摘要
地表糙度是人为土地管理和土壤侵蚀共同作用的结果,它常常造成地表高低起伏和凹凸不平,严重地影响着地表径流和侵蚀过程。地表填洼量与地表糙度息息相关,粗糙的地表要比光滑的地表临时储水量大,但其机理如何还需要展开研究。本文以陕西杨凌的耕层土为试验用土,借助人工锄耕、人工掏挖、等高耕作产生不同水平的地表糙度,分析了不同侵蚀阶段地表糙度、填洼量的变化规律及二者的相关关系,探讨了不同水平地表糙度的产流时间差异,在实测数据的基础上提出了填洼量估算方法。主要结论如下:
1分段降雨试验过程中,三种处理的地表糙度均呈不断减小趋势。人工锄耕在三个侵蚀演化阶段减小了9.0%、6.5%、25.6%,人工掏挖依次为11.3%、6.4%、27.8%,等高耕作依次为6.4%、3.9%、38.8%,地表糙度变化均以细沟侵蚀阶段为主。连续降雨试验过程中人工锄耕、人工掏挖、等高耕作的地表糙度分别减小了33.7%、30.0%、33.8%。
2分段降雨试验过程中,三种处理的实际填洼量在三个侵蚀演化阶段均呈减小趋势,人工锄耕在三个侵蚀演化阶段减小了5.7%、15.0%、30.3%,;人工掏挖依次为7.0%、14.0%、40.8%;等高耕作依次为8.0%、12.7%、46.5%。连续降雨试验过程中,人工锄耕、人工掏挖、等高耕作实际填洼量分别减小了39.8%、29.2%、42.5%。
3三种处理的最大填洼量在三个侵蚀演化阶段均呈减小趋势,人工锄耕依次减小了8.8%、21.2%、9.0%;人工掏挖依次为7.2%、24.0%、8.1%;等高耕作依次为13.5%、11.0%、13.8%,三个侵蚀阶段减小幅度相差不大。连续降雨试验过程中人工锄耕、人工掏挖、等高耕作最大填洼量分别减小了23.7%、24.7%、35.0%。结合不同侵蚀演化阶段地表糙度变化可以发现,地表糙度与地表填洼量的变化趋势是一致的,只不过变化幅度不一致。
4最大填洼量与实际填洼量呈极显著线性正相关,这说明通过实际填洼量推算最大填洼量是切实可行的,这为后续研究提供了简便方法与理论依据。与此同时,不同侵蚀演化阶段二者的变化规律一致也从另一个角度揭示了二者关系密切,用实际填洼量代替最大填洼量应用于相应的径流-侵蚀模型是切实可行的。
5填洼量是坡面初始产流的主要影响因素。降雨强度为1.0mm/min、2.0mm/min时,实际填洼量(DSC)与起流时间(T)的关系可以分别表述为:T(1.0)=2.4214DSC+2.5844 (DSC<10L) T(1.0)=0.7819DSC-1.7127 (DSC≥10L) T(2.0)=0.2737DSC+1.82
6在实测数据的基础上提出了本地区地表填洼量的估算方法。结果表明,MUD指标(MUD)与填洼量(DSC)线性相关,关系式为: DSC=3.9741MUD-10.404 (MUD>3.72); DSC=0.6456MUD +0.1166 (MUD≤3.72)。填洼量(DSC)与R指标(R)及坡度(S)的数量关系可以表述为: DSC=6.427R-0.327S+2.404。
采用R指标、MUD指标估算地表填洼量均可以取得满意效果,但后者更简单,更实用。
Surface roughness is resulted in the action of artificial management and soil erosion. It means concave and convex on the surface, and has great effect on overland runoff and erosion process. Depression storage capacity has close relationship with surface roughness. Compared with smooth surface, the depression storage capacity of rougher surface is greater. In order to understand the relationship between surface roughness and depression storage, we have to analyze the difference of depression storage under different surface conditions and their relationship. Artificial rainfall was applied and surface soil of farmland in Yangling was selected to study the effect factors of depression storage capacity, to analyze runoff-yielding time under different roughness conditions, to discuss changes of surface roughness and depression storage capacity at different erosion stage and their relationship. Based on experimental data estimation models were put forward to offer scientific basis for utilizing and exploring slope farmland.
1 Surface roughness of three treatments decreased consecutively at three erosion stage. Artificial hoe decreased by 9.0%、6.5%、25.6% , artificial dig were 11.3%、6.4%、27.8%, contour tillage were 6.4%、3.9%、38.8%,dominent change occurred at grill erosion stage. During single rain event, surface roughness of straight slope increased by 32.5%,Surface roughness of artificial hoe slope, artificial dig slope and contour tillage decreased33.7%、33.0%、33.8% separately.
2 Real depression storage capacity of artificial hoe decreased by 5.7%,15.0%,30.3% at three erosion stage, artificial dig were 7.0%,14.0%,40.8%; contour tillage were 8.0%,12.7%,46.5%. During single rain event, real depression storage of artificial hoe, artificial dig and contour tillage decreased by 39.8%,29.2%,42.5% separately.
3 Maximum depression storage of artificial hoe decreased by 8.8%, 21.2% and 9.0% at three erosion stage. Artificial dig decreased by 7.2%,24.0%,8.1% at three erosion stage, and contour tillage slope decreased by 13.5%、11.0%、13.8%. During single rain event, maximum depression storage of artificial hoe, artificial dig and contour tillage decreased by 23.7%, 24.7%, 35.0% separately. The results showed that changes of surface roughness and depression storage were the same. Although change intensities were not the same at different erosion stage, it could also testify that surface roughness was the main effect factor of depression storage capacity.
4 The results of experiments showed that maximum depression storage capacity was significantly correlative with real depression storage capacity in linear relationship.At the same time, changes of them was the same at different erosion stages testified the close relationship between them from another point. Maximum depression storage could be replaced by real depression storage, and be used in runoff-erosion models.
5 Depression storage was main effect factor of runoff-yielding time.Runoff-yielding time (T) was significantly correlative with depression storage capacity (DSC) in linear relationship: T(1.0)=2.4214DSC +2.5844 (DSC<10L) T(1.0)=0.7819DSC -1.7127 (DSC≥10L) T(2.0)=0.2737DSC +1.82.
6 MUD index(MUD) was significantly correlative with depression storage (DSC) in linear relationship: DSC=3.9741MUD-10.404 (MUD>3.72) DSC=0.6456MUD+0.1166 (MUD<3.72).
The relationship between depression storage(DSC) and R index(R), slope gradients(S) could be writhen as: DSC=6.427R-0.327S+2.404.
引文
[1] Burwell R.E. and Larson W.E. Infiltration as influenced by tillage-induced random roughness and pore space[J].Soil Sci. Soc. Am. Proc, 1969, 33:449-452.
[2] Kruipers H.A relief-meter for soil cultivation studies[J]. Agric. Sci,1957, 5:255-262.
[3] Podmore T.H and Huggins L.F.An automated profile meter for surface roughness measurements[J]. Trans Am Soc. Agric. Eng., 1981,24:663-665,669.
[4] Onstad C.A. Depressional storage on tilled soil surface[J]. Trans. Am. Soc. Agric. Eng., 1984a, 27:729-732.
[5] Onstad C.A.Effect of rainfall on tilled soil properties[J]. Am.Soc.Agric. Eng., 1984b,84:2525.
[6] Planchon O.,Esterves M.,Silvera N.et.al. Raindrop erosion of tillage induced microrelife[J].Soil Till.Res,2000,56:131-144.
[7] Linden D.K and Van D.M Doren JR.Parameter for characterizing tillage-induced soil surface roughness [J].Soil Sci. Soc. Am.J. 1986, 50:1561-1565.
[8] Romkens M.J.M.and Wang J.Y. Soil roughness changes of tillage system from rainfall[J]. Trans. American Society of Agricultural Engineers, 1987,30(1):101-107.
[9] Lehrsch G.A., Whisler F.D and Romkens M.J. Spatial variation of parameters describing soil surface roughness. Soil Sci. Am. J. 1988. 52:311-319.
[10] Bertuzzi R.,Rouws G. and Couroult D. Testing roughness indices to estimate soil surface roughness changes due to simulated rainfall[J].Soil Tillage Res,1990, 17:87-99.
[11] Borselli,L. Segmentation of soil roughness profiles. Earth Surf. Processes Landform 1999, 24:71-90.
[12] Dong Z., Fryrear D.W, and S.Gao. Modeling the roughness properties of artificial soil clods. Soil Sci. 1999,164:930-935.
[13] Hansen B., Schonning P., Sibbesen, E.. Roughness indices for estimation of depression storage capacity of tilled soil surface [J]. Soil Till. Res.,1999,52: 103–111.
[14] Kamphorst E.C.,Jetenetl.Predicting depressional storage from soil surface roughness[J].Soil Sci.Am.J,2000,64:1749-1758.
[15] Cogo N.P., Moldenhaver W.C. and Foster G.R. Effect of crop residue,tillage induced roughness and runoff velocity on size distribution of eroded soil aggregates[J].Soil Sci.Soc .Am .J.,1983, 47:1005-1008.
[16] Darboux ph.,F.,Dary,.Gascuel-Odoux C et.al. Evolution of soil surface roughness and flow path connectivity in overland flow experiments [J].Catena,2001,46: 125-139.
[17] 赵西宁,王万忠,吴发启. 不同耕作管理措施对坡耕地降雨入渗的影响[J]. 西北农林科技大学学报,2004,32(2): 69-72.
[18] 吕悦来,李广毅.地表粗糙度与土壤风蚀.土壤学进展,1983, (2): 38-41
[19] Larson W.E. Tillage requirements for corn [J].Soil Water Cons., 1962,17(l):3-7.
[20] Allmaras R.R., Burwell, R.E., Larson W.E. and .Holt. R.F. Total porosity and random roughness of the interrow zone as influenced by tillage.1966, USDA Conserv.Res.Rep.7.
[21] Hagen L.J. New wind erosion model developments in the SDA. In Proceedings Wind Erosion Conference,1988,pp.104-116.
[22] 成都科技大学水利学教研室编:《水力学》上册 (第二版, 北京:高等教育出版社,1962.
[23] 吴发启,赵晓光,刘秉正等.地表糙度的量测方法及对地面径流和侵蚀的影响.西北林学院学报,1998, (2): 15-19.
[24] Romkens M. J. M. and Wang. J. Y. The effect of tillage on surface roughness[J].Am.Soc.Agric.Eng. 1984,84:2026-2042.
[24] Allmaras R.R.,Burwell R.E.and Holt R.F. Plow-layer porosity and surface roughness tillage as affected by initial porosity and soil moisture at tillage time. Soil Sci .Soc. Am.Proc.,1967,31:550-556
[25] Ah Saleh. Soil roughness measurement:chain methed[J]. Soil and Water Cons. 1993a,8(6):527-529.
[26] Warner, W.S., 1995. Mapping a three-dimensional soil surface with handheld 35 mm photography. Soil Tillage Res. 34, 187–197.
[27] Wegmann, H., Rieke-Zapp, D., Folke, S. Digital photogrammetry for measuring soil surface roughness. Proc. ASPRS 2001 Annual Conference, St. Louis, MO, USA.
[28] O.Taconet. Estimating soil roughness indices on a ridge-and-furrow surface using stereo photogrgrammetry. [J].Soil Tillage Res.2006,4:251-262.
[29] Romkens,M.J.M. and Wang ,J.Y. Soil roughness changes of tillage system from rainfall. Am. Soc. Agric. Eng.,1985a, 85:2048-2068.
[30] Robichaud P.R., Molnau M. Measuring soil roughness changes with an ultrasonic profiler. Trans. ASAE, 1990,33 (6), 1851-1858.
[31] Brough D. L and Jarrett. A. R. Simple technique for approximating surface storage of slit- tilled fields[J]. Trans. American Society of Agricultural Engineers, 1992,35(3):885-890.
[32] Huang C., White,Thwaite,E.G. and Bendeli A. A noncontact laser system for measuring soil surface topography. Soil Sci .Soc. Am.J.1989,52:350-355.
[33] Huang C and Bradford J.M. Applications of a laser scanner to quantify soil microtopography. Soil Sci.Soc.Am.J.1992, 56:14-21.
[34] Hung C.H.,Noton,L.D.,Parker,S.C..Laser scanner for erosion plot measurements.Trans.ASAE, 1995,38(3),703-710.
[35] Darboux F., Huang, C.H., 2003. An instantaneous-profile laser scanner to measure soil surface microtopography. Catena,2005,64:174–192,191.
[36] Helming K.,M.J.M.Romkens and S.N.Prasad. Surface roughness related processes of runoff and soil loss: A flume study.Soil Sci.Soc.Am.J. 1998,62:243-250.
[37] Cremers N.H.D.T,Van.Dijk P.M,Roo A.P.J.DE et al. Spatial and temporal variability of soil surface roughness and the applications in hydrological and soil erosion modeling. Hydrological processes. 1996,10:1035-1047.
[38] Boiffin.J.Structural degradation of the soil surface by the action of rainfall.Ph.D.Diss.Inst.Natl. Paris.France.1984
[39] Linden D. R,Van Doren. D. M Allmaras, R. R.. A modle of the effects of tillage-induced soil surface roughness on erosion[R]. Proceedings of the 11th International Conference of the International Soil and Tillage Research Organization, Edinburgh,Scotland,1988
[40] Barron N.A. Soil surface depression storage calculated by geometrical models.1971.MS Thesis, University of Illinois.
[41] Allmaras, R.R.,Nelson,WWand Hallauef,E.A.Fall versus spring plowing and related soil heat balanceIn the western corn Belt.Minn.Agric.Expt.Stn. Tech.Bull.1972,283,22pp.
[42] Cogo N.P.,Moldenhaver WC. and Foster G.R. Soil loss reductions from conservation tillage practices. Soil Sci.Soc.Am.J.1984, 48:368-373.
[43] Magunda, M.K..Larson, W.E. Linden, D.R. and Nater E.A. Changes in micro relief and their effects on infiltration and erosion during simulated rainfall [J]. Soil Technology.1997, 10:57-67.
[44] Mitchell J.K. and Jones Jr.,B. A Micro-relief surface depression storage: analysis of models to describe the depth storage function. AWRA Water Resources Bull., 1976.12:1205-1222.
[45] Moore, I.D. and Larson C.L. Estimating micro-relief surface storage from point data. Trans. Am.Soc.Agric. Eng., 1979.22:1073-1077.
[46] Huang C., and Bradford J. M.. Depressional storge for Markor-Gaussian surfaces[J]. Water Resources Research. 1990, 26:2235-2242.
[47] Planchon O.,Darboux f. A fast simple and versatile method to fill in the depressions of Digital Elevations Models. Cetena,2001,146:159-176.
[48] Mike Kirkby. Modelling the interactions between soil surface properties and water erosion. Catena,2001,46:89-102.
[49] 吴发启, 赵哓光, 刘秉正等. 地表糙度的量测方法及对地面径流和侵蚀的影响[J]. 西北林学院学报, 1998, (2):15-19.
[50] Johnson, C.B., Mannering J., Vand Moldenhauer WC. Influence of surface roughness and clod size and stability on soil and water Iosses. Soil Sci. Soc. Am. J. 1979,43:772-777.
[51] Steichen. J.M. Infiltration and random roughness of a tilled and unitlled clay pan soil[J].Soil Tillage Res.1984,4:251-262.
[52] Moldenhauer W.C.and W.D.Kemper.lnterdependence of water drop energy and clod size on infiltration and clod stability. Soil Sci.Soc.Am.Proc.1969, 33:297-301.
[53] Helming, K., Jeschke W., Storl J., Surface reconstruction and change detection for agricultural purposes by close range photogrammetry. International Society for Photogrammetry and Remote Sensing Congress. 1992,part B5.
[54] Helming K.,C.H.Roth ,R.Wolf and J.Diestel. Characterization of microrelif interactions with runoff using parameters derived from Digital Elevation Models(DEMs).Soil Technol,1993,6:2235-2242.
[55] J.A. Gomez, M.A. Nearing. Runoff and sediment losses from rough and smooth soil surfaces in a laboratory experiment[J]. Catena.2005,59:253–266.
[56] 王治国.黄土残源区人工降雨条件下坡耕地水蚀研究(J).水土保持学报,1995,9(2): 51-57.
[57] Ingrid Takken, Gerard Govers, Victor Jetten et.al. Effects of tillage on runoff and erosion patterns. Soil and Tillage, 2001,65:55-60.
[58] Dexter A.R. Effect of rainfall on the surface microrelief of tilled soil[J]. Terramech,1977.14:11-22.
[59] Sadeghian and M.R. Mitchell, J.K.Response of surface roughness storage to rainfall on tilled soil.Trans,ASAE,1990,33(6):1875-1881.
[60] Potter.K.N.and Zobeck T.M. Estimation of soil microrelief. Trans. American Society of Agricultural Engineers, 1990,33:156-161.
[61] Huang C, Gascuel-Odoux C and Craas-Cayot S. Hill slope topographic and hydrologic effects on overland flow and erosion [J].Cetena.2001, 46:177-188.
[62] Gayle G.A. and Skaggs R.W. Surface storage on bedded cultivated lands.Trans. ASAE,1978,21(1):101 一 104,109.
[63] Auerswald, K., 1992. Changes in soil surface roughness during erosive rains. Internal report Lehrstuhl fur Bodenkunde TU Munchen D-8050 Freisning,20.
[64] Ullha W., Dickinson, W.t. Quantitative description of depression storage using a digital surface model. Determination of depression storage[J].Hydrol. 1979a, 42,63-75.
[65] Martz, L.W., and J. Garbrecht. Automated extraction of drain age network and watershed data from digital elevation models. Water Resour. Bull,1993,29: 901–908.
[66] 郑子成,吴发启。降雨对地表糙度影响的研究[J]。水土保持研究,2003,10(2):151-154.
[67] 郑子成,吴发启。坡耕地地表糙度的初探[J]。西北林学院院报,2004,19(2):39-41.
[68] Hillel D.Soil and water-physical principles and processes[M]. New York: Academic Press, 1971.
[69] 吴普特,周佩华.雨滴击溅对薄层水流水力摩阻系数的影响[J].水土保持学报,1994,8 (2):39-42.
[70] 吴普特,周佩华.坡面薄层水流流动形态与侵蚀搬运方式的研究[J].水土保持学,1992,6(1):20-24)
[71] 柯克拜 M J,摩根.土壤侵蚀[M].王礼先,吴斌,洪惜英译.北京:水利电力出版社,1986,水土保持学报第 17 卷.