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Farzin Parchami-Araghi; Adnan Sadeghi-Lari
Abstract
It is important to assess the uncertainties involved in agro-hydrologic simulations because they are subject to varying degrees of uncertainty. Uncertainty analysis of the agro-hydrological models can provide useful insights into the degree of confidence in the model results. In this study, uncertainty ...
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It is important to assess the uncertainties involved in agro-hydrologic simulations because they are subject to varying degrees of uncertainty. Uncertainty analysis of the agro-hydrological models can provide useful insights into the degree of confidence in the model results. In this study, uncertainty analysis of a distributed application of the SWAP model to a sugarcane field with subsurface controlled drainage was conducted using a hybrid uncertainty analysis scheme, combining Generalized Likelihood Uncertainty Estimation (GLUE) and Unified Particle Swarm Optimization (UPSO). The results revealed a high variability of the calibrated parameters and the necessity of an uncertainty assessment for the SWAP simulations. Strong parameter correlations highlighted the need for calibration of the model parameters against diverse calibration data in a simultaneous manner. The 95% prediction uncertainty bands obtained for the hydrological (soil water content, water table level, sub-surface drainage outflow), solute transport (soil water solute concentration and sub-surface drainage outflow salinity), and biophysical (leaf area index, cane, and sucrose dry yield) simulations enveloped 73-80%, 45-58%, and 75-100% of the corresponding total observed data (including both calibration and validation datasets), respectively, with an r-factor (the ratio of the average thickness of the 95PPU band to the standard deviation of the corresponding measured variable) of 0.83-0.98, 1.43-1.96, and 0.75-1.11. The thickness of the derived 95PPU bands for the biophysical simulations showed an increasing trend over the simulation period.
Farzin Parchami-Araghi; Fatemeh Samipour; Adnan Sadeghi
Abstract
Realistic agro-hydrological modeling of the sugarcane fields with subsurface drainage in Khuzestan Province, Iran, is a challenging problem, due to rapid fluctuations of the shallow groundwater and, hence, water balance components, and significant size (~ 20 ha) of the fields. In this work, a distributed ...
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Realistic agro-hydrological modeling of the sugarcane fields with subsurface drainage in Khuzestan Province, Iran, is a challenging problem, due to rapid fluctuations of the shallow groundwater and, hence, water balance components, and significant size (~ 20 ha) of the fields. In this work, a distributed agro-hydrological modeling scheme was developed through the application of a modified version of the SWAP model and an improved variant of Unified Particle Swarm Optimization (UPSO) algorithm with capability of sub-daily calibration and simulation of controlled drainage. The developed modeling scheme was applied to a sugarcane (CP48-103 cultivar) field with controlled drainage (at 90 cm below ground level) in Imam Khomeini Sugarcane Agro-industrial Company farms, during 2010-2011 (481 days). The results demonstrated the success of the developed modeling scheme in retrieving the measured soil moisture, groundwater level, subsurface drainage outflow (with an EF of 0.829, 0.922, and 0.857 for calibration dataset; and 0.877, 0.781, and 0.712 for validation dataset, respectively), soil water solute concentration, subsurface drainage outflow salinity (with a NRMSE of 0.124 and 0.079 for calibration dataset; and 0.152 and 0.072 for validation dataset, respectively), Leaf Area Index, cane yield, and sucrose yield (with an EF of 0.997, 0.993, and 0.988, respectively). Based on the solute balance components simulated throughout the simulation period, ~ 30.10 ton salt ha-1 was added to the soil due to saline irrigation water, and ~ 45.25 ton salt ha-1 was discharged into the receiving water bodies via surface/subsurface field drains.
s r; a s
Abstract
The technology of magnetic water has been widely studied and adopted in the field of agriculture in many countries. The objective of the present study was to investigate the effect of magnetic water on germination and vegetative growth of two varieties of tomato (lycopercicum esculentum) seeds. A factorial ...
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The technology of magnetic water has been widely studied and adopted in the field of agriculture in many countries. The objective of the present study was to investigate the effect of magnetic water on germination and vegetative growth of two varieties of tomato (lycopercicum esculentum) seeds. A factorial experiment in completely randomized design was carried out using three replications, in 2014. Based on the results, seeds irrigated with magnetic water exhibited marked increases in rate of germination, vegetative growth, vigor index, root length, seedling length, seedling fresh weight and chemical constituents i.e. photosynthetic pigments (chlorophyll a and b and carotenoids), over the control. Percentage of germination for seeds irrigated with magnetized water was 94.6 for the two varieties, while for the control it was 90 and 93 in Sunseed and Sudin, respectively. Results indicated that irrigation with magnetized water induced positive significant effect on all studied parameters. It appears that utilization of magnetized water may lead to improved quantity and quality of tomato production.