Fig 1.
The Mediterranean California study region.
(A) The Oak Woodlands and Central Valley ecological regions and 46 counties. (B) Land use and land cover (LULC) in 1992 at model onset. (C) Aggregated regions for water demand reporting. Shaded relief map from the U.S. Geological Survey’s National Atlas of the United States [64].
Fig 2.
Model validation results over the historical period (1992–2012).
Comparison of historical rates (1992–2012) of urbanization, agricultural expansion, and agricultural contraction (bars) in Mediterranean California derived from the Farmland Mapping and Monitoring Program data [24] with LUCAS model estimates across the 40 Monte Carlo simulations of the model (whiskers with mean, min, and max) modified from Wilson, et. al [56]. High and low rates for of each LULC transition type are indicated by red and blue bars, respectively. For agricultural expansion and contraction, high and low years are interdependent (e.g. high agriculture years defined where agriculture expansion exceeds agricultural contraction).
Table 1.
Land use and land cover scenario groups and associated sampling options for each transition type from the historical (1992–2012) record for Mediterranean California.
Fig 3.
Schematic diagram of the Land Use and Carbon Scenario Simulator (LUCAS) model.
Diagram shows model inputs and outputs, including the spatial initial conditions, the county and ecoregion spatial strata, Farmland Mapping and Monitoring Program (FMMP) derived scenarios spatial multipliers, state attributes (i.e. water), and model outputs.
Fig 4.
Projected land use and land cover (LULC) in Mediterranean California by 2062.
(A) Change in LULC from 2012 under business-as-usual (BAU) and in 2062 for the BAU, high agriculture (HA), highest of the high (HH), high urban (HU) low agriculture (LA), lowest of the low (LL), and low urban (LU) scenarios. Bars represent the mean LULC and maximum and minimum values across 40 Monte Carlo simulations. (B) Net change in land use and land cover (LULC) from 2012–2062 with the mean (bar) and maximum and minimum values across 40 Monte Carlo simulations.
Fig 5.
Annual transition probabilities across all seven scenarios for urbanization and agricultural expansion from 2012–2062.
(A) Average annual transition probability for urbanization across all scenarios. (B) Average annual transition probability for agricultural expansion across all scenarios. (C) Cumulative average annual transition probability for conversion to anthropogenic land uses (urbanization and agricultural expansion). Shaded relief map from the U.S. Geological Survey’s National Atlas of the United States [64].
Fig 6.
Average net change in water use demand across scenarios from 1992–2062 across scenarios.
Net water use demand values expressed in billions of cubic meters (109 m3) across seven future land use and land cover (LULC) scenarios for Mediterranean California. Shaded area shows the maximum and minimum value ranges across 40 Monte Carlo simulations for the BAU scenario only.
Fig 7.
Average net change in water demand (2012–2062) for each scenario by land use type.
Values for annual cropland (red) perennial cropland (blue) and developed (green) with black line indicating average net change summarized for all land use types across 40 Monte Carlo simulations.
Fig 8.
Projected net change in water demand by county and scenario.
Net change in water use demand (1992–2062) in billions of cubic meters (Bm3) for each county for annual cropland (red), perennial cropland (blue), and developed (green) land uses. The black dot indicates average net change value.
Fig 9.
Projected net change in water demand by geographic region.
Net change in water use from 1992–2062 for each land use category by geographic region (colored bars) and total (black points) under each scenario.