| Abstract | The non-perennial streams and rivers are predominant in the Mediterranean region and play an
important ecological role in the ecosystem diversity in this region. This class of streams is
particularly vulnerable to climate change effects that are expected to amplify further under most
climatic projections. Understanding the potential response of the hydrologic regime attributes to
climatic stress helps in planning better conservation and management strategies. Bouregreg
watershed (BW) in Morocco, is a strategic watershed for the region with a developed nonperennial stream network, and with typical assets and challenges of most Mediterranean
watersheds. In this study, a hybrid modeling approach, based on the Soil and Water Assessment
Tool (SWAT) model and Indicator of Hydrologic Alteration (IHA) program, was used to simulate the
response of BW's stream network to climate change during the period: 2035-2050. Downscaled
daily climate data from the global circulation model CNRM-CM5 were used to force the hybrid
modeling framework over the study area. Results showed that, under the changing climate, the
magnitude of the alteration will be different across the stream network; however, almost the
entire flow regime attributes will be affected. Under the RCP8.5 scenario, the average number of
zero-flow days will rise up from 3 to 17.5 days per year in some streams, the timing of the
maximum flow was calculated to occur earlier by 17 days than in baseline, and the timing of the
minimal flow should occur later by 170 days in some streams. The used modeling approach in this
study contributed in identifying the most vulnerable streams in the BW to climate change for
potential prioritization in conservation plans. |
| Text | 465212 2021 10.5194/egusphere egu21 9414 climate change intermittent rivers flow regime alterations Modeling the response of non perennial streams to climate change impact The Bouregreg watershed in Morocco Anna Maria De Girolamo, Youssef Brouziyne, Lahcen Benaabidate, Aziz Aboubdillah, Ali El Bilali, Lhoussaine Bouchaou, Abdelghani Chehbouni 1Mohammed VI Polytechnic University UM6P , International Water Research Institute, Benguerir, Morocco; 2Water Research Institute National Research Council, Bari, Italy; 3 Laboratory of Functional Ecology and Environmental Engineering, Faculty of sciences Techniques, P.O.Box 2202, Fez , 30000, Morocco; 4 Ecole Nationale d Agriculture de Meknes, BP/40, Meknes, 50001, Morocco; 5Hassan II University of Casablanca, Faculty of Sciences and Techniques of Mohammedia, Morocco; 6 Laboratory of applied Geology and Geo Environment, Faculty of Sciences, Ibn Zohr University, BP/8106, Cite Dakhla, Agadir, 8000, Morocco; 7 Institut de recherche pour le developpement IRD , unite mixte de recherche UMR Centre d etudes spatiales de la biosphere Cesbio ,Toulouse, 31400, France Postprint EGU2021 Vienna 19 21/04/2021 Internazionale Contributo The non perennial streams and rivers are predominant in the Mediterranean region and play an important ecological role in the ecosystem diversity in this region. This class of streams is particularly vulnerable to climate change effects that are expected to amplify further under most climatic projections. Understanding the potential response of the hydrologic regime attributes to climatic stress helps in planning better conservation and management strategies. Bouregreg watershed BW in Morocco, is a strategic watershed for the region with a developed nonperennial stream network, and with typical assets and challenges of most Mediterranean watersheds. In this study, a hybrid modeling approach, based on the Soil and Water Assessment Tool SWAT model and Indicator of Hydrologic Alteration IHA program, was used to simulate the response of BW s stream network to climate change during the period 2035 2050. Downscaled daily climate data from the global circulation model CNRM CM5 were used to force the hybrid modeling framework over the study area. Results showed that, under the changing climate, the magnitude of the alteration will be different across the stream network; however, almost the entire flow regime attributes will be affected. Under the RCP8.5 scenario, the average number of zero flow days will rise up from 3 to 17.5 days per year in some streams, the timing of the maximum flow was calculated to occur earlier by 17 days than in baseline, and the timing of the minimal flow should occur later by 170 days in some streams. The used modeling approach in this study contributed in identifying the most vulnerable streams in the BW to climate change for potential prioritization in conservation plans. Modeling the response of non perennial streams to climate change impact The Bouregreg watershed in Morocco EGU21 9414.pdf Abstract in atti di convegno annamaria.degirolamo DE GIROLAMO ANNA MARIA |
