Alteration of the Ecohydrological Status of the Intermittent Flow Rivers and Ephemeral Streams due to the Climate Change Impact (Case Study: Tsiknias River)

Abstract

Climate change projections predict the increase of no-rain periods and storm intensity resulting in high hydrologic alteration of the Mediterranean rivers. Intermittent flow Rivers and Ephemeral Streams (IRES) are particularly vulnerable to spatiotemporal variation of climate variables, land use changes and other anthropogenic factors. In this work, the impact of climate change on the aquatic state of IRES is assessed by the combination of the hydrological model Soil and Water Assessment Tool (SWAT) and the Temporary Rivers Ecological and Hydrological Status (TREHS) tool under two different Representative Concentration Pathways (RCP 4.5 and RCP 8.5) using CORDEX model simulations. A significant decrease of 20–40% of the annual flow of the examined river (Tsiknias River, Greece) is predicted during the next 100 years with an increase in the frequency of extreme flood events as captured with almost all Regional Climate Models (RCMs) simulations. The occurrence patterns of hyporheic and edaphic aquatic states show a temporal extension of these states through the whole year due to the elongation of the dry period. A shift to the Intermittent-Pools regime type shows dominance according to numerous climate change scenarios, harming, as a consequence, both the ecological system and the social-economic one.

Declining Bank Erosion Rate Related to Climate‐Change Driven Hydrological Alteration of a Small Sub‐Alpine River

“…Moreover, by the end of the 21st century (RCP4.5 and RCP8.5 scenarios), droughts are predicted to become more frequent [43], increasing the length and frequency of low-stage periods. Similar, increasingly extreme flows have been observed in many rivers around the world [5,9,14,[23][24][25]37,50,51].…”

UAV-based Optical Methods to Estimate the Flow of Temporary Streams and Evaluate their Environmental Status

“…The flow in ephemeral streams is episodic while intermittent streams are characterized by flow cessation, usually followed by a complete drying of the channels [7,8]. The temporary streams constitute more than 50% of the global hydrologic network while this percentage is growing due to the impacts of the climatic crisis which alters the status of the majority of rivers from perennial to intermittent [9]. Temporary streams are prevalent in many countries across Europe but also in Mediterranean countries outside Europe; reaching a 26% coverage for the south Mediterranean terrestrial area [10,11].…”