Abstract
This study intends to establish the main relations between topographic characteristics of the watershed and the main parameters of the unit hydrograph measured at the outlet. It looks to remove the subjectivity found in traditional synthetic methods and the trial and error setting of the main parameters of the hydrograph. The work was developed through physical experimentation of the rainfall-runoff process using the observed information of different watersheds of Chiapas, Mexico, as the reference. The experiments were carried out on a state-of-the-art semi-automatic runoff simulator, which was designed and built specifically for this study. Polynomial regression and fuzzy logic models were obtained to confirm the hypothesis of hydrological parameters being obtained from topographic data only by assuming uniform precipitation. Empirical relations were found for the peak flow, time to peak, base time and volume of the unit hydrograph and the watershed area, the main stream average slope, and the length of the stream of highest order. The main finding is that a unit hydrograph can be described based only on the watershed area when fuzzy logic models are applied.
Highlights
The design of rainwater management structures and waterworks, the determination of floodplain limits, and the evaluation of river structures’ safety for gauged or ungauged watersheds requires water discharge information
It is of great importance to have an accurate estimation of the relations between rainfall and runoff, especially if they can be applied in a simple manner and obtained from precise and available data like topography, geomorphology, or measurable characteristics of the watershed
The purpose of this study is to present the experimentation, results, and analysis that confirm that the main hydrograph parameters are attainable through the watershed topography information
Summary
The design of rainwater management structures and waterworks, the determination of floodplain limits, and the evaluation of river structures’ safety for gauged or ungauged watersheds requires water discharge information. It is of great importance to have an accurate estimation of the relations between rainfall and runoff, especially if they can be applied in a simple manner and obtained from precise and available data like topography, geomorphology, or measurable characteristics of the watershed. Since precipitation varies constantly within a watershed and the availability and precision of pluviometric data can be questionable, especially in developing countries like Mexico, many researchers have focused their efforts on understanding the relationships between the watershed’s geomorphology and its hydrology through empiric relations using synthetic (the term “synthetic” suggests that it has been determined based on watershed measurable characteristics and not on the runoff-rainfall relationship information) methods [3,4,5,6,7,8,9,10,11,12,13] and not the actual hyetograph.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
