Preliminary Water Quality Assessment of Calumpang River in Batangas City, Philippines, Using Surface Water Analysis and UAV-Based Remote Sensing

Abstract:

Water is an integral part of nature; it is crucial in supporting life. Bodies of water in our planet include rivers, which provide various ecosystem services. Monitoring water quality is essential for assessment of current conditions of water bodies as well as of the progress of rehabilitation efforts. Calumpang River in Batangas City, Philippines, holds huge potential for ecosystem services; this potential is hindered by its degraded water quality at present. This study aims to develop an initial method for water quality assessment through interpolation of imagery from an unmanned aerial vehicle (UAV), and surface water quality data (Chl-A and CDOM) measured from in situ water sampling on defined reference points on the Calumpang River, with considerations for temporal variations (i.e. dry vs. wet season). Surface water quality data for dry and wet seasons and UAV imagery collected and analyzed from the dry season serve as preliminary results. Data indicate that there were higher Chl-A concentrations during the dry season, as expected. In contrast, CDOM concentrations were higher during the wet season. This is attributed to increased amount of detritus in the river accumulated through runoff and loading. The method of interpolating UAV imagery and water quality data can serve and be further improved as a means for rapid assessment of the water quality in water bodies in the future, and aid in the evaluation, monitoring, and management of water resources.