Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

A hill slope failure analysis: A case study of Malingoan village, Maharashtra, India

A hill slope failure analysis: A case study of Malingoan village, Maharashtra, India GEOLOGY, ECOLOGY, AND LANDSCAPES 2021, VOL. 5, NO. 1, 1–6 INWASCON https://doi.org/10.1080/24749508.2019.1695714 RESEARCH ARTICLE A hill slope failure analysis: A case study of Malingoan village, Maharashtra, India Chetan R. Shah, Sandip S. Sathe, Prashant. B. Bhagawati and Santosh S. Mohite Department of Civil Engineering, Annasaheb Dange College of Engineering and Technology, Ashta, India ABSTRACT ARTICLE HISTORY Received 13 May 2019 Landslide catastrophe happen on 30 July 2014 has buried almost 140 peoples under a loose Accepted 14 August 2019 soil mass in Malingaon village of Pune district, Maharashtra, India. Soil samples from a hill slope sections were collected (viz. bottom, middle, and top) for determination of the soil properties KEYWORDS and slope stability. Mainly excess rainfall triggered the land slide, which directly affected on Landslide; stability of slope; geotechnical properties of soil. The results showed that the hill slope was unstable with factor Arc-GIS; hilly terrain of safety less than one and which is prone to failure. The land use and land cover map (viz. before and after of land slide) analysis have inferred that the hill slope was unstable. The unscientific way of agriculture practices method and conversion of nonagricultural land into agricultural usage was the major cause for land slide in the study area. This study provides a technically viable solution method to avoid such disaster in same topographical features. 1. Introduction shortage of agricultural land. Landslides may also occur on stable areas due to other human activities such as Landslide is a common natural disaster often in hilly irrigation, lawn watering, draining of reservoirs (or creat- terrain, which causes huge loss of natural resources and ing them), leaking pipes, and improper excavating or human life (Ering & Babu, 2016). It is mainly attributed grading on hill slopes. Eventually, these areas discourage by natural factors, such as earthquakes and rainfall many habitants to live and use sloping land for agricul- occurred on these regions (Collins & Znidarcic, 2004; tural productivity (Singh et al., 2016). Rahardjo, Li, Toll, & Leong, 2001). A sudden downward In total 15% or 0.49 million km of the terrain in movement of the consolidated, unconsolidated soils, and India are susceptible to landslide are prone to land- rock matter from a geomorphic feature due to natural slide (Walde et al., 2017). The most affected parts of and man-made activities leads to landslide (Patil & landslide in India are Himalayas, Westerns Ghats, Gopale, 2018). Such movement can occur in many Nilgris, and Vindhyas (Chandrasekaran, Elayaraja, & ways, it can be a fall, topple, slide, spread, or flow (Ering Renugadevi, 2013; Mahanta, Sathe, & Mahagaonkar, &Babu, 2016). Thehypothesisfor land slidewas rain 2016; Ramakrishnan, Singh, Verma, Gulati, & Tiwari, water infiltration decreases metrics suction (i.e., negative 2012; Sathe, Goswami, & Mahanta, 2019; Sathe et al., pore water pressure) in the soil, which results in decrease 2019; Sathe, Mahanta, & Mishra, 2018; Thennavan, of shear strength and trigger the landslide phenomenon Ganapathy, Sekaran, & Rajawat, 2016; Vasantha in hilly terrian (Fredlund & Rahardjo, 1993). Kumar & Bhagavanulu, 2008; Wadhawan, 2018). On In 2008, Wenchuan earthquake happened in China the basis of landslide hazard map of states of India, like that caused more than 15,000 geohazards in the form of Sikkim and Mizoram, have found that they are falling landslides, rock falls, and debris flows, which resulted in under very high to severe hazard classes (Punmia and about 20,000 peoples death (Yin, Wang, & Sun, 2009). Jain 1970). In the Indian peninsular region, the hilly Cho (2014) has performed probabilistic slope stability states like Karnataka, Andhra Pradesh, and Kerala and seepage analyses method to determine the effects of constitute low to moderate hazard prone areas spatial variability on the slope stability and mean dis- (Ramesh, 2017). The western ghat of Maharashtra is charge. It was found that weak correlation increases an integral part of Indian peninsular region contains uncertainty in the sampled soil properties. Other exam- varying topographical features, such as mountains, hill ples include over steepening of slopes by undercutting locks, seasonal and perennial rivers, lakes, and ponds. the bottom and loading the top of a slope to exceed the On 30 July 2014, a landslide occurred in the village bearing strength of the soil or other component material. of Malingaon, Maharashtra, India caused by a burst of Populations expanding onto new lands, which convert heavy rainfall, killed 151 peoples and damaging 45 the agricultural land into non-agricultural land, causes CONTACT Chetan R. Shah crs_civil@adcet.in Department of Civil Engineering, Annasaheb Dange College of Engineering and Technology, A/P- Guruwar peth, Shirala, Sangli, Ashta 415408, India This article has been republished with minor changes. These changes do not impact the academic content of the article. © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of the International Water, Air & Soil Conservation Society(INWASCON). This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 2 C. R. SHAH ET AL. houses (Ering, Kulkarni, Kolekar, Dasaka, & Babu, tributary of Ghod river. This agriculturally productive 2015). In the current scenario, there are different land near hill slope produces economically source to the methods such as conventional soil testing and numer- poor villager’s living in this study area. Around 70 dwell- ical methods existing to study the landslide and slope ing units existed before landslide. The hill slopes were stability (Palma, Parise, Reichenbach, & Guzzetti, partially converted for paddy cultivation and agricultural 2011; Ramakrishnan et al., 2012; Sarkar, Kanungo, land by the local villagers. The geology of Malingaon Patra, & Kumar, 2008; Singh et al., 2016). This study village is mainly comprised by the basaltic strata (Singh focused on following objectives: (1) identify the typical et al., 2016). The topographic map of the area shows had hill slope parameters and valuranable soil properties; an evidenced of two low magnitudes seismic activities (2) application of Arc GIS for identification of vulner- (4.0–4.9) within 100 km radius of the landslide location. ability of hill slope failure; (3) suggest preventive mea- However, these seismic events do not appear to have sures to avoid landslide. played any significant role in inducing slope instability in Malingaon. The entire hill slope has divided into four zones: 2. Site description Zone 1: from the seasonal tributary to the road level, which was relatively flatter in its lower part followed Malingaonvillage is locatedinAmbegaontalukaofPune by gentle slope in upper part. Zone 2: from road level district, Maharashtra state, India. It is located at 786 m nd to the 2 slope level, this was relatively gentler. Zone ground elevation and about 95 km away from Pune city. rd 3: from 2nd major slope level to the 3 major slope Geographical co-ordinates of the village are N 19° rd break, this was moderately inclined. Zone 4: from 3 09ʹ34.4″ and E 73°41ʹ19″ (Figure 1). In last decade (i.e., level till the apex of the hill, this was moderately 2003 to 2012) average rainfall recorded in Ambegaon inclined. The top level i.e., zone 4 slope inclination taluka was 81 cm (CGWB, Pune 2013). This enough was measured from the base topographic map is rainfall and availability of water in this area have encour- around 35°. Considering the similarity of slope con- aged many peoples to practice agriculture activity. The figuration for the entire Malingaon hill slope, a study area bounded on the eastern side by a seasonal Figure 1. Study area map location of Malingaon with respect to India and Maharashtra. It also shows present topography of Malingaon in Pune district. GEOLOGY, ECOLOGY, AND LANDSCAPES 3 Figure 2. Cross section of Malingaon hill, showed a critical three zones of land slide and gradient study area. longitudinal section was drawn to the southern side of 4.2. Analytical methods the hill from across the river up to just above the The Plasticity Index (PI) is a measure of the plas- crown level of Malingaon landslide (Figure 2). This ticity of a soil. The PI is the difference between the section roughly reveals the pre-slide slope configura- liquid limit and the plastic limit (PI = LL – PL). tion of slide portion. Figure 2 shows the longitudinal Soils with a high PI tend to be clay, those with a topographical section along line of the slope. lowerPItendtobesilt, andthose with zero value indicate non-plasticity and tends to have little or no silt or clay content. 3. Features of the Malingaon landslide Plasticity index = liquid limit – plastic limit The height of the landslide is roughly estimated as 180 m while the width of the slide varies from 40 to Ip¼W W L P 132 m. The entire length of the slide from the crown to toe is 512 m and the area affected is 44,239 m .The crown of the landslide is at a height of 930 m and marks I ¼ 30  14 th the top of 4 zone. The width of the landslide in this zone varies from 40 to 132 m. The landslide depleted th rd part of 4 zone, entire 3 zone and maximum part of I ¼ 16% nd nd st 2 zone. Lowest part of 2 zone and 1 zone form the zone of accumulation, this zone of accumulation is the Soil descriptions based on PI: settlement area of the Malingaon village. The maximum 0 – Non-plastic, < 7 – Slightly plastic, 7–17 – Medium thickness of the material slided during landslide could plastic, > 17 – Highly plastic not be established accurately and it is approximated as 7 m because when the detailed mapping work was carried out, most of the failed slope material has been 4.3. Direct shear test removed from the place as part of rescue effort. It is laboratory test used for determination of shear strength properties of soil. This test is performed on 4. Material and methods three specimens of relatively undisturbed collected soil samples. A confining stress was applied vertically to 4.1. Field test the specimen and the upper ring is pulled laterally During field visit to Malingaon, selective field test were until sample was failed. Applied load and proving carried out on soil samples such as thumb penetration, ring reading was used to find the “C” and “ɸ” values, core cutter, and slope angle by abney level. For analy- after that factor of safety (FOS) at top hill for an tical method analysis, representative undisturbed core infinite slope under steady seepage condition during soil samples from four zones of hill slope were collected heavy rainfall was calculated by following equation for identifying geotechnical parameters in a laboratory. (Punmia and Jain 1970): 4 C. R. SHAH ET AL. Table 1. Results of soil properties. C þ γ cos ðiÞ tanΦ F:O:S Sr. no. Properties of soil Standard Result γ H cosðiÞ sinðiÞ sat 1 Specific gravity of Soil IS 2720: part 3 1.94 420 þð6:39  1000  cos 35  tan 36:66Þ 2 Bulk density of soil IS 2720: parts 7 and 8 0.62 g/cm 3 Dry density of soil IS 2720: parts 7 and 8 0.05 g/cm 16:2  1000  cos 35  sin 35 4 Liquid limit of soil IS 2720: part 5 30% ¼ 0:47 ffi 0:5 (1) 5 Plastic limit IS 2720: part 5 14% 6 Plasticity Index IS 2720: part 5 16% Where ɸ = internal friction of soil in degree 7 Cohesion Direct shear test 0.42 kg/cm i = Original slope angle of hill in degree 8 Internal friction angle Direct shear test 18.52° C = Cohesion in kg/cm ’ 3 ץ = Submerged unit weight of soil in kg/cm 3 the unplanned land was used for rice crop plantation in ץ = Saturated unit weight of soil in kg/cm sat rainy season. Using abney level, we have measured aver- age slope angle for hill from bottom to top, which was recorded as 35 (35 degree angle). 4.4. Land use land cover Google earth Pro 2018 version was used for interpreta- tion of land use and land cover map. Image was regis- 5.2. Geotechnical parameters tered in Arc GIS 9.1 software (UTM 1983 and datum Specific gravity, water content, liquid limit, plastic limit, WGS84). Individual bands of digital data were and PI test results are shown in Table 1.The average imported into the image processing software also the specific gravity of representative soil sample from top, noise renewal and enhancement was performed prior to middle, and bottom were recorded as 2.3, 2.2, and 2.4 the analysis. False Color Composite (FCC) was per- suggested that it contains high amount of sand particle formed from making observation on the individual whereas water content results classified it as sandy- bands for blue, green, and red combination. The precise clayey soil (Sathe, S. S., & Mahanta, C. 2019). Other interpretation of various land use and land cover for the parameters of soil such as liquid limit and plastic limit study area map was performed by supervised classifica- results showed that liquid limit was higher than the tion method in Arc GIS software. Land use and land plastic limit in all representative soil samples, which cover classes were classified insight categories viz., tress, further indicate that top soil required less water content losses soil with hard rock, paddy land, artificial agricul- to achieve a liquid limit and plastic limit comparative to tural land, loses soil, exposed hard rock. bottom hill soil. Similarly, PI results further indicates that the quick attendance of liquid limit of top soil than the bottom hill soil sample. These results clearly showed 5. Result and discussion that the top and middle hill slope soil was unstable and 5.1. Field test vulnerable for liquid state (Table 2). The Thumb penetration, core cutter test was conducted. It was observed that the thumb penetrated easily, which 5.3. Shear strength parameters of soil samples indicates that the top soil is sandy-clay. Similarly, in core cutter test indicates that the average dry density of top, The results of internal friction angle and un-drained middle, and bottom of the soil was 1.2 g/cc, 1.4 g/cc, and cohesion of representative soil samples were determined. 1.3 g/cc respectively (Table 1). According to United It has observed that the FOS for infinite slopeislessthan States Department of Agriculture, soil was texturally one, so that the slope of hill was unstable during heavy classified,the soil at thetop,middle, andbottomwas a rainfall where seepage was parallel to the slope. The sandy-clay, silty clay, and silty clayey loam, respectively. preliminary conclusion was drawn from the experimen- Crumble test indicated that pressure required to crumble tal reading that resisting force created by soil is less than the soil was negligible, which supports the core cutter test driving force and hence slope unstable. Table 2 shows results. The field observation such as on top of the hill, that the shear strength parameters for representative soil Table 2. Field test results for three regions on hill slope. Specific gravity Water content Dry density Liquid limit Plastic limit Plasticity Index Cohesion Internal friction Sample no. SG WC (%) DD (g/cc) LL (%) PL (%) PI C (kg/cm ) ɸ (°) Low 2.8 36.43 1.35 52.5 31.75 20.75 0.13 4.35 2.3 35.18 1.29 51.5 29.09 22.41 0.13 4.22 2.05 38.13 1.32 50.5 28.3 22.2 0.13 4.37 Middle 2.25 25.32 1.38 49 33.8 15.2 0.41 11.58 1.92 28.96 1.34 52 28.56 23.44 0.44 12.3 2.35 27.98 1.37 49.5 27.36 22.14 0.39 10.88 Top 2.38 40.32 1.18 45.5 32.35 13.15 0.42 38.18 2.19 39.35 1.29 46.5 28.65 17.85 0.43 42.25 2.25 37.56 1.26 52.5 27.88 24.62 0.42 36.4 GEOLOGY, ECOLOGY, AND LANDSCAPES 5 Figure 3. Land use land cover map of Malingaon before occurrence of landslide in year 2014 (a and b). Land use land cover map of Malingaon after occurrence of landslide in year 2014 (c and d). samples was observed decreasing from hill top to hill supported by internal friction angle results for the respec- bottom, which suggest that punching shear failure can tive zone tested soil. The land use and land cover analysis occurs at the bottom and middle section of hill. of topographical map have delineated the vulnerable zone. Land use and land cover by Arc GIS software would help to identify the topographical susceptible 5.4. Land use land cover zones for landslide.It further suggests the possible loca- tion of artificial drainage network system of such vulner- Land use and land cover map of the region showed able zone which can accommodate the excess surface that the previous scenario and after land slide sce- water and safely discharge into adjoining tributaries. nario of the study area. The map shows six color Soil erosion is also the causative factor; this can be category namely exposed rock, trees, losse soil, reduced by increasing the vegetative growth on the slop- paddy agricultural land, developed agricultural land, ing areas. Necessity of awareness about the changing and hard rock (Figure 3(a,b)). The patches of red and agricultural practices as well as controlling the human green coloronthe middle(i.e.,zone2)andtopzone activities leads to cause landslide. (i.e., zone 4 and 3) indicates the formation artificial land over the hill for agricultural purposes by the villagers. Therefore, it has developed a large volume Highlights of loose soil (Figure 3(b)). The second scenarios of the study area clearly showed the mass strip of loosen (1) Identification of causes for landslide soil drawn at foot hill by the natural disaster, which (2) Slope stability parameters analysis was used to predicate the future land slide zone in (3) Land use and land cover map method (4) Preventive measures for landslide similar topographical study area (Figure 3(c,d)). Drainage system throughout the hill slope was not observed. Acknowledgments The authors thank department of civil engineering, 6. Conclusion Annasaheb Dange College of Engineering and Technology, Ashta, affiliated to Shivaji University, Kolhapur, Hill slope monitoring is essential to avoid such landslide Maharashtra for providing the necessary facilities to carry near habitants area. Seriousness about the land slide and out this research work. Authors gratefully acknowledge the its effect on habitant should be properly conveyed to such Mrs. Sunita Mane gram-panchayat of Malingaon for her type of topographical regions which is very important to assistance and sharing data used for this study. The authors create an awerness amongest the people. The main cause would also like to acknowledge the two reviewers and the editor for their helpful comments on the earlier version of for hill slope failure was an improper drainage system at the manuscript. This research did not receive any specific the top and middle part of the hill, which have created a grant from funding agencies in the public, commercial, or more pore water pressure in respective sections. The not-for-profit sectors. other major factors for landslide in this area was unplanned agricultural land creation and deforestation which was inferred from land use and land cover map. Disclosure statement The results of soil analysis indicate that FOS is less than No potential conflict of interest was reported by the authors. one (i.e., < 1) which suggest that slope is unstable and 6 C. R. SHAH ET AL. Arsenic research and global sustainability: Proceedings of the ORCID Sixth International Congress on Arsenic in the Environment Prashant. B. Bhagawati http://orcid.org/0000-0003-4156- (As2016) (pp. 66). Stockholm, Sweden: CRC Press. Palma,B.,Parise,M.,Reichenbach,P.,&Guzzetti,F.(2011). Rockfall hazard assessment along a road in the Sorrento Peninsula, Campania, southern Italy. Natural Hazards, 61(1), 187–201. Patil, V., & Gopale, R. (2018). A geographical study of Future Studies landslide: A case study of malin village of ambegaon tahsil For the current study stability of slope is carried out by in pune district, Maharashtra. Peer Reviewed estimating FOS with respect to geotechnical properties of International Research Journal of Geography, 35,55–60. soil and slope angle of hill in Malingaon. Land use and land Punmia, B. C., & Jain, A. K. (1970). Soil mechanics and founda- cover by arc GIS is used to identify the various causes of tions (16th ed.). New Delhi: Laxmi publication (P) Ltd. landslide, further this work is carried out to identify such Rahardjo,H.,Li,X.W.,Toll, D. G.,&Leong,E.C.(2001). The villages having same situation like Malingaon, and suggest effect of antecedent rainfall on slope stability. Geotechnical some preventive techniques to avoid occurrence of such and Geological Engineering, 19(3/4), 371–399. type of landslide in future. Use different techniques to iden- Ramakrishnan,D., Singh, T. N.,Verma,A. K., Gulati, A., & tify stability of slope such as finite element method, GIS, Tiwari,K.C.(2012). Soft computing and GIS for landslide GPS Techniques, etc., in this present study seepage analysis susceptibility assessment in Tawaghat area, Kumaon were not determined for accurate results further work on Himalaya, India. Journal of the International Society for the seepage is essential. In the present study, only three samples Prevention and Mitigation of Natural Hazards, 65(1), 315–330. each (Top, Middle, and Bottom) of failure slope is collected Thambidurai, p. (2017). Slope stability investigation of to determine geotechnical properties of soil, it is further chandmari in Sikkim, Northeastern India. In Workshop suggested to collect more soil samples for identifying geo- on world landslide Forum (pp. 363–369). Cham: Springer. technical properties of soil will increase accuracy of results. Sarkar, S., Kanungo, D. P., Patra, A. K., & Kumar, P. (2008). GIS based spatial data analysis for landslide susceptibility mapping. Journal of Mountain Science, 5(1), 52–62. References Sathe, S. S., Goswami, L., & Mahanta, C. (2019). Integrated factors controlling arsenic mobilization in an alluvial Chandrasekaran, S. S., Elayaraja, S., & Renugadevi, S. floodplain. Environmental Technology & Innovation. (2013). Damages to transport facilities by rainfall induced ETI 100525, Vol. 17C. doi:10.1016/j.eti.2019.100525 landslides during November 2009 in Nilgiris, India. Sathe, S. S., & Mahanta, C. (2019). Groundwater flow and Landslide Science and Practice, (Vol. 2, pp 171–176). arsenic contamination transport modeling for a multi Cho, S. E. (2014). Probabilistic stability analysis of rain- aquifer terrain: Assessment and mitigation strategies. fallinduced landslides considering spatial variability of Journal of Environmental Management, 231, 166–181. permeability. Engineering Geology, 171,11–20. Sathe, S. S., Mahanta, C., & Mishra, P. (2018). Simultaneous Collins, B. D., & Znidarcic, D. (2004). Stability analyses of influence of indigenous microorganism along with abio- rainfall induced landslides. Journal of Geotechnical and tic factors controlling arsenic mobilization in Geoenvironmental Engineering, 130(4), 362–372. Brahmaputra floodplain, India. Journal of Contaminant Ering, P., & Babu, G. S. (2016). Probabilistic back analysis of Hydrology, 213,1–14. rainfall induced landslide-A case study of Malin land- Singh,T. N.,Singh,R.,Singh, B.,Sharma, L.K., Singh, R., & slide, India. Engineering Geology, 208, 154–164. Ansari, M.K.(2016). Investigations and stability analyses of Ering, P., Kulkarni, R., Kolekar, Y., Dasaka, S. M., & Babu, Malin village landslide of Pune district, Maharashtra, India. G. S. (2015). Forensic analysis of Malin landslide in India. Journal of the International Society for the Prevention and In IOP Conference Series: Earth and Environmental Mitigation of Natural Hazards, 81(3), 2019–2030. Science,Warwick,UK (Vol. 26, No. 1, pp. 012040). IOP Thennavan, E., Ganapathy, G. P., Sekaran, S. C., & Rajawat, Publishing A. S. (2016). Use of GIS in assessing building vulnerability Fredlund, D. G., & Rahardjo, H. (1993). Soil mechanics for for landslide hazard in The Nilgiris, Western Ghats,India. unsaturated soils. New York, NY: John Wiley& Sons. Journal of the International Society for the Prevention and IS 2720-1985: Part 13 direct shear test, Indian Standard Mitigation of Natural Hazards, 82(2), 1031–1050. methods of test for soils Vasantha Kumar, S., & Bhagavanulu, D. V. S. (2008). Effect of IS 2720-1985: Part 5 determination of liquid and plastic limit, deforestation on landslides in Nilgiris district — Acasestudy. Indian Standard methods of test for soils Journal of the Indian Society of Remote Sensing, 36(1), 105–108. IS 2720-1985: Part 7&8 determination of water content-dry Wadhawan, S. K. (2018). Landslide susceptibility mapping, density relation using light compaction, Indian standard vulnerability and risk assessment for development of methods of test for soils early warning systems in India. Advances in Natural IS2720-1985: Part-3 determination of specific gravity, Indian and Technological Hazards Research, 50,145–172. standard methods of test for soils Walde, S., Kale, K., Kundu, S., Nagaraj, P., Shelar, T., & Mahanta, C., Sathe, S. S., & Bhattacharya, P. (2012) Grain Shukla, V. K. (2017). GIS based landslide susceptibility size, mineralogy and sediment composition as factors assessment of malin area: A case study in watershed, controlling release and mobilization of arsenic in parts India. 17th Esri India user Conference 2017, New Delhi. of the Brahmaputra floodplains, northeastern India. GSA Yin, Y., Wang, F., & Sun, P. (2009). Landslide hazards annual meeting in Charlotte. triggered by the 2008 Wenchuan earthquake, Sichuan, Mahanta, C., Sathe, S. S., & Mahagaonkar, A. (2016,June19– China. Journal of the International Consortium on 23). Morphological and mineralogical evidences of arsenic Landslides, 6(2), 139–152. release and mobilization in some large floodplain aquifers. In http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Geology Ecology and Landscapes Taylor & Francis

A hill slope failure analysis: A case study of Malingoan village, Maharashtra, India

Download PDF
6 pages

Loading next page...
 
/lp/taylor-francis/a-hill-slope-failure-analysis-a-case-study-of-malingoan-village-Q5SJ6MBXGN

References (20)

Publisher
Taylor & Francis
Copyright
© 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of the International Water, Air & Soil Conservation Society(INWASCON).
ISSN
2474-9508
DOI
10.1080/24749508.2019.1695714
Publisher site
See Article on Publisher Site

Abstract

GEOLOGY, ECOLOGY, AND LANDSCAPES 2021, VOL. 5, NO. 1, 1–6 INWASCON https://doi.org/10.1080/24749508.2019.1695714 RESEARCH ARTICLE A hill slope failure analysis: A case study of Malingoan village, Maharashtra, India Chetan R. Shah, Sandip S. Sathe, Prashant. B. Bhagawati and Santosh S. Mohite Department of Civil Engineering, Annasaheb Dange College of Engineering and Technology, Ashta, India ABSTRACT ARTICLE HISTORY Received 13 May 2019 Landslide catastrophe happen on 30 July 2014 has buried almost 140 peoples under a loose Accepted 14 August 2019 soil mass in Malingaon village of Pune district, Maharashtra, India. Soil samples from a hill slope sections were collected (viz. bottom, middle, and top) for determination of the soil properties KEYWORDS and slope stability. Mainly excess rainfall triggered the land slide, which directly affected on Landslide; stability of slope; geotechnical properties of soil. The results showed that the hill slope was unstable with factor Arc-GIS; hilly terrain of safety less than one and which is prone to failure. The land use and land cover map (viz. before and after of land slide) analysis have inferred that the hill slope was unstable. The unscientific way of agriculture practices method and conversion of nonagricultural land into agricultural usage was the major cause for land slide in the study area. This study provides a technically viable solution method to avoid such disaster in same topographical features. 1. Introduction shortage of agricultural land. Landslides may also occur on stable areas due to other human activities such as Landslide is a common natural disaster often in hilly irrigation, lawn watering, draining of reservoirs (or creat- terrain, which causes huge loss of natural resources and ing them), leaking pipes, and improper excavating or human life (Ering & Babu, 2016). It is mainly attributed grading on hill slopes. Eventually, these areas discourage by natural factors, such as earthquakes and rainfall many habitants to live and use sloping land for agricul- occurred on these regions (Collins & Znidarcic, 2004; tural productivity (Singh et al., 2016). Rahardjo, Li, Toll, & Leong, 2001). A sudden downward In total 15% or 0.49 million km of the terrain in movement of the consolidated, unconsolidated soils, and India are susceptible to landslide are prone to land- rock matter from a geomorphic feature due to natural slide (Walde et al., 2017). The most affected parts of and man-made activities leads to landslide (Patil & landslide in India are Himalayas, Westerns Ghats, Gopale, 2018). Such movement can occur in many Nilgris, and Vindhyas (Chandrasekaran, Elayaraja, & ways, it can be a fall, topple, slide, spread, or flow (Ering Renugadevi, 2013; Mahanta, Sathe, & Mahagaonkar, &Babu, 2016). Thehypothesisfor land slidewas rain 2016; Ramakrishnan, Singh, Verma, Gulati, & Tiwari, water infiltration decreases metrics suction (i.e., negative 2012; Sathe, Goswami, & Mahanta, 2019; Sathe et al., pore water pressure) in the soil, which results in decrease 2019; Sathe, Mahanta, & Mishra, 2018; Thennavan, of shear strength and trigger the landslide phenomenon Ganapathy, Sekaran, & Rajawat, 2016; Vasantha in hilly terrian (Fredlund & Rahardjo, 1993). Kumar & Bhagavanulu, 2008; Wadhawan, 2018). On In 2008, Wenchuan earthquake happened in China the basis of landslide hazard map of states of India, like that caused more than 15,000 geohazards in the form of Sikkim and Mizoram, have found that they are falling landslides, rock falls, and debris flows, which resulted in under very high to severe hazard classes (Punmia and about 20,000 peoples death (Yin, Wang, & Sun, 2009). Jain 1970). In the Indian peninsular region, the hilly Cho (2014) has performed probabilistic slope stability states like Karnataka, Andhra Pradesh, and Kerala and seepage analyses method to determine the effects of constitute low to moderate hazard prone areas spatial variability on the slope stability and mean dis- (Ramesh, 2017). The western ghat of Maharashtra is charge. It was found that weak correlation increases an integral part of Indian peninsular region contains uncertainty in the sampled soil properties. Other exam- varying topographical features, such as mountains, hill ples include over steepening of slopes by undercutting locks, seasonal and perennial rivers, lakes, and ponds. the bottom and loading the top of a slope to exceed the On 30 July 2014, a landslide occurred in the village bearing strength of the soil or other component material. of Malingaon, Maharashtra, India caused by a burst of Populations expanding onto new lands, which convert heavy rainfall, killed 151 peoples and damaging 45 the agricultural land into non-agricultural land, causes CONTACT Chetan R. Shah crs_civil@adcet.in Department of Civil Engineering, Annasaheb Dange College of Engineering and Technology, A/P- Guruwar peth, Shirala, Sangli, Ashta 415408, India This article has been republished with minor changes. These changes do not impact the academic content of the article. © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of the International Water, Air & Soil Conservation Society(INWASCON). This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 2 C. R. SHAH ET AL. houses (Ering, Kulkarni, Kolekar, Dasaka, & Babu, tributary of Ghod river. This agriculturally productive 2015). In the current scenario, there are different land near hill slope produces economically source to the methods such as conventional soil testing and numer- poor villager’s living in this study area. Around 70 dwell- ical methods existing to study the landslide and slope ing units existed before landslide. The hill slopes were stability (Palma, Parise, Reichenbach, & Guzzetti, partially converted for paddy cultivation and agricultural 2011; Ramakrishnan et al., 2012; Sarkar, Kanungo, land by the local villagers. The geology of Malingaon Patra, & Kumar, 2008; Singh et al., 2016). This study village is mainly comprised by the basaltic strata (Singh focused on following objectives: (1) identify the typical et al., 2016). The topographic map of the area shows had hill slope parameters and valuranable soil properties; an evidenced of two low magnitudes seismic activities (2) application of Arc GIS for identification of vulner- (4.0–4.9) within 100 km radius of the landslide location. ability of hill slope failure; (3) suggest preventive mea- However, these seismic events do not appear to have sures to avoid landslide. played any significant role in inducing slope instability in Malingaon. The entire hill slope has divided into four zones: 2. Site description Zone 1: from the seasonal tributary to the road level, which was relatively flatter in its lower part followed Malingaonvillage is locatedinAmbegaontalukaofPune by gentle slope in upper part. Zone 2: from road level district, Maharashtra state, India. It is located at 786 m nd to the 2 slope level, this was relatively gentler. Zone ground elevation and about 95 km away from Pune city. rd 3: from 2nd major slope level to the 3 major slope Geographical co-ordinates of the village are N 19° rd break, this was moderately inclined. Zone 4: from 3 09ʹ34.4″ and E 73°41ʹ19″ (Figure 1). In last decade (i.e., level till the apex of the hill, this was moderately 2003 to 2012) average rainfall recorded in Ambegaon inclined. The top level i.e., zone 4 slope inclination taluka was 81 cm (CGWB, Pune 2013). This enough was measured from the base topographic map is rainfall and availability of water in this area have encour- around 35°. Considering the similarity of slope con- aged many peoples to practice agriculture activity. The figuration for the entire Malingaon hill slope, a study area bounded on the eastern side by a seasonal Figure 1. Study area map location of Malingaon with respect to India and Maharashtra. It also shows present topography of Malingaon in Pune district. GEOLOGY, ECOLOGY, AND LANDSCAPES 3 Figure 2. Cross section of Malingaon hill, showed a critical three zones of land slide and gradient study area. longitudinal section was drawn to the southern side of 4.2. Analytical methods the hill from across the river up to just above the The Plasticity Index (PI) is a measure of the plas- crown level of Malingaon landslide (Figure 2). This ticity of a soil. The PI is the difference between the section roughly reveals the pre-slide slope configura- liquid limit and the plastic limit (PI = LL – PL). tion of slide portion. Figure 2 shows the longitudinal Soils with a high PI tend to be clay, those with a topographical section along line of the slope. lowerPItendtobesilt, andthose with zero value indicate non-plasticity and tends to have little or no silt or clay content. 3. Features of the Malingaon landslide Plasticity index = liquid limit – plastic limit The height of the landslide is roughly estimated as 180 m while the width of the slide varies from 40 to Ip¼W W L P 132 m. The entire length of the slide from the crown to toe is 512 m and the area affected is 44,239 m .The crown of the landslide is at a height of 930 m and marks I ¼ 30  14 th the top of 4 zone. The width of the landslide in this zone varies from 40 to 132 m. The landslide depleted th rd part of 4 zone, entire 3 zone and maximum part of I ¼ 16% nd nd st 2 zone. Lowest part of 2 zone and 1 zone form the zone of accumulation, this zone of accumulation is the Soil descriptions based on PI: settlement area of the Malingaon village. The maximum 0 – Non-plastic, < 7 – Slightly plastic, 7–17 – Medium thickness of the material slided during landslide could plastic, > 17 – Highly plastic not be established accurately and it is approximated as 7 m because when the detailed mapping work was carried out, most of the failed slope material has been 4.3. Direct shear test removed from the place as part of rescue effort. It is laboratory test used for determination of shear strength properties of soil. This test is performed on 4. Material and methods three specimens of relatively undisturbed collected soil samples. A confining stress was applied vertically to 4.1. Field test the specimen and the upper ring is pulled laterally During field visit to Malingaon, selective field test were until sample was failed. Applied load and proving carried out on soil samples such as thumb penetration, ring reading was used to find the “C” and “ɸ” values, core cutter, and slope angle by abney level. For analy- after that factor of safety (FOS) at top hill for an tical method analysis, representative undisturbed core infinite slope under steady seepage condition during soil samples from four zones of hill slope were collected heavy rainfall was calculated by following equation for identifying geotechnical parameters in a laboratory. (Punmia and Jain 1970): 4 C. R. SHAH ET AL. Table 1. Results of soil properties. C þ γ cos ðiÞ tanΦ F:O:S Sr. no. Properties of soil Standard Result γ H cosðiÞ sinðiÞ sat 1 Specific gravity of Soil IS 2720: part 3 1.94 420 þð6:39  1000  cos 35  tan 36:66Þ 2 Bulk density of soil IS 2720: parts 7 and 8 0.62 g/cm 3 Dry density of soil IS 2720: parts 7 and 8 0.05 g/cm 16:2  1000  cos 35  sin 35 4 Liquid limit of soil IS 2720: part 5 30% ¼ 0:47 ffi 0:5 (1) 5 Plastic limit IS 2720: part 5 14% 6 Plasticity Index IS 2720: part 5 16% Where ɸ = internal friction of soil in degree 7 Cohesion Direct shear test 0.42 kg/cm i = Original slope angle of hill in degree 8 Internal friction angle Direct shear test 18.52° C = Cohesion in kg/cm ’ 3 ץ = Submerged unit weight of soil in kg/cm 3 the unplanned land was used for rice crop plantation in ץ = Saturated unit weight of soil in kg/cm sat rainy season. Using abney level, we have measured aver- age slope angle for hill from bottom to top, which was recorded as 35 (35 degree angle). 4.4. Land use land cover Google earth Pro 2018 version was used for interpreta- tion of land use and land cover map. Image was regis- 5.2. Geotechnical parameters tered in Arc GIS 9.1 software (UTM 1983 and datum Specific gravity, water content, liquid limit, plastic limit, WGS84). Individual bands of digital data were and PI test results are shown in Table 1.The average imported into the image processing software also the specific gravity of representative soil sample from top, noise renewal and enhancement was performed prior to middle, and bottom were recorded as 2.3, 2.2, and 2.4 the analysis. False Color Composite (FCC) was per- suggested that it contains high amount of sand particle formed from making observation on the individual whereas water content results classified it as sandy- bands for blue, green, and red combination. The precise clayey soil (Sathe, S. S., & Mahanta, C. 2019). Other interpretation of various land use and land cover for the parameters of soil such as liquid limit and plastic limit study area map was performed by supervised classifica- results showed that liquid limit was higher than the tion method in Arc GIS software. Land use and land plastic limit in all representative soil samples, which cover classes were classified insight categories viz., tress, further indicate that top soil required less water content losses soil with hard rock, paddy land, artificial agricul- to achieve a liquid limit and plastic limit comparative to tural land, loses soil, exposed hard rock. bottom hill soil. Similarly, PI results further indicates that the quick attendance of liquid limit of top soil than the bottom hill soil sample. These results clearly showed 5. Result and discussion that the top and middle hill slope soil was unstable and 5.1. Field test vulnerable for liquid state (Table 2). The Thumb penetration, core cutter test was conducted. It was observed that the thumb penetrated easily, which 5.3. Shear strength parameters of soil samples indicates that the top soil is sandy-clay. Similarly, in core cutter test indicates that the average dry density of top, The results of internal friction angle and un-drained middle, and bottom of the soil was 1.2 g/cc, 1.4 g/cc, and cohesion of representative soil samples were determined. 1.3 g/cc respectively (Table 1). According to United It has observed that the FOS for infinite slopeislessthan States Department of Agriculture, soil was texturally one, so that the slope of hill was unstable during heavy classified,the soil at thetop,middle, andbottomwas a rainfall where seepage was parallel to the slope. The sandy-clay, silty clay, and silty clayey loam, respectively. preliminary conclusion was drawn from the experimen- Crumble test indicated that pressure required to crumble tal reading that resisting force created by soil is less than the soil was negligible, which supports the core cutter test driving force and hence slope unstable. Table 2 shows results. The field observation such as on top of the hill, that the shear strength parameters for representative soil Table 2. Field test results for three regions on hill slope. Specific gravity Water content Dry density Liquid limit Plastic limit Plasticity Index Cohesion Internal friction Sample no. SG WC (%) DD (g/cc) LL (%) PL (%) PI C (kg/cm ) ɸ (°) Low 2.8 36.43 1.35 52.5 31.75 20.75 0.13 4.35 2.3 35.18 1.29 51.5 29.09 22.41 0.13 4.22 2.05 38.13 1.32 50.5 28.3 22.2 0.13 4.37 Middle 2.25 25.32 1.38 49 33.8 15.2 0.41 11.58 1.92 28.96 1.34 52 28.56 23.44 0.44 12.3 2.35 27.98 1.37 49.5 27.36 22.14 0.39 10.88 Top 2.38 40.32 1.18 45.5 32.35 13.15 0.42 38.18 2.19 39.35 1.29 46.5 28.65 17.85 0.43 42.25 2.25 37.56 1.26 52.5 27.88 24.62 0.42 36.4 GEOLOGY, ECOLOGY, AND LANDSCAPES 5 Figure 3. Land use land cover map of Malingaon before occurrence of landslide in year 2014 (a and b). Land use land cover map of Malingaon after occurrence of landslide in year 2014 (c and d). samples was observed decreasing from hill top to hill supported by internal friction angle results for the respec- bottom, which suggest that punching shear failure can tive zone tested soil. The land use and land cover analysis occurs at the bottom and middle section of hill. of topographical map have delineated the vulnerable zone. Land use and land cover by Arc GIS software would help to identify the topographical susceptible 5.4. Land use land cover zones for landslide.It further suggests the possible loca- tion of artificial drainage network system of such vulner- Land use and land cover map of the region showed able zone which can accommodate the excess surface that the previous scenario and after land slide sce- water and safely discharge into adjoining tributaries. nario of the study area. The map shows six color Soil erosion is also the causative factor; this can be category namely exposed rock, trees, losse soil, reduced by increasing the vegetative growth on the slop- paddy agricultural land, developed agricultural land, ing areas. Necessity of awareness about the changing and hard rock (Figure 3(a,b)). The patches of red and agricultural practices as well as controlling the human green coloronthe middle(i.e.,zone2)andtopzone activities leads to cause landslide. (i.e., zone 4 and 3) indicates the formation artificial land over the hill for agricultural purposes by the villagers. Therefore, it has developed a large volume Highlights of loose soil (Figure 3(b)). The second scenarios of the study area clearly showed the mass strip of loosen (1) Identification of causes for landslide soil drawn at foot hill by the natural disaster, which (2) Slope stability parameters analysis was used to predicate the future land slide zone in (3) Land use and land cover map method (4) Preventive measures for landslide similar topographical study area (Figure 3(c,d)). Drainage system throughout the hill slope was not observed. Acknowledgments The authors thank department of civil engineering, 6. Conclusion Annasaheb Dange College of Engineering and Technology, Ashta, affiliated to Shivaji University, Kolhapur, Hill slope monitoring is essential to avoid such landslide Maharashtra for providing the necessary facilities to carry near habitants area. Seriousness about the land slide and out this research work. Authors gratefully acknowledge the its effect on habitant should be properly conveyed to such Mrs. Sunita Mane gram-panchayat of Malingaon for her type of topographical regions which is very important to assistance and sharing data used for this study. The authors create an awerness amongest the people. The main cause would also like to acknowledge the two reviewers and the editor for their helpful comments on the earlier version of for hill slope failure was an improper drainage system at the manuscript. This research did not receive any specific the top and middle part of the hill, which have created a grant from funding agencies in the public, commercial, or more pore water pressure in respective sections. The not-for-profit sectors. other major factors for landslide in this area was unplanned agricultural land creation and deforestation which was inferred from land use and land cover map. Disclosure statement The results of soil analysis indicate that FOS is less than No potential conflict of interest was reported by the authors. one (i.e., < 1) which suggest that slope is unstable and 6 C. R. SHAH ET AL. Arsenic research and global sustainability: Proceedings of the ORCID Sixth International Congress on Arsenic in the Environment Prashant. B. Bhagawati http://orcid.org/0000-0003-4156- (As2016) (pp. 66). Stockholm, Sweden: CRC Press. Palma,B.,Parise,M.,Reichenbach,P.,&Guzzetti,F.(2011). Rockfall hazard assessment along a road in the Sorrento Peninsula, Campania, southern Italy. Natural Hazards, 61(1), 187–201. Patil, V., & Gopale, R. (2018). A geographical study of Future Studies landslide: A case study of malin village of ambegaon tahsil For the current study stability of slope is carried out by in pune district, Maharashtra. Peer Reviewed estimating FOS with respect to geotechnical properties of International Research Journal of Geography, 35,55–60. soil and slope angle of hill in Malingaon. Land use and land Punmia, B. C., & Jain, A. K. (1970). Soil mechanics and founda- cover by arc GIS is used to identify the various causes of tions (16th ed.). New Delhi: Laxmi publication (P) Ltd. landslide, further this work is carried out to identify such Rahardjo,H.,Li,X.W.,Toll, D. G.,&Leong,E.C.(2001). The villages having same situation like Malingaon, and suggest effect of antecedent rainfall on slope stability. Geotechnical some preventive techniques to avoid occurrence of such and Geological Engineering, 19(3/4), 371–399. type of landslide in future. Use different techniques to iden- Ramakrishnan,D., Singh, T. N.,Verma,A. K., Gulati, A., & tify stability of slope such as finite element method, GIS, Tiwari,K.C.(2012). Soft computing and GIS for landslide GPS Techniques, etc., in this present study seepage analysis susceptibility assessment in Tawaghat area, Kumaon were not determined for accurate results further work on Himalaya, India. Journal of the International Society for the seepage is essential. In the present study, only three samples Prevention and Mitigation of Natural Hazards, 65(1), 315–330. each (Top, Middle, and Bottom) of failure slope is collected Thambidurai, p. (2017). Slope stability investigation of to determine geotechnical properties of soil, it is further chandmari in Sikkim, Northeastern India. In Workshop suggested to collect more soil samples for identifying geo- on world landslide Forum (pp. 363–369). Cham: Springer. technical properties of soil will increase accuracy of results. Sarkar, S., Kanungo, D. P., Patra, A. K., & Kumar, P. (2008). GIS based spatial data analysis for landslide susceptibility mapping. Journal of Mountain Science, 5(1), 52–62. References Sathe, S. S., Goswami, L., & Mahanta, C. (2019). Integrated factors controlling arsenic mobilization in an alluvial Chandrasekaran, S. S., Elayaraja, S., & Renugadevi, S. floodplain. Environmental Technology & Innovation. (2013). Damages to transport facilities by rainfall induced ETI 100525, Vol. 17C. doi:10.1016/j.eti.2019.100525 landslides during November 2009 in Nilgiris, India. Sathe, S. S., & Mahanta, C. (2019). Groundwater flow and Landslide Science and Practice, (Vol. 2, pp 171–176). arsenic contamination transport modeling for a multi Cho, S. E. (2014). Probabilistic stability analysis of rain- aquifer terrain: Assessment and mitigation strategies. fallinduced landslides considering spatial variability of Journal of Environmental Management, 231, 166–181. permeability. Engineering Geology, 171,11–20. Sathe, S. S., Mahanta, C., & Mishra, P. (2018). Simultaneous Collins, B. D., & Znidarcic, D. (2004). Stability analyses of influence of indigenous microorganism along with abio- rainfall induced landslides. Journal of Geotechnical and tic factors controlling arsenic mobilization in Geoenvironmental Engineering, 130(4), 362–372. Brahmaputra floodplain, India. Journal of Contaminant Ering, P., & Babu, G. S. (2016). Probabilistic back analysis of Hydrology, 213,1–14. rainfall induced landslide-A case study of Malin land- Singh,T. N.,Singh,R.,Singh, B.,Sharma, L.K., Singh, R., & slide, India. Engineering Geology, 208, 154–164. Ansari, M.K.(2016). Investigations and stability analyses of Ering, P., Kulkarni, R., Kolekar, Y., Dasaka, S. M., & Babu, Malin village landslide of Pune district, Maharashtra, India. G. S. (2015). Forensic analysis of Malin landslide in India. Journal of the International Society for the Prevention and In IOP Conference Series: Earth and Environmental Mitigation of Natural Hazards, 81(3), 2019–2030. Science,Warwick,UK (Vol. 26, No. 1, pp. 012040). IOP Thennavan, E., Ganapathy, G. P., Sekaran, S. C., & Rajawat, Publishing A. S. (2016). Use of GIS in assessing building vulnerability Fredlund, D. G., & Rahardjo, H. (1993). Soil mechanics for for landslide hazard in The Nilgiris, Western Ghats,India. unsaturated soils. New York, NY: John Wiley& Sons. Journal of the International Society for the Prevention and IS 2720-1985: Part 13 direct shear test, Indian Standard Mitigation of Natural Hazards, 82(2), 1031–1050. methods of test for soils Vasantha Kumar, S., & Bhagavanulu, D. V. S. (2008). Effect of IS 2720-1985: Part 5 determination of liquid and plastic limit, deforestation on landslides in Nilgiris district — Acasestudy. Indian Standard methods of test for soils Journal of the Indian Society of Remote Sensing, 36(1), 105–108. IS 2720-1985: Part 7&8 determination of water content-dry Wadhawan, S. K. (2018). Landslide susceptibility mapping, density relation using light compaction, Indian standard vulnerability and risk assessment for development of methods of test for soils early warning systems in India. Advances in Natural IS2720-1985: Part-3 determination of specific gravity, Indian and Technological Hazards Research, 50,145–172. standard methods of test for soils Walde, S., Kale, K., Kundu, S., Nagaraj, P., Shelar, T., & Mahanta, C., Sathe, S. S., & Bhattacharya, P. (2012) Grain Shukla, V. K. (2017). GIS based landslide susceptibility size, mineralogy and sediment composition as factors assessment of malin area: A case study in watershed, controlling release and mobilization of arsenic in parts India. 17th Esri India user Conference 2017, New Delhi. of the Brahmaputra floodplains, northeastern India. GSA Yin, Y., Wang, F., & Sun, P. (2009). Landslide hazards annual meeting in Charlotte. triggered by the 2008 Wenchuan earthquake, Sichuan, Mahanta, C., Sathe, S. S., & Mahagaonkar, A. (2016,June19– China. Journal of the International Consortium on 23). Morphological and mineralogical evidences of arsenic Landslides, 6(2), 139–152. release and mobilization in some large floodplain aquifers. In

Journal

Geology Ecology and Landscapes – Taylor & Francis

Published: Jan 2, 2021

Keywords: Landslide; stability of slope; Arc-GIS; hilly terrain

There are no references for this article.