Modeling watershed health assessment for five watersheds in Lampung Province, Indonesia

A healthy watershed is important not only for the ecosystem but also for human socioeconomic activities. Therefore, a compatible assessment model is required to recognize watershed health. In Indonesia, the watershed health assessment is directed by the Ministry of Forestry regulation number 60/2014. A critic might be posed to this directive for not including the biotic aspects of the watershed. This research aims to assess the five watersheds in Lampung Province, Indonesia. Afterward, we develop a mathematical model using multiple linear regression analysis to identify influential indicators. In developing the model, we combined indicators in the Ministry of Forestry regulation number 60/2014 with the US-EPA directive to include the biotic indicators. To collect the data, we accessed secondary data officially launched by the authorities and did field observation if the secondary data is not available. Our assessment based on the Indonesian official regulation shows that 3 sub-watersheds are in unhealthy status while the rest can be categorized as healthy watershed. Furthermore, the mathematical model of the sub-watershed health assessment shows that the percentage of critical land and vegetation coverage plays an essential role in determining watershed health status. Besides, investment in the water-related infrastructure also significantly contributes to watershed health.