The efficiency of the systematic horizontal drainage under irrigation conditions in low-and non-irrigated areas

Abstract

The purpose. To determine efficiency of regular horizontal drainage in conditions of irrigation on low-runoff and drainless territories. Methods. Analytical, comparative-calculation, field, experimental-production sectors. Efficiency of drain is determined by analysis of dynamics, actual and normative depths of occurrence of groundwater table (OGW) concerning depths of underlay of sewers and absorbing wells. Results. Long irrigation has generated intense infiltration feed, ascending gradient of subsoil waters and underflooding of terrains. These processes were observed in by-channel zones, centers of sprinklers “Frigate” and on the end plates of drainless lowering. For the last 34 years waterflooding of terrains was observed in excessively wet seasons 5 times. On low-runoff and drainless terrains of irrigated lands regular shut horizontal drainage of self-flowing type due to continuous operation of deep sewers ensured essential heightening of their general drainity, reliable protection from damage effect of waters and decrease of load by field absorbing wells. Deep underlay of sewers has created conditions for formation of powerful zone of aerification and automorphic regime of pedogenesis. In wet seasons they observed formation of nucleation sites for of underflooding on the end plates of drainless lowering, in places of connection of sprinklers to hydranths and in by-channel zone despite of availability of drain. Conclusions. Regular shut horizontal drainage with deep underlay of collection network will ensure protection of low-runoff and drainless terrains from underflooding and decrease of specific extent of field absorbing wells. On the lowered landforms there is a necessity of intensification of water removal, transfer of surface runoff in underground, arrangement of additional drain and water absorbers from volume filters.