California land-change projections

Science Center Objects

This dataset consists of modeled projections of land use and land cover and population for the State of California for the period 1970-2101. For the 1970-2001 period, we used the USGS's LUCAS model to "backcast" LULC, beginning with the 2001 initial conditions and ending with 1970. For future projections, the model was initialized in 2001 and run forward on an annual time step to 2100. In total 5 simulations were run with 10 Monte Carlo replications of each simulation.

For more information visit the Land Use and Climate Change Team website.

Project Description

Animated map of projected land-change in California, 2001-2100.

Animated map of projected land-change in California under a Business as Usual scenario from 2001-2100. (Credit: Benjamin M. Sleeter, USGS. Public domain.)

This dataset consists of modeled projections of land-change and population for the State of California for the period 1970-2100, developed to support various activities within the State of California's 4th Climate Assessment.

Land-use and population was simulated using the Land-use and Climate Scenario Simulator (LUCAS) model under multiple scenarios. Eleven land-cover types were simulated through space and time at the 1km scale for the State of California.

In total 5 simulations were run with 10 Monte Carlo replications of each simulation. The simulations include:

  1. Historical backcast from 2001-1970.
  2. Business-as-usual (BAU) projection from 2001-2101.
  3. Three modified BAU projections based on California Department of Finance population projections based on high, medium, and low growth rates from 2001-2101.

Methods

Land-use and population for the state of California were modeled using the LUCAS model. For the 1970-2001 period, a “backcast” was performed beginning with 2001 initial conditions. Initial conditions for forest age, land-use/land cover, and population were set using the GNN, NLCD 2001, and California Department of Finance population datasets, respectively. Land-use and population within California were then simulated between 2001 and 1970, over 10 Monte Carlo replications using historical rates of urbanization, agricultural contraction, and agricultural expansion from the California Farmland Mapping and Monitoring (FMMP) dataset and forest harvest from the Hansen Global Forest Change product.

Land-cover state and transition diagram for the LUCAS model.

Land-cover state and transition diagram for the LUCAS model.(Credit: Benjamin M. Sleeter, USGS. Public domain.)

Results

For future projections, the model was initialized in 2001 and run forward on an annual time step to 2101. In total 4 simulations were run with 10 Monte Carlo replications of each simulation. The simulations include: 1) Business-as-usual (BAU) projection from 2001-2101, and 2) three modified BAU projections based on California Department of Finance population projections based on high, medium, and low growth rates. For the four scenarios, FMMP and Hansen Global Forest Change transition rates were sampled from the period 2001-2014 to determine annual transition rates out to 2101.

Animated gif showing Land-cover change in California Bay Area

Land-cover change between 2001-2100 under a Business as Usual Scenario in the California Bay Area.(Public domain.)