Monitoring grassland reclamation in the Mu Us Desert using remote sensing from 2010 to 2015

Abstract

New conversion from grassland to cropland was effectively curbed with the implementation of the Grain-to-Green Program (GTGP) in northern China from 1999 to 2010. However, the phenomenon of grassland reclamation has significantly increased since 2010. Here, the latest trend of conversion from grassland to cropland was evaluated using a Landsat dataset from 2010 and 2015 in the Mu Us Desert (MUD) of northern China. An object-based approach was chosen to classify grassland and farmland information, and the classification accuracy was 98.33% based on 120 cropland verification points, which were obtained through available Google Earth and field survey data. The area of grassland reclamation increased by 411.29 km2 from 2010 to 2015 and was mainly distributed in the southeastern and southwestern parts of the MUD, accounting for 9.78% of the total cropland area in 2015. There were two ways to reclaim grassland, including herdsmen cultivating grasslands on their own pastures and grassland reclamation projects implemented by enterprises under the direction of local governments. Exposed cultivated land is more susceptible to wind erosion and eventually leads to decreasing agricultural productivity and desertification. Therefore, strategies to reduce wind erosion on reclaimed grassland in the study area should be implemented as soon as possible, including several alternative cultivation systems and ridge tillage. If conditions permit, conservation tillage should be changed in the MUD.