Evaluation of Interaction between Aquifer and river Using Integrated SWAT-MODFLOW-NWT Model (Case study: Mahabad plain)

Surface and groundwater dynamically interact at different spatial or temporal scales within a plain. Accurate estimation of water balance components is an important simulation of such interactions. Despite the rapid expansion of numerical models over the past two decades, there is still room for improvement for comprehensive and integrated assessment as well as management of surface and groundwater resources. In particular, the use of coupled surface and groundwater models is important to connect both surface and groundwater, and for proper representation of the water balance in the unsaturated root zone. The results of various studies suggest that the combination of SWAT and MODFLOW models can satisfactorily simulate the interaction between surface and groundwater at different spatial and temporal dimensions (Sophocleous and Perkins, 2000; Sun and Cornish, 2005; Bejranonda et al., 2007). Indeed, if both models are used simultaneously, not only the limitations of the two individual models can be improved, but also the temporal-spatial properties of the target area can be adequately reflected (Kim et al., 2008; Park and Bailey, 2017; Wei et al., 2018). Specifically in the Urmia Lake Basin, which has been severely affected by indiscriminate exploitation of water resources, these models can be used to maximize the supply of Urmia Lake based on the pattern of supplying irrigation needs from integrated water sources. This requires the interaction of surface and groundwater resources in different locations of plains and aquifers to be simulated and predicted based on different shares of agricultural water supply from integrated water sources.The main purpose of this study was to evaluate the interaction between ground and surface water in Mahabad plain using the coupled SWAT-MODFLOW-NWT model as a comprehensive and integrated model. The main challenge in this study is the interaction and monitoring of water table adjacent to the surface water bodies

How Can Researchers and Managers Better Collaborate on Lake Urmia Restoration?

The large decline in Lake Urmia\u27s level since 1995 has prompted a correspondingly large increase in research to help inform lake restoration. Here we synthesize results from 451 English-language articles (Figure 1) to answer four lake restoration questions of interest to the public and lake managers. We ask: 1) What lake restoration levels were considered besides the ecological level of 1274.1 m? 2) How has the causeway affected lake conditions? 3) Do we know enough about lake limnology and ecology to facilitate recovery? And 4) what to learn from Great Salt Lake management? We seek to share these findings with Lake Urmia managers, solicit feedback, and identify next steps for restoration and collaborative work

Distribución y pérdidas de agua y nitrato bajo fertirriego por surcos alterno y convencional

16 Pags., 4 Tabls., 11 Figs.Alternate furrow irrigation and surface fertigation have been known as techniques to control water and fertilizer losses. The main goal of this field study was to characterize the combined effect of these techniques on water and nitrate losses and on soil water and nitrate concentration. Two types of alternate furrow irrigation, i.e., variable alternate furrow irrigation (AFI) and fixed alternate furrow irrigation (FFI), as well as conventional furrow irrigation (CFI) were considered in the experiments. Results evidenced higher infiltration at irrigated furrows under AFI and FFI as compared to CFI. Increased lateral water movement under alternate irrigation resulted in lower water and nitrate losses via runoff and deep percolation. Water application efficiency for the CFI, FFI and AFI strategies amounted to 61.3%, 71.8% and 77.0% in the first fertigation and 36.4%, 58.8% and 60.7% in the second fertigation, respectively. Nitrate runoff for the CFI, FFI and AFI strategies amounted to 32.4%, 31.2% and 25.7% in the first fertigation and 44.3%, 35.1% and 32.7% in the second fertigation, respectively. Soil water content and nitrate concentration at the upstream part of the experimental field were larger than at the middle and downstream parts for all three irrigation regimes. Overall, alternate furrow fertigation, particularly AFI, stands as a simple and practical management practice for water and fertilizer conservation in agricultural fields.This research was funded by The Center of Excellence for Evaluation and Rehabilitation of Irrigation and Drainage Networks in the University of Tehran.Peer reviewe

Climate change and irrigation demand: Uncertainty and adaptation

Study region: The Kalamazoo River Watershed, southwest Michigan, USA. Study focus: Climate change is projected to have significant impacts on agricultural production. Therefore, understanding the regional impacts of climate change on irrigation demand for crop production is important for watershed managers and agricultural producers to understand for effective water resources management. In this study, the Soil and Water Assessment Tool was used to assess the impact of climate change on corn and soybean irrigation demand in the Kalamazoo River Watershed. Bias-corrected statistically downscaled climate change data from ten global climate models and four emissions scenarios were used in SWAT to develop projections of irrigation demand and yields for 2020–2039 and 2060–2079. Six adaptation scenarios were developed to shift the planting dates (planting earlier and later in the growing season) to take advantage of periods with greater rainfall or lower temperature increases. New hydrological insights for the region: Uncertainty in irrigation demand was found to increase moving from 2020–2039 to 2060–2079, with demand generally decreasing moving further into the future for corn and soybean. A shift in timing of peak irrigation demand and increases in temperature lead to corn yield reductions. However, soybean yield increased under these conditions. Finally, the adaptation strategy of planting earlier increased irrigation demand and water available for transpiration, while delaying planting resulted in demand decreases for both crops. Keywords: Irrigation demand, Climate change, SWAT, Crop yield, Adaptation, Uncertaint

Simulation of 1D surface and 2D subsurface water flow and nitrate transport in alternate and conventional furrow fertigation

48 Pags., 3 Tabls., 11 Figs. The definitive version is available at: http://link.springer.com/journal/271Increasing water and fertilizer productivity stands as a relevant challenge for sustainable agriculture. Alternate furrow irrigation and surface fertigation have long been identified as water and fertilizer conserving techniques in agricultural lands. The objective of this study was to simulate water flow and fertilizer transport in the soil surface and in the soil profile for variable and fixed alternate furrow fertigation and for conventional furrow fertigation. An experimental data set was used to calibrate and validate two simulation models: a 1D surface fertigation model and the 2D subsurface water and solute transfer model HYDRUS-2D. Both models were combined to simulate the fertigation process in furrow irrigation. The surface fertigation model could successfully simulate runoff discharge and nitrate concentration for all irrigation treatments. Six soil hydraulic and solute transport parameters were inversely estimated using the Levenberg–Marquardt optimization technique. The outcome of this process calibrated HYDRUS-2D to the observed field data. HYDRUS-2D was run in validation mode, simulating water content and nitrate concentration in the soil profiles of the wet furrows, ridges and dry furrows at the upstream, middle and downstream parts of the experimental field. This model produced adequate agreement between measured and predicted soil water content and nitrate concentration. The combined model stands as a valuable tool to better design and manage fertigation in alternate and conventional furrow irrigation.This research was funded by The Center of Excellence for Evaluation and Rehabilitation of Irrigation and Drainage Networks of the University of Tehran.Peer reviewe

An experimental data set for alternate and continuous furrow fertigation: water and nitrate transfer [Dataset]

1 File .xls with data (AltFurFer.xls). Related publications: Ebrahimian, H., Liaghat, A., Parsinejad, M., and Playán, E. 2012. Distribution and loss of water and nitrate under alternate and conventional furrow fertigation. Spanish Journal of Agricultural Research, In press; Ebrahimian, H., Liaghat, A., Parsinejad, M., Playán, E., Abbasi, F. and Navabian M. 2012. Simulation of 1D surface and 2D subsurface water flow and nitrate transport in alternate and conventional furrow fertigation. Irrigation Science, In press.This data set contains the results of the experimental evaluation of two alternate and conventional furrow fertigation events. Experiments were performed at the College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran. Three irrigation treatments were considered: Variable Alternate Furrow Irrigation (AFI), Fixed Alternate Furrow Irrigation (FFI) and Conventional Furrow Irrigation (CFI). Liquid fertilizer was injected in the irrigation water during part or the irrigation event. The data set contains advance and recession, soil water and nitrate, inflow and outflow discharge and nitrate concentration, and meteorological data.Peer reviewe

Optimum design of alternate and conventional furrow fertigation to minimize nitrate loss

47 Pags., 5 Tabls., 3 Figs. The definitive version is available at: http://ascelibrary.org/loi/jidedhAlternate-furrow fertigation has shown potential to improve water and fertilizer application efficiency in irrigated areas. A combination of simulation and optimization approaches permits researchers to identify optimum design and management practices in furrow fertigation, resulting in optimum cost, irrigation performance, or environmental impact. The objective of this paper is to apply one-dimensional (1D) surface and two-dimensional (2D) subsurface simulation-optimization models to the minimization of nitrate losses in two types of alternate-furrow fertigation, as follows: (1) variable alternate-furrow irrigation, and (2) fixed alternate-furrow irrigation. For comparison purposes, optimizations are also reported for conventional furrow irrigation. The model uses numerical surface fertigation and soil-water models to simulate water flow and nitrate transport in the soil surface and subsurface, respectively. A genetic algorithm is used to solve the optimization problem. Four decision variables (inflow discharge, cutoff time, start time, and duration of fertilizer solution injection) were optimized to minimize the selected objective function (nitrate loss) for two fertigation events performed during a maize-growing season. The simulation-optimization model succeeded in substantially reducing the value of the objective function as compared with the field conditions for all irrigation treatments. In the experimental conditions, optimization led to decreased inflow discharge and fertilizer injection during the first half of the irrigation event. This was because of the high potential of the field experiment to lose water and nitrate through runoff. In the optimum conditions, alternate-furrow fertigation strongly reduced water and nitrate losses compared with conventional furrow irrigation. The simulation-optimization model is a valuable tool for alleviation of the environmental impact of furrow irrigation.This research was funded by the Center of Excellence for Evaluation and Rehabilitation of Irrigation and Drainage Networks in University of Tehran.Peer reviewe

Assessing Potentials of Rainfed Lands and Optimum Water Allocation between Irrigated and Rainfed Lands (Case Study: Qazvin Plain)

In this study, water allocation managements between irrigation and rainfed lands were surveyed in different climate conditions. Objective function was maximizing the net benefit. It is supposed that the cropped area of irrigation and rainfed lands have been kept unchanged and deficit irrigation has been only applied to a part of irrigation lands while supplementary irrigation has been applied to a part of rainfed lands. Also the total available water in each decade in initial management is allocated in the same decade or until 4 decades later to the irrigation of same crops in deficit irrigation conditions and in supplementary irrigation conditions for rainfed crops. The optimization model results in the Qazvin Plain indicated net benefit increased under new water allocation management in case of water conveyance from 2000, 4000, 6000, 8000 and 10000 meters in a climatically normal year to be 11.1, 13.5, 19.2, 16.6 and 15.8 percent, respectively, while in a wet year 9.0, 10.9, 17.0, 15.9 and 13.4 and in a dry year 8.05, 12.5, 16.1, 19.1 and 19.9, respectively. Also barley was the best choice for deficit irrigation in three climate conditions. Depths of deficit irrigation were 20, 25 and 30 mm in the first decade of November and 50, 50 and 60 mm in the second decade of May in normal, wet and dry conditions. Also lentil was the first choice for supplementary irrigation. The best treatments for supplementary irrigation in lentil rainfed fields were 75 mm in the third decade of May in normal years, 75 mm in the second decade of May in wet years and 100 in the second decade of May in dry years. With these treatments, the yield of lentil increased from 1000, 1300 and 0 to 3000, 3000 and 2000 kg/ha in normal, wet and dry years, respectively