Land use driven vegetation processes and regional climate change
Abstract
Recent reports from the Intergovernmental Panel on Climate Change (2007) confirm that climate change is occurring at a larger and more rapid rate of change than was thought likely only six years ago. Temperatures are increasing, and higher associated rates of evaporation will likely bring drier conditions in large portion of monsoon Asia areas where ecosystems and social-economy are under pressure of water deficit. Human activities have emerged as an important driving force that induces global and regional climatic change. In the past decades, human being have been enhancing their contributions to the trend of global warming at global scale and intensifying their impacts on regional climate by transforming land surface. It is therefore an essential issue to examine land use change to interpret the magnitudes of human impact on regional climate. Here, relationship between climate change and terrestrial ecological processes driven by land use options such as urbanization is discussed with case studies in monsoon Asia region. This study investigated the decadal changes of major land-use types over greater Guangzhou area by analyzing 1980s-2000s land- use raster dataset derived from landsat images, meteorological records, and census data. The results from change detection analysis show a general trend of decrease of cropland and increase of build-up in the past two decades. We then examined the temporal-spatial relationship between thermal climate index and fractional land-use types. Based on water-energy balance equation, calculated how temperature increased as a direct or indirect consequence of land-use change. Our results show that there were positive correlations between temperature and fractional cover of build-up and negative correlation between temperature and fractional cover of cropland. The temperature increased by 0.90°C in the period, and among which 0.37°C may have been contributed by land-use changes in the region. Meanwhile, strong urban heat islands are also evident from observations of air temperature over pairs of urban vs. suburban meteorological stations, indicating the climate effects of urbanization at least at local to regional scales.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFM.B41D..07H
- Keywords:
-
- 1218 Mass balance (0762;
- 1223;
- 1631;
- 1836;
- 1843;
- 3010;
- 3322;
- 4532);
- 1610 Atmosphere (0315;
- 0325);
- 1635 Oceans (1616;
- 3305;
- 4215;
- 4513);
- 1855 Remote sensing (1640);
- 4815 Ecosystems;
- structure;
- dynamics;
- and modeling (0439)