Hydrological classification of natural flow regimes to support environmental flow assessments in intensively regulated Mediterranean rivers, Segura River Basin (Spain).

摘要: Hydrological classification constitutes the first step of a new holistic framework for developing regional environmental flow criteria: “Ecological Limits Hydrologic Alteration (ELOHA)”. The aim this study was to develop 390 stream sections Segura River Basin based on 73 hydrological indices that characterize their natural regimes. were calculated with 25 years monthly flows (1980/81–2005/06) derived from rainfall-runoff model developed by Spanish Ministry Environment and Public Works. These included, at or annual basis, measures duration droughts central tendency dispersion magnitude (average, low high conditions). Principal Component Analysis (PCA) indicated redundancy among most indices, as well two gradients: mainstream rivers temporal variability tributary streams. A eight flow-regime classes chosen easily interpretable in Basin, which supported ANOSIM analyses. can be simplified 4 broader groups, different seasonal discharge pattern: large rivers, perennial stable streams, streams intermittent ephemeral They showed degree spatial cohesion, following gradient associated climatic aridity NW SE, defined terms fundamental variables Mediterranean streams: flows. Therefore, is tool support water management planning Basin. Future research will allow us alteration-ecological response relationship each river type, set basis design scientifically credible ELOHA framework.