Climate Change Implications for Water Availability: A Case Study of Barcelona City

Abstract

Barcelona city has a strong dependence on the Ter and Llobregat reservoir system to provide drinking water. One main concern for the next century is a potential water scarcity triggered by a severe and persistent rainfall shortage. This is one of the climate-driven impacts studied within the EU funded project RESCCUE. To evaluate potential drought scenarios, the Hydrologiska Byråns Vattenbalansavdelning (HBV) hydrological model reproduces the water contributions by month that have reached the reservoirs, regarding the accumulated rainfall over each sub-basin, representing the available historical-observed water levels. For future scenarios, we adjusted the input data set using climate projections of rainfall time series data of the project RESCCUE. Local outputs from 9 different climate models were applied to simulate river basins' responses to reservoirs' incoming water volume. Analyzing these results, we obtained average trends of the models for each scenario, hypothetical extreme values, and quantification for changes in water availability. Future water availability scenarios for Barcelona central water sources showed a mean decrease close to 11% in comparison with the period 1971-2015, considering the representative concentration pathway 8.5 (RCP8.5) climate change scenario in the year 2100. This research forecasts a slight downward trend in water availability from rainfall contributions from the mid-21st century. This planned future behavior does not mean that the annual water contributions are getting lower than the current ones, but rather, identifies an escalation in the frequency of drought cycles.

Increased Urban Resilience to Climate Change—Key Outputs from the RESCCUE Project

“…Sea level rise analysis performed by GIS tools indicated moderate loss of beaches for the horizon of 2050 and 2100, although its effects should not affect critical infrastructures located in the vicinity of the coast. Drought analysis is in line with other recent studies related to the water availability for the city of Barcelona and predicts a 9% to 11% decrease in surface water volume availability over the reservoir system for the horizon of 2050 and 2100, respectively, due to precipitation reduction and warming-enhanced evaporation [12]. The simulations of adaptation measures considered the implementation of Sustainable Urban Drainage Systems (SUDS), resulting in high hazard reductions.…”

“…In this framework, some potential hazards for strategic urban services produced by a set of selected climate change pressures have been identified and selected depending on their significance and the interest in each research site (Table 3). The effects of these climate drivers on strategic urban services have been analyzed through detailed models and tools developed and calibrated within the project [11][12][13][14][15].…”

Monitoring embankment dams from space using satellite radar interferometry: Case studies from RemoDams project

“…Global changes are rapidly transforming the needs and requirements of water supply systems in the world, especially in areas where drought has increased in recent decades (Estrela et al, 2012;Forero-Ortiz et al, 2020). Dams are an important part of the water cycle infrastructure, which can provide our society with water, energy and food, and need to urgently adapt to the ever-changing environment.…”

Effects of Climate Change on Water Quality in the Jucar River Basin (Spain)

“…In general terms, significant modifications of local and global climate patterns are projected at very different time scales, especially affecting temperature and rainfall, either in terms of average values or in terms of the frequency, intensity or duration of extreme events [24,25]. The impacts caused by these extreme phenomena directly affect water bodies (both, surface water and groundwater) and as a consequence, the quantity and quality of raw water available for drinking water [13,26,27]. Moreover, it should be highlighted that the Mediterranean region is a hotspot for changes in the hydrological cycle, especially for the winter rainfall regimes [28].…”

“…For the Mediterranean region, some of the most consensual effects of climate change on water resources are, on the one hand, a considerable decrease over water availability and incomes, produced by reduction in precipitation patterns and changes in hydrological temporal distribution and, on the other hand, a progressive rise of average temperatures that increments the potential evapotranspiration [12,27]. These impacts also indirectly affect water resources treatments, so in the case of necessary treatments carried out at drinking water treatment plants (DWTPs), adjustments are needed to maintain water quality standards and requirements.…”