CURRENT STATE OF ENVIRONMENTAL FLOW METHODOLOGIES: OBJECTIVES, METHODS AND THEIR APPROACHES

Abstract

 The objective of this paper is to offer a comprehensive review of environmental flow (e-flow) research of the world. We reviewed 779 articles in 77 countries published from 2009 to 2016 which handle with e-flows. The publications were investigated from the viewpoint of objectives, types of e-flows, methods and verification. We found that the purpose of the e-flows has been shifting from protecting individual organisms to enhance soundness of whole riverine ecosystems. Accordingly, the indices also expanded from commercial fish such as salmonidae to diverse objects such as plants, biological communities and food webs. A new eco-hydrological method which tries to quantitatively combine flow regime and ecological responses has been increasing. More verifications after e-flow applications are required. Also, in order to manage sustainable water resource use under climate change, it is necessary to deepen the discussion about the role and objective of environmental flow in the future condition.