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Effect of ground gauges density on areal reduction factor /

Yehia Ahmed Adel

Effect of ground gauges density on areal reduction factor / تأثير كثافة المحطات الأرضية على معامل تخفيض المساحة Yehia Ahmed Adel ; Supervised Alaa Eldin M. Elzawahry , Ayman Georges Awadallah - Cairo : Yehia Ahmed Adel , 2020 - 89 P . : charts , facsmilies ; 30cm

Thesis (Ph.D.) - Cairo University - Faculty of Engineering - Department of Civil Engineering

Rainfall ground gauges measures the rainfall depth only at the location of the gauges while the storm is natural phenomena with a variable intensity varying from the center to the edge of the storm. Usually, most of catchment areas have only limited rainfall gauges count as each gauge has capital and running costs and governmental agencies tends to minimize these costs. As such, it is important to enhance the estimation of runoff quantities and determine the optimum number of gauges to be built. Researchers studied the areal reduction factor concept in which a reduction factor is used to decrease the runoff estimation to account for the difference between the point rainfall measurement and the variable intensity of the rainfall across the watershed. However, the relation between the number of gauges used to determine the areal reduction factors and its value was not investigated. Thus, the main objective of this study is to identify the optimum rainfall gauges density required and introduce a new coefficient that can be used to consider the gauges density. In this study, rainfall records from 90 gauges located in Walnut Gulch, Arizona, USA experimental watershed were used to study the effect of the rainfall gauges density within a watershed on the value of the areal reduction factor calculated. It was found that there the areal reduction factor values decrease proportionally with the increase of the rainfall gauges density. Optimum density of rainfall gauges was identified, and charts for the new coefficient GDC (Gauges Density Coefficient) were created



Areal reduction factor Orthogonal sampling Runoff estimation