Land-cover Characterization and Water Quality Assessment of the Sambunotan Watershed, Dinagat Islands in Support of the Development of the Watershed Management Plan

The Sambunotan Watershed covers an area of 28 sq. km. within the Tubajon and Loreto municipalities in the province of Dinagat Islands, Philippines. Recently, the Sambunotan Watershed Management Plan's development was initiated within the 5-year Dinagat Islandscape Development Framework and Strategies through a collaborative effort among municipal and provincial local government units, non-government, and civil society organizations. In this paper, we present the land-cover characterization and water quality assessment to support the development of the watershed management plan. Freely available land-cover maps of the watershed from 2017-2021 were analyzed to quantify the extent and changes of the watershed’s land cover. Field measurements to measure various water quality (WQ) parameters (pH, total dissolved solids, dissolved oxygen, and temperature) were conducted in May and November 2022, representing the watershed’s dry and wet seasons. These WQ parameters/variables were correlated with the watershed’s land cover characteristics. Major results showed that through the years, the dominant land cover classes are trees and rangeland.