胡凱衡+馬超
基金項目:中國科學院重點部署項目(KZZDEW0501);國家自然科學基金重點項目(41030742);中國科學院水利部成都山地災害與環(huán)境研究所青年百人團隊項目(110900K235)
摘要:傳統(tǒng)的泥石流預警方法多基于前期和實時降雨量等間接指標,但實際上直接影響泥石流啟動的關鍵物理參數是土體含水量,通過分析土體含水量的變化來判斷泥石流啟動更為直接可靠。首先定義了泥石流啟動的臨界土體含水量的概念,然后基于國內外泥石流啟動的觀測試驗數據,采用逐步回歸分析方法,建立了臨界土體含水量與土體滲透系數、孔隙度和顆粒曲率系數的經驗關系,進而提出一種基于臨界土體含水量和實時降雨的泥石流預警方法。最后,以云南東川蔣家溝1999年7月16日發(fā)生的一場泥石流為實例進行演算和驗證。結果表明:該方法在可靠性和準確性上優(yōu)于傳統(tǒng)利用臨界線和暴發(fā)線判別泥石流的預測模型。
關鍵詞:泥石流;預警;臨界土體含水量;孔隙度;滲透系數;曲率系數;降雨
中圖分類號:P642.23文獻標志碼:A
Critical Soil Moisture for Debris Flow Initiation and Its Application in Forecasting
HU Kaiheng1,2, MA Chao1,2,3
(1. Key Laboratory of Mountain Hazards and Earth Surface Processes, Chinese Academy of Sciences, Chengdu 610041,
Sichuan, China; 2. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences
and Ministry of Water Resources, Chengdu 610041, Sichuan, China; 3. University of
Chinese Academy of Sciences, Beijing 100049, China)
Abstract: Most of traditional debris flow forecasting methods are based on indirect variables such as antecedent and realtime rainfalls. But the key factor influencing directly the debris flow initiation is soil moisture, which is more reliable for debris flow forecasting. Firstly, the concept of critical soil moisture for debris flow initiation was defined; secondly, based on the experimental and observation data of debris flow initiation at home and abroad, the empirical relationships between critical soil moisture and permeability coefficient, porosity, coefficient of paritcle curvature were obtained by the means of stepwise regression analysis; finally, the forcasting method for debris flow based on critical soil moisture and realtime rainfall was proposed. The method was tested and verified by the debris flow happened at Jiangjiagou of Dongchuan, Yunnan on 16 July, 1999. The results show that the reliability and accuracy of new forcasting method is better than the traditional forecast method for debris flow based on critical line and occurrence line.
Key words: debris flow; forecasting; critical soil moisture; porosity; permeability coefficient; coefficient of curvature; rainfall
0引言
自然界中,泥石流往往由上游溝岸或坡面的固體物質失穩(wěn)進入溝道,并在溝道水流的動力作用下形成。初始形成的泥石流規(guī)模不大,在運動過程中通過侵蝕、裹挾松散物質,規(guī)模才逐漸增長[12]。
一般而言,坡面土體要達到一定的含水量(體積比,下同)才能啟動形成泥石流。坡面土體的含水量是反映泥石流形成的直接參數。目前常用的前期降雨和當期降雨量預警指標,間接體現(xiàn)了降雨使土體含水量增加,抗剪強度和土體穩(wěn)定性降低,從而使泥石流發(fā)生的可能性增大[36]。國內外許多泥石流預警模型多以“前期有效雨量雨強/雨強歷時”為基本模式[710]。但是前期有效雨量與流域下墊面特性、巖土體物理特性等有關,其計算過程中涉及的遞減系數、前期降水衰減系數等重要常數的確定需要長時間的土體含水量和降雨量觀測,且不同學者使用的計算方法以及得到的結果可能不一樣[1114]。不同泥石流溝的有效前期雨量衰減規(guī)律也不同。因此,前期降雨量預警模式存在局地性強、預警精度不高、參數不易確定等缺點。
針對“有效前期雨量雨強/雨強歷時”預警模型所存在的不足,筆者通過分析國內外大量泥石流形成過程中的土體含水量變化數據,直接以土體含水量為預警指標,提出泥石流啟動臨界土體含水量的概念和經驗計算公式;經過云南東川蔣家溝泥石流觀測數據的驗證,所得到的方法和公式可應用于泥石流預警工作中。
1泥石流臨界土體含水量
1.1泥石流形成過程中土體含水量變化
Cannon等對美國加利福利亞、科羅拉多火災地區(qū)大量野外土體含水量和泥石流暴發(fā)時間監(jiān)測表明,不同深度坡面土體(一般監(jiān)測最大深度為60 cm)在泥石流暴發(fā)時的含水量都未達到飽和[1517]。以加利福尼亞南部桑加布里埃爾山區(qū)2009年發(fā)生的泥石流為例,167 mm的累積雨量共造成7條流域產生泥石流,而流域中的土體含水量卻始終維持在22%,遠小于飽和度40%[18]。這些地區(qū)的泥石流在較好的地表植被條件下(比如火災過后植被逐漸恢復后),可由徑流觸發(fā)轉變?yōu)榛录ぐl(fā),1 h激發(fā)雨量也逐漸增大[19];蔣家溝暴雨泥石流的多年監(jiān)測也表明:降雨過程中,雨水在坡面松散土體最大可以下滲60~80 cm,斜坡坡腳位置的土體含水量最大,但是都未超過孔隙度 [2021];一些模型試驗結果也表明,在土體啟動時大部分土體處于未飽和狀態(tài)[2224]。這與傳統(tǒng)認識的泥石流形成理論并不一致,尤其從非飽和土力學角度來看,泥石流啟動的原因應是土體飽和后短歷時雨強造成孔隙水壓力劇增、有效應力下降或喪失。事實上,降雨過程中土體含水量空間分布不均勻,垂直深度上土體含水量是非線性關系。對孔隙度大、強度低、顆粒間黏結程度差的坡面松散物源體來說,土體失穩(wěn)不僅僅是由于含水量增加、抗剪強度減小、下滑力增加導致的,土體失穩(wěn)在泥石流形成過程中只是初步階段也是必不可少的階段,降雨下滲在土體中形成壤中流以及表面形成地表徑流也是非常重要的原因。在一些地區(qū)甚至徑流作用在泥石流形成作用中更是起主導作用。例如,根據蔣家溝流域坡面徑流和溝道匯流匯集過程的觀測,大多是清水變成泥石流體的過程,在很多情況下,在坡面上就初步形成了小泥石流體或漿體[25]。美國加利福尼亞南部、科羅拉多地區(qū)火災后的泥石流多是流域坡面土體含水量達到一定值后,由峰值降雨時段在引發(fā)一定水力條件的坡面徑流激發(fā)形成的[26]。
1.2臨界土體含水量定義和經驗計算公式
無論是土力類還是水力類的泥石流,暴發(fā)時刻大多在峰值降雨時段附近。隨著雨水入滲,土體含水量逐漸增加,當含水量達到某個臨界值時,源區(qū)坡面土體達到極限平衡狀態(tài),或者坡面土體入滲和失水達到動態(tài)平衡。后續(xù)的降雨強度如果能夠達到或者超過滲透率,坡面產生地表徑流而且土體失穩(wěn)下滑,形成最初的泥石流。這一臨界含水量稱為泥石流啟動的臨界土體含水量。國內外研究中有關臨界土體含水量的概念已有所涉及。例如,在Brocca等提出的一些降雨徑流模型中,土體水分平衡主要考慮了降雨入滲率、雨強、蒸發(fā)率以及因壤中流和深層土體滲透的土體排水率,臨界土體含水量與飽和度并不一致[27]。楊大文等將遂川江流域實測土體含水量與不同時間的雨量結合起來,建立流域內不同點土體飽和度和警戒雨量的關系[28]。該結果間接反映了含水量越大,警戒雨量越小。實測的土體飽和度中也反映了臨界土體含水量的概念。
通過對國內外大量降雨激發(fā)淺表層滑坡、泥石流過程中土體含水量變化與土體物理參數的分析(表1),發(fā)現(xiàn)泥石流暴發(fā)時的土體含水量與土體滲透系數、孔隙度以及顆粒級配存在正相關關系,用Matlab的Stepwise函數作交互式逐步回歸分析,得到多重線性關系式
Wa =-1.12K+0.46n+0.12Cc-0.165(1)
式中:Wa為臨界土體含水量;K為土體滲透系數;n為土體孔隙度;Cc為土體顆粒的曲率系數,Cc=d230/(d10d60),其中d10、d30和d60分別是土體顆粒質量累計含量(質量分數,下同)為10%、30%和60%時的粒徑。
式(1)擬合所用數據如表1,判定系數為0.896 5,調整判定系數為0.883,均方根誤差為0.055 6。對該方程顯著性進行F檢驗,查表得到F0.05(3,23)值為3028,遠小于統(tǒng)計量F值(66.4),因此,回歸公式顯著。
從式(1)可以看出,臨界土體含水量與滲透系數成負相關關系,與孔隙度和土體顆粒曲率系數成正相關關系。滲透系數越大,說明土體在一定水力梯度下可以很快下滲并在短時間內轉化為壤中流。因內部壤中流流動和深層滲漏的土體排水速度與雨強大小接近時,土體含水量才達到臨界值,并短時間維持在相對穩(wěn)定的水平。孔隙度越大,說明水、氣兩相占據土體內部空間越大。一般而言,在非飽和階段,土體內部顆粒之間具有一定的黏聚力和咬合力并使土體具備一定的抗剪強度,從而保持穩(wěn)定。國內外許多研究證明土體啟動時是非飽和的,土體內部需要更多的水才能使抗剪強度下降,下滑力增加。因此,臨界土體含水量與孔隙度成正相關關系說明水分在松散碎屑坡面體穩(wěn)定性中具有重要作用。土體顆粒的曲率系數反映了土顆粒粒徑分布曲線形態(tài)。從表1中曲率系數可以看出,泥石流源區(qū)粒徑級配累計曲線斜率比較連續(xù),細顆粒在泥石流源區(qū)土體仍占很大部分。盡管級配連續(xù),但是泥石流源區(qū)土體是不均勻的,存在不連續(xù)粒徑,且均勻系數變化較大。由此說明臨界土體含水量與曲率系數成正相關關系,曲率系數越大,土體內部存在不連續(xù)粒徑,土顆粒間的存水空間越多,臨界土體含水量越大。
另外,式(1)中的3個變量綜合反映了流域內土體的平均最大蓄水量。臨界土體含水量實際上與平均最大蓄水量物理涵義一致。超過臨界土體含水量或者平均最大蓄水量的降水將從地表流走,形成地表徑流,并聚集形成足夠水動力條件的溝道水流。坡面匯流而來的初步小規(guī)模泥石流漿體與溝道水流
表1泥石流形成時的土體含水量、滲透系數、孔隙度以及曲率系數
Tab.1Soil Moisture, Permeability Coefficient, Porosity and
Coefficient of Curvature when Debris Flow Formed
編號WaK/(mm·s-1)nCc
1
2
30.500 00.023 5100.753.333 333
0.590 00.014 4930.763.333 333
0.660 00.004 6670.693.333 333
0.540 00.007 6190.723.333 333
0.480 00.003 7040.763.333 333
0.540 00.005 0720.763.333 333
0.240 00.005 6260.542.000 000
0.133 00.005 6260.450.408 333
0.120 00.010 2600.580.888 889
0.113 00.087 7600.580.888 889
0.124 00.010 2600.580.888 889
0.103 60.087 7600.580.888 889
0.161 80.010 2600.580.888 889
0.152 60.005 6260.450.408 333
0.117 40.010 2600.580.888 889
0.152 90.005 6260.451.125 000
0.326 00.003 8190.691.481 481
0.310 00.003 8190.691.481 481
0.357 00.003 8190.691.481 481
0.237 00.003 8190.691.481 481
0.340 00.003 8190.691.481 481
0.340 00.003 8190.691.481 481
0.352 00.003 8190.691.481 481
0.378 00.003 8190.691.481 481
0.313 00.003 8190.691.481 481
0.347 00.003 8190.691.481 481
0.347 00.003 8190.691.481 481
注:編號1的數據引自文獻[29];編號2的數據引自文獻[30];編號3的數據引自文獻[24]。
匯集增大了其中的含沙量和攜帶固體物質能力。溝道水流在流經泥石流動床時強烈侵蝕固體物質并形成泥石流。由于式(1)中的3個參數是泥石流源區(qū)土體物理特征值,所以該公式主要針對泥石流形成區(qū)的土體,尤其是細顆粒含量多的泥石流物源體。
2基于臨界土體含水量和實時降雨的預警方法
根據臨界土體含水量的定義以及泥石流預警模式中有效前期降雨難以精確計算的問題,筆者提出一種基于臨界土體含水量和實時降雨的泥石流預警方法(圖1),該方法的具體流程如下。
圖1基于土體含水量和實時降雨的泥石流預警方法實施過程
Fig.1Flow Chart of Debris Flow Forecasting System Based on Critical Soil Moisture and Realtime Rainfall
(1)計算泥石流啟動的臨界土體含水量。根據泥石流形成區(qū)的巖土體特征,利用式(1)計算對應臨界土體含水量Wa。
(2)計算當前土體含水量與臨界土體含水量的差值。在得到臨界土體含水量的情況下,通過土壤含水量傳感器,以太陽能板和蓄電池作為電源,運用GPRS無線網絡信息傳輸和室內數據接收終端,得到降雨過程中t時刻的土體含水量Wt。通過室內數據處理系統(tǒng)反復計算差值含水量ΔW,其表達式為
ΔW=Wa-Wt(2)
(3)根據當前雨強計算達到臨界土體含水量所需要的時間T。具體計算方法為:通過雨量傳感器,以無線網絡方式發(fā)出和接收雨量值,通過室內系統(tǒng)判定t時刻雨強Rt和土體滲透系數K的大?。徊⑦x擇大于滲透系數的計算公式和小于滲透系數的計算公式對達到臨界土體含水量所需要的時間進行計算。
T=(Wa-Wt)/KRt>K
(Wa-Wt)/RtRt≤K(4)
(4)根據計算的T值進行預警,并每隔一定時間重復第(3)、(4)步直至達到臨界土體含水量或降雨結束。
如果T>0,則多通道數據反復確認降雨過程中土體含水量是否達到臨界土體含水量,并每隔一定時間(比如10 s)重復第(2)、(3)步操作內容。如果降雨一直持續(xù)且T≤0,那么安排現(xiàn)場查看或發(fā)出泥石流即將發(fā)生的警報。如果降雨結束,則停止泥石流預警。
3實例分析
筆者利用提出的基于臨界土體含水量和實時降雨的泥石流預警方法,對云南東川蔣家溝1999年7月16日泥石流進行演算。
3.1臨界土體含水量確定
蔣家溝角礫土密度為1.954 g·cm-3,孔隙度n為0.381 8,滲透系數k為0.008 07 mm·s-1,d10為0.01 mm,d30為0.25 mm,d60為3 mm,角礫土顆粒級配曲線的曲率系數Cc為3.125(圖2)。由此得到蔣家溝泥石流暴發(fā)的臨界土體含水量為401%。陳曉清等在蔣家溝人工降雨激發(fā)滑坡失穩(wěn)形成泥石流的試驗中發(fā)現(xiàn),盡管不同深度的土體含水量不同,但每一組試驗中土體含水量最大值都介于45%和35%之間,且土體破壞前的土體含水量大致在40%上下劇烈波動[23]。土體在降雨作用下達到破壞前狀態(tài),其含水量劇烈變動,但是變動的幅度基本在40%左右。這與通過式(1)計算得到的土體含水量值基本相同。因此,蔣家溝源區(qū)土體含水量接近越該值,泥石流暴發(fā)的可能性就越大。
圖2云南東川蔣家溝角礫土的顆粒級配曲線
Fig.2Particle Grading Curve of Breccia Soil in Jiangjiagou of Dongchuan, Yunnan
3.2演算過程
根據東川泥石流觀測站提供的降雨數據,激發(fā)蔣家溝1999年7月16日泥石流的降雨過程見圖3。
圖31999年7月16日泥石流暴發(fā)前的降雨過程和前20 d的雨量過程
Fig.3Rainfall Processes Before Occurrence of
Debris Flow on 16 July, 1999 and During the 20 Days Before the Debris Flow
(1)計算差值含水量。初始時土體含水量為4%,未達到臨界土體含水量(40.1%),因此,在此時沒有泥石流發(fā)生,差值含水量ΔW為36.1%。
(2)比較雨強、滲透系數大小并計算每單位時間的土體含水量。蔣家溝角礫土的滲透系數為0008 07 mm·s-1,相當于每10 min降雨484 mm,與該溝的始發(fā)雨強(5 mm)非常接近。滲透系數0008 07 mm·s-1是經過原位滲透試驗得到的參數,即土體達到穩(wěn)定滲透階段時的滲透系數。滲透系數是隨時間和土體含水量變化的,但無論滲透系數在降雨過程中如何變化,穩(wěn)定滲透階段的滲透系數在不同測試手段下差異不是很大。比如陳寧生等經人工降雨試驗測得降雨開始時的土體初始滲透系數為0009 2 mm·s-1 [31],相當于每10 min降雨552 mm的等效雨強。
通過實際10 min雨量(R10)與滲透系數的對比,以單位面積和單位垂直深度的土體作為分析對象得到每單位10 min末的含水量
Wt=WtΔt+ΔtRAHA(5)
式中:WtΔt為tΔt時刻(對應t時刻之初)的土體含水量;t為實際降雨記錄時刻;Δt為單位雨量記錄持續(xù)時間(這里為10 min);R為雨強;
A為土體面積;ΔtRA為時間Δt內進入土體的降水體積;HA為土體的總體積,H為一般含水量傳感器的探針長度(60 mm)。
(3)根據筆者提出的預警方法演算。由于蔣家溝沒有實測的泥石流暴發(fā)過程土體含水量變化,這里在得到臨界土體含水量、確定基本土體含水量和實際雨量過程后,根據提出的方法具體流程進行演算。演算結果見表2。
表2基于臨界土體含水量和實時降雨的泥石流預警方法演算過程
Tab.2Calculation Process by the Forcasting
Method for Debris Flow Based on Critical Soil Moisture and Realtime Rainfall
編號時間段R10/mmWtΔtWa-WtΔtT/min
121:50~22:000.50.040 00.361 0433.200 0
222:00~22:101.70.048 30.352 7124.482 4
322:10~22:201.60.076 70.324 3121.612 5
422:20~22:301.10.103 30.297 7162.381 8
522:30~22:400.80.121 70.279 3209.475 0
622:40~22:500.90.135 00.266 0177.333 3
722:50~23:001.30.150 00.251 0115.846 2
823:00~23:102.00.171 70.229 368.790 0
923:10~23:204.40.205 00.196 026.727 3
1023:20~23:301.40.278 30.122 752.585 7
1123:30~23:401.10.301 70.099 354.163 6
1223:40~23:503.00.320 00.081 016.200 0
1323:50~次日00:002.30.370 00.031 08.087 0
14次日00:00~次日00:101.30.408 3<0.000 0<0.000 0
注:次日01:12:34時刻,監(jiān)測到泥石流;R10值始終小于滲透系數。
3.3精度比較
將本文提出的預警方法與蔣家溝泥石流預報臨界線和暴發(fā)線判別式進行結果對比,得到以下結果
R10=5.5-0.098(Pa0+h)>0.5 mm(6)
R10=6.9-0.123(Pa0+h)>1.0 mm(7)
式中:Pa0為泥石流暴發(fā)前某一天的指數;h為泥石流暴發(fā)前的當日降雨量。
臨界線式(6)的物理意義是:在10 min雨強大于0.5 mm的降水過程中,某10 min降水量只要等于5.5-0.098(Pa0+h),則蔣家溝泥石流就可能暴發(fā);暴發(fā)線式(7)的物理意義為:在10 min雨強大于1 mm的降水過程中,某10 min降水量只要等于69-0.123(Pa0+h),則蔣家溝就會暴發(fā)泥石流。
利用該次泥石流過程之前的降雨量過程和蔣家溝前期雨量計算公式,得到臨界線和暴發(fā)線10 min雨量分別為2.26、2.86 mm(圖3)。從該次降雨過程來看,23:10~23:20時段4.4 mm的降雨是造成該次泥石流的主要原因。但泥石流暴發(fā)時并不與該次降雨過程的峰值雨量時段重合,滯后近1 h。表1演算結果表明,該時段土體含水量并未達到臨界土體含水量。而泥石流暴發(fā)時段雨強僅0.9 mm,大于臨界線而小于暴發(fā)線。從達到臨界土體含水量和泥石流暴發(fā)時間上來看,達到臨界土體含水量和泥石流暴發(fā)之間相差約1 h,而原方法可提前預警17~200 min[8]。因此,從臨界土體含水量結合實時降雨過程來判別泥石流的發(fā)生更準確。筆者提出的基于臨界土體含水量和實時降雨的預警方法比傳統(tǒng)利用臨界線和暴發(fā)線判別泥石流的物理意義更明確,方法更可靠。
4結語
(1)在泥石流形成過程中,一般理論認為前期降雨使源區(qū)土體飽和,短歷時雨強造成飽和后的土體產生高孔隙水壓力使土體失穩(wěn)并轉化為泥石流。但是國內外大量泥石流形成過程監(jiān)測表明,源區(qū)坡面土體降雨過程和泥石流形成過程中土體都未達到飽和,且土體含水量存在一個臨界值。由此,本文提出了臨界土體含水量的概念,并通過擬合國內外野外監(jiān)測數據得到計算臨界土體含水量的經驗公式。
(2)基于臨界土體含水量的概念和經驗公式,發(fā)展了一種基于臨界土體含水量和實時降雨的泥石流預警方法。通過云南東川蔣家溝1999年7月16日暴發(fā)的泥石流的實際觀測資料,對該方法進行了實例演算。演算結果表明,該場泥石流暴發(fā)時刻并未與峰值降雨時段重合,而是在達到臨界土體含水量后約1 h。
(3)由于臨界土體含水量計算公式是經驗性的,在后續(xù)研究中有必要從土體降雨入滲以及激發(fā)坡面土體失穩(wěn)的物理過程并結合泥石流形成區(qū)監(jiān)測進行深入研究,提出更具有物理意義的臨界土體含水量概念,建立以水文學、水力學、泥沙運動學等為基礎的預警模型。
參考文獻:
References:
[1]崔鵬.泥石流起動條件及機理的實驗研究[J].科學通報,1991,36(21):16501652.
CUI Peng.Experiment Study on the Mechanism and Condition of Starting Up of Debris Flow[J].Chinese Science Bulletin,1991,36(21):16501652.
[2]崔鵬.中國山地災害研究進展與未來應關注的科學問題[J].地理科學進展,2014,33(2):145152.
CUI Peng.Progress and Prospects in Research on Mountain Hazards in China[J].Progress in Geography,2014,33(2):145152.
[3]CAINE N.The Rainfall Intensity:Duration Control of Shallow Landslides and Debris Flows[J].Geografiska Annaler.Series A,Physical Geography,1980,62(1/2):2327.
[4]WIECZOREK G F,GLADE T.Climaticc Factors Influencing Occurrence of Debris Flows[M]∥JAKOB M,HUNGR O.Debrisflow Hazards and Related Phenomena.Berlin:Springer,2005:325362.
[5]馬超,胡凱衡,宋國虎,等.汶川地震災區(qū)帽殼子滑坡形成泥石流的過程和特征[J].地球科學與環(huán)境學報,2013,35(4):98103.
MA Chao,HU Kaiheng,SONG Guohu,et al.Processes and Characteristics of Debris Flows Induced by Maoqiaozi Landslide in Wenchuan Earthquake Stricken Area[J].Journal of Earth Sciences and Environment,2013,35(4):98103.
[6]謝洪,劉維明,趙晉恒,等.四川石棉2012年“7·14”唐家溝泥石流特征[J].地球科學與環(huán)境學報,2013,35(4):9097.
XIE Hong,LIU Weiming,ZHAO Jinheng,et al.Characteristics of Tangjiagou Debris Flow in Shimian of Sichuan in July 14,2012[J].Journal of Earth Sciences and Environment,2013,35(4):9097.
[7]譚萬沛,王成華,姚令侃,等.暴雨泥石流滑坡的區(qū)域預測與預報:以攀西地區(qū)為例[M].成都:四川科學技術出版社,1994.
TAN Wanpei,WANG Chenghua,YAO Lingkan,et al.Regional Forecasting and Predicting of Rainfall Induced Debris Flows and Landslides:Take the Western Panzhihua as an Example[M].Chengdu:Sichuan Science and Technology Press,1994.
[8]陳景武.降雨預報泥石流的原理及方法[C]∥中國科學院水利部成都山地災害與環(huán)境研究所.第二屆全國泥石流學術會議論文集.北京:科學出版社,1989:8490.
CHEN Jingwu.The Principle and Method of Debris Flow Forecast Based on Rainfall[C]∥Institute of Mountain Hazards and Environment,Chinese Academy of Sciences and Ministry of Water Resources.Proceeding of the Second National Debris Flow Conference.Beijing:Science Press,1989:8490.
[9]GUZZETTI F,PERUCCACCI S,ROSSI M,et al.The Rainfall Intensityduration Control of Shallow Landslides and Debris Flows:An Update[J].Landslides,2008,5(1):317.
[10]戚國慶,黃潤秋.泥石流成因機理的非飽和土力學理論研究[J].中國地質災害與防治學報,2003,14(3):1215.
QI Guoqing,HUANG Runqiu.Study on Genetic and Mechanical Anlysis of Debris Flow Based on Unsaturated Soils Mechanics[J].The Chinese Journal of Geological Hazard and Control,2003,14(3):1215.
[11]崔鵬,楊坤,陳杰.前期降雨對泥石流形成的貢獻——以蔣家溝泥石流形成為例[J].中國水土保持科學,2003,1(1):1115.
CUI Peng,YANG Kun,CHEN Jie.Relationship Between Occurrence of Debris Flow and Antecedent Precipitation—Taking the Jiangjia Gully as an Example[J].Science of Soil and Water Conservation,2003,1(1):1115.
[12]韋方強,胡凱衡,陳杰.泥石流預報中前期有效降水量的確定[J].山地學報,2005,23(4):453457.
WEI Fangqiang,HU Kaiheng,CHEN Jie.Determination of Effective Antecedent Rainfall for Debris Flow Forecast[J].Journal of Mountain Science,2005,23(4):453457.
[13]李鐵鋒,叢威青.基于Logistic回歸及前期有效雨量的降雨誘發(fā)型滑坡預測方法[J].中國地質災害與防治學報,2006,17(1):3335.
LI Tiefeng,CONG Weiqing.A Method for Rainfallinduced Landslides Prediction Based on Logistic Regression and Effective Antecedent Rainfall[J].The Chinese Journal of Geological Hazard and Control,2006,17(1):3335.
[14]王裕宜,鄒仁元,李昌志.泥石流土體侵蝕與始發(fā)雨量的相關性研究[J].土壤侵蝕與水土保持學報,1999,5(6):3438.
WANG Yuyi,ZOU Renyuan,LI Changzhi.Study on Relationship Between Erosion of Debris Flows and Critical Rain Quantity[J].Journal ofSoil Erosion and Soil and Water Conservation,1999,5(6):3438.
[15]CANNON S H,KIRKHAM R M,PARISE M.Wildfirerelated Debrisflow Initiation Processes,Storm King Mountain,Colorado[J].Geomorphology,2001,39(3/4):171188.
[16]SANTI P M,DEWOLFE V G,HIGGINS J D,et al.Sources of Debris Flow Material in Burned Areas[J].Geomorphology,2008,96(3/4):310321.
[17]CANNON S H,GARTNER J E,WILSON R C,et al.Storm Rainfall Conditions for Floods and Debris Flows from Recently Burned Areas in Southwestern Colorado and Southern California[J].Geomorphology,2008,96(3/4):250269.
[18]KEAN J W,STALEY D M,CANNON S H.In Situ Measurements of Postfire Debris Flows in Southern California:Comparisons ofthe Timing and Magnitude of 24 Debrisflow Events with Rainfall and Soil Moisture Conditions[J].Journal of Geophysical Research:Earth Surface,2011,116(F4):121.
[19]MEYER G A,PIERCE J L,WOOD S H,et al.Fire,Storms,and Erosional Events in the Idaho Batholith[J].Hydrological Processes,2001,15(15):30253038.
[20]吳積善,康志成,田連權,等.云南蔣家溝泥石流觀測研究[M].北京:科學出版社,1990.
WU Jishan,KANG Zhicheng,TIAN Lianquan,et al.Observation Investigations on Debris Flows in Jiangjia Ravine,Yunnan Province[M].Beijing:Science Press,1990.
[21]王裕宜,詹錢登,嚴壁玉.泥石流體結構和流變特性[M].長沙:湖南科學技術出版社,2001.
WANG Yuyi,ZHAN Qiandeng,YAN Biyu.Debris flow Structure and Rheology[M].Changsha:Hunan Science and Technology Press,2001.
[22]PONZIANI F,PANDOLFO C,STELLUTI M,et al.Assessment of Rainfall Thresholds and Soil Moisture Modeling for Operational Hydrogeological Risk Prevention in the Umbria Region(Central Italy)[J].Landslides,2012,9(2):229237.
[23]陳曉清,崔鵬,馮自立,等.滑坡轉化泥石流起動的人工降雨試驗研究[J].巖石力學與工程學報,2006,25(1):106116.
CHEN Xiaoqing,CUI Peng,FENG Zili,et al.Artificial Rainfall Experimental Study on Landslide Transition to Debris Flow[J].Chinese Journal of Rock Mechanics and Engineering,2006,
25(1):106116.
[24]CHAE B G,KIM M I.Suggestion of a Method for Landslide Early Warning Using the Change in the Volumetric Water Content Gradient Due to Rainfall Infiltration[J].Environmental Earth Sciences,2012,66(7):19731986.
[25]李椷,吳濟難.云南東川蔣家溝泥石流形成條件的初步分析[C]∥中國科學院水利部成都山地災害與環(huán)境研究所.泥石流論文集(1).重慶:科學技術出版社重慶分社,1981:8792.
LI Jian,WU Jinan.Preliminary Analysis on the Formation Conditions of Debris Flows in Jiangjia Ravine,Dongchuan,Yunnan Province[C]∥Institute of Mountain Hazards and Environment,Chinese Academy of Sciences and Ministry of Water Resources.Proceedings of Debris Flows:The First Volume.Chongqing:Chongqing Branches of Science and Technology Press,1981:8792.
[26]LARSEN I J,MACDONALD L H,BROWN E,et al.Causes of Postfire Runoff and Erosion:Water Repellency,Cover,or Soil Sealing?[J].Soil Science Society of America Journal,2007,73(4):13931407.
[27]BROCCA L,BARBETTA S,MELONE F,et al.A Continuous Rainfallrunoff Model Derived from Investigations in a Small Experimental Basin[C]∥SCHUMANN S A,HOLKO L.Status and Perspectives of Hydrology in Small Basins.GoslarHahnenklee:IAHS Press,2010:179185.
[28]楊大文,龔偉,劉志雨,等.基于分布式模型土壤含水量評估的山洪預警指標體系[C]∥中國水利學會.中國水利學會2010學術年會論文集:上冊.鄭州:黃河水利出版社,2010:464473.
YANG Dawen,GONG Wei,LIU Zhiyu,et al.An Fooding Forecasting Method Based Distributed Model of Estimating Soil Moisutre[C]∥Chinese Hydraulic Engineering Society.2010 Annual Conference Proceedings of Chinese Hydraulic Engineering Society:The First Volume.Zhengzhou:Yellow River Water Conservancy Press,2010:464473.
[29]GRECO R,GUIDA A,DAMIANO E,et al.Soil Water Content and Suction Monitoring in Model Slopes for Shallow Flowslides Early Warning Applications[J].Physics and Chemistry of the Earth,Parts A/B/C,2010,35(3/4/5):127136.
[30]COE J A,KINNER D A,GODT J W.Initiation Conditions for Debris Flows Generated by Runoff at Chalk Cliffs,Central Colorado[J].Geomorphology,2008,96(3/4):270297.
[31]陳寧生,張軍.泥石流源區(qū)弱固結礫石土的滲透規(guī)律[J].山地學報,2001,19(1):169171.
CHEN Ningsheng,ZHANG Jun.The Research of Permeability on Lose Gravelly Soil in Debris Flow Original Area[J].Journal of Mountain Science,2001,19(1):169171.
CHEN Xiaoqing,CUI Peng,FENG Zili,et al.Artificial Rainfall Experimental Study on Landslide Transition to Debris Flow[J].Chinese Journal of Rock Mechanics and Engineering,2006,
25(1):106116.
[24]CHAE B G,KIM M I.Suggestion of a Method for Landslide Early Warning Using the Change in the Volumetric Water Content Gradient Due to Rainfall Infiltration[J].Environmental Earth Sciences,2012,66(7):19731986.
[25]李椷,吳濟難.云南東川蔣家溝泥石流形成條件的初步分析[C]∥中國科學院水利部成都山地災害與環(huán)境研究所.泥石流論文集(1).重慶:科學技術出版社重慶分社,1981:8792.
LI Jian,WU Jinan.Preliminary Analysis on the Formation Conditions of Debris Flows in Jiangjia Ravine,Dongchuan,Yunnan Province[C]∥Institute of Mountain Hazards and Environment,Chinese Academy of Sciences and Ministry of Water Resources.Proceedings of Debris Flows:The First Volume.Chongqing:Chongqing Branches of Science and Technology Press,1981:8792.
[26]LARSEN I J,MACDONALD L H,BROWN E,et al.Causes of Postfire Runoff and Erosion:Water Repellency,Cover,or Soil Sealing?[J].Soil Science Society of America Journal,2007,73(4):13931407.
[27]BROCCA L,BARBETTA S,MELONE F,et al.A Continuous Rainfallrunoff Model Derived from Investigations in a Small Experimental Basin[C]∥SCHUMANN S A,HOLKO L.Status and Perspectives of Hydrology in Small Basins.GoslarHahnenklee:IAHS Press,2010:179185.
[28]楊大文,龔偉,劉志雨,等.基于分布式模型土壤含水量評估的山洪預警指標體系[C]∥中國水利學會.中國水利學會2010學術年會論文集:上冊.鄭州:黃河水利出版社,2010:464473.
YANG Dawen,GONG Wei,LIU Zhiyu,et al.An Fooding Forecasting Method Based Distributed Model of Estimating Soil Moisutre[C]∥Chinese Hydraulic Engineering Society.2010 Annual Conference Proceedings of Chinese Hydraulic Engineering Society:The First Volume.Zhengzhou:Yellow River Water Conservancy Press,2010:464473.
[29]GRECO R,GUIDA A,DAMIANO E,et al.Soil Water Content and Suction Monitoring in Model Slopes for Shallow Flowslides Early Warning Applications[J].Physics and Chemistry of the Earth,Parts A/B/C,2010,35(3/4/5):127136.
[30]COE J A,KINNER D A,GODT J W.Initiation Conditions for Debris Flows Generated by Runoff at Chalk Cliffs,Central Colorado[J].Geomorphology,2008,96(3/4):270297.
[31]陳寧生,張軍.泥石流源區(qū)弱固結礫石土的滲透規(guī)律[J].山地學報,2001,19(1):169171.
CHEN Ningsheng,ZHANG Jun.The Research of Permeability on Lose Gravelly Soil in Debris Flow Original Area[J].Journal of Mountain Science,2001,19(1):169171.
CHEN Xiaoqing,CUI Peng,FENG Zili,et al.Artificial Rainfall Experimental Study on Landslide Transition to Debris Flow[J].Chinese Journal of Rock Mechanics and Engineering,2006,
25(1):106116.
[24]CHAE B G,KIM M I.Suggestion of a Method for Landslide Early Warning Using the Change in the Volumetric Water Content Gradient Due to Rainfall Infiltration[J].Environmental Earth Sciences,2012,66(7):19731986.
[25]李椷,吳濟難.云南東川蔣家溝泥石流形成條件的初步分析[C]∥中國科學院水利部成都山地災害與環(huán)境研究所.泥石流論文集(1).重慶:科學技術出版社重慶分社,1981:8792.
LI Jian,WU Jinan.Preliminary Analysis on the Formation Conditions of Debris Flows in Jiangjia Ravine,Dongchuan,Yunnan Province[C]∥Institute of Mountain Hazards and Environment,Chinese Academy of Sciences and Ministry of Water Resources.Proceedings of Debris Flows:The First Volume.Chongqing:Chongqing Branches of Science and Technology Press,1981:8792.
[26]LARSEN I J,MACDONALD L H,BROWN E,et al.Causes of Postfire Runoff and Erosion:Water Repellency,Cover,or Soil Sealing?[J].Soil Science Society of America Journal,2007,73(4):13931407.
[27]BROCCA L,BARBETTA S,MELONE F,et al.A Continuous Rainfallrunoff Model Derived from Investigations in a Small Experimental Basin[C]∥SCHUMANN S A,HOLKO L.Status and Perspectives of Hydrology in Small Basins.GoslarHahnenklee:IAHS Press,2010:179185.
[28]楊大文,龔偉,劉志雨,等.基于分布式模型土壤含水量評估的山洪預警指標體系[C]∥中國水利學會.中國水利學會2010學術年會論文集:上冊.鄭州:黃河水利出版社,2010:464473.
YANG Dawen,GONG Wei,LIU Zhiyu,et al.An Fooding Forecasting Method Based Distributed Model of Estimating Soil Moisutre[C]∥Chinese Hydraulic Engineering Society.2010 Annual Conference Proceedings of Chinese Hydraulic Engineering Society:The First Volume.Zhengzhou:Yellow River Water Conservancy Press,2010:464473.
[29]GRECO R,GUIDA A,DAMIANO E,et al.Soil Water Content and Suction Monitoring in Model Slopes for Shallow Flowslides Early Warning Applications[J].Physics and Chemistry of the Earth,Parts A/B/C,2010,35(3/4/5):127136.
[30]COE J A,KINNER D A,GODT J W.Initiation Conditions for Debris Flows Generated by Runoff at Chalk Cliffs,Central Colorado[J].Geomorphology,2008,96(3/4):270297.
[31]陳寧生,張軍.泥石流源區(qū)弱固結礫石土的滲透規(guī)律[J].山地學報,2001,19(1):169171.
CHEN Ningsheng,ZHANG Jun.The Research of Permeability on Lose Gravelly Soil in Debris Flow Original Area[J].Journal of Mountain Science,2001,19(1):169171.