摘要
基于川北紫色土区3个径流小区整地前后近20a实测数据,通过建立降雨因子和产流产沙的关系对其降雨特征及产流产沙规律进行对比研究。结果表明:整地后年均降水量较整地前减少约10%,但径流系数和含沙率分别减少了88%和83%。其中,自然破坏小区经过混交造林调整后产流、产沙分别减少95%和88%(P<0.05),封坡育草小区经过人工补植调整后分别减少90%和80%,荒坡垦种小区经过青砖护埂调整后分别减少78%和81%,说明混交造林水土保持效果最明显。整地前产流、产沙均表现为荒坡垦种>自然破坏>封坡育草,整地后表现为青砖护埂>人工补植>混交造林;荒坡垦种小区与其他小区间整地前后产流产沙差异均显著(P<0.05);由产流产沙量与降雨特征指标的相关分析和回归分析可知,整地后的相关系数均较小,且产流的相关性明显高于产沙。说明降雨因子对整地后的产流、产沙影响较小,水土保持措施起到关键作用。植物措施和耕作措施结合有效减少该区的产流产沙量,可在该区水土保持建设中推广应用。
Based on the measured data of nearly 20 years in 3 runoff plots of purple soil area in northeastern Sichuan, we compared rainfall characteristics with runoff and sediment yield by analyzing relationships among rainfall characteristics, runoff coefficient and sediment yield before and after soil preparation. The results showed that average annual precipitation reduced by 10 % after soil preparation, while average runoff coefficient and sediment yield reduced by 88% and 83% respectively. Runoff and sediment yield of plot I （natural destructive slope） reduced by 95% and 88% after mixed afforestation, respectively（P〈0. 05）, while those of plot Ⅱ （enclosed grassland slope） reduced by 90% and 80% after artificial replantation and those of plot Ⅲ（cultivated barren slope） reduced by 78 % and 81% after ridge protection by brick, respectively. Therefore, mixed afforestation showed more obvious effects on soil and water conservation than the other two vegetation adjustment strategies. Before soil preparation, runoff and sediment yield of 3 runoff plots listed in the following order. Cultivated barren slope〉naturally destructive slope〉enclosed grassland slope, while they rearranged after different measures of soil preparation were conducted as follows. Cultivated barren slope（ridge protection by brick） 〉 enclosed grassland slope（artificial replantation）〉natural destructive slope （mixed afforestation）. There were significant differences in both runoff and sediment yield between cultivated barren slope plot and other plots（P〈0.05）. By using correlation analysis and regression analysis, we found that soil preparation lowered the coefficients of correlations among runoff and sediment yield and rainfall characteristics, and sediment yield showed more significant correlation with rainfall characteristics than runoff yield. The results indicated that rainfall had slighter influence on runoff and sediment yield after soil preparation, which proved the key role of the measures of soil a
出处
《水土保持学报》
CSCD
北大核心
2015年第3期81-85,共5页
Journal of Soil and Water Conservation
基金
中国博士后科学基金面上项目(2012M511938)
四川省高等学校"水土保持与荒漠化防治重点实验室"建设项目
国家林业局公益行业专项(201104109)
关键词
紫色土
整地措施
植被恢复
径流系数
产沙量
purple soil
soil preparation
vegetation restoration
runoff coefficient
sediment yield
