This data collection is the product of the CA LCC-funded project “Climate Change/Land Use Change Scenarios for Habitat Threat Assessments on California Rangelands”.
The project aids conservation of California rangelands by identifying future integrated threats of climate change and land use change, and quantifying two main co-benefits of rangeland conservation – water supply and carbon sequestration. Through a multi-stakeholder partnership, the project proponents developed integrated climate change/land use change scenarios for the Central Valley and Chaparral and Oak Woodland eco-regions, and disseminated information about future potential threats to high priority conservation areas within the California Rangeland Conservation Coalition (CRCC) study area, which includes the foothills around the Central Valley and most of the southern Inner Coast Range.
The project teRatio of Recharge to Runoff for each 30-year climate period These maps display the ratio of average recharge to average runoff for each watershed for the present-day climate period and for three future climate periods. The present-day climate period is 1981-2010 and the future climate periods include 2010-2039, 2040-2069 and 2070-2099. Recharge:runoff is provided for two climate projections for each of the three IPCC-SRES scenarios – A1B, A2 and B1. Watershed boundaries are from the 8-digit Watershed Boundary Dataset (http://water.usgs.gov/GIS/huc.html). The ratio of in-place recharge to runoff indicates the mechanisms, including soils, geology, and precipitation patterns that likely control ground-water recharge for a given watershed. A ratio of 0.5 or less indicates that more than twice as much water has the potential to become runoff than to become in-place recharge. A ratio of 2.0 or greater indicates that water has at least twice as much potential to become in-place recharge than to become runoff (Flint and Flint, 2007). Recharge and runoff were modeled using the U.S. Geological Survey’s Basin Characterization Model (BCM), a regional water balance model (Flint et al. 2013, Flint and Flint, 2012). The BCM was run with two statistically downscaled global climate models (GCMs) (a warm, wet future and a hot, dry future) for each emissions scenario. Selected GCMs included variables for minimum or maximum temperatures, which were considered important determinants of vegetation distribution. Table 1 summarizes the GCMs for each emission scenario. Table 1. Summary of Global Climate Models (GCMs) Emission scenario Hot, dry scenarios Warm, wet scenarios A2 B1 GFDL = GFDL CM2.1 model, NOAA Geophysical Fluid Dynamics Laboratory PCM = National Center for Atmospheric Research and Department of Energy Parallel Climate Model A1B MIROC = MIROC 3.2 (medres), Model for Interdisciplinary Research on Climate, Japan CSIRO = CSIRO Mark 3.5, Commonwealth Scientific and Industrial Research Organisation, Australia These representative projections were downscaled to 270 meter spatial resolution for monthly estimates of precipitation and maximum and minimum air temperature. The BCM uses the downscaled precipitation and temperature as well as elevation, geology, and soils to produce 270 meter-resolution maps of potential evapotranspiration, runoff, recharge, CWD, actual evapotranspiration, sublimation, soil water storage, snowfall, snowpack, snowmelt, and excess water. Thirty-year water year summaries of recharge and runoff were used for this rangelands project. The maps display the ratio of the 30-year averages of recharge to runoff, averaged by watershed area. The recharge:runoff ratio is calculated as: Rch/Run, where Rch = the 30-year recharge average, averaged by watershed area, and Run = the 30-year runoff average, averaged by watershed area. References Flint, L.E., A.L. Flint, J.H. Thorne, and R. Boynton. 2013. Fine-scale hydrologic modeling for regional landscape applications: the California Basin Characterization Model development and performance. Ecological Processes 2:25. Available online at: http://www.ecologicalprocesses.com/content/2/1/25 Flint, L.E. and A.L. Flint. 2012. Downscaling future climate scenarios to fine scales for hydrologic and ecologic modeling and analysis. Ecological Processes 1:2. Available online at: http://www.ecologicalprocesses.com/content/1/1/2 Flint, L.E. and A.L. Flint. 2007. Regional analysis of ground-water recharge. In: Stonestrom, D.A., J. Constantz, T.P.A. Ferré, and S.A. Leake (eds). Ground-water recharge in the arid and semiarid southwestern United States. Professional Paper 1703. Reston (VA): U.S. Geological Survey. Available online at: http://pubs.usgs.gov/pp/pp1703/b/. am calculated metrics at the landscape and watershed scale for the California Rangeland Conservation Coalition (CRCC) focus area and quantified fragmentation of grazing land; change in bioclimatic distribution of oaks, grassland and shrubland; change in wildlife habitat; change in runoff, recharge and stream discharge; and change in carbon stocks and flux. The project team also developed an on-line tool that includes maps of important areas where changes in water availability and wildlife habitat coincide. Economic analysis of scenarios were applied to quantify costs and benefits to the CRCC landscape. Comparison of analyses across scenarios allows resource managers to identify potential risks and opportunities – both biological and economical – for rangeland across alternative futures.
