EVALUASI SISTEM DRAINASE BERWAWASAN LINGKUNGAN DI KECAMATAN NGEMPLAK, SLEMAN, YOGYAKARTA

Abstract

Sleman is one of the most influential districts in Yogyakarta. Sleman became the center of tourist attractions, education, business and residential for the community. Ongoing development causes land constriction and land use change. According to the Regional Spatial Plan (RTRW) of Sleman Regency 2011-2031, Ngemplak sub-district is a rainwater catchment area. The rapid development in Ngemplak sub-district must be balanced with the construction of environmentally sound drainage system (ecodrainage). In this study will conduct an evaluation of existing ecodrainage system in Ngemplak sub-district. Evaluation begins with rainfall analysis using 3 methods, namely Gumbel Method, Log Pearson Method III and Normal Log Method. The Rain Distribution Calculation is performed using the Hasper-Weduwen Method. Calculation of concentration time with Kirpich method. Mononobe method is used to calculate hourly rainfall and Rational Method to calculate runoff discharge. Then calculate the effectiveness of the ecodrainage by calculating the recharge Debit of the ecodrainage system.The results show that from 3 research sites the runoff discharge is still greater than the discharge of ecodrainage absorption. The ecodrainage drainage system in Lodadi hamlet 20 absorption wells can absorb 1576.9 m3 / s from 2096.87 m3 / s and produce the rest that will be puddle is 519.93 m3. While the drainage of soil on Jl. The jangkang can reduce 1926.10 m3 from 2218.56 m3. Then for the effectiveness of biopori in hamlet conclusion that is with 15 pieces 2700 m3 from runoff discharge 3496,96 m3. Coupled with the lack of care and evaluation of the system, ecodrainage so as not to absorb optimally.