Reconnaissance survey report of landslide in Mansa Devi Loose sediment, rock and weathered materials usually remain stationary and stable on a slope, however matter can be disturbed naturally by earthquakes or by heavy rainfall, or by human activity such as road construction, when disturbed, the debris is pulled down by gravity and, with water acting as a lubricant, a landslide is created. The damage can be disastrous- wiping out communications networks or causing damage to life and property but the good news is that, unlike other geological hazards, landslides can be predicted with technology. Main area of Haridwar which is highly effected due to landslide Mansa Devi hill is spread out the area of approximately 2 km. (?) from Mansa Devi main gate to at the end of Bhemgoda road. A reconnaissance survey had been carried out around the Mansa Hill locating the landslide prone areas. It has been found that there are many, small as well as large, landslides along the slopes of the Mansa hill and ominous for highly built-up areas and populations that has been developed along the foot hills and adjoining areas near Mansa hill specifically along the Bhemgoda road, Haridwar. The built-up areas are in danger zone due to landslide in Mansa hill towards the loss of human properties and human being himself. On the date 25/08/08 to 26/08/08 of my visit, I visit the route from Haridwar bus stop to Mansa Devi hill. The distance from the bus stop to Mansa Devi gate is 2 km. and the time taken is 5 minutes by local vehicle. There are two route for go to Mansa Devi temple – one route by the trolley and the second route by on foot. The distance from the gate to Mansa temple by on foot is approximately 1 hour i.e. speed 0.89 km/hr. I visit this area but there is no such type of deformation due to landslide by which the temple is coming up in the prone situation. Some years ago in 1994, 1996, and 2004 there had been a lot of area deformities due to landslide and all the observation i.e. how much area deformities, what is the % deformation and how much properties losses are currently available on the forest department of Haridwar. There are two latest prone area of my visit which is regularly damaged and in the future there will be definitely landslide occur and also would be loss of human being and their properties as follows – (1) Bheemgoda road hill by pass (2) Hill by pass between the seedy marg and road marg On the date of 29/08/08 to 30/08/08 of my second visit /survey i checked both both the area and collect all the information for our land warning system. Above the two prone areas, the first one description is as followsROUTE OF BHEEMGODA ROAD: Mansa Devi gate to hari ki pauri distance is 1 km. and from hari ki pauri to Bheemgoda road is another approximately 1 km. In the range of Bheemgoda road the sankar ashram area has spoiled due to landslide and in observe also the property loss due to the latest landslide on the previous date 20/08/08. I have to taken all the advice through Haridwar local public for forthcoming landslide at the same place. I have already collected the coordinates of that area by the Magellan GPS receiver. The total area from hari ki pauri to bheemgoda road (sankar ashram) is very close to landslide. In this area and all the area has to be damaged or dangerous to local public in the rainy season. The work has been done by the PWD department but no progress has been seen for the Haridwar Public to the protection of landslide. ORGANIATION WHO IS PRESENTLY WORKING MANSA HILL LANDSLIDE By central scientific instrument organization, council of scientific and industrial research, Govt. of India, Chandigarh and Thaper institute of Engg. And Technology. By this organization recently developed technique for landslide monitoring is based on time- domain reflectometry. This Technology uses coaxial cable and a cable tester; however, it suffers from errors in reading caused by water seepage and electromagnetic interference. Experiments were performed at an active landslide site near Mansa Devi temple in uttaranchal, India. At landslide prone location, a fiber optic interrogation system was installed, along with the conventional instrumentation. The idea was to fix the threshold by comparing the data obtained from the optic interrogator with that from conventional instrumentation such as the tilt meter, inclinometer etc. The fiber optic sensor installed along the hill slope has micro bend resolution enhancer with a real for holding about 10m of fiber enclosed in a biconical casing, which was used at the junction of the two micro bend – resolution enhancer to simulate the effect of a landslide. The sensor cable show is 20m long, so it is sufficient to monitor the bulk of the landslide’s movement. The cable length can be increased according to the size of the area to be monitored. During monsoon one or two incidents lightning of cloud burst and health floods are occurring Mansa hill in 1991. In contrast to the slides along the “main boundary thrust” (MBT) and “main central thrust” (MCT), the slides along the “delhi-haridwar-harsil” (DHH) fringes are on the eastern / western side of hill slope as the DHH trends in NNE- SSW direction e.g. Mansa Devi slides in Haridwar facing eastward. These slides block the road, communication and pose danger to the settlements while show movement or creep that are seen in soil, that are quite thin (hardly 20cm thick) on the hill slope. There are several tear faults parallel to the trend of the DHH which are causing problems of mass movement. The landslide/ slope failures can be minimized by taking suitable remedial measure and the treatment have to location specific. In our study field of visit of landslide in Mansa Devi hill on the date 23/09/08. We observed firstly the area which is very highly effected due to landslide e.g. most population of Haridwar are comming in the range of landslide. Then we have to establish the one reference point at the Baraj Bridge (bench mark) and the 6 observation point on the landslide area which is as follows with their photograph. 1- Baraj bridge reference point (N 29º57.522´ E 78º10.705´) 2-CP-4 (Bhemgoda Road Shankar Ashram) Coordinate (N 29º57.850´ E 78º10.347´) Bhemgoda road shankar ashram 3-CP-1(By pass road between the Mansa hill) Coordinate (N 29º58.067´ E 78º10.056´) Observation area of landslide 4- CP-2(By pass road between Mansa hill) Coordinate (N29º57.994´ E 78º10.101´) Observation area of landslide 5- CP-3 (By pass road Mansa hill) Coordinate (N29º57.967´ E 78º10.150´) Observation area of landslide 6-CP-6(By pass Mansa hill road band) Coordinate (N29º58.180´ E 78º10.105´) Observation area of landslide 7- CP-5 (The area between Shankar ashram and hill by pass band road of Mansa) Coordinate (N29º58.131´ E 78º10.132´) CP-5 (N29º58.131´ E 78º10.132´) Observation area of landslide Then we have to create a route path between all the observation point and landslide area during our reconnaissance survey with the help of “GARMIN GPS RECEIVER” (WGS 84) . Reference Point of Baraj Bridge near bheemgoda road Route created during field survey Route created our field survey at CP- 1 Route created of landslide area due to flow of water Route created of landslide area at CP-2 Route created of landslide at CP-3 Landslide area of along the road of Mansa hill Landslide area due flow of water WAY POINT PROPERTIES WAY POINT Reference at Baraj bridge CP-4(Shankar Ashram) CP-6 CP-5(Between shankar Ashram and Mansa hill road) CP-1(Between Mansa hill) CP-2(Between Mansa hill) CP-3(Between Mansa hill) ALTITUDE 272.7 m 276.3 m 324.9 m 313.5 m 405.9 m 391.5 m 385.8 m TIME 11:18:06 am 10:56:05 am 10:23:30 am 9:43:03 am 9:50:20 am 9:55:18 am Distance, area, and bearing from Baraj Bridge to all observation point: Reference point Baraj Bridge Baraj bridge Baraj bridge Baraj bridge Baraj bridge Baraj bridge Way point Distance To To To To To To CP-4 CP-6 CP-5 CP-2 CP-3 CP-1 0.5 mi 1.0 mi 0.9 mi 0.8 mi 0.8 mi 0.9 mi Area 4740.12 sq m 56804.67 sq m 44034.75 sq m 41154.48 sq m 31862.97 sq m, 25240.05 sq m Bearing 316º,true 322º,true 321º,true 312º,true 313º,true 314º,true Distance, area, and bearing of all landslide area from Shankar ashram CP-4 Shankar ashram reference point CP-4 CP-4 CP-4 CP-4 CP-4 To To To To To Landslide way point CP-5 CP-6 CP-1 CP-3 CP-2 Distance Area 0.4 mi 0.5 mi 0.5 mi 0.6 mi 0.5 mi 2148.03 sq m 4189.68 sq m 50757.21 sq m 43157.16 sq m 54611.46 sq m Bearing 327º, true 328º, true 311º, true 305º, true 304º, true Latitude and longitude of all way point in terms of hdddº mm.mmm´ Way point CP-1 CP-2 CP-3 CP-4 CP-5 CP-6 LS-2 LS-1-P REF. BARAJ Latitude N 29º52.154´ N 29º57.994´ N 29º57.967´ N 29º57.850´ N 29º58.131´ N 29º58.180´ N 29º58.039´ N 29º58.067´ N 29º57.522´ Longitude E 77º53.903´ E 78º10.101´ E 78º10.150´ E 78º10.347´ E 78º10.132´ E 78º10.105´ E 78º10.080´ E 78º10.056´ E 78º10.705´ Map of landslide prone area PRADEEP KUMAR (
[email protected]) Research scholor IIT-Roorkee (Uttarakhand)