南方紅壤區(qū)坡面次降雨產(chǎn)流產(chǎn)沙特征

黃俊,亢慶,金平偉,姜學(xué)兵,李樂,韋聰謀,劉斌,寇馨月,徐舟

(1.珠江水利委員會(huì)珠江水利科學(xué)研究院,510610,廣州;2.珠江水利委員會(huì)珠江流域水土保持監(jiān)測(cè)中心站,510610,廣州; 3.水利部黃土高原水土流失過程與控制重點(diǎn)實(shí)驗(yàn)室,450003,鄭州)

南方紅壤區(qū)坡面次降雨產(chǎn)流產(chǎn)沙特征

黃俊1,2,3,亢慶1,2,金平偉1,2,姜學(xué)兵1,2,李樂1,2,韋聰謀1,2,劉斌1,2,寇馨月1,2,徐舟1,2

(1.珠江水利委員會(huì)珠江水利科學(xué)研究院,510610,廣州;2.珠江水利委員會(huì)珠江流域水土保持監(jiān)測(cè)中心站,510610,廣州; 3.水利部黃土高原水土流失過程與控制重點(diǎn)實(shí)驗(yàn)室,450003,鄭州)

研究坡面次降雨土壤入滲及產(chǎn)流產(chǎn)沙特征,對(duì)于坡地水土流失防治及水土資源管理利用具有重要意義?；趶V東省五華縣水土保持試驗(yàn)推廣站野外徑流場(chǎng)2014年的觀測(cè)數(shù)據(jù),研究不同下墊面條件下坡面入滲及產(chǎn)流產(chǎn)沙特征。次降雨入滲量與地表植被蓋度間存在顯著相關(guān)關(guān)系(P＜0.05,R=0.95)。入滲量隨降雨強(qiáng)度增加,呈先增后減的變化趨勢(shì),存在入滲量達(dá)最大值的臨界降雨強(qiáng)度;人工林及灌草地臨界降雨強(qiáng)度為19.9～27.8mm/h,均高于自然撂荒地。次降雨徑流深和土壤流失量與地表植被蓋度間,存在顯著負(fù)相關(guān)關(guān)系(P＜0.05),相關(guān)系數(shù)超過0.9。土壤侵蝕率隨徑流系數(shù)呈冪函數(shù)增加趨勢(shì),徑流中泥沙濃度隨徑流系數(shù)、降雨侵蝕力呈對(duì)數(shù)函數(shù)增加趨勢(shì),土壤流失量隨降雨侵蝕力及次降雨徑流深均呈線性遞增趨勢(shì)。次降雨徑流深20mm為土壤流失量變化拐點(diǎn),徑流深超過20mm后,土壤流失量隨徑流深遞增速率較快。

臨界降雨強(qiáng)度;土壤入滲;植被覆蓋;徑流場(chǎng)

南方紅壤區(qū)地形地貌復(fù)雜、降水豐沛,加之經(jīng)濟(jì)社會(huì)快速發(fā)展,導(dǎo)致水土流失問題十分嚴(yán)重[1]。南方紅壤區(qū)水土流失面積約占其總面積的30%[2],加強(qiáng)對(duì)其水土流失規(guī)律研究,可為南方紅壤區(qū)水土保持及水土資源管理利用提供科學(xué)參考。

坡面作為土壤侵蝕的重要組成單元,其降雨產(chǎn)流產(chǎn)沙特征研究具有重要意義[3]。次降雨產(chǎn)流是坡面土壤侵蝕源動(dòng)力[4],是影響坡面土壤侵蝕的關(guān)鍵因素[5]。降雨特征及植被覆蓋是影響坡面產(chǎn)流產(chǎn)沙的關(guān)鍵因素[6]。魯克新等[7]進(jìn)一步研究發(fā)現(xiàn),降雨強(qiáng)度是影響徑流量的關(guān)鍵因子,而植被覆蓋及坡度是影響侵蝕量的關(guān)鍵因子。顧禮彬等[8]在黔西高原研究發(fā)現(xiàn),坡面產(chǎn)流產(chǎn)沙量與年內(nèi)降雨分布關(guān)系密切,產(chǎn)沙量與降雨量間存在顯著的指數(shù)關(guān)系。李君蘭等[9]基于模擬試驗(yàn)條件研究發(fā)現(xiàn),含沙量的變化主要受降雨強(qiáng)度及坡度交互作用影響,而坡長對(duì)含沙量未有顯著影響。呂玉娟等[10]研究發(fā)現(xiàn),紅壤區(qū)不同土地利用方式對(duì)產(chǎn)流產(chǎn)沙量影響較大,農(nóng)地徑流產(chǎn)沙量遠(yuǎn)大于經(jīng)果林,且后者呈逐漸降低趨勢(shì);汪邦穩(wěn)等[11]基于對(duì)比試驗(yàn)也得出類似結(jié)論。耿曉東等[12]基于室內(nèi)模擬降雨試驗(yàn)發(fā)現(xiàn),紅壤坡面入滲率隨降雨強(qiáng)度增大,呈先增加后降低變化趨勢(shì),產(chǎn)流速率主要受到降雨強(qiáng)度的影響;代數(shù)等[13]基于人工模擬降雨試驗(yàn)研究,認(rèn)為平均降雨強(qiáng)度是影響黃壤旱地坡面產(chǎn)流產(chǎn)沙的關(guān)鍵因素,徑流泥沙量與將雨強(qiáng)度間均存在冪函數(shù)關(guān)系。李新平等[14]采用通用水土流失方程,計(jì)算不同下墊面小流域尺度土壤侵蝕量,發(fā)現(xiàn)常綠闊葉林土壤侵蝕量較灌木牧草具有更好的保持水土效果。孫佳佳等[15]研究發(fā)現(xiàn),馬尾松純林地保持水土效益一般,但采用“馬尾松+牧草”復(fù)合土地利用方式,可減少土壤侵蝕模數(shù)90%以上。盡管坡面產(chǎn)流產(chǎn)沙特征相關(guān)研究成果豐碩,但有關(guān)紅壤區(qū)不同土地利用方式、不同降雨強(qiáng)度及地表植被蓋度條件下坡面產(chǎn)流產(chǎn)沙特征研究仍需進(jìn)一步深入。本文基于南方紅壤區(qū)野外定位觀測(cè)徑流小區(qū),研究不同土地利用方式下、不同降雨強(qiáng)度及地表植被蓋度對(duì)次降雨坡面入滲、產(chǎn)流產(chǎn)沙特征影響,以期為南方紅壤區(qū)坡地水土流失防治及水土資源管理提供參考。

1 研究區(qū)概況

試驗(yàn)在廣東省五華縣水土保持試驗(yàn)推廣站野外徑流場(chǎng)(E 115.62°,N 24.09)開展。該徑流場(chǎng)屬珠江流域的廣東韓江上游典型的紅壤丘陵區(qū),亞熱帶季風(fēng)氣候,年降雨量為1 300～1 900 mm。該區(qū)以山地丘陵為主,水土流失類型齊全,面蝕、溝蝕和崩崗侵蝕等各類型均有大量分布。地表植物主要有馬尾松(Pinusmassoniana Lamb.)、桉樹(Eucalyptus grandis Hill)、柚樹(Citrusmaxima(Burm.)Merr.)、木荷(Schima kwangtungensis Hung T.Chang)、絹毛薔薇(Rosa sericea Lindl.)、芒萁(Dicranopteris dichotoma(Thunb.)Bernh.)、蔗鴣草(Eriachne pallescens R.Br.)等。土壤田間持水量及飽和含水量分別為26.7%～36.7%和42.5%～44.4%,有機(jī)質(zhì)質(zhì)量分?jǐn)?shù)為0.78%～1.69%。該試驗(yàn)站于2008年共修建8個(gè)人工徑流小區(qū)(20m×5 m),各小區(qū)具體參數(shù)如表1所示。為保證本研究結(jié)果的可比性,各徑流小區(qū)采用相關(guān)的管理方式,灌木保持在0～50 cm、牧草保持在0～20 cm,小區(qū)內(nèi)枯枝落葉進(jìn)行不定期清理,以保證各小區(qū)下墊面條件基本一致。

2 材料與方法

依托于水利部發(fā)布的《全國水土流失動(dòng)態(tài)監(jiān)測(cè)與公告項(xiàng)目管理辦法》(試行)(辦水保[2014]257號(hào)),基于五華縣水土保持試驗(yàn)推廣站8個(gè)人工徑流小區(qū)開展2014年自然降雨觀測(cè)試驗(yàn)。

降雨量(日降雨量、次降雨量和降雨過程)由雨量筒和自記雨量計(jì)連續(xù)監(jiān)測(cè),并使用RainRecord?1.06軟件包計(jì)算得到次降雨侵蝕力數(shù)據(jù)。小區(qū)土壤含水量采用傳統(tǒng)烘干法測(cè)定。地表植被蓋度采用照相法和目估法相結(jié)合確定,具體參照《徑流小區(qū)和小流域水土保持監(jiān)測(cè)手冊(cè)》執(zhí)行。土壤含水量及地表植被蓋度均為每15～20 d測(cè)定一次。小區(qū)徑流量通過集流池和分流池水位計(jì)算得到,泥沙質(zhì)量濃度通過人工取樣獲得,并計(jì)算次降雨產(chǎn)沙量數(shù)據(jù)。

表1　徑流小區(qū)詳細(xì)參數(shù)Tab.1 Detailed information of the runoff plot

觀測(cè)數(shù)據(jù)均來源于自然降雨事件。由于自然降雨事件降雨強(qiáng)度相對(duì)于模擬降雨試驗(yàn)偏小,且次降雨歷時(shí)均相對(duì)較短;所以,次降雨過程中植被截留、土壤蒸發(fā)及填凹水量也相對(duì)較小。經(jīng)估算次降雨事件植被截留、土壤增發(fā)及填凹水量均不超過次降雨量的4%,因此,忽略次降雨事件中植被截留、土壤蒸發(fā)與填凹水量。那么坡面次降雨入滲量為

式中:Inf為次降雨入滲量,mm;Rain為次降雨量,mm; Run為次降雨徑流深,mm。

為對(duì)比分析各處理侵蝕產(chǎn)沙能力,計(jì)算各處理次降雨坡面土壤侵蝕率,該指標(biāo)反映降雨過程中單位時(shí)間、單位面積上的土壤侵蝕量。其計(jì)算公式如下:

式中:ER為侵蝕率,t/(hm2·h);SL為土壤流失量,t/ hm2;T為次降雨產(chǎn)流歷時(shí),h。

經(jīng)過初步篩選,使用2014年該徑流場(chǎng)產(chǎn)生的共計(jì)280組(35組×8個(gè)徑流小區(qū))有效觀測(cè)數(shù)據(jù)。使用Microsoft Excel 2013軟件包進(jìn)行數(shù)據(jù)處理,使用Origin Pro 8.5軟件包繪圖。

3 結(jié)果與分析

3.1次降雨入滲量

各處理次降雨入滲量變化范圍為6.2～90.0 mm,其中,處理2和1入滲量平均值分別為最大和最小,各處理平均入滲率統(tǒng)計(jì)結(jié)果如圖1所示。各處理間,入滲量存在極顯著差異(P＜0.01)。處理2入滲量顯著大于處理1、3、7和8(P＜0.05),處理1和7均顯著低于處理2、5和6(P＜0.05)。次降雨平均入滲量與地表植被蓋度間,存在顯著的正相關(guān)關(guān)系(P＜0.05,R=0.948 1),人工林及灌草地次降雨入滲量,均高于自然撂荒地。

圖2為各處理次降雨入滲量與降雨強(qiáng)度散點(diǎn)圖?？梢钥闯?入滲量隨降雨強(qiáng)度增加,呈先增加后降低變化規(guī)律,這與耿曉東等[12]和黃俊等[16]研究結(jié)果一致。水分入滲主要依靠土壤中非毛管孔隙和部分毛管孔隙,當(dāng)降雨強(qiáng)度增大后,坡面水深增加,靜水壓力變大,導(dǎo)致入滲率增大,入滲水量增加[17];此外,雨滴打擊作用,使得部分靜止毛管水變成流動(dòng)下滲水[18],使得土壤入滲量得到一定程度提升。當(dāng)降雨強(qiáng)度增加到一定值,雨滴打擊動(dòng)能過大,而破壞表層土壤結(jié)構(gòu)或形成土壤結(jié)皮[19],導(dǎo)致土壤入滲率急劇降低,入滲水量呈下降趨勢(shì)。

圖1 各處理次降雨入滲量及地表植被覆蓋度統(tǒng)計(jì)分析Fig.1 Statistical results of the infiltration amount and land surface vegetation cover under different treatments

圖2　各處理次降雨入滲量與降雨強(qiáng)度散點(diǎn)圖Fig.2 Scatter diagram between the infiltration amount per individual rainfall and individual rainfall intensity under different treatments

各處理次降雨入滲量(Inf)與降雨強(qiáng)度(Rain)間的關(guān)系可采用方程式Inf=aR2ain+bRain+c定量描述,其擬合結(jié)果如表2所示。由方程式確定的系數(shù)可以看出,各處理Inf變異中有40%～60%是由Rain引起的,表明Rain是影響土壤入滲的關(guān)鍵因素。對(duì)擬合方程求一階導(dǎo)數(shù),可以得到Inf最大時(shí)對(duì)應(yīng)的臨界降雨強(qiáng)度。臨界降雨強(qiáng)度與地表植被蓋度間存在顯著相關(guān)關(guān)系,相關(guān)系數(shù)為0.960 3(P＜0.05)。人工林地及灌草地臨界降雨強(qiáng)度在20.0～27.8 mm/h之間波動(dòng),均高于自然撂荒地處理。自然撂荒地表植被蓋度相對(duì)較低,一旦降雨強(qiáng)度增加,雨滴打擊地表作用,使得表土結(jié)構(gòu)遭到破壞,土壤滲透性能大幅降低;因而該處理臨界降雨強(qiáng)度相對(duì)較低。

表2　各處理次降雨入滲量與降雨強(qiáng)度擬合方程Tab.2 Fitted equations between the infiltration amount and rainfall intensity for different treatments

3.2次降雨徑流侵蝕量

各處理次降雨徑流深和土壤流失量統(tǒng)計(jì)結(jié)果見表3。各處理間徑流深及土壤流失量均無顯著性差異(P＞0.05),但自然撂荒地處理徑流深及土壤流失量較其他處理均偏大。受試驗(yàn)條件限制,本文并未得出徑流深及土壤流失量與坡度間規(guī)律性關(guān)系;但總體而言,坡度越大,徑流深及土壤流失量均越大。王全九等[20]和陳正維等[21]分別在黃土和紫色土野外徑流小區(qū)試驗(yàn)中,在一定坡度范圍內(nèi),也得出類似研究結(jié)論。徑流深及土壤流失量與地表植被蓋度間存在顯著負(fù)相關(guān)關(guān)系(P＜0.05),相關(guān)系數(shù)分別為-0.953 6和-0.926 3;地表植被蓋度越大,次降雨入滲量越大,徑流量(深)越小,其侵蝕產(chǎn)沙及輸沙量也越小,土壤流失量亦越小。

次降雨徑流深及土壤流失量隨次降雨量呈線性遞增變化規(guī)律,可采用線性函數(shù)定量描述二者變化關(guān)系,各處理擬合方程均達(dá)到顯著或極顯著水平(P＜0.05),且方程確定系數(shù)R2均＞0.9;這表明徑流深及土壤流失量變異中,有90%以上是由次降雨量引起的,說明次降雨量是影響坡面徑流深及土壤流失量的關(guān)鍵影響因素[6-7,22]。但也有研究表明,冪函數(shù)和二次拋物線也能較為準(zhǔn)確地描述次降雨量與徑流量及土壤流失量間的動(dòng)態(tài)變化關(guān)系[23],這可能與次降雨特征有密切關(guān)系。

表3　各處理次降雨平均徑流深和土壤流失量Tab.3 Mean runoff depth and soil loss under different treatments under different treatments

圖3 各試驗(yàn)處理徑流系數(shù)與侵蝕率及泥沙質(zhì)量濃度和降雨侵蝕力與泥沙質(zhì)量濃度及土壤流失量散點(diǎn)圖Fig.3 Scatter plots between runoff coefficient and erosion rate as well as sediment concentration,rainfall erosivity and sediment concentration as well as erosion loss under different treatments

圖3為各試驗(yàn)處理次降雨徑流系數(shù)與侵蝕率及泥沙質(zhì)量濃度、降雨侵蝕力與泥沙質(zhì)量濃度及土壤流失量間散點(diǎn)圖。土壤侵蝕率、泥沙質(zhì)量濃度與徑流系數(shù)和泥沙質(zhì)量濃度、土壤流失量與降雨侵蝕力間均存在正相關(guān)變化關(guān)系,這與A.Cerdà等[24]的研究結(jié)果一致。徑流系數(shù)越大,降雨后徑流量越大,其侵蝕及攜沙輸沙能力均越大,因而導(dǎo)致土壤侵蝕率及泥沙質(zhì)量濃度均越大。降雨侵蝕力越大,雨滴打擊,導(dǎo)致土壤顆粒分散形成泥沙,既提升徑流中泥沙質(zhì)量濃度,又增加土壤侵蝕量。

土壤侵蝕率與徑流系數(shù)間存在顯著正相關(guān)冪函數(shù)關(guān)系(ER=a RbC,P＜0.05);ER為土壤侵蝕率,t/ (hm2·h);RC為徑流系數(shù);a和b為方程擬合參數(shù)。各處理ER變異中,有47%～67%是由RC引起的。RC越大,單位降雨產(chǎn)流量越大,水流侵蝕及攜沙輸沙能力均越大;且隨著RC增加,水流這種侵蝕攜輸沙能力迅速變大,由于ER與RC間非線性關(guān)系,因而可以采用正相關(guān)冪函數(shù)描述ER隨RC的動(dòng)態(tài)變化關(guān)系。泥沙質(zhì)量濃度與徑流系數(shù)、降雨侵蝕力間,存在均顯著的正相關(guān)對(duì)數(shù)函數(shù)關(guān)系(P＜0.05)。若僅考慮單個(gè)因素的影響作用,可以看出各處理SL變異中,有46%～78%是由RC引起的,有41%～51%是由RE力引起的。徑流中SC變化,主要受到徑流侵蝕產(chǎn)沙能力的影響,降雨初期RC及RE增加,均導(dǎo)致表層土壤顆粒持續(xù)被剝離,而增加了SC;但隨著降雨持續(xù)進(jìn)行,坡面流道趨于穩(wěn)定,可侵蝕泥沙顆粒量逐漸減少,考慮到降雨初期SC迅速增加,而后逐漸放緩,趨于穩(wěn)定的這一非線性變化關(guān)系,因而可以采用對(duì)數(shù)函數(shù)定量描述SC隨RC及RE變化趨勢(shì)。土壤流失量與降雨侵蝕力間存在顯著的正相關(guān)線性關(guān)系(SL=aRE+b;式中SL為土壤流失量,t/hm2; a、b為方程擬合參數(shù)。P＜0.05),各處理SL變異中,有64%～72%是由RE引起的。SL是降雨過程中的1個(gè)累計(jì)量,RE越大,水流剝離表土顆粒而產(chǎn)生的侵蝕量越大,SL隨RE表現(xiàn)為線性遞增的變化規(guī)律。

圖4為各處理次降雨土壤流失量與徑流深散點(diǎn)圖,可以看出隨徑流深變化,土壤流失量呈線性遞增變化規(guī)律,可采用SL=aRun+b的方程,定量描述二者關(guān)系,這與A.J.Parsons等[25]和A.M.Raya等[26]研究結(jié)果一致。各處理擬合方程均達(dá)到極顯著水平(P＜0.01),且方程確定系數(shù)R2＞95%,表明采用線性函數(shù),描述SL與Run間動(dòng)態(tài)變化關(guān)系是合理可行的。M.C.Zheng等[2930]認(rèn)為冪函數(shù)也能較為準(zhǔn)確地反映降雨徑流量與產(chǎn)沙量間動(dòng)態(tài)變化關(guān)系,這與降雨特征、研究尺度和下墊面條件等均有密切關(guān)系[31-32]。此外,當(dāng)次降雨徑流深＜20 mm時(shí),SL隨Run增加速率較快,當(dāng)Run＞20mm時(shí),SL增加速率放緩。這可能因?yàn)镽un=20mm左右時(shí),坡面易侵蝕剝離土壤顆粒已經(jīng)被分散,并隨水流脫離坡面表層土壤,而此后盡管水流侵蝕及攜沙輸沙能力均相對(duì)增加,但坡面流道及床面均趨于穩(wěn)定,土壤流失量增加放緩。以Run=20mm為界,將8個(gè)處理分為2組進(jìn)行線性擬合(圖4中①和②)擬合方程分別為SL= 0.139 7Run-0.360 8(R2=0.883 2,P＜0.05,Run＜20mm)和SL=0.108 7Run-0.388 3(R2=0.782 6, P＜0.05,Run＞20mm)。

圖4　各處理次降雨土壤流失量與徑流深散點(diǎn)圖Fig.4 Scatter plot between runoff depth and soil loss under different treatments

4 結(jié)論

1)人工林地及灌草地次降雨入滲量均高于自然撂荒地。次降雨入滲量與地表植被蓋度間存在顯著正相關(guān)關(guān)系(P＜0.05,R=0.948 1)。次降雨入滲量隨降雨強(qiáng)度變化,呈先增后減的變化趨勢(shì),存在使入滲量達(dá)最大值的臨界降雨強(qiáng)度。人工林地及灌草地臨界降雨強(qiáng)度在19.9～27.8 mm/h間波動(dòng),均高于自然撂荒地。臨界降雨強(qiáng)度與地表植被蓋度間存在顯著正相關(guān)關(guān)系(P＜0.05,R=0.960 3)。

(2)次降雨徑流深、土壤流失量與植被覆蓋度間相關(guān)系數(shù)分別為-0.953 6和-0.926 3(P＜0.05);徑流深及土壤流失量隨次降雨量增加呈線性遞增變化趨勢(shì)。土壤侵蝕率隨徑流系數(shù)增加呈正相關(guān)冪函數(shù)遞增變化規(guī)律,徑流中泥沙質(zhì)量濃度隨徑流系數(shù)和降雨侵蝕率增加,均呈正相關(guān)對(duì)數(shù)函數(shù)遞增變化趨勢(shì);而土壤流失量隨降雨侵蝕力、徑流深增加,均呈線性遞增變化規(guī)律。次降雨徑流深20 mm為土壤流失量變化拐點(diǎn),20 mm之上,土壤流失量隨徑流深遞增速率較大。

[1] 趙其國.我國南方當(dāng)前水土流失與生態(tài)安全中值得重視的問題[J].水土保持通報(bào),2006,26(2):1. Zhao Qiguo.Some considerations for present soil and water conservation and ecology security of South China[J]. Bulletin of Soil and Water Conservation,2006,26(2): 1.(in Chinese)

[2] 鄭華,歐陽志云,王效科,等.不同森林恢復(fù)類型對(duì)南方紅壤侵蝕區(qū)土壤質(zhì)量的影響[J].生態(tài)學(xué)報(bào), 2004,24(9):1994. Zheng Hua,Ouyang Zhiyun,Wang Xiaoke,et al. Effects of forest restoration types on soilquality in red soil eroded region,Southern China[J].Acta Ecologial Sinica,2004,24(9):1994.(in Chinese)

[3] 余新曉,秦永勝.森林植被對(duì)坡地不同空間尺度侵蝕產(chǎn)沙影響分析[J].水土保持研究,2001,8(4):66. Yu Xinxiao,Qin Yongsheng.Effect of forest cover on sediment yield produced by erosion in different spatial scales[J].Research of Soil and Water Conservation, 2001,8(4):66.(in Chinese)

[4] 王玉寬,王勇強(qiáng),傅斌,等.紫色土坡面降雨侵蝕試驗(yàn)研究[J].山地學(xué)報(bào),2006,24(5):597. Wang Yukuan,Wang Yongqiang,Fu Bin,et al.A study on the process simulation of soil erosion by rainfall on the purple soil slopes[J].Jouranl of Mountain Science, 2006,24(5):597.(in Chinese)

[5] 王民,崔靈周,李占斌,等.模擬降雨條件下徑流侵蝕力與地貌特征的動(dòng)態(tài)響應(yīng)關(guān)系[J].水利學(xué)報(bào), 2008,39(9):1105. Wang Min,Cui Lingzhou,Li Zhanbin,et al.Dynamic response relationship between runoff erosivity and topographic feature under the condition of artificial simulated rainfall[J].Journal of Hydraulic Engineering,2008,39 (9):1105.(in Chinese)

[6] 黃俊,趙西寧,吳普特.基于通徑分析和灰色關(guān)聯(lián)理論的坡面產(chǎn)流產(chǎn)沙影響因子分析[J].四川大學(xué)學(xué)報(bào)(工程科學(xué)版),2012,44(5):64. Huang Jun,Zhao Xining,Wu Pute.Factors analysis of runoff and sediment based on path analysis and grey relational analysis[J].Journal of Sichuan University(Engineering Science Edition),2012,44(5):64.(in Chinese)

[7] 魯克新,李占斌,張霞,等.室內(nèi)模擬降雨條件下徑流侵蝕產(chǎn)沙試驗(yàn)研究[J].水土保持學(xué)報(bào),2011,25 (2):6. Lu Kexin,Li Zhanbin,Zhang Xia,et al.Experimental study on law of runoff-erosion-sediment yield under indoor simulated rainfall condition[J].Journal of Soiland Water Conservation,2011,25(2):6.(in Chinese)

[8] 顧禮彬,張興奇,楊光檄,等.黔西高原坡面次降雨產(chǎn)流產(chǎn)沙特征[J].中國水土保持科學(xué),2015,13 (1):23. Gu Libin,Zhang Xingqi,Yang Guangxi,et al.Characteristics of slope runoff and sediment production under rainfall events in the plateau area ofwestern Guizhou[J]. Science of Soil and Water Conservation,2015,13(1): 23.(in Chinese)

[9] 李君蘭,蔡強(qiáng)國,孫莉英,等.降雨強(qiáng)度、坡度及坡長對(duì)細(xì)溝侵蝕的交互效應(yīng)分析[J].中國水土保持科學(xué), 2011,9(6):8. Li Junlan,CaiQiangguo,Sun Liying,et al.Analysis of interaction effects of rainfall intensity,slope degree and slope length on rill erosion[J].Science of Soil and Water Conservation,2011,9(6):8.(in Chinese)

[10] 呂玉娟,彭新華,高磊,等.紅壤丘陵崗地區(qū)坡地產(chǎn)流產(chǎn)沙特征及影響因素研究[J].水土保持學(xué)報(bào), 2014,28(6):19. Lyu Yujuan,Peng Xinhua,Gao Lei,etal.Characteristics of runoff and soil loss and their influential factors on sloping land in red soil hilly region[J].Journal of Soil and Water Conservation,2014,28(6):19.(in Chinese)

[11] 汪邦穩(wěn),肖勝生,張光輝,等.南方紅壤區(qū)不同利用土地產(chǎn)流產(chǎn)沙特征試驗(yàn)研究[J].農(nóng)業(yè)工程學(xué)報(bào), 2012,28(2):239. Wang Bangwen,Xiao Shengsheng,Zhang Guanghui,et al.Study on runoff and sediment yield characteristics under different land uses in red soil area of Southern China[J].Transactions of the Chinese Society of Agricultural Engineering,2012,28(2):239.(in Chinese)

[12] 耿曉東,鄭粉莉,張會(huì)茹.紅壤坡面降雨入滲及產(chǎn)流產(chǎn)沙特征試驗(yàn)研究[J].水土保持學(xué)報(bào),2009,23 (4):39. Geng Xiaodong,Zheng Fenli,Zhang Huiru.Effect of rainfall intensities and slope gradient on characteristics of rainfall infiltration,runoff and sediment on red soil [J].Journal of Soil and Water Conservation,2009,23 (4):39.(in Chinese)

[13] 代數(shù),蔣光毅,夏清,等.坡度和雨強(qiáng)對(duì)重慶市黃壤旱坡地產(chǎn)流產(chǎn)沙特征的影響[J].水土保持學(xué)報(bào), 2011,25(4):1. Dai Shu,Jiang Guangyi,Xia Qing,et al.Effects of slopes and rainfall intensities on runoff and sediment characteristic of arid hillside land with yellow soil in Chongqing[J].Journal of Soil and Water Conservation, 2011,25(4):1.(in Chinese)

[14] 李新平,陳欣,王兆騫,等.等高植物籬笆條件下紅壤坡耕地水土流失的發(fā)生特征[J].浙江大學(xué)學(xué)報(bào)(農(nóng)業(yè)與生命科學(xué)版),2003,29(4):368. Li Xinping,Chen Xin,Wang Zhaoqian,et al.The characteristics of water and soil loss occurrence under contour hedges condition in red soil slope fields[J]. Journal of Zhejiang University(Agric.&Life Sci.), 2003,29(4):368.(in Chinese)

[15] 孫佳佳,于東升,史學(xué)正,等.植被葉面積指數(shù)與覆蓋度定量表征紅壤區(qū)土壤侵蝕關(guān)系的對(duì)比研究[J].土壤學(xué)報(bào),2010,47(6):1060. Sun Jiajia,Yu Dongsheng,Shi Xuezheng,et al.Comparison of beterrn land and VFC in relationship with soil erosion in the red soil hilly region of South China[J]. Acta Pedologica Sinica,2010,47(6):1060.(in Chinese)

[16] 黃俊,吳普特,趙西寧.坡面生物調(diào)控措施對(duì)土壤水分入滲的影響[J].農(nóng)業(yè)工程學(xué)報(bào),2010,26(10): 29. Huang Jun,Wu Pute,Zhao Xining.Impactof slope biological regulatedmeasures on soilwater infiltration[J]. Transactions of the Chinese Society of Agricultural Engineering,2010,26(10):29.(in Chinese)

[17] 劉汗,雷廷武,趙軍.土壤初始含水率和降雨強(qiáng)度對(duì)黏黃土入滲性能的影響[J].中國水土保持科學(xué), 2009,7(2):1. Liu Han,Lei Tingwu,Zhao Jun.Effects of initial soil water content and rainfall intensity on Loess infiltration capacity[J].Science of Soil and Water Conservation, 2009,7(2):1.(in Chinese)

[18] 吳發(fā)啟,趙西寧,佘雕.坡耕地土壤水分入滲影響因素分析[J].水土保持通報(bào),2003,23(1):16. Wu Faqi,Zhao Xining,She Diao.Analysis on affecting factors of soil infiltration in slope farmland[J].Bulletin of Soil and Water Conservation,2003,23(1):16.(in Chinese)

[19] 楊永輝,趙世偉,雷廷武,等.耕作對(duì)土壤入滲性能的影響[J].生態(tài)學(xué)報(bào),2006,26(5):1624. Yang Yonghui,Zhao Shiwei,Lei Tingwu,et al.Tillage on soil infiltration under simulated rainfall conditions [J].Acta Ecologial Sinica,2006,26(5):1624.(in Chinese)

[20] 王全九,穆天亮,王輝.坡度對(duì)黃土坡面徑流溶質(zhì)遷移特征的影響[J].干旱地區(qū)農(nóng)業(yè)研究,2009,27 (4):176. Wang Quanjiu,Mu Tianliang,Wang Hui.The effects of slope on solute concentration in runoff on the loess slope [J].Agricultural Research in the Arid Areas,2009,27 (4):176.(in Chinese)

[21] 陳正維,劉興年,朱波.基于SCS-CN模型的紫色土坡地徑流預(yù)測(cè)[J].農(nóng)業(yè)工程學(xué)報(bào),2014,30(7): 72. Chen Zhengwei,Liu Xingnian,Zhu Bo.Runoff estimation in hillslope cropland of purple soil based on SCSCN model[J].Transactions of the Chinese Society of Agricultural Engineering,2014,30(7):72.(in Chinese)

[22] WeiW,Chen L,Fu B,et al.The effect of land uses and rainfall regimes on runoff and soil erosion in the semi-arid loess hilly area,china[J].Journal of Hydrology,2007,335(3/4):247.

[23] 韓永剛,王維明,楊玉盛.閩北不同土地利用方式徑流量動(dòng)態(tài)變化特征[J].水土保持研究,2006,13 (5):262. Han Yonggang,WangWeiming,Yang Yusheng.Ch-ange in dynamics of runoff in different land use in Northern Fujian[J].Research of Soil and Water Conservation, 2006,13(5):262.(in Chinese)

[24] CerdàA,Morera A G,BodíM B.Soil and water losses from new citrus orchards growing on sloped soils in the western Mediterranean basin[J].Earth Surface Processes and Landforms,2009,34(13):1822.

[25] Parsons A J,Brazier R E,Wainwright J,et al.Scale relationships in hillslope runoff and erosion[J].Earth Surface Processes and Landforms,2006,31(11): 1384.

[26] Raya A M,Zuazo V,Martínez J.Soil erosion and runoff response to plant-cover strips on semiarid slopes(SE Spain)[J].Land Degradation&Development,2006, 17(1):1.

[27] Zheng M G,Cai Q G,Cheng Q J.Sediment yield modeling for single storm events based on heavy-discharge stage characterized by stable sediment concentration [J].Intemanonal Journal of Sediment Research,2007, 22(3/4):208.

[28] Van de Giesen N,Stomph T J,Ajayi A E.Scale effects in hortonian surface runoff on agricultural slopes in west Africa:field data and models[J].Agriculture Ecosystems&Environment,2011,142(1):95.

[29] Smets T,Poesen J,Bochet E.Impact of plot length on the effectiveness of different soil-surface covers in reducing runoff and soil loss by water[J].Progress in Physical Geography,2008,32(6):654.

Characteristics of slope runoff and sediment yield under individual rainfall events in southern red soil region

Huang Jun1,2,3,Kang Qing1,2,Jin Pingwei1,2,Jiang Xuebing1,2,Li Le1,2,Wei Congmou1,2, Liu Bin1,2,Kou Xinyue1,2,Xu Zhou1,2

(1.Pearl River Hydraulic Research Institute,Pearl River Water Resources Commission,Ministry ofWater Resources,510611,Guangzhou,China; 2.Soil and Water Conservation Monitoring Center of Pearl River Basin,Pearl RiverWater Resources Commission,Ministry ofWater Resources, 510611,Guangzhou,China;3.Key Laboratory of Soil and Water Loss Process and Control on the Loess Plateau,Ministry ofWater Resources, 450003,Zhengzhou,China)

[Background]It is significant for slope soil loss control,soil and water resources utilization and management to study slope soil infiltration,runoff and sediment yield characteristics at slope scales. [M ethods]Based on the field artificial runoff plots in the Promotion Test Station of Wuhua County in Guangdong Province,the characteristics of soil infiltration and runoff and sediment yield were investigated and analyzed with the natural rainfall events of 2014.The experimental treatment includes:the natural abandoned land(NAL),artificial forest(AF),as well as shrubs and grass land(SGL).[Results] There was a significant correlation(P＜0.05,R=0.95)between infiltration amount(Inf)and the surface vegetation cover(Lsvc).Infincreased firstly and then decreased with the rainfall intensity(Rai) increasing.There was a critical Raiwhich induced the largest infiltration amount.The critical Raifor theAF and SGL ranged from 19.9 to 27.8 mm/h,both were larger than that under the NAL.There are significant negative correlations(P＜0.05)between runoff depth,soil loss and Lsvcwith all the correlation coefficients over 0.9.Erosion rate was positively related to runoff coefficient by a power function,the sediment concentration increased with runoff coefficient and rainfall erosivity increasing by logarithmic functions,soil loss increased with both rainfall erosivity and runoff depth increasing by linear functions.[Conclusions]The runoff depth of 20 mm was an inflection point for soil loss,the soil loss rate was high when the runoff depth was over 20 mm.Compared with the NAL,the AF and SGL obviously improved soil infiltration and reduced runoff and sediment yield.

critical rainfall intensity;soil infiltration;land surface vegetation cover;runoff plot

S157.1

A

1672-3007(2016)02-0023-08

10.168431/j.sswc.2016.02.004

2015-10-28

2015-11-03

項(xiàng)目名稱:水利部黃土高原水土流失過程與控制重點(diǎn)實(shí)驗(yàn)室開放課題基金資助項(xiàng)目“紅壤區(qū)小流域水沙輸移規(guī)律研究”(2016006);國家自然科學(xué)基金青年項(xiàng)目“天然林演替為人工林對(duì)林地水量平衡及土壤水影響作用機(jī)制”(41501019)

黃俊(1983—),男,博士,工程師。主要研究方向:水土保持與水土資源管理。E-mail:jie1002520@sina.cn