Developing of Rainfall Intensity-Duration-Frequency Model for Sulaimani City

ABSTRACT Rainfall intensity equations are fundamental in hydrological studies of road design, which require a project rainfall definition to estimate the project flow and the subsequent design of the hydraulic structure. This paper develops an integrated framework for rainfall intensity equations analyses from global optimization via Differential Evolution. The code was specially developed to facilitate the Gumbel model adjustment in the frequency analysis of annual series, as well as the intensity-duration-frequency model fit, without prior knowledge about the parameters of both models. The developed system was evaluated by using Markov chain Monte Carlo simulation, that search efficiently the model parameter space in pursuit of posterior samples and the posterior prediction uncertainty for both models. The results indicate that simulations are shown to be in good agreement with the measured flow and precipitation data. The optimal parameters obtained with the developed framework agreed with the maximum a-posteriori value of the Monte Carlo simulations. The paper illustrates explicitly the benefits of the method using real-world precipitation data collected for a hydrologic study of a highway design.

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Rainfall Intensity-Duration-Frequency Relationships for Risk Analysis in the Region of Matopiba, Brazil

Revista Brasileira de Meteorologia ◽

10.1590/0102-77863340239 ◽

2019 ◽

Vol 34 (2) ◽

pp. 247-254

Author(s):

Luciele Vaz da Silva ◽

Derblai Casaroli ◽

Adão Wagner Pêgo Evangelista ◽

José Alves Júnior ◽

Rafael Battisti

Keyword(s):

Rainfall Intensity ◽

Frequency Function ◽

Annual Rainfall ◽

Frequency Model ◽

Maximum Rainfall ◽

Rainfall Duration ◽

The North ◽

Gumbel Model ◽

Intensity Duration Frequency ◽

Agricultural Areas

Abstract The region of study was MATOPIBA, located in the north of Brazilian Savanna biome (Cerrado), encompassing part of north/northeast of Brazil. The region has been gaining prominence in the last years due to the expansion of agricultural over this area. The aims of this study were: to adjust parameters for rainfall intensity-duration-frequency; and to identify the most vulnerable agricultural areas to erosion based on erosivity and erodibility. The rainfall intensity-duration-frequency function were adjusted using series of maximum annual rainfall event from 105 rainfall gauges. Gumbel model was the most efficient to simulate the maximum rainfall intensity, where these data were used to adjusted the rainfall intensity-duration-frequency model based on K, a, b and c parameters. The most rainfall gauges showed intensity between 51 and 80 mm h-1 and 81 and 120 mm h-1, respectively, for return period of 2 and 100 years with rainfall duration of 30 minutes. The higher rainfall intensity was observed mainly in the central-north of the region associated with rainfall systems. The rainfall intensity showed a huge capacity to cause soil erosion based on the erosivity energy, while the moderate erodibility was observed for areas with Ferralsols and Leptosols and low erodibility for areas with Arenosols.

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Estimation of the G2P Design Storm from a Rainfall Convectivity Index

Water ◽

10.3390/w13141943 ◽

2021 ◽

Vol 13 (14) ◽

pp. 1943

Author(s):

Rosario Balbastre-Soldevila ◽

Rafael García-Bartual ◽

Ignacio Andrés-Doménech

Keyword(s):

Shape Parameter ◽

Rainfall Intensity ◽

Analytical Relationship ◽

Urban Drainage ◽

Practical Application ◽

Resolution Time ◽

Simple Method ◽

Design Storm ◽

Intensity Duration Frequency ◽

Two Parameter

The two-parameter gamma function (G2P) design storm is a recent methodology used to obtain synthetic hyetographs especially developed for urban hydrology applications. Further analytical developments on the G2P design storm are presented herein, linking the rainfall convectivity n-index with the shape parameter of the design storm. This step can provide a useful basis for future easy-to-handle rainfall inputs in the context of regional urban drainage studies. A practical application is presented herein for the case of Valencia (Spain), based on high-resolution time series of rainfall intensity. The resulting design storm captures certain internal statistics and features observed in the fine-scale rainfall intensity historical records. On the other hand, a direct, simple method is formulated to derivate the design storm from the intensity–duration–frequency (IDF) curves, making use of the analytical relationship with the n-index.

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