基于RWEQ的三江源地区防风固沙与NPP研究

Study on sand fixation based on RWEQ and NPP in the Three-River headwaters region

分别基于RWEQ模型和改进的CASA模型对2015年三江源地区的防风固沙量和NPP进行评估,并利用格网法探究两者之间的关系。结果表明,该地区的潜在风蚀和实际风蚀程度整体上都表现为西高东低,固沙量呈现出中部高、西部和东部较低的空间分布特征,平均固沙量为29.51kg/m^2,土壤风蚀处于中等水平;与土壤风蚀相反的是NPP呈现出东高西低的空间分布特征;该地区潜在风蚀量与NPP存在着一定程度的线性关系(R2=0.47),而实际风蚀量与NPP表现为显著的指数关系(R2=0.91)。此外,固沙量随着NPP的增加先增加后减少,固沙量达到最值时,NPP约为300gC/m^2。

The sand-fixing amount and NPP were evaluated in the Three-River headwaters region in 2015 based on RWEQ model and improved CASA model respectively, and the relationship between them explored using the grid. The results showed that the potential wind erosion and actual wind erosion degree in this area were high in the west and low in the east as a whole, and the sand-fixing amount was high in the middle and low in the west and the east. The average sand fixation amount was 29.51 kg/m^2, and the soil wind erosion was at the middle level. Contrary to the soil wind erosion, the spatial distribution characteristic of NPP was high in the east and low in the west. There was a linear relationship between the amount of potential wind erosion and NPP(R2=0.47), while the actual wind erosion and NPP showed a significant exponential relationship (R2=0.91). In addition, with the increase of NPP, the sand-fixing capacity firstly increased and then decreased. At the maximum of sand-fixing capacity, NPP was about 300 gC/m^2.