Determination of land degradation causes in Tongyu County, Northeast China via land cover change detection Jay Gao, Liu Yansuiㄗ隸栫呴ㄘ. Determination of land degradation causes in Tongyu County, Northeast China via land cover change detection. International Journal of Applied Earth Observation and Geoinformation. 2010, 12(1): 9-16. Abstract: Tongyu County in Northeast China is highly prone to land degradation due to its fragile physical settings characterized by a flat topography, a semi-arid climate, and a shallow groundwater table. This study aims to determine the causes of land degradation through detecting the long-term trend of land cover changes. Degraded lands were mapped from satellite images recorded in 1992 and 2002. These land cover maps revealed that the area subject to land degradation in the form of soil salinization, waterlogging and desertification increased from 2400 to 4214?km², in sharp contrast to most severely degraded land that decreased by 122.5?km². Newly degraded land stems from productive farmland (263?km²), harvested farmland (551?km²), and grassland (468?km²). Therefore, the worsened degradation situation is attributed to excessive reclamation of grassland for farming, over cultivation, overgrazing, and deforestation. Mechanical, biological, ecological and engineering means should be adopted to rehabilitate the degraded land. Keywords: Land degradation; Rehabilitation of degraded land; Change detection; Landsat TM; Northeast China

Jay Gao, Liu Yansuiㄗ隸栫呴ㄘ. Determination of land degradation causes in Tongyu County, Northeast China via land cover change detection. International Journal of Applied Earth Observation and Geoinformation. 2010, 12(1): 9-16.

Abstract:

Tongyu County in Northeast China is highly prone to land degradation due to its fragile physical settings characterized by a flat topography, a semi-arid climate, and a shallow groundwater table. This study aims to determine the causes of land degradation through detecting the long-term trend of land cover changes. Degraded lands were mapped from satellite images recorded in 1992 and 2002. These land cover maps revealed that the area subject to land degradation in the form of soil salinization, waterlogging and desertification increased from 2400 to 4214?km², in sharp contrast to most severely degraded land that decreased by 122.5?km². Newly degraded land stems from productive farmland (263?km²), harvested farmland (551?km²), and grassland (468?km²). Therefore, the worsened degradation situation is attributed to excessive reclamation of grassland for farming, over cultivation, overgrazing, and deforestation. Mechanical, biological, ecological and engineering means should be adopted to rehabilitate the degraded land.

Keywords: Land degradation; Rehabilitation of degraded land; Change detection; Landsat TM; Northeast China

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