Study of ecodrainage system for hydrometeorological disaster mitigation

Abstract

Hydrometeorological disasters such as floods and landslides are triggered by high rainwater. The disasters often cause loss of property, loss of fertile soil layers, and loss of life. Ecodrainages such as biopore holes, silt pits, and infiltration wells are soil and water conservation technique that can be useful for reducing surface runoff and increasing infiltration so that they can be used for hydrometeorological disaster mitigation. The study was carried out in the Keduang Sub-Watershed, Wonogiri District. The purpose of the study was to calculate the volume of rainwater during the year 2017 and the volume of rainwater that could be stored. Based on the Minister of Public Works Regulation of the Republic of Indonesia No.14 / PRT / M / 2010, each person needs an average of 60 liters/day of clean water. Monthly rainwater data were obtained from the Department of Agriculture and Food Crops Wonogiri district; the population data were obtained from the Central Bureau of Statistics (BPS), and administrative and sub-watershed maps were analyzed from the Indonesia Topographic Map (RBI) scale of 1: 25,000. Total rainwater during the year 2017 was 1,027,523,049.78 m3, while the population in the year 2017 was 492,725 people. Based on the calculation, the need for clean water was 10,790,677,500 liters (10,790,677.5 m3). The average runoff coefficient in the study area was 38.57%. Therefore during 2017, there was a rainwater surplus of 631,117,906,037.99 liters (631,117,906.04 m3) in The Keduang Sub Watershed.