Water Management Simulation Model Research Articles

Simulation of Soil Salinity using DRAINMOD-S Model under Subsurface Drainage System in Arid and Semi-arid Regions of Punjab, India

Water management simulation model DRAINMOD-S was calibrated (1995-96) and validated (1997) using 3-year experimental field data (1995-1997) from the installed subsurface drainage system at 1.8 m drain depth with 40, 60, and 80 m drain spacing at Golewala watershed, Faridkot, Punjab, India. Sensitivity analysis of the model parameters revealed that lateral saturated hydraulic conductivity, drain depth, and drain spacing are the most effective parameters in changing the model output. The root mean square error, efficiency, and coefficient of determination between observed and simulated soil salinity ranged from 0.01to 0.06 dS.m-1, 0.647 to 0.834 dS.m-1 and 0.957 to 0.999 dS.m-1 for three drain spacings (40, 60 and 80 m), respectively, during calibration and validation period. The calibrated and validated model was used to predict the soil salinity (EC) for five consecutive years (1998-2003). The average soil salinity of root zone (300-600 mm), (600-900 mm) and (900-1200 mm) decreased from January, 1998 to December, 2003. The predicted values of soil salinity were found to decrease from 2.23, 2.34, and 1.92 dS.m-1 to 1.68 dS.m-1, 1.70 and 1.42 dS.m-1 for 40 m drain spacing at root zone depth of 300-600 mm, 600-900 mm, and 900-1200 mm, respectively. Similarly, the salinity values for the same period and root zone depth were found to decrease from 2.20, 2.31, and 1.90 dS.m-1 to 1.75,1.78, and 1.74 dS.m-1 for 60 m drain spacing; and 2.21, 2.31, and 1.93 dS.m-1 to 1.80,1.82, and 1.48 dS.m-1 for 80 m drain spacing, respectively, at the end of five years. DRAINMOD-S model was reliably applicable for predicting soil salinity under sub-surface drainage system in arid and semi-arid region of Punjab, India.

Assessment of Options for the Sustainable Use of Agricultural Drainage Water For Irrigation in Egypt by Simulation Modelling

The water management simulation model DRAINMOD-S was applied to simulate different strategies for using agricultural drainage water for irrigation over a 20-year period. The irrigation strategies considered were: (i) fresh/non-saline water as the baseline for comparison; (ii) drainage water of different salinities; (iii) cyclic use of fresh water and drainage water; (iv) deficit irrigation combined with controlled drainage; and (v) interseasonal cyclic use of drainage water and fresh water (2 years drainage/2years fresh). The study area was in the North-West Delta of Egypt which already uses fresh canal water blended with agricultural drainage water for irrigation. The most common 2-year crop rotation in the area of wheat–maize–berseem–cotton was simulated. Four different drainage water salinities (4, 8, 12, 16 dS m−1) were simulated and three different options for the freshwater/drainage water cycle. Better results were found, yields being maintained, for the strategies of deficit irrigation combined with controlled drainage, cyclic use of agricultural drainage water of 4–12 dS m−1 with fresh water and the inter-seasonal cycling of drainage and fresh water. These results provide a set of sustainable options for using agricultural drainage water for irrigation. Copyright © 2016 John Wiley & Sons, Ltd.

Application of the system of environmental economic accounting for water SEEAW to the Spanish part of the Duero basin: Lessons learned

The System of Environmental-Economic Accounting for Water (SEEA-W) consists of an agreed international framework for organizing hydrological and economic information in a coherent and consistent manner. The methodology yields to the SEEA-W physical tables focusing on the quantitative assessment of the stocks and their changes in a river basin during the accounting period. For that purpose, the information on the abstraction and water discharge is linked with the environment water stocks, which assesses how current levels of abstraction and discharge affect such water stocks. This study presents the methodology and results to fill out the SEEAW tables for asset accounts on the Spanish Duero basin. Duero is a transboundary river between Spain and Portugal where 80% of its basin area (78,860km2) runs into the Spanish territory. The Spanish part is divided in five zones and 13 management systems. The methodology applied the three models used by the Spanish Water Authorities for the planning and allocation of water resources in Spain: ‘SIMPA’ model (rainfall-runoff model), ‘ASTER’ model (hydro-meteorological model related to snow processes) and ‘SIMGES’ model (water management simulation model). The required information was collected with the support from the Duero River basin Authority and the Spanish Ministry of Agriculture. Special care was paid to issues such as: inter-annual variability, the selection of spatial and temporal scale, seasonality, disaggregation of human abstractions into use's type, and transboundary agreements. The results highlighted some drawbacks in the SEEAW methodology for the Duero basin. However, the developed balances are a valuable tool to support the decisions of the Spanish Duero basin Authority on the management and allocation of water in the basin and in the transboundary area with Portugal. Finally, the paper outlines some recommendations for future work.

Integrated assessment of policy interventions for promoting sustainable irrigation in semi-arid environments: A hydro-economic modeling approach

Sustaining irrigated agriculture to meet food production needs while maintaining aquatic ecosystems is at the heart of many policy debates in various parts of the world, especially in arid and semi-arid areas. Researchers and practitioners are increasingly calling for integrated approaches, and policy-makers are progressively supporting the inclusion of ecological and social aspects in water management programs. This paper contributes to this policy debate by providing an integrated economic-hydrologic modeling framework that captures the socio-economic and environmental effects of various policy initiatives and climate variability. This modeling integration includes a risk-based economic optimization model and a hydrologic water management simulation model that have been specified for the Middle Guadiana basin, a vulnerable drought-prone agro-ecological area with highly regulated river systems in southwest Spain. Namely, two key water policy interventions were investigated: the implementation of minimum environmental flows (supported by the European Water Framework Directive, EU WFD), and a reduction in the legal amount of water delivered for irrigation (planned measure included in the new Guadiana River Basin Management Plan, GRBMP, still under discussion). Results indicate that current patterns of excessive water use for irrigation in the basin may put environmental flow demands at risk, jeopardizing the WFD's goal of restoring the ‘good ecological status’ of water bodies by 2015. Conflicts between environmental and agricultural water uses will be stressed during prolonged dry episodes, and particularly in summer low-flow periods, when there is an important increase of crop irrigation water requirements. Securing minimum stream flows would entail a substantial reduction in irrigation water use for rice cultivation, which might affect the profitability and economic viability of small rice-growing farms located upstream in the river. The new GRBMP could contribute to balance competing water demands in the basin and to increase economic water productivity, but might not be sufficient to ensure the provision of environmental flows as required by the WFD. A thoroughly revision of the basin's water use concession system for irrigation seems to be needed in order to bring the GRBMP in line with the WFD objectives. Furthermore, the study illustrates that social, economic, institutional, and technological factors, in addition to bio-physical conditions, are important issues to be considered for designing and developing water management strategies. The research initiative presented in this paper demonstrates that hydro-economic models can explicitly integrate all these issues, constituting a valuable tool that could assist policy makers for implementing sustainable irrigation policies.

Water and Salt Regulation Mode of Soil Salinization Based on Change of Land Utilization

Soil Salinization poses a potential threat to human health, socio-economic development, national food security, local ecological environment, and also leads to substantial risks. Therefore, non-engineering and engineering control measures are required to reduce the risks and hazard levels. To achieve the goal, the nature of factors, which affect the salinity formation whether it can be regulated or not, had been first made a thorough analysis. Then the combined control mode which was water and salt regulation management simulation model of soil salinization based on change of land utilization had been put into pratice in Songyuan irrigated district. The specific process is as follows: under the premise of land utilization re-adjustment, three-dimensional hydrogeological numerical model was used as a tool to evaluate the distribution ratio of surface water and groundwater, taking the water table changes as clues to achieve the goal that verifies the mode of soil salinization in Songyuan irrigated district, and can forecast the water and salt movement tendency. On the other hand, from the perspective of critical groundwater depth of soil salinization to analyze its variation trend, different management measures were suggested. The research results showed that the mode of regulation can effectively head off the deterioration of salinization, and taking environmental and economic benefits into account, it can also provide basis for scientific amelioration and field management for saline soil.

Impact of drained and un-drained soil conditions on water table depths, soil salinity and crop yields

The purpose of this study was to determine the comparison of salt accumulation in soil profile and crop yields under drained and un-drained conditions. Current field conditions were used to represent poorly drained conditions where drainage system was not installed yet. Simulations were performed to illustrate well drained condition using the water management simulation model while controlling soil salinity in root zone. To put forward drainage system impacts; soil salinity and relative crop yields for well drained conditions were compared to poorly drained conditions. Soil, crop and site parameters were obtained from coordinated 40 soil sampling locations where dry bean, winter wheat and fallow crop rotations were applied. Results of the study showed that water table decreased rapidly after installing proper drainage system. Percentage of salt decreases in soil profile occurred by 24.1, 37.9 and 14.4% for wheat, bean and fallow locations respectively with adequate drainage conditions. On the drained soils, the relative yield of the winter wheat was higher by 11.2%, on the average, whereas that of bean was higher by 24.7%. Overall the net impact of yield enhancement due to drainage was about 36%. This shows the positive impact of drainage system on crop yields in this area.

Estimating effects of drainage design parameters on crop yields under irrigated lands using DRAINMOD

The purpose of this study is to predict optimal drainage design parameters for ensuring maximum crop yield under irrigated arid lands. The water management simulation model, DRAINMOD was applied to compute the effects of land drainage on soil moisture conditions in the root zone and their effect on crop yield in Bala-Koprukoy Basin in Central Anatolia Region of Turkey. Soil, crop and site parameters were obtained as inputs from field experiments. Model was run for 5 years to simulate optimum drainage design parameters (drain depth, drain spacing) while controlling soil salinity in root zone. Soil water conditions were simulated for crop rotation of corn and wheat. Yields of individual crops were predicted for each growing season. Results of the simulations were analyzed to identify alternative of subsurface drainage system that would satisfy maximum crop productions. According to the simulation results the optimum drain depth were found to be 1.2 m and drain spacing were 160 m for the multiple croppingsystem in study area. Key words: DRAINMOD, drainage, drain space, drain depth, wheat, corn.

The Suitability of Controlled Drainage and Subirrigation in Paddy Fields

DRAINMOD, an agricultural water management simulation model, was used to investigate the suitability of controlled drainage/subirrigation scenarios in 52 ha of northern Iran paddy fields which planted in April to September and the rest of the time being waterlogged and pounded and could not be cultivated because of high water table, low permeable top soils and unsuitable drainage systems. The model as run for 30 year climate data. Various drain depth and spacing combinations and different weir setting were simulated. Simulation results showed that the xcess soil moisture was the main factor for yield reduction and the best conditions of controlled drainage and subirrigation were obtained when the depth of weir setting was the same as drain depth and these systems acted as conventional drains. Based on results, controlled drainage and subirrigation were not suitable because of high rainfall in the region. But the conventional controlled drainage system can be used for these fields, so that in wet season the system acts like a conventional or free drainage system and in paddy rice growth periods, it operates as controlled drainage by installing a weir setting outlet drain.

Optimal Drainage Design Under Iraqi Conditions Using DRAINMOD

DRAINMOD is a field and watershed scale water management simulation model that has been used to design subsurface drainage systems and characterize drainage and water table control practices in poorly drained soils. DRAINMOD is also used as a research tool to investigate the performance of drainage and sub irrigation systems and their effects on water use, crop response, land treatment of wastewater, and pollutants transport from agricultural fields. The model is based on a water balance in the profile to quantify hydrologic components such as infiltration, subsurface drainage, surface runoff, deep and lateral seepage and evapotranspiration. The objective of this research is to examine the capability of DRAINMOD to obtain an optimal drainage systems design for Iraqi conditions using the information of Dujailah project. This is done by obtaining the minimum drain depth and maximum spacing that meet the criteria for water table control. The results obtained from DRAINMOD for the drainage systems design show a good agreement with those previously obtained for Dujailah project. Therefore DRAINMOD is a suitable simulation model which can be used to simulate the performance of drainage and water table control systems in Iraq. Keywords :DRAINMOD, optimal drainage design, drainage in Iraq

Assessing Water Availability under a Water Rights Priority System

The Texas Natural Resource Conservation Commission, its partner agencies, and contractors are conducting a statewide Water Availability Modeling (WAM) Project pursuant to Senate Bill 1 enacted by the Texas Legislature in 1997. The Water Rights Analysis Package (WRAP) is the river basin water management simulation model used in the WAM Project. WRAP provides flexible capabilities for analyzing water availability and reliability under a priority-based water allocation system. The water management and use requirements modeled may be quite complex, involving numerous water users governed by various institutional arrangements and configurations of water control facilities. WRAP may be applied to essentially any river basin whether in Texas or elsewhere. This paper describes both the generalized WRAP model and the Texas WAM Project.

Predicting Corn Yield Response to Planting Date Delay

A two-year field study was conducted to determine the effect of delay in planting on corn yield in eastern North Carolina. The relationship between yield and planting date is needed in order to quantify the effects of trafficability, as influenced by drainage system design, on yield. Corn was planted on drained and subirrigated plots at planting dates ranging from mid-March to early June. Results indicated that yield decreased with planting date delay after 10 April. Results were in general agreement with those in earlier unirrigated experiments. The relationship between relative yield, Y, and planting date delay, D (days), beyond 10 April could be described by a piecewise linear relationship: Y = 1.0 – 0.0088 D, for D < 40; and Y = 1.3 – 0.0162 D, for 40 = D < 80. Similar relationships were derived from data published in the literature for eight other locations. Although there were differences in the threshold date beyond which yields decreased with delay in planting, the equation parameters fell within a relatively small range for most locations. These relationships can be used in the water management simulation model, DRAINMOD, to predict the effect of drainage design on planting delay and relative yield.

Surface and subsurface drainage simulations for a claypan soil

A water management simulation model, DRAINMOD, was used to investigate the suitability of drainage systems for maize production on the claypan soils that occur widely in the midwest of the United States of America. These soils have a very slowly permeable shallow subsoil which severely limits root development and reduces crop yield. Climatological, crop and soil data, collected on a claypan soil, over several years, were used in this study. Various subsurface drain spacings and combinations of surface and subsurface drainage systems on a claypan soil were simulated. Results indicated that supplemental irrigation water is required for optimum maize production on these soils. With supplemental irrigation, a subsurface drain spacing of 12 m under good surface drainage, and one of 10 m under poor surface drainage, are required.

Comparison of Two Drainage Simulation Models Using Field Data

ABSTRACT The transient, one-dimensional finite-difference model, SWATREN, was tested using field data from Aurora, North Carolina. The SWATREN model could not be used for conditions when the water table rose to the surface. Since the water table frequently rises to the surface on poorly drained soils in the humid regions of the United States, SWATREN was modified by the authors to enable the simulation of these high water tables. The simulation results were compared with the performance of the water management simulation model, DRAINMOD, which had previously been tested using the same data. The field site consisted of three drainage treatments with provision for subirrigation and controlled drainage. Rainfall intensity and water table elevations were continuously measured at the site from 1973 to 1977 (a total of approximately 4,600 site days). Input data, such as saturated hydraulic conductivity, soil water characteristic, and crop rooting depths used in the previous DRAINMOD study were used in the SWATREN model. Comparison of daily water table depths predicted with the modified version of the SWATREN model were in good agreement with measured values, with standard errors of estimate ranging from 8.9 cm to 29 cm. The DRAINMOD model had standard errors of estimate ranging from 7.5 cm to 19 cm. The average absolute deviation between predicted and measured water table depths for the 15 site years of data was 13.4 cm for SWATREN, as compared to 11.4 cm for DRAINMOD. Based on the results of this study, either the modified version of SWATREN or the DRAINMOD model can be used to simulate drainage response on soils with a fluctuating water table that may rise to the surface.

Irrigation scheduling and cantaloupe yield model for the Jordan Valley

A crop yield and soil water management simulation model (CRPSM) developed at Utah State University was modified and calibrated using data from a trickle irrigation experiment with different mulched treatments on cantaloupe ( Cucumis melo L.) in the Jordan Valley. The soil water budget model was adapted to the field conditions through input describing rooting depth, field capacity, wilting point and wet soil surface air-drying characteristics. Observed field crop growth progress was used for the model's phenology clock. Calibration of the yield model was accomplished by adjusting model parameters to obtain a reasonable match between model and field yields. Simulated possible irrigation schedules were tested using different options provided by the model. By using 1.5 cm per irrigation for a total of 44 to 47 irrigations and starting the first instead of the last of April, simulated yields were about double what was actually obtained in the field. This indicates that the date of first irrigation as well as total water applied is important for maximizing yield. Plants in the field were apparently subjected to water stress prior to late April when irrigation was initiated. The use of the CRPSM model could reduce the number of plots needed in further field experimentation since the less successful possibilities could be identified by simulation. Thus, field efforts can be concentrated on treatments most likely to provide higher yields with improved irrigation management.

Simulation of Corn Yield by a Water Management Model for a Coastal Plain Soil in Virginia

ABSTRACT DRAINMOD, a water management simulation model for artificially-drained soils, was evaluated for a Virginia Coastal Plain soil by comparing predicted and measured water table depths from a subirrigation/controlled-drainage site over a period of 3 years. Water table evaluations predicted by the model were in good agreement with measured water table elevations, with an average deviation of 9.47 cm for the 3 years of record. The YIELD version of DRAINMOD was used to predict relative corn yield for the subirrigation/controlled-drainage site. Average corn yield predictions by the model agreed reaonably well with the observed average corn yield, with relative errors of 19.2, 4.4, and 8.1% for 1984, 1985, and 1986, respectively. Additionally, corn yields predicted for a conventional drainage system were considerably lower than those predicted for subirrigation/controlled-drainage, reaffirming the need for irrigation of corn in the Coastal Plain region of Virginia. Research indicate that DRAINMOD is a powerful tool for the design and evaluation of subirrigation/controlled-drainage practices in the Virginia Coastal Plain. Simualations were performed for a 20-year period to determine the effects of system design on corn yield. An economic analysis was performed to determine optimal system design for maximizing profits from corn production. A drain spacing of 21.30 m, a drain depth of 1.10 m, and a 0.65 m weir depth were the design parameters recommended as optimal for maximizing profits from subirrigation/controlled-drainage of corn on a Myatt fine sandy loam soil in the Virginia Coastal Plain.

Influence of Spatially Variable Soil Hydraulic Properties on Predictions of Water Stress

AbstractModels are often used to predict drainage system effects on crop production. Variability of soil hydraulic properties on predictions made by many models have not been evaluated. This study evaluated several methods for predicting water transport properties and corn (Zea mays L.) stress as influenced by variable soil hydraulic properties in a field of Portsmouth sandy loam (Typic Umbraquults). Upflux, drainage volume, and infiltration parameters as functions of water table depth were predicted using hydraulic conductivity and soil water retention functions for three soil horizons measured at 150 locations in a field. Crop stress due to both deficient and excess soil water conditions and relative crop yield were estimated using DRAINMOD, a water management simulation model, for three selected methods of averaging soil property inputs. Small differences existed among the three approaches for the 30‐yr average relative corn yield. Large differences in relative corn yield occurred in dry years indicating that the variability of the soil properties was important to consider in predicting crop stress during relatively dry years. More information for the field soil‐drainage response was obtained using the individual locations method which allowed soil property inputs to vary from location to location at each of the 150 points in the field. However, the field averages approach is more practical because fewer data are required to perform the necessary computations and only a 3% difference in the 30‐yr relative yield resulted between the individual location and field average methods.

Irrigation Scheduling and Watermelon Yield Model for the Jordan Valley

AbstractA crop yield and soil water management simulation model (CRPSM) developed at Utah State University was modified, calibrated and tested using local weather data and field results from a trickle irrigation experiment with different mulching on watermelon (Citrullus lanatus), carried out at the University of Jordan Research Station, in the Jordan Valley.Simulated irrigation schedules were then applied with some of the four options provided by the model. The water yield index, WYI, introduced by Battikhi and Hill (1985) to select the most efficient schedule as based on yield and water use efficiency, was then determined. WYI ranged from 27 to 87. The field schedule, WM2, had a WYI of 62. Whereas, the model provided a much better schedule, WM7 (WYI = 86). WM7 requires 17 irrigations of 2.0 cm per irrigation totaling a water supply of 44.1 cm with an irrigation season starting on April 7 to give a yield equivalent to the potential yield, 80.0 MT/ha. On the other hand, the best field schedule, WM2 under transparent mulch, required 14 irrigations to provide 45.9 cm (including rainfall and soil moisture change), with a season starting on April 28 resulted in a yield of 68.8 MT/ha. So we can see that by using the same amounts of total water supply but with different schedule we can get the potential yield. The model has, therefore, provided few better schedules that can be tested in the field at lower costs before final recommendations are made.

Controlled-Drainage/Subirrigation Simulation for a Claypan Soil

ABSTRACT THERE are about 4 million hectares of claypan soils in the Mid-west. These soils have a very slowly permeable clay subsoil which severely limits root development and water penetration. The crop yield on these soils is usually low because of limited water management. A water management simulation model, DRAINMOD, was used to investigate the suitability of controlled-drainage/subirrigation of corn on these soils. Several years of crop, soil and weather data collected on a clay pan soil in Illinois were used in this study. Various drain spacing and depth combinations for both good and poor surface drainage were simulated. Results indicated that the optimum drain spacing would be 6 m for controlled-drainage/subirrigation on these soils under good surface drainage and with a weir setting of 35 cm on a 5-year recurrence interval basis.

Predicting the effects of drainage systems on corn yields

Stress day index (SDI) models were incorporated in the water management simulation model, DRAINMOD, to quantify the effect of soil water stresses on corn yields. The effects of a combination of excessive and deficient soil water conditions were approximated by a simple first-order crop response model, YR = YRw × YRd, where YR is the overall relative yield, and YRw and YRd are the relative yields due to excessive and deficient soil water conditions, respectively. The accuracy of the modified water management model was evaluated by comparing predicted and measured corn yields for 16 plot years of experimental data on the Tidewater Research Station near Plymouth, NC. The predicted and measured results were in good agreement with the model describing 63% of the variation in yields for the 12-year period. Use of the modified water management model was demonstrated by simulating the performance of several drainage system designs for a Portsmouth sandy loam soil. The results of the simulation show that a maximum long-term relative yield of 80% of the potential corn yield can be obtained with a drain spacing of 40 m or less with good surface drainage. Higher yields could not be obtained without irrigation to reduce deficit soil water conditions. The response of long-term average corn yields to surface drainage varies inversely with the intensity of subsurface drainage. The 25-year average yield for 100 m spacing was only 47% of the potential yield when the surface drainage was poor as compared to 61% of potential yield for good surface drainage.

Field Evaluation of a Water Management Simulation Model

ABSTRACT THE water management simulation model, DRAINMOD, was tested using field data for over 5 yr of record from three locations in the NC Coastal Plains. Each site had field scale drainage systems with provisions for subirrigation and controlled drainage. Three soil types and five different drainage system designs were included in the experiment from which 21 site-yr of data were obtained. Rainfall intensity and water table elevations were measured continuously at each site and the observed day end water table elevations were compared to predicted values. Effective lateral hydraulic conductivity values were measured in the field using both auger hole and water table drawdown methods. Numerous other field and laboratory mea-surements were made for each soil to determine input soil property and site parameter data. Comparison of predicted and measured water table elevations were in excellent agreement with the daily water table depths having standard errors of estimate ranging from 7.5 to 19.6 cm. The average absolute devia-tion between predicted and observed water table depths for 21 site-years of data (approximately 7400 pairs of daily predicted and measured values) was only 8.1 cm. Based on the results of the study, DRAINMOD can be reliably used to predict the effect of drainage system design on water table elevations.