The Detection of Forest Health Level as an Effort to Protecting Main Ecosystem in the term of Watershed Management in Maros Watershed, South Sulawesi

Abstract

Abstract Forests have an important role in the balance of watershed systems, mainly as water management regulators by providing sustainable water resources for humans and the environment. The changing of forest conditions could give a huge impact to the balance of the watershed. The effect of this imbalance has caused flooding problems in the rainy season and drought in the dry season as it’s happened in the Maros watershed. These problems occur because of the lack of optimal carrying capacity of forest ecosystems due to changes in forest conditions. Healthy forest conditions have a very different response compared to unhealthy forests, particularly in regulating watershed management. Based on these problems, this research was conducted to identify the condition of forests in the Maros watershed by detecting the level of forest health in forest types in Maros watershed through forest health analysis using Landsat 8 recording image of 2013 and to identify the impact of forest conditions on water availability (blue water and green water) by using SWAT model on the scenario of changing forest conditions and to make optimum forest condition direction which supported to become a sufficient Maros watershed management and to identify the condition of the forest related to air (blue water and green water) by using the SWAT model as much as possible and sustainable through reforestation or afforestation activities. The forest types in Maro’s watershed consists of primary and secondary dryland forests, plantations forest and mangrove forests, with an area of 162.07 km2. The results of forest health analysis obtained a good level of forest health (very healthy and healthy) covering an area of 128.54 km2 and a poor (unhealthy and dead) forest health covering an area of 33.53 km2. The presence of unhealthy forests condition in Maros Watershed influenced the optimal proportion of the forest area in providing water yields. A good forest area in the Maros watershed produces 3,289,440 m3 of blue water. This value is very far from the water needs of the people around Maros watershed (3,308,977 m3/year). Therefore, it is necessary to optimize forest land through reforestation (improvement of forest conditions) and afforestation (forest addition). From the SWAT modeling results, it was found that the addition of forest area would increase the value of blue water, but to the optimum extent of forest addition with an area of 33.44% of Maro’s watershed. The addition of forest area that exceeds this capacity will reduce the value of the blue water of the Maros watershed due to the increasing of green water through the evapotranspiration process.