Resources Science ›› 2019, Vol. 41 ›› Issue (5): 980-991.doi: 10.18402/resci.2019.05.14

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Sand-fixing function of the grassland ecosystem in Ningxia based on the revised wind erosion model

Yangyang WANG1,2(), Yu XIAO1,2(), Gaodi XIE1,2, Jie XU1,2   

  1. 1. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2018-01-04 Online:2019-05-25 Published:2019-05-25

Abstract:

Grassland in Ningxia Hui Autonomous Region plays a crucial role in sand-fixing. But most of the existing studies are based on micro-scale research, therefore the temporal and spatial patterns of grassland wind-breaking and sand-fixing functions at the regional scale in Ningxia are still unclear. Based on the revised wind erosion equation (RWEQ) model, we quantitatively estimated the sand-fixing function of the grassland ecosystem in Ningxia from 2000 to 2015 with ArcGIS and ENVI. The results show that: (1) The amount of total potential wind erosion ranged from 1028.30×104 t to 7540.50×104 t while the amount of total actual wind erosion was calculated to be from 269.75×104 t to 3318.71×104 t. (2) The total amount of fixed material of the grassland in Ningxia ranged from 729.80×104 t to 4120.04×104 t, increased by 124.13×104 t through the study period, and the average amount of fixed material per unit area ranged between 0.33 kg/m2 and 1.77 kg/m2, with a spatial distribution pattern of high in the central region and low in the north and south. Retention rates increased and averaged between 0.65 and 0.79. (3) The levels of sand-fixing function of grassland in Ningxia from 2000 to 2015 were mainly moderate and weak, accounting for 47% to 65% of the total amount of sand fixation. The area of grassland with moderate and above levels of sand-fixing function increased, while the area with weak and relatively weak grades kept reducing. (4) The proportion of sand-fixing function in the grasslands of the southern mountainous areas and the central arid areas was more than 90%, while that in the northern irrigation grassland decreased first and then increased. The northern and central arid areas need more attention on the management of sandstorm in the future. This study revealed the temporal and spatial patterns of sand fixation of grassland in Ningxia, providing a reference for future wind and sand management.

Key words: Ningxia, grassland, sand-fixing function, revised wind erosion equation (RWEQ), ecosystem services, wind erosion, spatiotemporal patterns