Philippine E-Journals

Identifying the Mixing Regime of Lake Taal, Batangas, Philippines: Implications of Lake Mixing and Stratification to Lake Management

Justine De Leon | Dale Anthony L To | Elfritzson M Peralta | Kenneth Xavier O Sanchez | John Claude Renan B. Salluta | Cyrille V Zubiri | Dino T Tordesillas | Rey Donne S. Papa S Papa

Discipline: Engineering

 

Abstract:

Lake Taal is one of the major lakes in the Philippines which have been supporting several economic sectors for the past five decades. Its exposure to a number of unsustainable practices have resulted in the decline of its water quality. Monitoring activities have been conducted in the lake as early as the year 2000s; however, techniques used in these endeavors are limited. In this study, the vertical profiles of selected physicochemical parameters of Lake Taal including temperature, dissolved oxygen, pH, conductivity, were monitored from February to December 2022. Six sampling points were identified to equally represent its northern and southern basins. Results showed that the lake undergoes complete lake turnover (mixing) during the northeast monsoon, then remains to be stratified for the rest of the year. During its stratified months, dissolved oxygen was only highly concentrated up until 10 m especially during the hot-dry season. In contrast, conductivity showed equal readings between surface and bottom layers with no variation between sampling points and months; a probable indication of the homogeneity of the nutrients of Lake Taal. The application of these techniques, as well as establishing long-term daily monitoring activities, may help in designing a more specific and adaptive lake management program for this important lake ecosystem.