黄土丘陵沟壑区自然恢复草被对浅沟侵蚀的影响
|
摘要
浅沟侵蚀是黄土高原丘陵沟壑区的一种重要侵蚀类型.以往研究多侧重于农地浅沟,有关自然恢复草被对浅沟侵蚀影响的研究甚少.本研究采用野外原位冲刷试验,以裸地浅沟为对照,探究放水流量为5、10、15、20和25 L·min~(-1)条件下草地浅沟的径流产沙特征及侵蚀机理.结果表明:与裸地相比,草地浅沟平均流速、稳定径流率、雷诺数、弗劳德数分别减小25.4%～67.3%、8.4%～26.6%、54.9%～80.5%、18.6%～65.1%,阻力系数增大0.09～7.18倍.草地浅沟最大产沙率、稳定产沙率和平均产沙率较裸地浅沟分别减小55.1%～90.9%、61.8%～95.4%和64.8%～92.4%; 5～25 L·min~(-1)放水流量下,自然恢复草被的减沙效益可达65.9%～88.8%,且随放水流量增大,减沙效益呈减小趋势.与裸地相比,草地浅沟的平均径流功率和平均径流剪切力分别减小54.9%～80.5%和12.4%～51.1%,临界径流功率增大1.43倍,临界剪切力增大33.7%;草地和裸地浅沟平均产沙率与平均径流功率、平均径流剪切力均呈显著线性相关.自然恢复草被显著增加了浅沟抗蚀性能,降低了浅沟径流侵蚀能力.
Ephemeral gully erosion is an important erosion type in hilly and gully regions of Loess Plateau. While previous studies mainly focused on ephemeral gullies in agricultural land,little is known about the effects of naturally restored grassland on ephemeral gully erosion. In this study,taking the bare ephemeral gullies as the baseline,we conducted in-situ flushing tests to explore runoff and sediment yield characteristics and erosion mechanism of grassland ephemeral gullies under the runoff conditions of 5,10,15,20 and 25 L·min~(-1). Compared to the bare ephemeral gully,average flow velocity,stable runoff rate,Reynolds number and Froude number of grassland ephemeral gullies was reduced by 25. 4%-67. 3%,8. 4%-26. 6%,54. 9%-80. 5%,18. 6%-65. 1%,respectively,whereas resistance coefficient was increased by 0.09-7.18 folds. Compared to the bare ephemeral gully,the maximum sediment yield rate,stable sediment yield rate,average sediment yield rate of grassland ephemeral gullies was decreased by 55. 1%-90. 9%,61. 8%-95. 4%,and64.8%-92.4%,respectively. The sediment yield reduction benefit of the naturally restored grassland under the discharge flow rate of 5-25 L·min~(-1) could reach 65.9%-88.8%,which decreased with increasing discharge flow rate. Compared to the bare ephemeral gully,average stream power and average shear stress of grassland ephemeral gullies was reduced by 54.9%-80.5% and 12.4%-51.1%,respectively,whereas the critical stream power and critical shear stress was increased by1.43 folds and 33.7%,respectively. The average sediment yield of grassland and bare ephemeral gullies was signifi-cantly linearly related to average stream power and shear stress. Naturally restored grassland significantly increased the erosion resistance and reduced runoff erosion potential of ephemeral gullies.
Ephemeral gully erosion is an important erosion type in hilly and gully regions of Loess Plateau. While previous studies mainly focused on ephemeral gullies in agricultural land,little is known about the effects of naturally restored grassland on ephemeral gully erosion. In this study,taking the bare ephemeral gullies as the baseline,we conducted in-situ flushing tests to explore runoff and sediment yield characteristics and erosion mechanism of grassland ephemeral gullies under the runoff conditions of 5,10,15,20 and 25 L·min~(-1). Compared to the bare ephemeral gully,average flow velocity,stable runoff rate,Reynolds number and Froude number of grassland ephemeral gullies was reduced by 25. 4%-67. 3%,8. 4%-26. 6%,54. 9%-80. 5%,18. 6%-65. 1%,respectively,whereas resistance coefficient was increased by 0.09-7.18 folds. Compared to the bare ephemeral gully,the maximum sediment yield rate,stable sediment yield rate,average sediment yield rate of grassland ephemeral gullies was decreased by 55. 1%-90. 9%,61. 8%-95. 4%,and64.8%-92.4%,respectively. The sediment yield reduction benefit of the naturally restored grassland under the discharge flow rate of 5-25 L·min~(-1) could reach 65.9%-88.8%,which decreased with increasing discharge flow rate. Compared to the bare ephemeral gully,average stream power and average shear stress of grassland ephemeral gullies was reduced by 54.9%-80.5% and 12.4%-51.1%,respectively,whereas the critical stream power and critical shear stress was increased by1.43 folds and 33.7%,respectively. The average sediment yield of grassland and bare ephemeral gullies was signifi-cantly linearly related to average stream power and shear stress. Naturally restored grassland significantly increased the erosion resistance and reduced runoff erosion potential of ephemeral gullies.
引文
[1] Zhang K-L(张科利),Tang K-L(唐克丽),Wang BK(王斌科). A study on characteristic value of shallow gully erosion genesis on slope farmland in the Loess Plateau. Journal of Soil and Water Conservation(水土保持学报),1991,5(2):8-13(in Chinese)
[2] Zhu X-M(朱显谟). Classification on the soil erosion in the loess region. Acta Pedologica Sinica(土壤学报),1956,4(2):99-115(in Chinese)
[3] Zheng F-L(郑粉莉),Wu M(武敏),Zhang Y-B(张玉斌),et al. Ephemeral gully development process at loess steep hillslope. Scientia Geographica Sinica(地理科学),2006,26(4):438-442(in Chinese)
[4] Qin W(秦伟),Zhu Q-K(朱清科),Zhao L-L(赵磊磊),et al. Topographic characteristics of ephemeral gully erosion in loess hilly and gully region based on RS and GIS. Transactions of the Chinese Society of Agricultural Engineering(农业工程学报),2010,26(6):58-64(in Chinese)
[5] Zheng F-L(郑粉莉),Xu X-M(徐锡蒙),Qin C(覃超). A review of gully erosion process research. Transaction of the Chinese Society for Agricultural Machinery(农业机械学报),2016,47(8):48-59(in Chinese)
[6] Tang K-L(唐克丽),Zheng S-Q(郑世清),Xi D-Q(席道勤),et al. Soil and water loss and control of slope farmland in Xingzihe watershed. Bulletin of Soil and Water Conservation(水土保持通报),1983,3(5):43-48(in Chinese)
[7] Cheng H(程宏),Wang S-T(王升堂),Wu Y-Q(伍永秋),et al. Study on hole-ephemeral gullies erosion. Journal of Soil and Water Conservation(水土保持学报),2006,20(2):39-41(in Chinese)
[8] Jiang Y-Q(姜永清),Wang Z-L(王占礼),Hu G-R(胡光荣),et al. Distribution features of shallow gully.Research of Soil and Water Conservation(水土保持研究),1999,6(2):181-184(in Chinese)
[9] Zhao W-J(赵维军),Xu Z-C(许智超),Zhang Y(张岩),et al. Study on distribution of epemeral gullies in semiarid loess area. Arid Zone Research(干旱区研究),2011,28(4):586-591(in Chinese)
[10] Li A-Y(李安怡),Wu X-Q(吴秀芹),Zhu Q-K(朱清科). Distribution characteristics and relation with site type of ephemeral gully in Loess Plateau of Northern Shaanxi Province. Journal of Northwest A&F University(西北农林科技大学学报),2010,38(4):79-85(in Chinese)
[11] Gong J-G(龚家国),Zhou Z-H(周祖昊),Jia Y-W(贾仰文),et al. Simulation experiment of ephemeral gully erosion on basis hydraulics parameters of concentrated flow and erosion morphology in loess area. Journal of Soil and Water Conservation(水土保持学报),2010,24(5):92-96(in Chinese)
[12] Guo M-M(郭明明),Wang W-L(王文龙),Li J-M(李建明),et al. Effect of tillage on runoff and sediment yields and morphology development characteristic of ephemeral gully in loessial region. Transactions of the Chinese Society of Agricultural Engineering(农业工程学报),2015,31(15):114-123(in Chinese)
[13] Kang H-L(康宏亮),Wang W-L(王文龙),Xue Z-D(薛智德),et al. Erosion morphology and runoff generation and sediment yield on ephemeral gully in loess hilly region in field scouring experiment. Transactions of the Chinese Society of Agricultural Engineering(农业工程学报),2016,32(20):161-170(in Chinese)
[14] Cui M(崔明),Cai Q-G(蔡强国),Zhang Y-G(张永光),et al. Development of ephemeral gully during rainy season in the slope land in rolling-hill black-soil region of Northeast China. Transactions of the Chinese Society of Agricultural Engineering(农业工程学报),2007,23(8):59-65(in Chinese)
[15] Wu M(武敏),Zheng F-L(郑粉莉). Research progress on ephemeral gully erosion process and its prediction model. Research of Soil and Water Conservation(水土保持研究),2004,11(4):113-116(in Chinese)
[16] Guo J-Q(郭军权). Experimental Study on Character on Ephemeral Gully Occurred and Dynamic Process on Loess Plateau. PhD Thesis. Yangling:Northwest A&F University,2006(in Chinese)
[17] Wang J-X(王佳欣). The Study on Temporal and Spatial Response Relationship between Sediment Yield and Hydraulic Parameters of the Slope-gully System. PhD Thesis. Zhengzhou:North China University of Water Resources and Electric Power,2016(in Chinese)
[18] Capra A,Porto P,Scicolone B. Relationships between rainfall characteristics and ephemeral gully erosion in a cultivated catchment in Sicily(Italy). Soil&Tillage Research,2009,105:77-87
[19] Xu X-M(徐锡蒙),Zheng F-L(郑粉莉),Wu M(武敏). Quantification study of rainfall intensity and slope gradient impacts on ephemeral gully morphological characteristic on steep loessial hill slope. Transactions of the Chinese Society of Agricultural Engineering(农业工程学报),2017,33(11):124-132(in Chinese)
[20] Li B-B(李斌兵),Zheng F-L(郑粉莉),Zhang P(张鹏). Geomorphic threshold determination for ephemeral gully and gully erosion areas in the loess hilly gully region. Bulletin of Soil and Water Conservation(水土保持通报),2008,28(5):16-20(in Chinese)
[21] Gong JG,Jia YW,Zhou ZH,et al. An experimental study on dynamic processes of ephemeral gully erosion in loess landscapes. Geomorphology,2011,125:203-213
[22] Liu S,Bliss N,Sundquist E,et al. Modeling carbon dynamics in vegetation and soil under the impact of soil erosion and deposition. Global Biogeochemical Cycles,2003,17:1074-1078
[23] Zhang K-L(张科利). A study on the distribution of erosion and sediment yield on the loess slope and the relationship between the distribution and rain characteristics. Journal of Sediment Research(泥沙研究),1991(4):39-47(in Chinese)
[24] Zheng F-L(郑粉莉),Gao X-T(高学田). Soil Erosion Process and Simulation on Loess Slope. Xi’an:Shaanxi People’s Press,2000(in Chinese)
[25] Hou Q-C(侯庆春),Han R-L(韩蕊莲),Han S-F(韩仕峰). Preliminary research on the“dry soil layer”in man-made grassland on Loess Plateau. Soil and Water Conservation in China(中国水土保持),1999(5):11-14(in Chinese)
[26] Min Q-W(闵庆文),Yu W-D(余卫东). Vegetation eco-construction in Loess Plateau region viewing from precipitation resource. Research of Soil and Water Conservation(水土保持研究),2002,9(3):109-112(in Chinese)
[27] Yang G(杨光). Soil Moisture and Biomass and Biodiversity of Vegetation in the Yan’er Valley. PhD Thesis. Yangling:Northwest A&F University,2011(in Chinese)
[28] Yang C-X(杨春霞),Wu Q(吴卿),Yang J-F(杨剑锋),et al. Study and test on artificial simulated slope surface yield. Water and soil Conservation in China(中国水土保持),2003(6):27-28(in Chinese)
[29] Xia J(夏军),Qiao Y-F(乔云峰),Song X-F(宋献方),et al. Analysis about effect rules of underlying surface change to the relationship between rainfall and runoff in the Chabagou catchment. Resources Science(资源科学),2007,29(1):70-76(in Chinese)
[30] Guo M(郭曼). Assessment and Response of Soil Quality to Vegetation Natural Restoration Processes in the Loessial Hilly-gully Region. PhD Thesis. Yangling:Northwest A&F University,2009(in Chinese)
[31] Wu Q-X(吴钦孝),Zhao H-Y(赵鸿雁),Han B(韩冰). Benefit and characteristics of grass-shrub vegetation for reducing soil erosion in loess hilly region. Acta Agrestia Sinica(草地学报),2003,11(1):23-26(in Chinese)
[32] Li G,Abrahams AD,Atinson JF. Correction factors in the determination of mean velocity of overland flow.Earth Surface Processes Landforms,1996,21:509-515
[33] Dong Y-Q(董月群),Lei T-W(雷廷武),Zhang Q-W(张晴雯),et al. Ephemeral gully flow velocity under concentrated water flow. Transactions of the Chinese Society for Agricultural Machinery(农业机械学报),2013,44(5):96-100(in Chinese)
[34] Wang W-L(王文龙),Lei A-L(雷阿林),Li Z-B(李占斌),et al. Study on dynamic mechanism of rills,shallow furrows and gully in the soil erosion chain.Advance in Water Science(水科学进展),2003,14(4):471-475(in Chinese)
[35] Zhang K-L(张科利),Tang K-L(唐克丽). Ephemeral Gully on Slope Farmland in Loess Hilly-gully Region of Northern Shaanxi and Its Control Measures. Yangling:Institute of Soil and Water Conservation, Chinese Academy of Sciences&Ministry of Water Resources,1988(in Chinese)
[36] Wang Y-K(王玉宽). The experimental study of overland flow erosion in loess hilly and gully region. Soil and Water Conservation of China(中国水土保持),1993(7):222-224(in Chinese)
[2] Zhu X-M(朱显谟). Classification on the soil erosion in the loess region. Acta Pedologica Sinica(土壤学报),1956,4(2):99-115(in Chinese)
[3] Zheng F-L(郑粉莉),Wu M(武敏),Zhang Y-B(张玉斌),et al. Ephemeral gully development process at loess steep hillslope. Scientia Geographica Sinica(地理科学),2006,26(4):438-442(in Chinese)
[4] Qin W(秦伟),Zhu Q-K(朱清科),Zhao L-L(赵磊磊),et al. Topographic characteristics of ephemeral gully erosion in loess hilly and gully region based on RS and GIS. Transactions of the Chinese Society of Agricultural Engineering(农业工程学报),2010,26(6):58-64(in Chinese)
[5] Zheng F-L(郑粉莉),Xu X-M(徐锡蒙),Qin C(覃超). A review of gully erosion process research. Transaction of the Chinese Society for Agricultural Machinery(农业机械学报),2016,47(8):48-59(in Chinese)
[6] Tang K-L(唐克丽),Zheng S-Q(郑世清),Xi D-Q(席道勤),et al. Soil and water loss and control of slope farmland in Xingzihe watershed. Bulletin of Soil and Water Conservation(水土保持通报),1983,3(5):43-48(in Chinese)
[7] Cheng H(程宏),Wang S-T(王升堂),Wu Y-Q(伍永秋),et al. Study on hole-ephemeral gullies erosion. Journal of Soil and Water Conservation(水土保持学报),2006,20(2):39-41(in Chinese)
[8] Jiang Y-Q(姜永清),Wang Z-L(王占礼),Hu G-R(胡光荣),et al. Distribution features of shallow gully.Research of Soil and Water Conservation(水土保持研究),1999,6(2):181-184(in Chinese)
[9] Zhao W-J(赵维军),Xu Z-C(许智超),Zhang Y(张岩),et al. Study on distribution of epemeral gullies in semiarid loess area. Arid Zone Research(干旱区研究),2011,28(4):586-591(in Chinese)
[10] Li A-Y(李安怡),Wu X-Q(吴秀芹),Zhu Q-K(朱清科). Distribution characteristics and relation with site type of ephemeral gully in Loess Plateau of Northern Shaanxi Province. Journal of Northwest A&F University(西北农林科技大学学报),2010,38(4):79-85(in Chinese)
[11] Gong J-G(龚家国),Zhou Z-H(周祖昊),Jia Y-W(贾仰文),et al. Simulation experiment of ephemeral gully erosion on basis hydraulics parameters of concentrated flow and erosion morphology in loess area. Journal of Soil and Water Conservation(水土保持学报),2010,24(5):92-96(in Chinese)
[12] Guo M-M(郭明明),Wang W-L(王文龙),Li J-M(李建明),et al. Effect of tillage on runoff and sediment yields and morphology development characteristic of ephemeral gully in loessial region. Transactions of the Chinese Society of Agricultural Engineering(农业工程学报),2015,31(15):114-123(in Chinese)
[13] Kang H-L(康宏亮),Wang W-L(王文龙),Xue Z-D(薛智德),et al. Erosion morphology and runoff generation and sediment yield on ephemeral gully in loess hilly region in field scouring experiment. Transactions of the Chinese Society of Agricultural Engineering(农业工程学报),2016,32(20):161-170(in Chinese)
[14] Cui M(崔明),Cai Q-G(蔡强国),Zhang Y-G(张永光),et al. Development of ephemeral gully during rainy season in the slope land in rolling-hill black-soil region of Northeast China. Transactions of the Chinese Society of Agricultural Engineering(农业工程学报),2007,23(8):59-65(in Chinese)
[15] Wu M(武敏),Zheng F-L(郑粉莉). Research progress on ephemeral gully erosion process and its prediction model. Research of Soil and Water Conservation(水土保持研究),2004,11(4):113-116(in Chinese)
[16] Guo J-Q(郭军权). Experimental Study on Character on Ephemeral Gully Occurred and Dynamic Process on Loess Plateau. PhD Thesis. Yangling:Northwest A&F University,2006(in Chinese)
[17] Wang J-X(王佳欣). The Study on Temporal and Spatial Response Relationship between Sediment Yield and Hydraulic Parameters of the Slope-gully System. PhD Thesis. Zhengzhou:North China University of Water Resources and Electric Power,2016(in Chinese)
[18] Capra A,Porto P,Scicolone B. Relationships between rainfall characteristics and ephemeral gully erosion in a cultivated catchment in Sicily(Italy). Soil&Tillage Research,2009,105:77-87
[19] Xu X-M(徐锡蒙),Zheng F-L(郑粉莉),Wu M(武敏). Quantification study of rainfall intensity and slope gradient impacts on ephemeral gully morphological characteristic on steep loessial hill slope. Transactions of the Chinese Society of Agricultural Engineering(农业工程学报),2017,33(11):124-132(in Chinese)
[20] Li B-B(李斌兵),Zheng F-L(郑粉莉),Zhang P(张鹏). Geomorphic threshold determination for ephemeral gully and gully erosion areas in the loess hilly gully region. Bulletin of Soil and Water Conservation(水土保持通报),2008,28(5):16-20(in Chinese)
[21] Gong JG,Jia YW,Zhou ZH,et al. An experimental study on dynamic processes of ephemeral gully erosion in loess landscapes. Geomorphology,2011,125:203-213
[22] Liu S,Bliss N,Sundquist E,et al. Modeling carbon dynamics in vegetation and soil under the impact of soil erosion and deposition. Global Biogeochemical Cycles,2003,17:1074-1078
[23] Zhang K-L(张科利). A study on the distribution of erosion and sediment yield on the loess slope and the relationship between the distribution and rain characteristics. Journal of Sediment Research(泥沙研究),1991(4):39-47(in Chinese)
[24] Zheng F-L(郑粉莉),Gao X-T(高学田). Soil Erosion Process and Simulation on Loess Slope. Xi’an:Shaanxi People’s Press,2000(in Chinese)
[25] Hou Q-C(侯庆春),Han R-L(韩蕊莲),Han S-F(韩仕峰). Preliminary research on the“dry soil layer”in man-made grassland on Loess Plateau. Soil and Water Conservation in China(中国水土保持),1999(5):11-14(in Chinese)
[26] Min Q-W(闵庆文),Yu W-D(余卫东). Vegetation eco-construction in Loess Plateau region viewing from precipitation resource. Research of Soil and Water Conservation(水土保持研究),2002,9(3):109-112(in Chinese)
[27] Yang G(杨光). Soil Moisture and Biomass and Biodiversity of Vegetation in the Yan’er Valley. PhD Thesis. Yangling:Northwest A&F University,2011(in Chinese)
[28] Yang C-X(杨春霞),Wu Q(吴卿),Yang J-F(杨剑锋),et al. Study and test on artificial simulated slope surface yield. Water and soil Conservation in China(中国水土保持),2003(6):27-28(in Chinese)
[29] Xia J(夏军),Qiao Y-F(乔云峰),Song X-F(宋献方),et al. Analysis about effect rules of underlying surface change to the relationship between rainfall and runoff in the Chabagou catchment. Resources Science(资源科学),2007,29(1):70-76(in Chinese)
[30] Guo M(郭曼). Assessment and Response of Soil Quality to Vegetation Natural Restoration Processes in the Loessial Hilly-gully Region. PhD Thesis. Yangling:Northwest A&F University,2009(in Chinese)
[31] Wu Q-X(吴钦孝),Zhao H-Y(赵鸿雁),Han B(韩冰). Benefit and characteristics of grass-shrub vegetation for reducing soil erosion in loess hilly region. Acta Agrestia Sinica(草地学报),2003,11(1):23-26(in Chinese)
[32] Li G,Abrahams AD,Atinson JF. Correction factors in the determination of mean velocity of overland flow.Earth Surface Processes Landforms,1996,21:509-515
[33] Dong Y-Q(董月群),Lei T-W(雷廷武),Zhang Q-W(张晴雯),et al. Ephemeral gully flow velocity under concentrated water flow. Transactions of the Chinese Society for Agricultural Machinery(农业机械学报),2013,44(5):96-100(in Chinese)
[34] Wang W-L(王文龙),Lei A-L(雷阿林),Li Z-B(李占斌),et al. Study on dynamic mechanism of rills,shallow furrows and gully in the soil erosion chain.Advance in Water Science(水科学进展),2003,14(4):471-475(in Chinese)
[35] Zhang K-L(张科利),Tang K-L(唐克丽). Ephemeral Gully on Slope Farmland in Loess Hilly-gully Region of Northern Shaanxi and Its Control Measures. Yangling:Institute of Soil and Water Conservation, Chinese Academy of Sciences&Ministry of Water Resources,1988(in Chinese)
[36] Wang Y-K(王玉宽). The experimental study of overland flow erosion in loess hilly and gully region. Soil and Water Conservation of China(中国水土保持),1993(7):222-224(in Chinese)