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田间土壤的流失与土壤侵蚀的类型有关。土壤侵蚀的过程是很复杂的,并且表现得各种各样。对于季风地区的日本和东南亚国家来说,重要的是预测一次降雨或长期降雨以及最大暴雨过后的土壤流失量。然而,到目前为止,还没有定量预测土壤流失量的有效方法。本文作者通过引进一个新的物理概念——土壤侵蚀系数k_e,能够定量地表示田间土壤侵蚀的各方面因素,并且提出了一个由降雨量(q_r)直接计算土壤流失量(qγ)的经验公式: q_e=aK_eL_d~αsin~βQq_r~γ其中:a——系数 α,β,γ——指数。 L_d——坡地长度。 Q——坡度。 土壤侵蚀系数k_e主要与地表的植被,地面覆盖层(覆盖系数K_c),耕作形态(地形系数K_s),或田间建设(田间建设系数K_w)有关,可表示为: k_c=1.0-(A_1/A_0)(a_c)~H/D, K_e=K_c·K_s·K_w K_c,K_s和K_w分别由下面公式计算得出: K_s=b(D_b/d_b)sinQ_r K_w=c·(S_1/S_0)[2.0-(S_1/S_0)~w]其中A_1/A_0,H/D,a_c,D_L/d_b,Q_r,b,S_1/S_0,W和C是由植被条件,耕作形态,地形趋势和田间建设方法等具体计算得到,具体方法将在第六部分进一步讨论。本文提出了如果能通过降雨类型,产流速度和雨滴侵蚀能量定出公式中的系数a和指数γ,我们可以估算不同程度的降雨(即单位小时降雨量或最大降雨量)引起的土壤流失?
Field soil loss is related to the type of soil erosion. The process of soil erosion is complex and varied. For countries in Japan and Southeast Asia in the monsoon region, it is important to predict the amount of soil loss after a single rainfall or prolonged rainfall and after a maximum rainfall. However, so far, there is no effective way to quantitatively predict soil loss. By introducing a new concept of physical-soil erosion coefficient k_e, the authors can quantify various aspects of soil erosion in the field and put forward an empirical formula for calculating soil loss (qγ) directly from rainfall (q_r) q_e = aK_eL_d ~ αsin ~ βQq_r ~ γ where: a - coefficient α, β, γ - index. L_d-- slope length. Q - slope. The soil erosion coefficient k_e is mainly related to vegetation, ground cover (coverage coefficient K_c), tillage form (topography coefficient K_s), or field construction (field construction coefficient K_w), which can be expressed as: k_c = 1.0- (A_1 / A_0 K_e = K_c · K_s · K_w K_c, K_s and K_w are respectively calculated by the following formulas: K_s = b (D_b / d_b) sinQ_r K_w = c · (S_1 / S_0) (S_1 / S_0) ~w] where A_1 / A_0, H / D, a_c, D_L / d_b, Q_r, b, S_1 / S_0, W and C are all determined by vegetation conditions, farming patterns, topographic trends and field construction methods Calculated, the specific method will be further discussed in the sixth part. In this paper, we propose that we can estimate the soil loss caused by different degrees of rainfall (ie, the number of hourly rainfall or the maximum amount of rainfall) if we can determine the coefficient a and the index γ in the formula by the type of rainfall, runoff velocity and rainfall erode energy.