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以岩石边坡基质-植被系统为研究对象,结合人工模拟降雨试验和养分损失模型,对基质径流养分损失量与降雨场次、降雨时间之间的关系进行了定量分析及预测。降雨试验中,N、P、K营养元素损失量与降雨场次呈负向关系,但随着降雨场次的增加,损失量减少幅度变小;营养元素累积损失量随降雨时间呈幂函数增长;营养元素损失量在降雨场次和降雨时间变化上均表现出极显著差异(P=0.00)。养分损失模型能较准确地对径流养分损失量进行预测,确定系数均在0.86以上,实测结果与拟合预测结果接近,其相对误差<27%。其中,K在第一场降雨时,模型预测结果最好;N、P则在最后一场降雨时,预测效果最为显著。该模型的建立,可描述营养元素径流损失量随降雨时间的变化过程,从而为岩石边坡基质-植被系统制定合理的养分配比提供理论依据。
Taking the rock-matrix-vegetation system as the research object, this paper quantitatively analyzes and predicts the relationship between nutrient loss of runoff from runoff and rainfall time by combining artificial simulated rainfall test and nutrient loss model. In the rainfall test, the loss of N, P and K nutrition elements was negatively correlated with the rainfall times, but the decreasing extent of loss decreased with the increase of rainfall times. The cumulative loss of nutrient elements increased exponentially with rainfall time. The amount of elemental loss showed extremely significant difference in the rainfall episode and rainfall time (P = 0.00). Nutrient loss model can accurately predict runoff nutrient loss, the coefficients are above 0.86, the measured results are close to the fitted prediction results, the relative error is less than 27%. Among them, K predicts the best model in the first rainfall and N and P predict the most obviously in the last rainfall. The establishment of this model can describe the change process of runoff loss of nutrient elements with rainfall time, so as to provide a theoretical basis for formulating reasonable nutrient allocation of rock slope substrate-vegetation system.