Evaluation of DRAINMOD‐S for simulating water table management under semi‐arid conditions

Abstract

The water table management simulation model, DRAINMOD-S, was evaluated under semi-arid conditions using field data from the Maruit experimental field in the western delta of Egypt for three cropping seasons; maize 1999, wheat 1999/2000 and maize 2000. Two water table management systems (conventional drainage (FD) and controlled drainage (CD)) were applied in the study area. The recorded data included daily ground water table depths, drain outflows during flow events, soil salinity to depth of 1.20 m from the soil surface (0.30 m interval), and relative crop yield. DRAINMOD-S was run to simulate the applied water table management systems for the same study periods. The reliability of the model was evaluated by comparing measured and predicted values of the daily ground water table depth, cumulative outflow based on total monthly outflow, soil salinity during each season, and relative crop yield. Good agreement was found between the measured and predicted values. DRAINMOD-S predicted values within an absolute deviation ranged from 11.0 to 16.0 cm for ground water table depth, from 18 to 75 mm for drain outflows, from 0.22 to 1.08 dS m −1 for soil salinity, and from 4.62 to 4.86% for relative crop yield. The model showed the potential for long-term simulation and planning of ground water (CD)) ontété appliquésàla superficie de l'étude. Le data qui s'est remis en ordre s'inclut les mesures des profondeurs de la table d'eau souterraine, lesécoulements des drains pendant lesévènements de l'écoulement, la salinité du sol au profondeur de 1.20 m souterrain aux intervalles de 30 cm, etles produits agricoles relatifs. DRAINMOD-S S'est mis en courant pour simuler l'application des systèmes de la direction pour la même période d'étude. La véracité du modèle aétéévaluée en comparant les valeurs mésurées avec lcelles des produits agricoles sur le profondeur de la table d'eau quotidien, l'écoulement cumulatif basé sur l'écoulement total du mois, la salinité du sol pendant chaque saison, et les produits agricoles relatifs. On a trouvé un bon accord entre les valeurs mésurées et celles qu'on

Modeling subsurface drainage for salt load management in southeastern Australia

“…Previous evaluation of the DRAINMOD model under different soil and climatic conditions indicated that the values of average absolute deviation and standard error of estimate for (Wahba et al, 2002). Based on the results obtained and considering the methods of filed measurement, spatial variability of field data, and the approximation of model inputs, it can be concluded that the model provides reasonable approximation of water table trends under these conditions in Southeastern Australia.…”

“…For the conditions of the Western Delta of Egypt, the model simulated the total outflows with an average absolute deviation from 18 to 75 mm (Wahba et al, 2002). The average absolute deviation and the standard error are statistical measures for the difference between observed and simulated values.…”

“…The reliability of DRAINMOD-S for simulating water management (conventional drainage) in irrigated lands under actual field conditions was tested against data sets from the Zankalon Experimental Field (ZEF) in the Eastern Delta of Egypt , tested under semi-arid conditions in India (Merz, 1996) and tested for simulation of controlled drainage in Western Delta of Egypt (Wahba et al, 2002). The model has not been evaluated for predicting the salt load export from agricultural field under semi-arid conditions of Australia, it has only been evaluated for predicting water logging intensity and drain performance in surface drains in South-Western Australia (Cox et al, 1994).…”

Irrigation water saving by management of existing subsurface drainage in Egypt

“…The model showed the potential for longterm simulation and planning of groundwater table management under semi-arid conditions of the Western Delta of Egypt (Wahba et al, 2002).…”

Application of Soil–water–atmosphere–plant Model to Assess Performance of Subsurface Drainage System Under Semi‐arid Monsoon Climate

“…From these results, it could be concluded that in spite of small deviations at some points, an excellent visual match could be obtained between the observed and simulated values. The deviations between predicated and measured data revealed that AD for the groundwater table depth was 0.18 m while SE was 0.24 m. Evaluation of this and the other model under different soil and climate conditions previously indicated that the values of AD and SD for groundwater table depth ranged from 0.11 to 0.16 m and from 0.13 to 0.19 m respectively (Wahba et al ., ), from 0.14 to 0.24 m and from 0.15 to 0.30 m respectively (Gupta et al ., ), from 0.04 to 0.20 m and from 0.06 to 0.24 m respectively (Chang et al ., ; Skaggs, ; Abdel‐Dayem and Skaggs, ) and 0.13 and 0.15 respectively (Hirekhan et al ., ). The AD and SE were 1.07 and 2.15 mm day ‐1 respectively for the drainage discharge rate, and 7.8 and 9.6 mm respectively for the cumulative drainage discharge.…”