Search

This study analyzed the effects of population and urban growth on water demand for irrigation and other water users, as well as municipal wastewater quantity changes, by developing a new mathematical model. The model was developed to consider the potential for reuse of treated wastewater for agricultural irrigation, by analyzing the increasing quantity of wastewater production in an urban area. It was applied to a case study in Logan, Utah, whereby results from the model showed a total water demand of 0.7 and 1.27 m/s in 2020 and 2050, respectively, while the model predicted that the average wastewater influent for Logan City would be more than double from 2010 to 2050. Accordingly, a model-predicted increase of 16% in the annual production of wastewater was observed from 2010 to 2025. The amount of wastewater production in 2030 was estimated to be 14.2 million m/year, which is enough to produce food from irrigated agriculture for 11% of the future population of Logan City. This emphasizes the potential importance of reusing wastewater for irrigated agriculture. Water conservation was also studied and it showed that a 5% conservation of water volume could cover the needs of an additional 4.2 thousand people in 2030. [ABSTRACT FROM AUTHOR]

The coefficient of uniformity, CU, and the distribution uniformity, DU, are perhaps the two most common indicators of irrigation application uniformity, especially for pressurized irrigation methods. The magnitude of CU is usually greater than that of DU, but this is not the case for all data sets, as has been observed in practice by irrigation engineers and researchers. This paper describes the conditions under which CU > DU, and vice versa, proving that either situation can occur in practice. A comparison of some alternative measures of irrigation application uniformity is also compared using two data sets from agricultural sprinklers operating at different pressures. [ABSTRACT FROM AUTHOR]