No abstract

Reuse of wastewater has been widespread in this era to support the water sustainability process. Therefore, treated wastewater should be conveyed to suitable places and adopted for different uses. This study presents an empirical relationship between the Darcy-Weisbach and Hazen-Williams equations for four types of pipe material (ductile iron, GRP, concrete, and plastic) by using WaterCAD Version 8i. Two hydraulic models were developed to estimate the head loss in pipes by using different diameters: first, using pipe diameters from 800 mm to 1,200 mm for a flow rate of 1.16 m3/s, second, adopting pipe diameter from 1,600 mm to 2,000 mm for a flow rate of 4.63 m3/s. The study results are the head loss values obtained from the Darcy-Weisbach and Hazen-Williams equations, which were used to correlate them using IBM SPSS Statistics. The correlation coefficient between both equations turned out to be 0.991, 0.990, 0.990, and 0.990 for ductile iron, GRP, concrete, and plastic pipe materials. Additionally, the relationship between head loss and pipe diameter is negatively proportioned for both equations. Also, both head loss equation results are the same. The head loss values in the Darcy’s equation were higher for ductile iron and GRP materials, while being lower for concrete and plastic materials for both models. Selecting concrete or plastic pipes to convey treated wastewater is better than other pipe materials. Another conclusion is that the pipe diameter affects the head loss magnitude irrespective of the kind of equation whether Darcy-Weisbach or Hazen-William equation. Finally, this relationship is very useful for designers in converting the head loss values obtained using these equations.

The Urban Heat Island (UHI) effect can best be described as an increase in the temperature of urban areas relative to their surroundings. This effect can exceed 5 o C in places. This study investigates how vegetation, in particular urban parklands, can be used to reduce the intensity of the UHI effect. To achieve this, the study uses a ground based approach relying on high spatial and temporal resolution temperature measurements using both a hand-held weather meter and a hand-held thermal laser-gun. The study focusses on one medium sized park in Melbourne, Australia and samples air temperatures (at 5 cm and 1.5 m above the ground) and land surface temperature profiles six times a day over one month starting within the park and extending to approximately 1 km outside of the park. The study shows that the park has a significant cooling effect for a distance of up to 860 m from its boundaries and that this is most significant in the early morning. The study also shows that land surface temperatures are more sensitive to park cooling effects than are air temperatures.

Efficiency of water use in irrigation field always motivates researchers to find a way which could reduce irrigation quantity and obtain approximately the same crop yields. This study estimated the relationship between the paucity irrigation with the reduction in yield for eight crops (cotton, maize, alfalfa, small grain, summer vegetable, sesame, sunflower, and palms) by using various paucity irrigation stages from evapotranspiration of crops (5, 10, 15, 20, and 25%) as an indication of all crop outgrowth using medium soil. This study selected the project of Al-Hussainiyah irrigation that lies in Karbala province, which is close to Baghdad relative to the South. Also, the project has high importance because most dwellers have used the province for agriculture and drinking purposes. These are reasons of choosing it as a case study to implement paucity irrigation strategy on most crops (eight crops) within the project. The necessary records related to this study were obtained from specialized offices in Iraq, particularly water resources and agriculture ministries. Computer programs such as CROPWAT version 8.0, statistical program SPSS statistics version 20, and table curve 2D version 5.0 are considered the software for solving this model. This model was tested for its application and sensitivity by changing paucity levels for each crop. The comparison between the available and the estimated water demand showed that the paucity in irrigation water demand was very clear during the period from February to December for the average present state of agriculture. The correlation analysis gives a result that the paucity irrigation level with yield reduction manifested that the yield reduction rate of maize recorded higher than the other crops, while cotton recorded lower yield reduction rate than the other crops during all paucity stages.

Evapotranspiration represents one of the main parameters in the hydrological cycle. It is usually expressed by the term reference evapotranspiration (ETo) that is affected by certain meteorological parameters. This study aimed to find the difference amount in ETo between urban and suburban quarters in Karbala city. The study methodology involved selecting once urban area and four suburban quarters. Two methods of determining the reference evapotranspiration were applied: first, a direct method which measured ETo at selected fields by using a hand-held device, and second, an indirect method using the Penman-Monteith equation. The findings showed that the magnitudes of ETo by the Penman-Monteith equation are higher than the values measured by the direct method for urban and suburban quarters. Moreover, it was found that the absolute percentage of difference in the average amount of ETo between urban and suburban quarters is 13% by using the direct method and 61% by using Penman-Monteith equation. The study conclusion is that suburban area has higher magnitude of ETo than urban quarter by using any of direct method and indirect method (Penman-Monteith equation).