geosciences

Communication A Brief Report of Pingdi Landslide (23 July 2019) in Guizhou Province,

Tao Yan 1, Shui-Long Shen 2,* , An-Nan Zhou 3 and Jun Chen 1 1 State Key Laboratory of Ocean Engineering, Department of Civil Engineering, School of Naval Architecture, Ocean, and Civil Engineering, Jiao Tong University, Shanghai 200240, China 2 Key Laboratory of Intelligent Manufacturing Technology ( University), Ministry of Education, and Department of Civil and Environmental Engineering, College of Engineering, Shantou University, Shantou, 515063, China 3 Civil and Infrastructure Engineering Discipline, School of Engineering, Royal Melbourne Institute of Technology (RMIT), Melbourne, Victoria 3001, Australia * Correspondence: [email protected]; Tel.: +86-21-3420-4301

 Received: 30 July 2019; Accepted: 22 August 2019; Published: 24 August 2019 

Abstract: This short communication reports on a large landslide with a movement of 2 million m3 of soil and rock that occurred on 23 July, 2019 in the village of Pingdi, located in the county of Shuicheng, Guizhou Province, China. This landslide resulted in 42 deaths and 9 missing people. This report describes the preliminary investigation, rescue effort, and possible cause. The total rainfall in the 6 days prior to the landslide was 189.1 mm, which may be held responsible as the major cause. Some recommendations are proposed to reduce human casualties and property losses.

Keywords: landslide; pingdi; rainfall; recommendations

1. Introduction As a result of global climate change and alteration of the natural environment by human engineering activities, the frequent occurrence of geological disasters has posed an enormous threat to both property and safety of humans [1–3]. According to a report, 130 million people were affected by natural disasters in 2008. Natural disasters also resulted in 589 deaths and 46 missing people and totalled 264.46 billion Ren Min Bi (RMB) of direct economic losses [4]. Landslides, which are major geological disaster, have frequently occurred in recent years, posing a significant risk to property and safety of people [5–7]. According to the National Bureau of Statistics (NBS), 5524 landslides occurred nationwide in 2017 [8]. Therefore, the early warning and prevention of landslides are of tremendous importance and are urgently required. In recent years, with the development of Remote Sensing (RS) and the Geographic Information System (GIS), spatial information processing technology has been widely used in the evaluation of landslide vulnerability [9–15]. The combination of spatial information processing software and statistical analysis tools significantly improves the efficiency of data acquisition, processing, and analysis, and promotes the application of the state-of-the-art methods and models in evaluating landslide risks. In addition, a satellite image receiving system has been used to cover the entire country to obtain the information about geological disasters and a weather radar can be used to predict the possible rainfall in advance to warn humans against geological disasters [16]. Despite the efforts made by governments and researchers, it is still an enormous challenge to predict and/or prevent landslides. Recently, a large landslide (23 July, 2019) occurred in the village of Pingdi, Shuicheng County, Guizhou Province. This article presents a preliminary investigation of the Pingdi landslide. In this article, the landslide and rescue measures are presented, the main causes of the landslide are discussed, and recommendations are provided to reduce human casualties and property losses.

Geosciences 2019, 9, 368; doi:10.3390/geosciences9090368 www.mdpi.com/journal/geosciences Geosciences 2019, 9, 368 2 of 10

Geosciences 2017, 7, x FOR PEER REVIEW 2 of 9 2. Methodology 2. Methodology 2.1. Preliminary Investigation 2.1. Preliminary Investigation A large landslide occurred in Pingdi village at approximately 9:20 p.m. on 23 July (see Figure1). PingdiA large village, landslide with a populationoccurred in of Pingdi approximately village at 6000,approximately is located in9:20 the p.m. west on of 23 , July (see theFigure capital 1). Pingdiof Guizhou village, Province. with a population In this landslide, of approximately approximately 6000, 2 millionis located m3 inof the soil west and of rock Guiyang, moved the down capital the ofmountain Guizhou foot Province from a. In height this landslide, of 500 m (the approximate vertical distancely 2 million between m3 of the soil highest and rock point moved and down toe of the mountainlandslide). foot The from landslide a height destroyed of 500 m 27 (the houses, vertical of distance which 21 between were buried the highest and some point were and dislodgedtoe of the landslide).a distance ofThe approximately landslide destroyed 100 m. 27 Figure houses,2a,b of show which the 21 houses were buried in a three-dimensional and some were dislodged (3D) view a distancefrom Google of approximately Earth before the100 landslide m. Figure ands 2a a photographand 2b show captured the houses after in thea three landslide,-dimensional respectively. (3D) Theview altitude from Google of the landslide Earth before was located the landslide at a longitude and a ofphoto 104◦40graph0 E and captured latitude after of 26 ◦ the150 landslide,N, and its respectively.duration was The estimated altitude to of be the approximately landslide was 60 located s. at a longitude of 104°40′ E and latitude of 26°15′ N, and its duration was estimated to be approximately 60 s.

(b) (c)

Guiyang

Pingdi Village N 0 1,000 km N 0 1100 km

Figure 1. 1.(a ) Pingdi(a) village Pingdi after the village landslide after (Source: thehttp: //baijiahao.baidu.comlandslide (Source:/s?id= 1639927165371855884http://baijiahao.baidu.com/s?id=1639927165371855884)(b) location of Guizhou, and (c)) Location(b) location of Pingdi of Guizhou village., and (c) Location of Pingdi village.

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GeosciencesGeosciences 201 20177, ,7 7, ,x x FOR FOR PEER PEER REVIEW REVIEW 3 3of of 9 9

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FigureFigure 2. (a) 2. Three(a) Three-dimensional-dimensional (3D) (3D)View View from fromGoogle Google Earth Earth before before the landslide the landslide (b) Photo (b) Photo captured captured Figure 2. (a) Three-dimensional (3D) View from Google Earth before the landslide (b) Photo captured afterafter the landslide the landslide (Source: (Source: http://gz.people.com.cn/n2/2019/0724/c194849 http://gz.people.com.cn/n2/2019/0724/c194849-33174976-7.html-33174976-7.html). ). after the landslide (Source: http://gz.people.com.cn/n2/2019/0724/c194849-33174976-7.html). Figure 2. (a) Three-dimensional (3D) View from Google Earth before the landslide (b) Photo captured Figure3 presents an overview of the site after the landslide. The vertical distance and sliding afterFigure the landslide3 presents (Source: an overview http://gz.people.com.cn/n2/2019/0724/c194849 of the site after the landslide.-33174976 The vertical-7.html) .distance and sliding trajectoryFigure along 3 presents the sliding an overview surface of of the the landslide site after were the approximately landslide. The 500 vertical m and distance 1400 m, respectively.and sliding trajectory along the sliding surface of the landslide were approximately 500 m and 1400 m, trajectory along the sliding surface of the landslide were approximately 500 m and 1400 m, Therespectively. averageFigure slope The 3 presents ofaverage the landslidean slope overview of was the of 18the landslide◦ ,site and after its was averagethe 18landslide.°, and thickness itsThe average vertical was 5 thicknessdistance m. In addition, and was sliding 5 barrier m. In respectively.trajectory The along average the sliding slope surface of the of landslide the landslide was 18 were°, and approximately its average 500 thickness m and was1400 5 m, m. In lakesaddition, were barrier formed lakes by thewere landslide, formed by which the landslide, could cause which some could secondary cause some hazards secondary and exacerbate hazards an thed addition,respectively. barrier lakes The average were formed slope ofby the the landslide landslide, was which 18°, couldand its cause average some thickness secondary was hazards 5 m. In and consequencesexacerbate the of consequence the landslides of (see the Figurelandslide4). As(see of Figure 23:00 on4). JulyAs of 28, 23:00 the on landslide July 28,had the landslide resultedin had 42 exacerbataddition,e the barrier consequence lakes weres of formed the landslide by the landslide, (see Figure which 4). could As of cause 23:00 some on secondaryJuly 28, the hazards landslide and had deathsresulted and in 942 missing deaths persons.and 9 missing persons. resultedexacerbat in 42e deaths the consequence and 9 missings of the persons landslide. (see Figure 4). As of 23:00 on July 28, the landslide had resulted in 42 deaths and 9 missing persons.

FigureFigure 3. O 3.verview Overview of ofthe the landslide landslide ( Source(Source:: http://baijiahao.baidu.com/s?id=1639927165371855884http://baijiahao.baidu.com/s?id=1639927165371855884). ). Figure 3. OverviewOverview of the landslide (Source:(Source: http://baijiahao.baidu.com/s?id=1639927165371855884http://baijiahao.baidu.com/s?id=1639927165371855884))..

Figure 4. Barrier lakes formed after the landslide (Source: http://www.chinanews.com /tp/hd2011/2019/ Figure 4. Barrier lakes formed after the landslide (Source: 07-24/893609.shtml). Figurehttp://www.chinanews.com/tp/hd2011/2019/07 4. Barrier lakes formed-24/893609.shtml) after . the landslide (Source: Figurehttp://www.chinanews.com/tp/hd2011/2019/07 4. Barrier lakes formed-24/893609.shtml) after . the landslide (Source: http://www.chinanews.com/tp/hd2011/2019/07-24/893609.shtml). Geosciences 2019, 9, 368 4 of 10

Geosciences 2017, 7, x FOR PEER REVIEW 4 of 9 Figure5 presents three points in the landslide where 21 houses were buried. Continuous rainfall causedFigure another 5 presents landslide three occurrence points in inthe point landslide B on Julywhere 25, 21 whereas houses point were C buried. received Continuous the soil and rainfall rock slidingcaused fromanother points landslide A and occurrence B. It was estimated in point B that on July point 25, C whereas had a high point risk C ofreceived debris the flow. soil Therefore, and rock thesliding rescue from at pointpoints C A was and suspended B. It was estimated on July 25. that point C had a high risk of debris flow. Therefore, the rescue at point C was suspended on July 25.

Figure 5. Three points A, B, and C of the rescue areas (Source: http://gz.people.com.cn/n2/2019/0724/ Figure 5. Three points A, B, and C of the rescue areas (Source: c194849-33174976-2.html). http://gz.people.com.cn/n2/2019/0724/c194849-33174976-2.html). 2.2. Data Source 2.2. Data Source To report and analyze this landslide, the photos captured from the site of the landslide were collectedTo report from websites,and analyze and thethis weather landslide, data the records photos were captured collected from from the the site National of the landslide Meteorological were Informationcollected from Center website of Chinas, and (NMC, the https: weather//data.cma.cn data records/). The were latter collected includes fromthe annual the National average monthlyMeteorological rainfall, Information highest temperature Center of (H-temperature), China (NMC, https://data.cma.cn/ and lowest temperature). The (L-temperature) latter includes the in Pingdiannual village. average Inmonthly addition, rainfall, the recent highest rainfall temperature data records (H-temperature), of Pingdi village and werelowest collected temperature from the (L- Meteorologicaltemperature) in Bureau Pingdi of village. Guizhou In province.addition, the recent rainfall data records of Pingdi village were collected from the Meteorological Bureau of Guizhou province. 3. Rescue Effort 3. Rescue Effort More than 1500 people were on the site to rescue victims immediately after the landslide, and more rescueMore teams than arrived 1500 peoplein the following were on the days site including to rescue firefighters, victims immediately police, mine after rescue the landslide, professionals, and themore Guiyang rescue Tunnel teams Rescue arrived Team, in the the Blue following Sky Rescue days Team, including and other firefighters, civilian rescue police, teams. mine On rescue the dayprofessionals, of the landslide, the Guiyang the Department Tunnel Rescue of Emergency Team, the ManagementBlue Sky Rescue of Guizhou Team, and Province other civilian immediately rescue dispatchedteams. On the 400 day tents, of the 400 landslide, quilts, and the 1000 Department raincoats, ofas Emergency well as lighting Management equipment, of Guizhou drinking Province water andimmediately food. Other dispatched rescue supplies 400 tents, began 400 arriving quilts, in and the 1000 following raincoats, days. as In well addition, as lighting numerous equipment, vehicles anddrinking helicopters water andwere food. involved Other in rescue the rescue supplies activities. began Rescuearriving teams in the used following helicopters days. toIn transportaddition, thenumerous injured (includingvehicles and two helicopters children) to were the Guizhou involved provincial in the rescue hospital activities. for treatment. Rescue As teams shown used in Figurehelicopters6a, firefighters to transport cleared the injured the barrier (including at the sitetwo of children) the landslide to the and Guizhou drained provincial the barrier hospital lake (see for Figuretreatment.4) to prevent As shown secondary in Figure disasters. 6a, firefighters However, cleared another the landslide barrier occurred at the site at point of the B landslide (see Figure and5) ondrained July 25, the and barrier a debris lake flow (see occurredFigure 4) at to point prevent C. Rescue secondary operators disasters. had evacuated However, the another people landslide at these twooccurred points at priorpoint toB (see the secondFigure 5) landslide, on July 25, resulting and a debris in no flow further occurred casualties. at point The C. rescueRescue e operatorsfforts are currentlyhad evacuated continuing, the people with 11at peoplethese two rescued. points Figure prior6 b,cto thedepict second the rescue landslide, professionals resulting saving in no people further fromcasualties. buried The houses. rescue In addition,efforts are the currently government continuing, urgently with allocated 11 people 30 million rescued. RMB Figures for disaster 6b and relief, 6c anddepict a further the rescue 12 million professionals RMB for investingsaving people in the from rescue buried activities houses. from Inthe addition, Guizhou theProvince. government urgently allocated 30 million RMB for disaster relief, and a further 12 million RMB for investing in the rescue activities from the Guizhou Province. Geosciences 2017, 7, x FOR PEER REVIEW 5 of 9

Geosciences 2019, 9, 368 5 of 10 Geosciences 2017, 7, x FOR PEER REVIEW 5 of 9

Figure 6. Rescue activities (a) Firefighters clearing a barrier (Source: http://www.chinanews.com) (b) FigureFigure 6 6.. RescueRescue activities activities (a) Firefighters (a) Firefighters clearing clearing a barrier a (Source: barrier http://www.chinanews.com (Source: http://www.chinanews.com) (b) ) Firefighter(Firefightersb) Firefighterss rescuing rescuing rescuing peo peopleple peoplefrom from buried buried from buriedhouses,houses, houses, andand ( c()c )Rescue andRescue (c team) Rescueteam rescuing rescuing team people rescuing peo fromple peoplefrom buried buried fromhouses buriedhouses (Source:houses(Source: http://ww (Source:http://www.360kuai.comw .360kuai.com/http://www.360kuai.com /(b) (b) an andd (c))(c))/ (b,c))

4.4.Analysis Analysi4. Analysiss andand and DiscussionsDiscussions Discussions

4.1.4.1. RainfallRainfall4.1. Rainfall Shuicheng,Shuicheng,Shuicheng, located located located in in the in the west the west west of Guizhou of Guizhou Province, Province,Province, is a ismountainous is a mountainousa mountainous area area bordering area bordering bordering the the the Yunnan Province. The average annual rainfall in Shuicheng is 1347.9 mm, particularly in June and Province.Yunnan Province. The average The annual average rainfall annual in rainfall Shuicheng in Shuicheng is 1347.9 mm, is 1347.9 particularly mm, particularly in June and in July, June when and July, when it is 305.3 and 265.5 mm, respectively (see Figure 7a). Therefore, a landslide probably itJuly, is 305.3 when and it is 265.5 305.3 mm, and respectively 265.5 mm, respectively (see Figure7 (seea). Therefore,Figure 7a).a Therefore, landslide probablya landslide occurs probably in Juneoccurs and July. in June The and cumulative July. The rainfallcumulative has rainfall reached has 288.9 reached mm 288.9 since mm this since July, this and July, heavy and rainfall heavy was occursrainfall in June was concentratedand July. The in thecumulative first 6 days rainfall before thehas landslide. reached The288.9 rainfall mm wassince 49 this mm July,on July and 19, heavy concentrated in the first 6 days before the landslide. The rainfall was 49 mm on July 19, 37.1 mm on rainfall37.1 wasmm concentratedon July 20, and in 98 the mm first on July6 days 23. Thebefore total the rainfall landslide. in the The6 days rainfall before was the landslide49 mm on was July 19, July37.1 20,189.1mm and mmon 98July (see mm 20,Figure on and July 7b), 98 23.mmwhich The on may July total be 23. rainfallblamed The totalas in the the rainfall major 6 days causein beforethe for 6 daysthis the landslide. landslidebefore the By was landslideauthors’ 189.1 mm was (see189.1 Figureopinion, mm 7(seeb), the whichFigure landslide may7b), may which be blamed be attributedmay asbe theblamed to major continuous as cause the major heavy for this cause rainfall. landslide. for Empirical this Bylandslide. authors’ evidence By opinion, [17] authors’ theopinion, landslidestrengthen the may landslidethis hypothesis be attributed may asbe the toattributed rainfall continuous peak to ofcontinuous heavy 23 July rainfall. (98 mmheavy in Empirical 24rainfall. hours) evidence isEmpirical higher than [17 evidence] almost strengthen [17] thisstrengthen hypothesisall the rainfall this ashypothesis thresholds the rainfall asfor peakthelandslide rainfall of 23 initiation Julypeak (98 of reported mm23 July in in 24(98 a h) recentmm is higher in review 24 hours) than at the almost isglobal higher allscale. thethan The rainfall almost thresholdsall thesurface rainfall for drainage landslide thresholds was initiationobstructed for landslide reported at some initiation inpoints a recent where reported review a large in at amounta therecent global of review stormwater scale. at The the was surfaceglobal collected scale. drainage The locally, resulting in sever water infiltrations [3,18]. The unit weight of soil increased significantly wassurface obstructed drainage at somewas obstructed points where at some a large points amount where of stormwater a large amount was collectedof stormwater locally, was resulting collected in when it was saturated with water, resulting in an increase in the sliding force. Concurrently, the pore severlocally, water resulting infiltrations in sever [3, 18water]. The infiltrations unit weight [3, of18 soil]. The increased unit weight significantly of soil whenincreased it was significantly saturated with water,water pressure resulting increased, in an increase significantly in the reducing sliding force. the soil Concurrently, shear strength the resulting pore water in a reduction pressure in increased, the whensliding it was resistance saturated [19 with,20]. Finally,water, resultinga catastrophic in an landslide increase occurred in the sliding when the force. sliding Concurrently, force exceeded the pore significantly reducing the soil shear strength resulting in a reduction in the sliding resistance [19,20]. waterthe pressure sliding resistance. increased, significantly reducing the soil shear strength resulting in a reduction in Finally, a350 catastrophic landslide occurred when30 the sliding120 force exceeded the sliding resistance. the (a) Rainfall H-temperature (b) Rainfall L-temperature 300 25 100 98 350 30 120 250 (a) Rainfall H-temperature Temperature (℃) 80 (b) Rainfall L-temperature 20 300 200 25 100 98 15 60 250 150 Temperature (℃) 49 20 80 10 40 200 100 30.1 15 60 Cumulative daily rainfall (mm) Cumulative daily rainfall Average monthly rainfall (mm) 5 20 150 50 49 5 10 40 0 0 0 0 0 100 1 2 3 4 5 6 7 8 9 10 11 12 18/7 19/7 20/7 30.121/7 22/7 23/7 8-12 p.m Date Month (mm) Cumulative daily rainfall Average monthly rainfall (mm) 5 20 50 5 Figure 7. (a) Average monthly rainfall, highest temperature (H-temperature), and lowest temperature0 0 0 0 0 1(L-temperature)2 3 4 5in Pingdi6 7 village8 9 and10 (b)11 the12 rainfall prior to the landslide.18/7 19/7 20/7 21/7 22/7 23/7 8-12 p.m Month Date

FigureFigure 7. 7.( (aa)) AverageAverage monthly monthly rainfall, rainfall, highesthighest temperaturetemperature (H-temperature), (H-temperature), and and lowest lowest temperature temperature (L-temperature)(L-temperature) in in Pingdi Pingdi village village and and ( b(b)) the the rainfall rainfall prior prior to to the the landslide. landslide. Geosciences 2019, 9, 368 6 of 10 Geosciences 2017, 7, x FOR PEER REVIEW 6 of 9

4.2. Recommendations Recommendations A landslide is considered as a most serious natural disaster, which leads to human casualties and enormous property losses. Numerous Numerous measures are used to monitor the occurrence occurrence of geological disasters. Instrument Instrument monitoring, monitoring, manual manual monitoring, monitoring, station station observation observation and and automatic remote sensing methodmethodss are commonly used in landslide monitoring [[21].]. According According to to the the Ministry of Emergency Management ofof ChinaChina (MEM), (MEM), numerous numerous locations locations remain remain that that may may be be blind blind spots spots for thefor theearly early warning warning of geological of geological disasters disasters [22]. Moreover,[22]. Moreover, in the Emergencyin the Emergency Response Response Law of theLaw People’s of the People'sRepublic Republic of China, of an China, early warningan early warning of a geological of a geological disaster can disaster only becan sent only to be the sent county to the level county [23]. levelHowever, [23]. thereHowever, are numerous there are villages numerous (particularly villages (particularly some in the mountainous some in the mountain area in theous west area of China)in the westwith poor of China communication.) with poor Therefore, communication. the hazard Therefore, management the hazard department management of the county department may be unable of the countyto inform may every be villageunable into itinform [22]. In every addition, village in the in disasterit [22]. In prevention addition, ofin China, the disaster in geological prevention disaster of Chinaemergency, in geological treatment, disaster villagers emergency are not involved treatment, in thevillagers early are warning not involved and evacuation in the early of geological warning anddisasters evacuation (see Figure of geological8). disasters (see Figure 8).

 Weather Bureau Step I  Bureau of Water Resource  Bureau Of Geological Survey Monitoring and early  Department of Emergency warning system Management  …

Report Large

Step II Contingency Landslide Medium Occurrence of landslide plan

Rescue Minor teams

 Emergency response  Evacuation Step III  Rescue Rescue headquarters  Disease prevention  Refugee resettlement …

Investigation Secondary disaster Step IV and evaluation prevention Post-disaster disposal Houses and roads reconstruction Others

Figure 8. Flow chart of geological disaster emergency treatment in China. Figure 8. Flow chart of geological disaster emergency treatment in China. Figure9 exhibits the disaster preparedness system in Japan. The laws and regulations may provide guidanceFigure for 9 disasterexhibits prevention. the disaster Rescue preparedness teams can system arrive inat a Japan. site immediately The laws and in a regulations geology disaster may providewith disaster guidance prevention for disaster system prevention. [24]. In addition,Rescue teams more can research arrive onat a geological site immediately disaster in prevention a geology disastermay provide with more disaster methods prevention to achieve system early [ warning.24]. In addition, The most more important research method on geolog to preventical disastergeology preventiondisaster is tomay increase provide the more resilience methods of citizens; to achieve therefore, earlydisaster warning. prevention The most education important and method disaster to preventprevention geology training disaster are necessary is to increase [25]. the resilience of citizens; therefore, disaster prevention educationAccording and disaster to the disaster prevention preparedness training are system necessary in Japan, [25] some. recommendations made should be adoptedAccording in the geology to the disaster disasters preparedness in China. (1) system The government in Japan, shouldsome recommendations improve the existing made emergency should be adopted in the geology disasters in China. (1) The government should improve the existing emergency management legislation and disaster prevention system to strength the efficiency and Geosciences 2019, 9, 368 7 of 10

managementGeosciences 2017, 7 legislation, x FOR PEER and REVIEW disaster prevention system to strength the efficiency and effectiveness7 of 9 of an early warning system. (2) The most important point is that the villagers should reinforce the awarenesseffectiveness and of knowledgean early warning of self-prevention system. (2) The and most enhance important their abilitypoint is to that save the themselves villagers should when encounteringreinforce the aawareness natural disaster. and Inknowledge addition, villagers of self-prevention should practice and disaster enhance prevention their ability training to save and evacuationthemselves rehearsal when encountering regularly. a natural disaster. In addition, villagers should practice disaster prevention training and evacuation rehearsal regularly.

Disaster preparedness system in Japan

Country Society Individual

Research on Popular disaster Disaster Laws and Early warning geological prevention education prevention regulations system disaster and normal disaster system prevention prevention training

Figure 9. Disaster preparedness system in Japan. Figure 9. Disaster preparedness system in Japan. At present, in view of the rapid development of the GIS technology, various quantitative or statistical At present, in view of the rapid development of the GIS technology, various quantitative or methods have been proposed to predict landslide susceptibility [26]. For example, Shahabi et al. [27] statistical methods have been proposed to predict landslide susceptibility [26]. For example, Shahabi compared the landslide susceptibility mapping models of logistic regression (LR), analytical hierarchy et al. [27] compared the landslide susceptibility mapping models of logistic regression (LR), analytical process (AHP) and frequency ratio (FR). Yalcin [28] compared the susceptibility maps produced by the hierarchy process (AHP) and frequency ratio (FR). Yalcin [28] compared the susceptibility maps analytical hierarchy process (AHP), statistical index (Wi), and weighting factor (Wf) methods. Based produced by the analytical hierarchy process (AHP), statistical index (Wi), and weighting factor (Wf) on the comparative study above mentioned, Yalcin [28] concluded that AHP method yielded a more methods. Based on the comparative study above mentioned, Yalcin [28] concluded that AHP method realistic scenario of the actual distribution of the landslide susceptibility. Zhu et al. [29] applied the yielded a more realistic scenario of the actual distribution of the landslide susceptibility. Zhu et al. load-unload response ratio theory to establish a landslide prediction model. et al. [30] applied a [29] applied the load-unload response ratio theory to establish a landslide prediction model. Yang et time series analysis and long short-term memory neural network to predict landslide displacement. al. [30] applied a time series analysis and long short-term memory neural network to predict landslide The RS and permanent scatter interferometry synthetic aperture radar (PSInSAR) techniques are widely displacement. The RS and permanent scatter interferometry synthetic aperture radar (PSInSAR) used to monitor the development of geohazards [31–37]. In addition, the most straightforward method to techniques are widely used to monitor the development of geohazards [31–37]. In addition, the most establish a territorial landslide early warning system is the definition of rainfall thresholds for landslide straightforward method to establish a territorial landslide early warning system is the definition of initiation [17,38–40]. The application of these model techniques could help in monitoring the occurrence rainfall thresholds for landslide initiation [17,38–40]. The application of these model techniques could of a landslide. help in monitoring the occurrence of a landslide. 5. Conclusions 5. Conclusions This short communication reports a large landslide that occurred on 23 July, 2019 in Guizhou Province,This short China. communication The following reports conclusions a large can landslide be drawn that based occurred on the on preliminary 23 July, 2019 investigation in Guizhou andProvince analysis., China. The following conclusions can be drawn based on the preliminary investigation and analysis. 1. 1.A largeA large landslide landslide of approximately of approximately 2 million 2 million m3 of soil m3 andof soil rock and occurred rock occurred at Pingdi at village, Pingdi resulting village, resultingin 42 in deaths 42 deaths and 9 missing and 9 missing persons (aspersons of July (as 28) of being July reported. 28) being In reported. the preliminary In the investigation,preliminary investigation,the vertical the distance vertical between distance the between highest pointthe highest and toe point of the and landslide toe of and the slidinglandslide trajectory and sliding along trajectorythe sliding along surfacethe sliding of the surface landslide of the were landslide approximately were approximately 500 and 1400 500 m, and respectively. 1400 m, respectively. 2. 2.Rainfall Rainfall was considered was considered as the mostas the important most important causing factor causing for factorthis landslide. for this The landslide. continuous The continuousheavy rainfallheavy rainfall significantly significantly deteriorated deteriorated the stormwater the stormwater of the sliding of the interface.sliding interface. The shear The stresses shear stressesdue due to the to deteriorationthe deterioration of the of sliding the sliding interface interface acted alongacted thealong shear the band, shear resulting band, resulting in a reduced in a reducedshear shear strength strength available available at the at shearthe shear band. band This. This in turn in turn caused caused a displacement a displacement of the of soil the and soil rockand rock above, thereby triggering this massive landslide. 3. 3.The governmentThe government should should strengthen strengthen the ability the ability of warning of warning and communication and communication to inform to villagers inform villagersin time. in time. In addition, In addition, the villagers the villagers should should be educated be educated regarding regarding rescue during rescue natural during disasters natural disasters and practice evacuation drills regularly. In addition, more risk prediction methods should be applied to prevent geological disasters.

Author Contributions: This paper represents a result of collaborative teamwork. S.L.S. developed the concept; Y.T. drafted the manuscript; Z.A.N. and C.J. provided constructive suggestions and revised for the manuscript. The four authors contributed equally to this work. Geosciences 2019, 9, 368 8 of 10

and practice evacuation drills regularly. In addition, more risk prediction methods should be applied to prevent geological disasters.

Author Contributions: This paper represents a result of collaborative teamwork. S.-L.S. developed the concept; T.Y. drafted the manuscript; A.-N.Z. and J.C. provided constructive suggestions and revised for the manuscript. The four authors contributed equally to this work. Funding: This research was funded by the Research Funding of Shantou University for New Faculty (Grant No. NTF19024-2019) and the Innovative Research Funding of the Science and Technology Commission of Shanghai Municipality (Grant No. 18DZ1201102). Acknowledgments: The authors would like to express their sincere appreciation to the anonymous reviewers and editors, whose constructive suggestions helped the authors to rethink and rework the manuscript to improve the quality greatly. Conflicts of Interest: The authors declare no conflict of interest.

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