Agricultural Watershed Health Monitoring Using Spatial Based Approach under Tropical Climate Environment

Department of Agricultural and Biosystems Engineering, Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia.

^* Corresponding author: chandra.tep@ugm.ac.id

Abstract

Massive agricultural activities in watershed areas cause severe environmental damage through soil erosion, sedimentation downstream and decreased water quality. A decrease in water quality can damage the aquatic ecosystem, which is an indication of a watershed health level. Hence, continuous monitoring of water quality is needed. This study aims to assess the level of watershed health as a result of agricultural activities. Five water quality indicators such as BOD, COD, pH, Nitrate, and KMnO4 were used in this study. The values of the five indicators were then analyzed quantitatively using scoring with three posibility categories and scores, namely good (score: 5), moderate (score: 3), and poor (score: 1). Categories were determined based on water quality standards for aquatic ecosystems. The results showed a good value category for all indicators. It reveals that in general the watershed is in a healthy condition. Some indicators that showed moderate values (BOD, COD, and KMnO₄) in the northern part of the watershed indicated changes in water quality. The results of this study provides a reference for developing a watershed health monitoring system using more complex indicators.