Effects of slope on the runoff and sediment yield in purple soil sloping farmland of Chongqing
XI Hong1, TANG Jidou1, SHI Dongmei2, RAN Wenjian3, YANG Jun3
1. Chongqing Soil and Water Conservation Monitoring Station, 401147, Chongqing, China; 2. Southwest University, 400700, Chongqing, China; 3. Water Conservancy Bureau of Wanzhou District, Chongqing City, 404020, Chongqing, China
Abstract：[Background] Purple soil is one of the main types of sloping farmland in the Three Gorges Reservoir area, which causes a lot of soil erosion under the action of rainfall and runoff all the year round, posing ecological threats to the safety of the reservoir area. In order to study the effect of slope on the characteristics of sand yielding in purple soil sloping farmland, and to further clarify the characteristics of sand yielding in purple soil sloping farmland under different slopes, the process of sediment yielding in purple soil sloping farmland under rainfall conditions was studied.[Methods] Based on the typical sub-rainfall and sediment production data of 5 runoff plots with different slopes (5°, 10°, 15°, 20° and 25°) in Tangfang Slope Runoff Observation Field, Wanzhou district, Chongqing from 2014 to 2017, combined with changes in rainfall, cropping system, field management and crop coverage, the characteristics of runoff and sediment yield in purple soil sloping farmland under different slopes were analyzed.[Results] 1) The runoff depth of sloping farmland has a positive correlation with the slope as a whole. The increase of the runoff depth gradually slows down with the increase of the slope. When the slope increases from 5° to 10°, the runoff depth increases between 66.56% and 1327.27%, and increases from 10°. When it reaches 20°, the runoff depth increases between 2.55% and 300.00%, the maximum runoff gradient is mainly 20°, and the minimum runoff gradient is mainly 5°.2) The sediment yield generally increases with the increase of the slope. When the slope exceeds 20°, the sediment yield begins to decrease; the maximum sediment yield slope is 20°, and the minimum sediment yield slope is 5°, the increase of the slope also leads to the weakening of the erosive force of raindrop splashing, and the sand production decreases with the increase of the slope. 3) The adoption of a reasonable planting system improved the crop coverage of sloping farmland, enhanced the soil fixation capacity of crop roots, and effectively reduced the runoff and sediment yield of sloping farmland by strengthening rainfall interception, slowing runoff and increasing infiltration.[Conclusions] Overall, the maximum 30-minute rainfall intensity and sub-rainfall in the slope and rainfall characteristics were the main factors affecting the sand yield of the purple soil sloping farmland. The research results can provide a reference for the evaluation of soil and water conservation effect of purple soil slope farmland and the layout of farming management measures, and provide a scientific basis for soil and water conservation in small watersheds.
奚宏, 唐继斗, 史东梅, 冉文建, 杨军. 坡度对紫色土坡耕地产流产沙特征的影响[J]. 中国水土保持科学, 2022, 20(4): 19-25.
XI Hong, TANG Jidou, SHI Dongmei, RAN Wenjian, YANG Jun. Effects of slope on the runoff and sediment yield in purple soil sloping farmland of Chongqing. SSWC, 2022, 20(4): 19-25.
何淑勤,郑子成.浅议四川盆地丘陵区的水土保持[J].水土保持研究,2005,12(2):101.HE Shuqin, ZHENG Zicheng.Preliminary opinions on the soil and water conservation in hilly areas in Sichuan Basin[J]Research of Soil and Water Conservation,2005,12(2):101.
[2]
鲍玉海,丛佩娟,冯伟,等.西南紫色土区水土流失综合治理技术体系[J].水土保持通报,2018,38(3):143.BAO Yuhai, CONG Peijuan, FENG Wei, et al.Comprehensive management system of soil and water loss in purple soil area of southwestern China[J].Bulletin of Soil and Water Conservation,2018,38(3):143.
[3]
KOMATSU Yoshitaka,KATO Hiroaki,ZHU Bo, et al.Effects of slope gradient on runoff from bare-fallow purple soil in China under natural rainfall conditions[J].Journal of Mountain Science,2018,15(4):738.
[4]
QIAN Feng,DONG Linyao,LIU Jigen, et al.Equations for predicting interrill erosion on steep slopes in the Three Gorges Reservoir, China[J].Journal of Hydrology and Hydromechanics,2020,68(1):59.
[5]
魏小燕,毕华兴,霍云梅.不同土壤坡面产流产沙特征对比分析[J].水土保持学报,2016,30(4):44.WEI Xiaoyan, BI Huaxing, HUO Yunmei.Comparative analysis of the features of runoff and sediment yield on the different soil slopes[J].Journal of Soil and Water Conservation,2016,30(4):44.
[6]
杨建霞,雷孝章,邱景,等.5°~25°坡耕地径流小区产流产沙规律[J].中国水土保持科学,2008, 6(S1):30.YANG Jianxia, LEI Xiaozhang, QIU Jing, et al.Law of water loss and soil erosion in the 5°-25° sloping field[J]Science of Soil and Water Conservation,2008,6(S1):30.
[7]
温永福,高鹏,穆兴民,等.野外模拟降雨条件下径流小区产流产沙试验研究[J].水土保持研究,2018,25(1):23.WEN Yongfu, GAO Peng, MU Xingmin, et al.Experimental study on runoff and sediment yield in runoff plot under field simulated rainfall condition[J].Research of Soiland Water Conservation,2018,25(1):23.
[8]
MANDAL D, CHANDRAKALA M, ALAM N M, et al.Assessment of soil quality and productivity in different phases of soil erosion with the focus on land degradation neutrality in tropical humid region of India[J].Catena, 2021, 204(8):105440.
[9]
赵龙山,侯瑞,吴发启,等.坡度对农业耕作措施水土保持作用的影响[J].水土保持学报,2017,31(3):69.ZHAO Longshan, HOU Rui, WU Faqi, et al.Effects of slope gradient on soil and water conservation benefit of tillage practices in agricultural lands[J]Journal of Soil and Water Conservation, 2017,31(3):69.
[10]
郑江坤,杨帆,王文武,等.不同降雨等级下耕作措施对坡地产流产沙的影响[J].中国水土保持科学,2018,16(1):38.ZHENG Jiangkun, YANG Fan, WANG Wenwu, et al.Effects of tillage measures on runoff and sediment yield of farmland under different rainfall levels.[J]Science of Soil and Water Conservation,2018,16(1):38.
[11]
曾凤铃,刘淑婧,运剑苇,等.模拟降雨条件下三峡库区紫色土坡地产流入渗特征[J].中国水土保持科学,2022,20(1):107.ZENG Fengling, LIU Shujing, YUN Jianwei, et al.Runoff and infiltration characteristics of purple soil slope in the Three Gorges Reservoir region under simulated rainfall[J].Science of Soil and Water Conservation,2022,20(1):107.
[12]
韩旭,田培,黄建武,等.基于2009-2018年径流小区观测数据的武汉市土壤侵蚀因子定量评价[J].生态学报,2021,41(10):3878.HAN Xu, TIAN Pei, HUANG Jianwu, et al.Quantitative evaluation of soil erosion factors in Wuhan based on observationdata of runoff plots during 2009-2018[J].Acta Ecologica Sinica,2021,41(10):3878.
[13]
陈炳,王苗,姚会恩,等.汤峪河流域径流小区水土保持监测点2017-2019年监测结果分析[J].中国水土保持,2021(5):55.CHEN Bing, WANG Miao, YAO Hui'en.et al.Monitoring results of soil and water conservation monitoring sites in runoff plots of Tangyu River watershed from 2017 to 2019[J].Soil and Water Conservation in China,2021(5):55.
[14]
DAI Jiadong, ZHANG Jianhui, ZHANG Zehong, et al.Effects of water discharge rate and slope gradient on runoff and sediment yield related to tillage erosion[J].Archives of Agronomy and Soil Science,2020,67(6):849.
[15]
LIU Yuxin, XIN Yan, XIE Yun, et al.Effects of slope and rainfall intensity on runoff and soil erosion from furrow diking under simulated rainfall[J].Catena,2019,177:92.
[16]
陈瑾,张佰林,王琨.安家沟流域地面监测数据质量及合理性评价[J].中国水土保持,2018(9):61.CHEN Jin, ZHANG Bailin, WANG Kun.Evaluation on the quality and rationality of ground monitoring data of Anjiagou watershed[J].Soil and Water Conservation in China,2018(9):61.
[17]
侯宁,王勇,赵虎,等.耕作侵蚀对不同坡度下紫色土侵蚀产沙的影响[J].山地学报,2021,39(4):49.HOU Ning, WANG Yong, ZHAO Hu, et al.Effects of tillage erosion on sediment yield of purple soil under different slopes[J].Mountain Research,2021,39(4):49.
2022, Vol. 20 
