Managing Flood Flows for Crop Production Risk Management with Hydraulic and GIS Modeling: Case study of Agricultural Areas in Shariatpur

AbstractShariatpur District, under Dhaka division with an area of 1181.53 sq km, is mainly surrounded by the two big rivers, the Padma at north and the Meghna at eastern side. Also, the Arial Khan River is located at the south western side of the district. When the Padma and the Meghna Rivers attain peak flood levels simultaneously, this district faces devastating floods. These floods have a destructive effect on agriculture especially on Aman (June- September) variety at optimum level of flood depth but also have a positive impact on next year's Boro (December- march) production due to sedimentation by the previous year's flood. So there is a scope of managing flood flows which ensures the optimum level of flood depth that promotes the crop production risk management. The present study provides a method for flood management aiming to crop production risk management. In this study, inundation maps have been produced using hydrodynamic model HEC-RAS and HEC-GeoRAS extension of ArcGIS9.2. Then calculation of optimal flood depth for crop production risk management has been done using some sophisticated statistical analysis. Finally, volume of water above the optimal flood depth has been calculated using GIS model with ArcGIS 9.2 and based on this, proposed some ways of flood flows management which ensure the crop production risk management. The study findings show that, the optimal flood depth is 1.85m (msl) in where Boro production would be safe and Aman production would face about 200 ton/yr loss, we can called this condition as crop production as farmers get more return from Boro variety. This study also find two equations that provide estimation of Mawa discharge depending on two upstream stations (Hardings Bridge and Bahadurabad Ghat) and targeted discharge of Mawa that needs to release from Mawa to the study area for ensuring the optimum flood depth

Behavior of bonded and unbonded prestressed normal and high strength concrete beams

AbstractThe major disadvantage of using ordinary reinforced concrete (RC) elements is the corrosion of steel, which occurs due to effect of cracks in tension zones. The main advantage of the fully prestressed concrete system is the absence of cracks in the concrete at the nominal service load and therefore better durability will be achieved. Combining the PC system with the use of high strength concrete is a milestone, which will potentially result in a new design approach. The disadvantage of the use of this combination is referred to the reduced ductility of concrete members.This paper presents an experimental program conducted to study the behavior of bonded and unbounded prestressed normal strength (NSC) and high strength concrete (HSC) beams. The program consists of a total of nine beams; two specimens were reinforced with non-prestressed reinforcement, four specimens were reinforced with bonded tendons, and the remaining three specimens were reinforced with unbonded tendons. The overall dimensions of the beams are 160×340×4400-mm. The beams were tested under cyclic loading up to failure to examine its flexural behavior. The main variables in this experimental program are nominal concrete compressive strength (43, 72 and 97MPa), bonded and unbonded tendons and prestressing index (0%, 70% and 100%). Theoretical analysis using rational approach was also carried out to predict the flexural behavior of the specimens. Evaluation of the analytical work is introduced and compared to the results of the experimental work

Effect of different dietary concentrations of brown marine algae (Sargassum dentifebium) prepared by different methods on plasma and yolk lipid profiles, yolk total carotene and lutein plus zeaxanthin of laying hens

The effect of different concentrations (0%, 3% and 6%) of brown marine algae (BMA,<em> Sargassum dentifebium</em>) prepared according to different methods (sun-dried, SBMA; boiled, BBMA; autoclaved, ABMA) on plasma and yolk lipid profiles, carotene, and lutein plus zeaxanthin in egg yolks was studied in hens aged from 23 to 42 weeks (30 hens per treatment). We determined the fatty acid profiles in BMA and in the egg yolk of hens fed different levels of BMA prepared according to different methods. In addition, plasma and yolk lipid profiles, yolk total carotene, and lutein plus zeaxanthin were determined at week 42 of age. Plasma and yolk cholesterol were significantly lower in groups fed diets containing either 3% or 6% BMA than in the control group, but high-density lipoprotein (HDL) significantly decreased as BMA concentration increased. There was a significant similar decline in yolk triglycerides with inclusion of either 3% or 6% BMA in the laying hen diet. Palmitic acid was the main saturated fatty acid (SFA) found in BMA and oleic acid (omega-9) and linoleic acid (omega-6) were the main unsaturated fatty acids (UFA), while there was a significant increase in palmitic acid in egg yolk when BMA was included at 6%. There was a significant increase in oleic acid (omega-9) when feed containing 3% BMA was given compared to the control group, but this decreased with a further increase in BMA. Linoleic acid (omega-6) also significantly decreased with inclusion of either 3% or 6% BMA. There was a significant increase in total carotene and lutein plus zeaxanthin in the laying hen eggs as a result of feeding diets containing 3% and 6% BMA