A new study was released Tuesday on how land use changes have distinct effects on surface temperatures. The study provides more detailed proof of the
heat island effect and how land use changes from forest to urban development
increases the heat island impact while, interestingly, changing the land use from forest to agriculture actually makes it cooler. This is probably due to 'increased evaporation.'
There are long range planning impacts on urban growth to these issues. Current high tech studies on the heat island effect, and on detailed information on the forest composition in Dallas, as well as the production of the
Roadmap for Tree Planting, are intended to, in part, address these concerns. We will hear more about these research projects and programs in the coming weeks and months ahead.
It's an exciting time to be an arborist in Dallas.
This map shows observation minus reanalysis (OMR) trends in the continental United States from 1979-2003. The trends are associated with land use and land-use changes. Researchers from Purdue and the universities of Colorado and Maryland conducted a study that showed land use can affect surface temperatures locally and regionally. Units are in degrees Celsius per decade.
From
EurekAlert!, this report:
"Researchers say regional surface temperatures can be affected by land use, suggesting that local and regional strategies, such as creating green spaces and buffer zones in and around urban areas, could be a tool in addressing climate change.
A study by researchers from Purdue University and the universities of Colorado and Maryland concluded that greener land cover contributes to cooler temperatures, and almost any other change leads to warmer temperatures. The study, published on line and set to appear in the Royal Meteorological Society's International Journal of Climatology later this year, is further evidence that land use should be better incorporated into computer models projecting future climate conditions, said Purdue doctoral student Souleymane Fall, the article's lead author.
"What we highlight here is that a significant trend, particularly the warming trend in terms of temperatures, can also be partially explained by land-use change," said Dev Niyogi, a Purdue earth and atmospheric sciences and agronomy professor, and the Indiana state climatologist. He is the study's corresponding author.
Niyogi and Fall say the idea that land use helps drive climate change has been poorly understood compared to factors such as greenhouse gas emissions. But that is changing.
"People realize that land use cover also is an important force and not only at the local but also at the regional scale," said Fall, whose doctoral research focuses on the impacts of land surface properties on near-surface temperature trends.
The researchers used higher resolution temperature data than previous studies, meaning the data was more detailed, Niyogi said. They also employed dynamic data on land-use changes from 1992-2001, which was derived from satellite imagery.
Niyogi said having an understanding of land use's affects on climate change could have climatic and other benefits. For instance, creating green spaces and buffer zones in and around urban areas also could be aesthetically attractive, he said.
Among the study's findings:
- In general, the greener the land cover, the cooler is surface temperature.
- Conversion to agriculture results in cooling, while conversion from agriculture generally results in warming.
- Deforestation generally results in warming, with the exception of a shift from forest to agriculture.
- No clear picture emerged from the impact of planting or seeding new forests.
- Urbanization and conversion to bare soils have the largest warming impacts.
In general, land use conversion often results in more warming than cooling.