Usability of Standard MonitoredRainfall-Runoff Data in Panama, Juan Diaz River Basin

Abstract:

Water resources demand and natural disasters related to hydro meteorological events haveincreased the interest in hydrological studies in Panama. Runoff estimations are importantfor effective water resources management in any catchment, but the limited quantity andquality of the available hydrological and meteorological data in Panama make it hard forresearchers to come to conclusive statements that can help in good planning. This issue hasto be addressed, but meanwhile, the challenge is to try to understand the hydrologicalprocesses occurring in any catchment with the available data.The relationship between rainfall and runoff in the Juan Diaz River basin is not wellunderstood and its fast response due to high rainfall intensities in the area is a concern inthe community and authorities. The meteorological and hydrological data in the Juan DiazRiver basin are also limited. The main objective of this thesis was to establish how well theJuan Diaz River basin can be hydrologically represented by records of the availableinstrumentation. This was performed with a hydrological, WASMOD, and a statistical model,linear multiple regression. Both models simulated daily and monthly runoff for a period of 21years. For the long term water balance, a graph showing discharge against rainfall data wasplotted in the yearly scale to establish a relationship between the two variables.Precipitation records from an active meteorological station, which was the closest to thebasin from the ones with available records, were used in this study to estimate the arealmean precipitation of the basin, since nowadays there are no active meteorological stationswithin the basin.It was not possible to represent the Juan Diaz River basin well with the two models in thedaily and monthly resolution. Uncertainties in the precipitation input and in the dischargeoutput data were considered to be the reasons for the poor simulations. That said, it can bestated that the available instrumentation at this point is not sufficient for modeling. In thelong term water balance, the instrumentation can be used for water estimations, but carehas to be taken if this approach is used since the limited quantity of data in this scale werescattered around the predictions.Efforts have to be made to encourage decision makers to increase the availableinstrumentation in the Juan Diaz River basin, in order to make accurate simulations orforecasting that will better support water resources management.