2005 Progress Report: Regional Development, Population Trend, and Technology Change Impacts on Future Air Pollution Emissions in the San Joaquin ValleyEPA Grant Number: R831842
Title: Regional Development, Population Trend, and Technology Change Impacts on Future Air Pollution Emissions in the San Joaquin Valley
Investigators: Kleeman, Michael J. , Handy, Susan , Lund, Jay , Niemeier, Deb , Sullivan, Dana Coe
Current Investigators: Kleeman, Michael J. , Handy, Susan , Lund, Jay , Niemeier, Deb
Institution: University of California - Davis , Sonoma Technology, Inc.
Current Institution: University of California - Davis
EPA Project Officer: Chung, Serena
Project Period: October 1, 2004 through September 30, 2007 (Extended to September 30, 2010)
Project Period Covered by this Report: October 1, 2004 through September 30, 2005
Project Amount: $680,000
RFA: Regional Development, Population Trend, and Technology Change Impacts on Future Air Pollution Emissions (2004) RFA Text | Recipients Lists
Research Category: Global Climate Change , Climate Change , Air
The objective of this research project is to combine innovative land use forecasting models, water constraint models, travel demand models, emissions models, and a source-oriented air quality model into a modeling system with feedback loops to predict future emissions and associated air quality impacts. The modeling system will be used to assess the sensitivity of emissions inventories to future policy scenarios in the areas of land use policies, transportation investments, technological innovations, air quality regulations, and agricultural practices in the San Joaquin Valley (SJV) in the year 2030. The results of this research will improve our understanding of the long-term air quality impacts of both incremental and radical changes in land use and infrastructure policies.
Four future policy scenarios have been developed for the SJV in the year 2030. These policy scenarios were constructed in consultation with experts from public agencies and private industry. Two scenarios bound extreme cases ranging from no policy controls on regional development to strict land use policy controls. The remaining two scenarios focus on interim policies that likely are to be implemented. We expect to develop additional scenarios as the air quality implications of the first scenarios are better understood.
The land use patterns associated with the four policy scenarios were modeled using the UPLAN urban growth model. UPLAN allocates the area of each land use type to grid cells using a set of user-specified rules based on projected population increases, local land use plans, existing cities, and existing and planned transportation routes. The assumptions underlying each of the policy scenarios were translated into inputs to the UPLAN model. Each of the 4 scenarios were performed for each of the 8 counties in the San Joaquin Valley, for a total of 32 different model runs. The UPLAN model output predicts future land use patterns, which then feed into downstream travel demand models (mobile emissions), stationary-source models, and area-source models.
Preliminary UPLAN analysis results show that regional land use policies have a strong effect on urban development density in the SJV. The absence of any land use policies encourages population growth outside of the original urban zone, resulting in almost complete development of the SJV by the year 2030. Under the scenario of strict land use policies, which encourage redevelopment of core regions within existing cities using high density housing, it appears that the anticipated population growth within the SJV can be accommodated with virtually no enlargement of the urban footprint.
The travel demand associated with each of the UPLAN land use projections were estimated using the four-step travel demand models currently supported by the regional and county planning agencies. Using predicted population and employment by zone along with a defined transportation network, estimates of vehicle trips for each segment of the network were generated.
Travel demand modeling results are consistent with expectations, showing that regional policies on land use have a strong effect on estimated vehicle miles traveled (VMT) within the SJV. Strict land use policies, which encourage redevelopment of core regions within cities using high density housing, result in approximately 40 percent less VMT than scenarios with less stringent land use policies (leading to some sprawl). As we might expect given predicted growth in the SJV, for all scenarios, VMT for the year 2030 is predicted to be greater than the present-day VMT. These interim findings suggest that new technology likely will be needed to reduce the emissions per unit mile from mobile sources if the air quality in the SJV is to be improved to the current National Ambient Air Quality Standards. The type and degree of possible strategies will be refined during the next stage of the project in which mobile source emissions and photochemistry modeling is performed.
The UPLAN land use modeling results also were used to support the development of area and stationary emissions inventories in Year 1 of the project. The starting point for these inventories was the California Air Resources Board’s 2002 emission inventory for the California Regional PM2.5/PM10 Air Quality Study. Predictions of land use change were used to distribute new emissions associated with increased population and economic development. Algorithms were developed to cross-reference growth surrogates and spatial surrogates to specific emissions source categories. Methods also were developed to account for reductions associated with the application of emissions reduction strategies during future scenarios. Preliminary results indicate that air quality emissions from most major area and stationary sources will increase in the year 2030 regardless of policy scenario. Once again, this finding suggests that technological advances in emissions control technology will be needed to reach the National Ambient Air Quality Standards in the SJV.
Emissions inventories will be generated for the SJV in the year 2030 under each of the four policy scenarios. Air quality models will be used to evaluate the effect of regional policy decisions on air quality in the SJV.