has been changed completely after the construction of the High Aswan Dam, the previous derived equations are not applicable any more, and using them leads to a shortage in the carrying capacity of the canals. In the current study, extensive field measurements have been carried out on 15 stable Egyptian canals, which cover various discharges of irrigation canals with sandy soils starting from 5 m3/s to 50 m3/s and d50 ranging from 0.196 to 0.538 mm. Then, applicable regime relationships for designing stable sandy channels were determined. The new equations are useful for designing new stable canals and redesigning unstable canals within the same range. The new regime equations were verified by using the HEC- RAS program. Finally, sensitivity analysis has been performed in order to investigate the effect of changing the deduced parameters on the discharge.

Silting-up of High Aswan Dam

2017 ◽  
pp. 377-382
Author(s):  
H.M. Osman ◽  
M.K. Osman ◽  
A.S. Karmy
Keyword(s):  
High Aswan Dam ◽  
Aswan Dam

Experiment and Simulation Analysis of the Pressure Carrying Capacity of X80 Pipe with Metal Loss Defect on the Girth Weld

2021 ◽  
Vol 1035 ◽  
pp. 813-818
Author(s):  
Zheng Long Li ◽  
Lin Chen ◽  
Zhi Hong Li ◽  
Guo Shuai Yan ◽  
Wei Li
Keyword(s):  
Sensitivity Analysis ◽  
Carrying Capacity ◽  
Simulation Analysis ◽  
Water Pressure ◽  
Metal Loss ◽  
Factors Affecting ◽  
Element Simulation ◽  
Simulation Based ◽  
Blasting Test ◽  
Water Pressure Blasting

In order to study the pressure carrying capacity of X80 pipe with metal loss defect on the girth weld the water-pressure blasting test of the pipe with metal loss defect was analyzed by experiment and finite element simulation. Based on this, the sensitivity analysis of the factors affecting the pressure carrying of the pipeline, such as the circular size, the axial size, and the depth of the metal loss defect, was carried out. The research results show that the circular size of the metal loss defect on the girth weld had little impact to the pressure carrying capacity of the pipe while it reduced with the increasing of the axial size and the depth of the metal loss defect.

Impacts of the High Aswan Dam

2011 ◽  
pp. 379-395 ◽  
Author(s):  
Asit K. Biswas ◽  
Cecilia Tortajada
Keyword(s):  
High Aswan Dam ◽  
Aswan Dam

Simulation Analysis of the Pressure Carrying Capacity of X80 Pipe with Plain Dents

2019 ◽  
Vol 944 ◽  
pp. 835-840
Author(s):  
Peng Song ◽  
Zheng Long Li ◽  
Yu Ran Fan ◽  
Lei Guo ◽  
Xi Xi Zhang ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Carrying Capacity ◽  
Formation Process ◽  
Simulation Analysis ◽  
Hydraulic Test ◽  
Factors Affecting ◽  
Element Simulation ◽  
Simulation Based

In order to study the pressure carrying capacity of X80 pipe with plain dents, the formation process and the hydraulic test were analyzed by finite element simulation. Based on this, the sensitivity analysis of the factors affecting the pressure carrying capacity of the pipeline, such as the internal pressure, the confinement state and the material performance, is carried out. Research results show that springback amount of the pipeline decreases due to the initial internal pressure, and constraint state has little effect on the pressure carrying capacity while increases with the increasing of the material tensile properties. When the depth of the dent is less than 6% pipe diameter or the strain of the dent is less than 6%, the dent has little impact to the pressure carrying capacity of the pipe.

On the Efficient Use of High Aswan Dam for Hydropower and Irrigation

1966 ◽  
Vol 12 (8) ◽  
pp. B-296-B-311 ◽  
Author(s):  
Harold A. Thomas ◽  
Roger Revelle
Keyword(s):  
High Aswan Dam ◽  
Aswan Dam

scholarly journals Fine dust emissions from active sands at coastal Oceano Dunes, California

2019 ◽  
Vol 19 (5) ◽  
pp. 2947-2964 ◽  
Author(s):  
Yue Huang ◽  
Jasper F. Kok ◽  
Raleigh L. Martin ◽  
Nitzan Swet ◽  
Itzhak Katra ◽  
...  
Keyword(s):  
Climate Models ◽  
Hydrological Cycle ◽  
Large Fraction ◽  
Sand Dunes ◽  
Dust Emission ◽  
Sandy Soils ◽  
Field Measurements ◽  
Dust Storms ◽  
Dust Emissions ◽  
Mineral Coatings

Abstract. Sand dunes and other active sands generally have a low content of fine grains and, therefore, are not considered to be major dust sources in current climate models. However, recent remote sensing studies have indicated that a surprisingly large fraction of dust storms are generated from regions covered by sand dunes, leading these studies to propose that sand dunes might be globally relevant sources of dust. To help understand dust emissions from sand dunes and other active sands, we present in situ field measurements of dust emission under natural saltation from a coastal sand sheet at Oceano Dunes in California. We find that saltation drives dust emissions from this setting that are on the low end of the range in emissions produced by non-sandy soils for similar wind speed. Laboratory analyses of sand samples suggest that these emissions are produced by aeolian abrasion of feldspars and removal of clay-mineral coatings on sand grain surfaces. We further find that this emitted dust is substantially finer than dust emitted from non-sandy soils, which could enhance its downwind impacts on human health, the hydrological cycle, and climate.

Evaporation from the reservoir of the High Aswan Dam, Egypt: A new comparison of relevant methods with limited data

1997 ◽  
Vol 56 (1-2) ◽  
pp. 57-66 ◽  
Author(s):  
M. F. Sadek ◽  
M. M. Shahin ◽  
C. J. Stigter
Keyword(s):  
Limited Data ◽  
High Aswan Dam ◽  
Aswan Dam

Valuation of growing stock using multisource GIS data, a stem quality database, and bucking simulation

2018 ◽  
Vol 48 (8) ◽  
pp. 888-897 ◽  
Author(s):  
Blanca Sanz ◽  
Jukka Malinen ◽  
Vesa Leppänen ◽  
Rubén Valbuena ◽  
Tuomo Kauranne ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Field Measurements ◽  
Product Yield ◽  
Optimization Methods ◽  
Raw Material ◽  
Diameter Distribution ◽  
Target Area ◽  
Product Price ◽  
Extensive Field ◽  
Stem Quality

Customer-oriented production as a sawmill strategy requires up-to-date information on the available raw material resources. Bucking is a process in which the tree stem is divided into products based on the roundwood user’s needs regarding products and their quality and dimensions. Optimization methods are employed in bucking to recover the highest value of the stem for a given product price matrix and requested length–diameter distribution. A method is presented here for assessing the value of harvestable timber stands based on their product yield. Airborne laser scanning, multispectral imagery, and field plots were used to produce timber statistics for a grid covering the target area. The statistics for the plots were generated from this grid. The value of the estimated tree list was assessed using a bucking-to-value simulator together with a stem quality database. Different product yield simulations in terms of volumes, timber assortment recoveries, wood paying capabilities (WPC) and value estimations based on the presented method, and extensive field measurements were compared. As a conclusion, this method can estimate WPC for pulpwood and sawlogs with root mean squared errors of 32.7% and 38.5%, respectively, relative to extensive field measurements.

Looking back in time: can safe pasture utilisation rates be determined using commercial paddock data in the Northern Territory?

2011 ◽  
Vol 33 (2) ◽  
pp. 131 ◽  
Author(s):  
Dionne Walsh ◽  
Robyn A. Cowley
Keyword(s):  
Carrying Capacity ◽  
Simulation Models ◽  
Field Measurements ◽  
Cost Effective ◽  
Northern Territory ◽  
Safe Level ◽  
Grazed Pasture ◽  
Utilisation Rate ◽  
Land Condition ◽  
Land Types

A ‘safe’ pasture utilisation rate is defined as the proportion of annual forage growth that can be consumed by domestic livestock without adversely affecting land condition in the long term. Pasture utilisation rates are thus a cornerstone of a sustainable grazing industry because they directly determine livestock carrying capacity. Until now, it has only been possible to determine utilisation rates in the Northern Territory via expensive and time-consuming grazing trials. Reliance on this method has limited the validation of safe utilisation rates for the range of land types used for pastoral production. This study tested an alternative cost-effective method for calculating utilisation rates based on an approach used previously in Queensland. The method retrospectively calculates utilisation rates using cattle records and modelled pasture growth from commercial paddocks in good land condition. The assumption underpinning the method is that paddocks in good land condition, with a long history of grazing, must have been managed in such a way as to achieve a safe level of pasture utilisation. Utilisation rates were calculated for 10 commercial paddocks on three properties in the Barkly Tableland region of the Northern Territory from 1999 to 2009. Animal intake for each paddock was calculated from detailed cattle records held in property databases. Pasture growth was estimated using simulation models and cross-checked with field measurements. An average utilisation rate of up to 25% of annual pasture growth was found to be safe on highly uniform, grey cracking-clays supporting Mitchell grass (Astrebla F. Muell. spp.) pastures. However, this level of utilisation had negative impacts on land condition on less resilient and preferentially grazed pasture communities in paddocks with a mix of land types. The implications of the results for carrying capacity, animal productivity and seasonal risk management are explored in this paper.

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