Accounting for Adaptive Water Supply Management When Quantifying Climate and Land Cover Change Vulnerability

Abstract

Climate and land cover change strongly shape water resources management, but understanding their joint impacts is extremely challenging. Consequently, there is limited research of their integrated effects on water supply systems, and even fewer studies that rigorously account for infrastructure investment and management interventions. We utilize ecohydrologic modeling to generate watershed outflows under scenarios of climate and land cover change, which in turn drive modeled water utility-level decision making for the Research Triangle region of North Carolina. In the Triangle region, land cover and climate change are both likely to increase water supply availability (reservoir inflows) individually and in tandem. However, improvements from water supply increases are not uniform across management system performance indicators of reliability, conservation implementation frequency (i.e., water use restrictions), and infrastructure investment. Utility decisions influence the impact of hydrologic change through both short-term (e.g., use restrictions and water transfers) and longer-term infrastructure investment actions, in some cases offsetting the beneficial effects of additional water supply. Timing and sequencing of infrastructure development are strongly sensitive to climate and land use change as captured by their impacts on utility performance outcomes. This work underscores the need to consider adaptive management system responses and decision-relevant performance measures when determining the impacts of hydrologic change on water availability. Key Points: • Utility-scale decision making influences the impact of climate and land use change on both short-and long-term outcomes • Timing and sequencing of infrastructure development is highly sensitive to hydrologic change as captured by utility performance indicators • Impacts of hydrologic change are not uniform across performance indicators, utilities, or time, owing to management actions Supporting Information: • Supporting Information S1 Vose, J. M., Coulston, J. W., et al. (2020). Accounting for adaptive water supply management when quantifying climate and land cover change vulnerability. Water Resources Research, 56, e2019WR025614. https://

Using a hybrid demand-allocation algorithm to enable distributional analysis of land use change patterns

“…A distributional approach addresses these questions by generating multiple, equally plausible realizations as a foundation for hypothesis testing. Accordingly, our seeding algorithm makes simplifying assumptions (e.g., a basic probability model generated from a short list of common, spatially explicit drivers of change, such as elevation and slope) in exchange for the greater computational efficiency to produce libraries of rasters at the finer scales (e.g., 30–90 meters) needed for many ecological service and indicator analyses (e.g., [ 6 , 12 – 14 , 54 ]).…”

Risk Assessment of Future Climate and Land Use/Land Cover Change Impacts on Water Resources

“…2 Normalized score using equation (1), dimensionless. 3 IQR is interquartile range. 4 Reach 1 is a losing reach and seepage is simulated; Reach 5 is a gaining reach without simulated seepage.…”

“…Climate and LULC changes are expected to have interactive impacts on water availability [2,3]. Many studies have examined the impacts of climate and LULC changes on ecosystem health, streamflow, or water availability [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. In these studies, future climate trends are incorporated using simulated weather from downscaled global climate models (GCMs) or regional climate models (RCMs) driven by one or more emissions scenarios.…”

The Regional Hydro-Ecological Simulation System for 30 Years: A Systematic Review

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“…However, RHESSys has a hierarchical structure that simulates various combinations of scenarios (e.g., climate, land use) at individual scales and thus is enabled to provide land management modeling and its far-reaching impacts on the local basins. Moreover, RHESSys is suitable for coupling with other models, which provides opportunities to study specific land-management measures, such as reservoir construction [6,9,17].…”