field experiments were conducted on an existing subsurface drainage system in roodasht region of esfahan, ian, to test the performance of drain spacing equations for transient flow. the water table profiles recorded from a series of observation wells indicated an essentially flat water surface. the effective hydraulic conductivity and the degree of anisotropy were calculated as 19.2 cm h-1 and ...

Backscatter X-ray technique is particularly convenient for the inspection of single-sided access objects, in order to detect subsurface defects or control subsurface layers thickness. This well known technique can benefit today from recent developments in detectors technology. Backscatter technique requires many parameters: relative geometry of source, detector and object, and associated collim...

the dominant traditional view to designing drainage systems explains drainage goals only in terms of crop yield increase and rhizosphere improvement while ignoring the environmental impacts of drainage projects. nowadays, this view has been changed into a new one in which both environmental and agricultural purposes are taken into consideration. depth and spacing of subsoil drains are important...

Urban water management has somewhat changed since the publication of The Sustainable Drainage System (SuDS) Manual in 2007 [1], transforming from building traditional sewers to implementing SuDS, which are part of the best management practice techniques used in the USA and seen as contributing to water-sensitive urban design in Australia. Most SuDS, such as infiltration trenches, swales, green ...

abstract one of the ways to increase economic and environmental efficiency of drainage systems is water table management. water table management consists of, controlled drainage and subirrigation. this study examines the effect of controlled drainage on yield, root distribution pattern and water use efficiency of maize (sc 704) in karaj. the experiment was performed as a randomized complete des...

ِdfferent drip (surface and subsurface) and furrow irrigation methods effects on grain, oil and water use efficiency based on grain black cumin(nigella sativa l.) as medicinal plants was investigated. for this purpose, experiment over the past two years (2009 and 2010) in a randomized complete block was designed in three replications. treatments in this research were consisting of 50, 75 and 100...

regarding the role and importance of subsurface drainage in water table control, many studies have been made throughout the world to find out new techniques and more economical solutions, especially as related to different pipe envelope material and their installations. this research was conducted to investigate the use of rice husk, as drain envelope material, in drainage installations. in add...

Urban flooding is a primary concern in all developed areas. Understanding what factors contribute to the magnitude and frequency of flooding is of primary importance when designing an engineering system to mitigate flooding. To understand the effect of impervious area versus the role of the storm drainage system in urban flooding, the U.S. Army Corps of Engineers Gridded Surface Subsurface Hydr...

For areas with seasonally shallow water tables and poorly drained soils, subsurface drainage systems are ideal for removing excess from the root zone improving soil workability, trafficability, timeliness of field operations. With increased interest in tile southern Manitoba, objective this study was to evaluate impacts on canola yield oil qualities over three growing seasons (2019-2021) Winkle...