Regression analysis to obtain the curves of intensity, duration and frequency of rain for the Rocafuerte river basin

Abstract

The management of water resources is a task that all the countries of the world approach in different ways, and this depends on the state and perspective of development of natural resources. Ecuador is a country whose climatic trend is based on two maritime currents: the Humboldt and the Niño, which regulate the rain regime during all months of the year. As a trend, it should be noted that the intensity of these currents is very irregular and to some extent unpredictable.
The diversity of rainfall patterns varies in the hydrographic demarcations of Ecuador, depending on their location and characteristics of the soils in terms of uses and vegetation cover. The objective of this work is aimed at obtaining the intensity, duration and frequency curves of one of the micro-basins of the Manabí River Basin, called Rocafuerte.
For this purpose, the rainfall data from the National Institute of Meteorology and Hydrology of Ecuador (INAMHI) corresponding to the period 1964-2019 were used. The records used correspond to the maximum rainfall in 24 hours. As an initial task, the missing data was filled in, then with the complete data, the maximum values in 24-hour rains were chosen for each of the years considered.
These data were processed following the Pearson type III methodology, for the respective extrapolation that allowed us to determine rainfall values corresponding to longer return periods. Finally, using least squares, the respective calculations were made to obtain the curves of Intensity, Duration and Frequency for 9 return periods.