Water quality assessment in various land use and land cover of Muleta Watershed Bukidnon, Philippines

Abstract

Changes in the land cover and land management practices in Muleta watershed have been considered as one of the key influencing factors behind threats affecting the water quality. The study aims to assess and analyze useful evidence on the influence of various land use/cover on the stream physico-chemical properties of Muleta River based on water quality monitoring data with the water quality guidelines for classification of the DENR Administrative Order No. 2016-08 (DAO 2016-08). Major LULC was delineated using satellite data specifically Landsat 8 OLI of year 2015 and was downloaded from USGS Earth Explorer. The watershed has six (6) existing land cover: forest, agricultural land, bareland, built-up area, grassland and water. The upstream was found to be covered with perennial vegetation; the midstream is used for agriculture and covered with least forest; the downstream was mainly used for residential and utilized for different forms of agriculture. The results obtained from the water quality were compared with existing land use/cover of the watershed at α=0.01 significance level. The result shows that temperature, TSS, nitrates and phosphates are significantly different water quality result in parallel to the LULC of the sampling site. On the other hand, the pH, turbidity, dissolved oxygen, and TDS are not significantly different from each other regardless land cover/land use surrounding the water system. Generally, the result is of great help in developing and implementing watersheds plans to protect land and water resources and improve the overall quality of the watersheds.