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...

Planning and license applications concerning groundwater diversion in areas containing water-dependent or water-favored habitats must take into account both hydrological effects and associated ecological consequences. There is at present no established methodology to assess such ecohydrological responses. Thus, this paper describes a new stepwise methodology to assess ecohydrological responses ...

Short-interval water level measurements using automatic water level recorder in a deep well in an unconfined crystalline rock aquifer at the campus of NGRI, near Hyderabad shows a cyclic fluctuation in the water levels. The observed values clearly show the principal trend due to rainfall recharge. Spectral analysis was carried out to evaluate correlation of the cyclic fluctuation to the synthet...

This paper presents the multi-criteria calibration of a regional distributed subsurface water flow model for a 1400 km irrigated agricultural area in the western San Joaquin Valley of California. Two global optimization algorithms were used to identify model parameters using data on spatially distributed local water table depth measurements, district-average groundwater pumping and district-ave...

The use of treated wastewater for irrigation of crops could result in high nitrate-nitrogen (NO(3)-N) concentrations in the vadose zone and ground water. The goal of this 2-yr field-monitoring study in the deep silty clay loam soils south of Dodge City, Kansas, was to assess how and under what circumstances N from the secondary-treated, wastewater-irrigated corn reached the deep (20-45 m) water...

The standard formulation of a block-centered finite-difference model, such as MODFLOW, uses the center of the cell as the location of a cell node. Simulations of a dynamic water table can be improved if the node of a cell containing the water table is located at the water table rather than at the center of the cell. The LPF package of MOD-FLOW-2000 was changed to position a cell's node at the w...

evaluating drainage systems, exploring their strengths and weaknesses, provides a comprehensive perspective to designers and organizers for optimum design and implementation of guidelines for the future. this study was conducted at an experimental site consisting of three plots on a subsurface drainage network under operation in behshahr, a coastal region in northern iran. to evaluate system pe...

in tunisia, kalâat el andalous irrigated district is one of the most affected areas by salinization. the objective of this study was to predict the root zone salinity (over 10 years) in this area using the saltmod simulation model for subsurface drainage system. saltmod is based on water balance, salt balance model, and seasonal agronomic aspects. in the pilot area, irrigated vegetables crops s...