Flushing Methods in Polder Drainage System to Obtain Better Environment QualityS. Imam Wahyudi, Robbe van de Lustgraaf, Loic de Moor, Rick Heikoop and Henny Pratiwi AdiMATEC Web Conf., 280 (2019) 03014DOI: https://doi.org/10.1051/matecconf/201928003014