Observation and modeling of black soil wind-blown erosion from cropland in Northeastern China

Abstract

Abstract As the nation’s bread basket, Northeastern China has experienced dramatic land use changes in the past decades, with much natural land being converted into cropland to feed the growing population. The long dormant season, coupled with frequent cold fronts and strong spring winds, makes the exposed cropland vulnerable to wind erosion. However, the rates and spatial–temporal characteristics of wind erosion in this particular soil type have been poorly studied. The present study aimed to measure and simulated the wind erosion characteristics from black soil cropland in the Dehui region of Northeastern China. Our results showed that wind-blown erosion was positively correlated with wind speed and negatively linked to soil moisture, vegetation and soil roughness in this region. The measured threshold friction velocity was 4.47 m/s at 2 m height, corresponding to 0.37 m/s at the surface ground. Based on WRF-CMAQ-FENGSHA model, we localized the parameters and simulated a significant wind erosion event in the Dehui region on May 31, 2013. The relationships between modeled dust flux and ground measurement were correlated (R2 = 0.78). In addition, the modeled aerosol optical depths were also captured by satellite observations (MODIS and CALIPSO). Our results indicate that the bare farmland areas over Northeastern China are important dust sources over this region, and should not be neglected in regional air quality models. The use of protective farming techniques, protection of grassland and plowing in autumn for cropland areas should be considered to combat dust emission.