黄土高原水蚀风蚀交错带坡耕地土壤风蚀速率空间分布
摘要
Wind erosion is difficult to separate from the total erosion in the wind-water erosion crisscross region of the Loess Plateau, regardless of its spatial distribution. Water erosion also contributes to the total erosion. Water and wind erosions affect each other. The methods and techniques used in current research present the most significant limitation. Therefore, the methods and techniques of the field must be improved. A short-lived radionuclide—<sup>7</sup>Be—was used to trace wind erosion in this study. Surface soil samples (0–30 mm) were collected from two north-faced farmland slopes with sandy loam and clay loam using the transect approach in the Liudaogou Watershed. This study estimated the rates of soil–wind erosion, analyzed the spatial distribution pattern of soil-wind erosion, and discussed its implication to wind conditions and local microreliefs. Results showed that the average rate of wind erosion was 1560.81 t/(km<sup>2</sup> a) on sandy loam slope A and 694.26 t/(km<sup>2</sup> a) on clay loam slope B. The wind erosion rate decreased from top to bottom for both slopes. Soil particles were coarser, specific surface areas were smaller, and organic matter contents were lower in the surface layer (0–30 mm) after wind erosion than those before wind erosion. The isolines of the wind erosion rate visually showed the wind erosion distribution and indicated that the north wind was the effective resultant wind direction that caused soil loss. The variation in the shape of the isolines reflected the microreliefs of the slopes, and their variation degree denoted the influence degree and scope of microreliefs on wind erosion.