Monitoring land cover dynamics in the Yellow River Delta from 1995 to 2010 based on Landsat TM

Abstract

The impact of anthropogenic activities in many deltas of the major rivers has caused considerable environmental change. The Yellow River (Huang He) delivers high sediment load to the sea, forming one of the fastest growing deltas worldwide. Population growth and rapid economic development have increased urbanization and wasteland cultivation, and threaten the natural environment of the delta. This is aggravated by the fact that a large amount of river water has been diverted for irrigation in the entire basin area, altering the river fluxes that are essential to maintain the health of the delta ecosystem. A supervised per-pixel classification approach using a decision tree algorithm was employed to generate land cover maps from Landsat 5 Thematic Mapper (TM) imagery acquired in 1995, 2004, and 2010. Statistical analysis of the land cover classifications indicates large landscape changes in the Yellow River Delta from 1995 to 2010, with severe conversions of the natural environment as a result of increasing anthropogenic activities. Land cover changes were mainly caused by intensified farming and urban sprawl, with increases of 1803.1 km² and 237.0 km² respectively. Since the 1960s, economic development involved considerable increase of built-up areas (industries, infrastructure, and residential areas) around the major cities in the delta, displacing natural vegetation and arable lands. Changes in the coastal areas were closely associated with coastward expansion of aquaculture farming and salt production.