Studies of Carrying Capacity and Zonation at Menjer Lake, Central Java Using A Multidisciplinary Approach for Sustainable Utilization

Abstract

Tropical lake is one of the unique ecosystems which are functioning in both ecological and economic services. Telaga Menjer as a volcanic lake, has strategic values as a hydropower plant, tourism, agriculture, capture fisheries and floating net cages farming. It influenced a degradation of water quality and quantity, nutrient enrichment and exceed the carrying capacity. Telaga Menjer has a catchment area of around 2.27 km2 with a lake surface area of 0.61 km2.The purpose of this research is to investigate the characteristic of lake to know the carryng capacity and utilization zone with a multidisciplinary approach. For measuring its depth, the Hondex PS-7 portable depth sensor is used with a maximum depth of 80 m. The water quality parameters stratification were measured by logger version CTD profiler with a depth interval of 1 m on July 2019. The results showed that DO values were observed until the bottom of lake (45 m). Moreover, Total Nitrogen (TN) was very high concentration, indicating more fertilizer from agriculture. Meanwhile, lower concentration of pesticides were obtained. Next, the land use management, economic values and social carrying capacity of Talaga Menjer should be elucidated in order to maintain the sustainability of the lake.