Infrastructure sufficiency in meeting water demand under climate-induced socio-hydrological transition in the urbanizing Capibaribe River basin – Brazil

Abstract

Abstract.Water availability for a range of human uses will increasingly be affected by climate change, especially in the arid and semiarid tropics. The main objective of this study is to evaluate the infrastructure sufficiency in meeting water demand under climate-induced socio-hydrological transition in the Capibaribe River basin (CRB). The basin has experienced spatial and sectoral (agriculture-to-urban) reconfiguration of water demands. Human settlements that were once dispersed, relying on intermittent sources of surface water, are now larger and more spatially concentrated, which increases water-scarcity effects. Based on the application of linked hydrologic and water-resources models using precipitation and temperature projections of the IPCC SRES (Special Report: Emissions Scenarios) A1B scenario, a reduction in rainfall of 26.0 % translated to streamflow reduction of 60.0 %. We used simulations from four members of the HadCM3 (UK Met Office Hadley Centre) perturbed physics ensemble, in which a single model structure is used and perturbations are introduced to the physical parameterization schemes in the model (Chou et al., 2012). We considered that the change of the water availability in the basin in the future scenarios must drive the water management and the development of adaptation strategies that will manage the water demand. Several adaptive responses are considered, including water-loss reductions, wastewater collection and reuse, and rainwater collection cisterns, which together have potential to reduce future water demand by 23.0 %. This study demonstrates the vulnerabilities of the infrastructure system during socio-hydrological transition in response to hydroclimatic and demand variabilities in the CRB and also indicates the differential spatial impacts and vulnerability of multiple uses of water to changes over time. The simulations showed that the measures proposed and the water from interbasin transfer project of the São Francisco River had a positive impact over the water supply in the basin, mainly for human use. Industry and irrigation will suffer impact unless other measures are implemented for demand control.

Hydrological Processes and Climate Change in Hydrographic Regions of Brazil

“…A large scale distributed hydrological model called MGB-IPH (an acronym from the Portuguese for Large Basins Model and Institute of Hydraulic Research) [39] was used in the simulations. This model has been widely applied in distinct South-American watersheds, for different purposes, such as stream flow forecasting [40], simulation of land-use changes [41], evaluation of climate change impacts [4], assessment of hydrological processes [2]. The MGB-IPH model may be distributed by cells or catchments and runs in daily time steps.…”

“…In the present study, the model parameters were not calibrated due to lack of available stream flow data for the entire area. The alternative was to use the values of the parameters obtained from earlier applications of the MGB-IPH in some Brazilian river basins [2] [39] [40]. As described in the prior section, the climate data simulated by Eta model is used as input for the MGB-IPH simulations, which comprise the baseline (1961-1990) and three time-slices (2011-2040, 2041-2070 and 2071-2099) for HadGEM2-ES (RCP 4.5 and 8.5) and MIROC5 (RCP 8.5).…”

“…The current strategy for estimating impacts of climate scenarios on river flow regimes is to use the Global Circulation Models (GCM) outputs as input for hydrological models. These studies may focus on hydrographic basin scale [2] [3] [4] or global scales [5] [6] [7] [8]. Arnell and Gosling (2013) [6] have used 21…”

Vulnerability assessment of flash floods in Wadi Dahab Basin, Egypt

“…The HEC-HMS model was designed for flow simulation based on three main components: the basin surface area, the prevailing climatic conditions, and the control indices. It has been applied to a variety of problems in a wide range of basins with different characteristics (Nandalal and Ratnayake 2010; Neto et al 2014;Koneti et al 2018). Such a model is capable of running a flood simulation and calculating hydrographs even for ungauged basins (e.g., Gumindoga et al 2016).…”

Moving sociohydrology forward: a synthesis across studies

“…Ribeiro Neto et al (2014) laid out a hypothesized sequence of coupled human-water system development. First human water demands exceed the locally available water supply, leading to infrastructure development to stabilize and/or enhance the local supply.…”