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Rice farmers in the study area as elsewhere in some developing parts of the world have been negatively affected by floods annually. There have been several solutions, some suggested and others implemented to mitigate the effect of these floods on the farmers. Different initiatives have been undertaken by various stakeholders in the food production chain. Providing a multidimensional approach to highlighting these initiatives is essential to an effective and efficient resolution. The prospects and challenges of incorporating technology, capacity development, business and government support have been evaluated. The solutions proposed in this paper would bring economic benefits to the rice farmers, private companies, and government, leading to the attainment of Sustainable Development Goal (SDG) 2- Zero Hunger and the other 16 SDGs.
 

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Research subject: Nanomaterials are substances that, because of their size, can easily penetrate small pores and apply their impact. Nanofluids can allow appropriate wettability change in the reservoir rock, therefore, an accurate understanding of the behavioral mechanisms of these nanofluids is important in changing the wettability. This is because if there is no proper understanding of these mechanisms, they may exhibit the opposite behavior and cause damage to the reservoir. In previous research, CuO / TiO2 / PAM nanocomposite was synthesized and mechanistically introduced.
Research approach: In this study, in continuation of the previous study, the behavioral and mechanism study has been investigated in a more accurate and documented manner, and spectral absorption tests, chemical flooding, and relative permeability diagrams confirm the effectiveness of enhanced oil recovery results of this nanocomposite. In carbonate rocks due to the positive surface charge of the rock and the negative charge of the nanocomposite, adsorption of nanomaterials in a double electrode layer state has been suggested as the dominant mechanism of wettability change. In sandstone rocks due to the charge coincidence of rock surface and nanomaterials which are both negative, the mechanism of disjoining pressure was the dominant mechanism of wettability change. To prove the abovementioned behaviors 200 ppm concentration of nanofluid was analyzed by spectroscopy method of adsorption analysis to validate the attraction forces of the nanocomposite with carbonate rocks and repulsion forces with sandstones.
Main results: Dynamic chemical flood tests were performed to confirm the effectiveness of this material in increasing oil production and showed 8.5% and 6.35% increase in oil production for carbonate and sandstone lithologies, respectively. Relative permeability diagrams showed an intersection point in the carbonate system with a 10% increase in water saturation and an intersection point in the sandstone system with a 12% increase in water saturation and the behavioral effect of the material at the studied concentrations.

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Research subject: In this study, the occurrence of flooding due to the accumulation of sediment in the downcomer area, which led to an excessive increase in liquid on the upper trays of the distillation column was investigated in a refinery.
Research approach: Vacuum pressure in the upper area of the column, boiler feed water flow from the inlet to the condenser and the discharge of the net product as three very important and effective operational parameters in controlling the severity of the flooding phenomena and the amount of coking value as an important laboratory parameter to reduce the volume of inlet sediments entering the distillation column. Data and results of changes made on each of these three operational parameters showed their effectiveness in controlling the severity of the flooding phenomena.
Main results: In order to control and reduce the problems caused by the simultaneous flooding phenomena around the vacuum pump, the boiler feed water flow of the inlet to the condenser and the flow of the net output product were proportionally increased until the operating conditions of the distillation column are normalized. In this study, how to control the flooding phenomena and reduce the adverse effects due to the accumulation of sediments in the downcomer area of tray No. 22 and above was investigated.
To overcome these problems, first the vacuum pump rotation speed was increased from 850 rpm to 1250 rpm and the boiler feed water inlet to the condenser from 1.95 m³/hr to 3.2 m³/hr was increased. On the other hand, in order to prevent contamination of the pure product, the net output product flow rate also increased from 925 kg/hr to 2300 kg/hr. Also, with regular and accurate control of the coking value index as a very important laboratory parameter, the volume of coke sediments in the coal tar feed entering the distillation column was reduced from 37.5% by weight to 18.4% in a 30-day period after centrifugation.

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  Research subject: Investigation of the effect of temperature on the polymer flooding performance at the pore scale, leads to an understanding of the behavior of the polymer solution in porous media with varying permeability.
Research approach: In this study, the effect of temperature on flooding of polyacrylamide polymer on enhanced oil recovery in two homogeneous micromodels at 25 and 70 °C was investigated. The polymer solution and DW were injected at the injection rate of 1 μl/min up to 1 PV into the micromodel and the amount of produced oil and the movement of the injected fluid in the porous medium were analyzed. In addition, polymer rheology and injected fluid viscosity were measured for better analysis of results. Then the results were compared with flooding of distilled water as the control test.
Main results: Examining the flood results, it was found that on the one hand, the temperature factor helped to increase oil recovery by reducing the viscosity of the oil. On the other hand, it has reduced the role of injected fluid viscosity in oil extraction by reducing the viscosity of the polymer. The results showed that the phenomenon of fingering decreases in the case of polymer injection, and the rate of improvement of oil recovery during polymer and water flooding in both micromodels increases with increasing temperature. Also, the rate of improvement of oil recovery during polymer flooding in the A micromodel increased from about 43% at ambient temperature to more than 51% and in the B micromodel from about 51% to more than 60% at 70 °C. In fact, it can be said that the flow pattern and stability of the polymer solution front and consequently the ultimate oil recovery are significantly affected by the morphology of the pores, the shape and the throats pores.
    

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Aim: Caspian locust, native to Hyrcanian forests of Iran, is one of the pioneer species, which it distributed in the moist soils of these forests. So far, the response of its seedlings to permanent and temporary flooded beds has not been reported. This study was conducted with the objective to analyze the physiological responses of Caspian locust seedlings to flooding and flooding-recovery conditions.

Materials & Methods: Flooding conditions were examined for 90 days in the greenhouse of the Tarbiat Modares University. The study was carried out in a factorial experiment as a completely randomized design with 5 treatments and 4 replications. Treatments included: (1) continuous flooding for 90 days (F90), (2) flooding for 60 days followed by a 30-day recovery (F60+R30), (3) flooding for 45 days followed by a 45-day recovery (F45+R45), (4) flooding for 30 days followed by a 60-day recovery (F30+R60) and (5) Control.
Findings: Results showed that flooding for 90 days induced a significant decrease in net photosynthesis (-91%), stomatal conductance (-77%), transpiration (-81%), Chl a (-63%), Chl b (-67%) and Chl _Tot (-64%) compared to the control (p<0.05). When flooding was removed for 30-60 days, plants were able to recover gas exchange activities from 30 to 90% and Chl content by 55-90%.
Conclusion: Based on our results, seedlings of G. caspica can survive and grow throughout a medium period of soil waterlogging. Therefore, Caspian locust appears to be a promising species for reforestation programs in the riverine areas and temporarily flooded wetlands.
 

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Salix integra Thunb. is a shrub distributed in China along the Huai River riparian zone, and plays an important role in water and soil conservation. S. integra shrub land is easily submerged during July to October due to the flooding of Huai River. In order to characterize the physiological mechanisms of waterlogging tolerance of S. integra and to help rationally select waterlogging-tolerant species to alleviate the flood damage to agricultural production, we studied the effects of flooding on the growth, leaf gas exchange, and chlorophyll fluorescence of S. integra cuttings during a growth season (from August to October 2011). The biomass production and photosynthesis of S. integra cv. qingpi were promoted under moderate waterlogging stress, whereas its growth, chlorophyll content, net photosynthetic rate, and stomatal conductance were all significantly lower than those of the control group. A significant increase in non-photochemical quenching (NPQ) and a reduction in PSII maximal quantum photochemistry efficiency (F_v/F_m) were observed inflooded seedlings of S. integra cv. hongpi. In the case of S. integra cv. qingpi, however, there were no significant differences in NPQ and F_v/F_mbetween the treatment and the controls. Our results demonstrated that S. integra cv. hongpi exhibited slight damage to its photosynthetic apparatus under flooding. In contrast, a moderate flooding stress promoted the leaf and root production of S. integra cv. qingpi, indicating that S. integra cv. qingpi can tolerate prolonged soil flooding better than S. integra cv. hongpi. Thus, S. integra cv. qingpi is more suitable for afforestation in the riparian zone.

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In the Small forest basins, mostly are the headwater of the Caspian sea basin, long historical data are unavailable, therefore physically bases model are suitable tools to evaluate them.The aim of this study was to simulate water balance components and estimate the impact of hydrogeological, morphological and hydrological conditions on water balance components in Kasilian representative basin. The BROOK90 model was applied and calibrated for the water balance analysis. Twenty years of hydro-climatology data were used for setting Brook90. Data from the period 1992–1993 was used for calibration, and the interval 2004–2006 was considered as the validation period. The calibration of Brook90 was done by trial and error. Visual inspection of the measured and simulated discharge curves and mean bias error were the indicators for model performance. The simulation results demonstrate that the model can give a fair estimation of the water balance components. The results of sensitivity analysis on model parameters indicates that geological, hydrological and land use factors play important roles in runoff generation and water balance components in the basin. The water balance investigation showed that about 76 percent of the annual precipitation released as evapotranspiration and 24 percent as streamflow. The average contribution of the individual streamflow component to total streamflow is 46.67% groundwater flow, 38.32% Source area flow, and 16.99% Bypass flow. The increase of vegetation cover reduces total evapotranspiration and total runoff that play an important role in reducing the potential of flooding and an increase in groundwater storage in the basin.