abstract although lateral drains play the main role in removal of excess water from soil profile in subsurface drainage systems, but it is assumed that perforated collectors can directly remove a part of drainwater from soils. this part of discharge in subsurface drains is not usually taken into consideration in drainage design criteria, due to lack required information and its difficult estima...

abstract aim of this research is landslide hazard zoning in syahdare watershed using logistic regression. therefore, outset landslide points recognized using air photography and extensive field studies. then distribution of landslide map was makes. then each effective element on landslide occurred for example slope, aspect, elevation, litho logy, land use, distance of road, distance of drainage...

A field experiment established in 1980 was conducted to evaluate the effects of open drainage ditch applied for water removal on bacterial and fungal communities of cold waterlogged paddy soils in 2011. In this experiment, traditional plate counting and temperature gradient gel electrophoresis were employed to characterize the abundance and diversity of soil bacterial and fungal communities. Fo...

Sand coverings account for a large part of the cost of a project. The purpose of this study is to evaluate the performance of different coatings for filtration of underground drains and reduce the cost of cornfield farms. The experiments were carried out in farm in Salman Farsi. The subsoil drainage was fitted to each test piece with a length of 120 meters, a diameter of 100 mm, and a distance ...

The research in the fields of irrigation and drainage network in the province Hamidieh to evaluate the performance of drainage was done in the land. For this purpose, three drainage server farm at intervals of 50, 70 and 80 meters in the area was selected. Blank observation on three drain pipes at intervals of 0.3,0.8,1.5,2.5 and 15 meters of lateral drains in the middle of the line in four row...