湘北红壤低山丘陵区典型水土流失治理模式径流泥沙效应

探明径流小区尺度下不同水土流失治理模式的径流泥沙效应,对于大尺度水土流失治理具有重要意义。通过野外标准径流小区自然降雨试验探究了湘北红壤低山丘陵地带3种典型水土流失治理模式(S1模式:坡改梯+经果林,S2模式:等高沟垄+农作物,S3模式:平整撂荒坡面+草本)径流泥沙效应。结果表明:3种治理模式在次降雨诱导下平均径流量为S3(1.84m~3)S1(1.03m~3)S2(0.78m~3),平均泥沙流失量为S3(1.191t/hm~2)S1(0.411t/hm~2)S2(0.311t/hm~2);3种治理模式在A、B、C雨型诱导下(K-均值聚类)累积径流量均为S3(33.19,15.25,14.13 m~3)S1(19.40,9.06,6.48 m~3)S2(16.60,5.89,4.15m~3),累积泥沙流失量也表现出了相同规律,即S3(14.474,10.863,15.153t/hm~2S1(7.521,2.695,3.766t/hm~2)S2(6.149,1.685,2.741t/hm~2);不同治理模式泥沙流失对径流响应特征均呈极显著正相关(P0.01,r0),相关系数(r)分别为0.853,0.920,0.677,其中,S1、S2和S3模式泥沙流失量与径流量线性回归斜率(k)分别为0.356,0.420,0.493,表明S3模式泥沙流失对径流的响应最明显,S2模式次之,S1模式泥沙流失对径流响应程度较小。因此,3种典型模式在控制水土流失方面具有明显不同的效果。

Effects of Typical Soil and Water Loss Control Patterns on Runoff and Sediment of Red Soil in Low Hilly Areas from the Northern Hunan Province

Clarifying the runoff and sediment in runoff plot under different soil and water loss control patterns plays an important role for large-scale soil and water loss. In this study, the runoff and sediment of red soil under three typical soil and water loss control patterns (S1 pattern: slope change ladder + Fruit trees, S2 pattern: contour trench and ridge + Crops, S3 pattern: flat wasteland slope + Herbs) were investigated through the field standard runoff areas under natural rainfall experiment in low hilly areas. The results showed that the average runoff volume under three control patterns was S3 (1.84?m3) > S1 (1.03?m3) > S2 pattern (0.78?m3), and the average sediment yield was S3 (1.191?t/hm2) > S1 (0.411?t/hm2) > S2 pattern (0.311?t/hm2). The cumulative runoff under the three control patterns was S3 (33.19, 15.25, 14.13?m3) > S1 (19.40, 9.06, 6.48?m3) > S2 pattern (16.60, 5.89, 4.15?m3) in the A, B, and C rainfall types (K-means clustering). The cumulative sediment also showed the similar trend that was S3 (14.474, 10.863, 15.153?t/hm2) > S1 (7.521, 2.695, 3.766?t/hm2) > S2 pattern (6.149, 1.685, 2.741?t/hm2). Different control patterns maintained a significant positive correlation between sediment yield had significant positive correlations with runoff volume under the tree control patterns (P<0.01, r > 0). The correlation coefficient (r) was 0.853, 0.920, and 0.677, respectively. Furthermore, the linear regression slope (k) of sediment yield and runoff volume was 0.356, 0.420 and 0.493, respectively under S1, S2, and S3 patterns, indicating the response degree of sediment to runoff in different control patterns was S3 > S2 > S1 pattern. Thus, three typical patterns have significantly different effects for controlling soil and water loss.