Measuring sensitivity of hydraulic structures is considered as an approach for evaluation of water projects performance, due to lower distribution efficiency in Irrigation and Drainage project schemes. Sensitivity analysis approach for irrigation structures is one of flow analysis methods which are developed in recent years in order to measure the behavior of flow in hydraulic structures in an ...

the depth control systems used in iranian tractors are mechanical and they produce variable tillage depth in uneven field surface. in this research a rotary type electronic control valve was designed and constructed. by using this valve, electro-hydraulic tillage depth control system was developed and installed on the tractor. the control system was composed of: a depth sensor, a programmable l...

there are human and animal health concerns related to drainage systems because nutrients, especially nitrogen and phosphorus, can contaminate water supplies. a field study was conducted on consolidated paddy fields of sari agricultural sciences and natural resources university, northern iran (36.3°n, 53.04°e), to determine the effect of subsurface drain depth and spacing on nitrogen (n) and pho...

Alburnoides manyasensis, sp. n., is described from the Koca Stream (Lake Manyas drainage, Marmara Sea basin) in Anatolia. It is distinguished from all species of Alburnoides in Turkey and adjacent regions, Alburnoides tzanevi (Rezovska [Rezve], Istranca and Terkos streams in the western Black Sea drainage), Alburnoides cf. smyrnae (Banaz Stream, a drainage of Büyük Menderes River, Aegean Sea ba...

In these notes on drainage design procedure, three drain spacing formulae are considered suitable for designing sub-surface drainage systems. The Hooghoudt and the Kirkham-Toksoz formulae have been developed for steady state conditions and the Glover formula is applicable to the transient state condition. The steady state condition implies that the surface inflow is equal to the outflow through...

Orifice-weir structures are being used to reduce peak drainage rates and to store water during the growing season in poorly drained pine plantations. Earlier studies have demonstrated their effectiveness in reducing drainage outflows while conserving water during the growing season. This study reports on criteria and preliminary guidelines for designing such structures. The guidelines were deve...

Aquaculture ponds are dominant features of the landscape in the coastal zone of China. Generally, aquaculture ponds are drained during the non-culture period in winter. However, the effects of such drainage on the production and flux of greenhouse gases (GHGs) from aquaculture ponds are largely unknown. In the present study, field-based research was performed to compare the GHG fluxes between o...