Urban Expansion and Its Influencing Factors in Natural Wetland Distribution Area in Fuzhou City, China

This paper principally focuses on land use dynamics, urban expansion and underlying driving forces in the Natural Wetland
Distribution Area (NWDA) of Fuzhou City in the southeastern China. Based on time series Landsat TM/ETM+ imageries and historical data,
relationships between urban land expansion and its influencing factors from 1989 to 2009 were analyzed by using an integrated approach
of remote sensing (RS) and geographic information system (GIS) techniques. The results showed that built-up land increased from 151.16
km2 in 1989 to 383.76 km2 in 2009. Approximately 64.25% of the newly emerging built-up land was converted from cropland (29.47%),
forest and shrub (25.78%), water (3.73%), wetland (4.61%), and bare land (0.66%) during 1989 and 2009. With a remarkable decrease
in cropland, the proportion of non-agricultural population increased by 23.6%. Moreover, rapid development of infrastructures, facilities,
industrial parks, and urban and rural settlements along the Minjiang River resulted in the eastward and southward expansion of built-up
land. Additionally, the growth pattern of built-up land in the NWDA is highly correlated with socio-economic factors, including the gross
domestic product (GDP), GDP per capita, and structure of industry. As a result, the observed environmental degradation such as loss of
cropland and wetland due to heavy pressure of rapid urbanization have greatly impaired the carrying capacity of city. Thus, in addition to
scientific and rational policies towards minimizing the adverse effects of urbanization, coordination between the administrative agencies
should be urgently strengthened to balance the conflicts between urban development and ecological conservation to make sure the
sustainable land use.