Isotopic study on the effect of reservoirs and drought on water cycle dynamics in the tropical Periyar basin draining the slopes of Western Ghats

River damming and drought affect water cycle dynamics in an ephemeral river based on stable isotopes: The Dagu River of North China

“…S4). The differences in isotopes between these two years highlighted the significant effect of drought on river water isotopes and water cycle dynamics, which was consistent with earlier studies (e.g., Marchina et al, 2017;Chiogna et al, 2018;Wu et al, 2018;Saranya et al, 2020). For example, Wu et al (2018) found that the Changjiang River presented more positive δD and δ 18 O isotopes under the extreme drought conditions.…”

“…The drought effect on precipitation in turn influenced river water isotopic enrichment and water cycle dynamics through increased evaporation signals (Saranya et al, 2020). Correspondingly, the average δD 2, Fig.…”

“…4a). It reflected that river water was mainly sourced from precipitation (Xiong et al, 2020) but has experienced strong water evaporation (Li et al, 2017;Hao et al, 2019;Saranya et al, 2020). River samples partly anchored by groundwater data points and river water were overall more enriched in heavy isotopes than groundwater (Fig.…”

“…These problems can be further aggravated by drought, which has been recognized as an extremely widespread and most expensive natural disaster. Drought can have adverse impacts on water cycle dynamics and water resources as well as on the society, the economy, and the environment (Mishra and Singh, 2010;Sheffield et al, 2012;Yang et al, 2019;Saranya et al, 2020). With global climate change and increased anthropogenic activities, drought disasters are expected to frequently occur mainly because of regional precipitation decreases and evaporation increases driven by global warming (Sheffield et al, 2012;Wang et al, 2020a).…”

“…The combined effects of river damming and drought on river water cycles have been seldom considered, but are essential for water resource management and river health protection. Stable isotopes of hydrogen and oxygen (H\ \O) can facilitate not only to characterize water cycles among precipitation, surface water and groundwater (Deng et al, 2016;Zhao and Li, 2017;Hao et al, 2019;Li et al, 2019a;Li et al, 2019b;Saranya et al, 2020), but also to explain flow alterations subjected to the water regulation effect of dams (Hillel et al, 2015;Soulsby et al, 2015;Deng et al, 2016;Vanplantinga et al, 2017;Wang et al, 2019) or under extreme conditions such as drought (Vanplantinga et al, 2017;Wu et al, 2018;Chiogna et al, 2018;Saranya et al, 2020) and flood (Adame et al, 2016). Studies on evaluating the damming and drought effects on water cycle dynamics using the H\ \O isotopes have been conducted but focused mostly on large river systems (e.g.…”