Commissioner & Secretary, Geology & Mining and Horticulture, Sentiyanger Imchen IAS is seen speaking during the meeting. (Morung Photo)
DIMAPUR, AUGUST 12 (MExN): The Department of Geology & Mining, Government of Nagaland held the 31st State Geological Programming Board (SGPB) meeting on Friday, August 12. The meeting held at the Directorate of Geology & Mining was chaired by Commissioner & Secretary, Geology & Mining and Horticulture, Sentiyanger Imchen IAS. Officials from the Geological Survey of India (GSI) were also present.
Besides reviewing the progress of works being undertaken by the GSI, NEIST, IBM, CGWB, NSMDC Ltd as well as the department, the highlight of the meeting was the release of two comprehensive reports on ‘Landslide Hazard Zonation and Disaster Management/Mitigation Plan’ and ‘Geological Hazard Studies of Townships’ (2009-10 2010-11). The reports prepared by the department of G & M are envisaged to be a base for all future land-use planning activities, disaster management, mitigation and remedial action. It was simultaneously compiled over a period of two years (2009-11) funded under the State Plan.
Dmr-Kma stretch: 96 landslides classified as active, 84 potential
The report, ‘Landslide Hazard Zonation and Disaster Management/Mitigation plan using Remote Sensing (RS) and Geographic Information System (GIS) – a case study along National Highway 29 between Dimapur and Kohima’ is a detailed scientific research based inventory (map) generated for the first time by the department making use of all existing information and current data on landslides between Kohima and Dimapur, National Highway 29 (formerly 39). The significance of the data generated is that it will play a key role in indentifying vulnerable zones, designing of early warning systems and adequate mitigation measures in landslide prone areas and will be of great help to the agencies shouldered with the responsibility of maintaining national and state highways and others.
The study was taken up based on the earlier works of the Geological Survey of India, DGM, CRRL, Department of Geology (Nagaland University) and the mapping was done with the help of high resolution images followed by intense fieldworks covering 17 villages/towns falling along and around NH 29 (Chumukedima-Kohima), in total 108.85 square kilometers in area. It used Remote Sensing and Geographic Information System Technology. “Landslide Hazard Zonation Maps in general, are useful tool for the planners, administrators or other decision makers to have quick appraisal regarding the relative stability of a given area.” It was carried out in consultation with Indian Institute of Remote Sensing, Dehradun with Prof. RC Lakhera, former head of Geosciences Division of the institute.
“The main goal of the Landslide Hazard Zonation (LHZ) Project is to create awareness to all the agencies involve in maintaining the NH as well as to the public by better describing and mapping all potentially unstable slope areas along the NH 29. The LHZ project also will provide information useful for appropriate mitigation. Hence during the period of investigation, in order to disseminate all the important technical information to the inhabitants settling along the highway, public awareness campaign has been conducted in five locations. The public response was very positive.” Thus, stated an excerpt from a summary of the report.
A total of 277 (land) slides were mapped and classified accordingly. According to the classification, 96 are active, 35 inactive, 84 potential, 3 reactive, 47 suspended and 12 dormant. “There are about 109 landslides including rockfalls and flows that are active or subsiding landmass having potential to damage the road. The magnitude and the geometry of the slides differ from one to another,” stated the abstract of the report.
The contributing factors were mainly anthropogenic i.e. an effect or object resulting from human activity and rainfall. It pointed out quarrying alongside the highway as the most worrying activity. The anthropogenic activities I the study area continue without any inhibition…” due to the lack of stringent laws or non-implementation of the laws. “There are 28 stone quarries within the area affecting road, human settlement and environment, which require immediate attention of the government,” it stated.
“It is ironic that though there had been some scientific research on landslides by various agencies since decades back no scientific remedial measures recommended by them was taken up although most of the recommendations were affordable.
There seemed to be no will from the government to invest in the scientific inputs for slope stability, apart from traditional stabilizing methods of constructing retaining walls and gabion along the road sides during or after the slides.” Medziphema-Kohima segment, it stated, demands urgent attention.
“The present study shows that scientific inputs are beneficial… Therefore separate annual fund allocation should be made to yield the benefit of scientific technology on landslides mitigation and stabilization support by strong and favourable legislations.”
Six district headquarters, namely - Phek, Mokokchung, Kohima, Wokha, Dimapur, Zunheboto came under the ambit of the Geological Hazard Studies of Townships. It is said to be the first phase of the project.
The basic objective of the project is to indentify, delineate and classify natural hazard and other related phenomenon and prepare hazard zonation map accordingly for the towns earmarked. A total area of 360 square kilometers was mapped. It identified “41 landslides/rockslides, 5 debris avalanche, 38 palaeo slides, 40 slide susceptible zones, 52 bank erosion, 50 soil erosion, 12 flooded, 10 water logging, 25 rock fall, 20 soil creep, 6 waste disposal, 2 lighting, 2 hailstorm, 26 quarry, 271 water wells and 71 natural springs” which were termed as ‘geological hazards’. All the six townships are being affected or under threat from one or the other geo-hazards like earthquakes, water contamination etc, it stated.
Besides reviewing the progress of works being undertaken by the GSI, NEIST, IBM, CGWB, NSMDC Ltd as well as the department, the highlight of the meeting was the release of two comprehensive reports on ‘Landslide Hazard Zonation and Disaster Management/Mitigation Plan’ and ‘Geological Hazard Studies of Townships’ (2009-10 2010-11). The reports prepared by the department of G & M are envisaged to be a base for all future land-use planning activities, disaster management, mitigation and remedial action. It was simultaneously compiled over a period of two years (2009-11) funded under the State Plan.
Dmr-Kma stretch: 96 landslides classified as active, 84 potential
The report, ‘Landslide Hazard Zonation and Disaster Management/Mitigation plan using Remote Sensing (RS) and Geographic Information System (GIS) – a case study along National Highway 29 between Dimapur and Kohima’ is a detailed scientific research based inventory (map) generated for the first time by the department making use of all existing information and current data on landslides between Kohima and Dimapur, National Highway 29 (formerly 39). The significance of the data generated is that it will play a key role in indentifying vulnerable zones, designing of early warning systems and adequate mitigation measures in landslide prone areas and will be of great help to the agencies shouldered with the responsibility of maintaining national and state highways and others.
The study was taken up based on the earlier works of the Geological Survey of India, DGM, CRRL, Department of Geology (Nagaland University) and the mapping was done with the help of high resolution images followed by intense fieldworks covering 17 villages/towns falling along and around NH 29 (Chumukedima-Kohima), in total 108.85 square kilometers in area. It used Remote Sensing and Geographic Information System Technology. “Landslide Hazard Zonation Maps in general, are useful tool for the planners, administrators or other decision makers to have quick appraisal regarding the relative stability of a given area.” It was carried out in consultation with Indian Institute of Remote Sensing, Dehradun with Prof. RC Lakhera, former head of Geosciences Division of the institute.
“The main goal of the Landslide Hazard Zonation (LHZ) Project is to create awareness to all the agencies involve in maintaining the NH as well as to the public by better describing and mapping all potentially unstable slope areas along the NH 29. The LHZ project also will provide information useful for appropriate mitigation. Hence during the period of investigation, in order to disseminate all the important technical information to the inhabitants settling along the highway, public awareness campaign has been conducted in five locations. The public response was very positive.” Thus, stated an excerpt from a summary of the report.
A total of 277 (land) slides were mapped and classified accordingly. According to the classification, 96 are active, 35 inactive, 84 potential, 3 reactive, 47 suspended and 12 dormant. “There are about 109 landslides including rockfalls and flows that are active or subsiding landmass having potential to damage the road. The magnitude and the geometry of the slides differ from one to another,” stated the abstract of the report.
The contributing factors were mainly anthropogenic i.e. an effect or object resulting from human activity and rainfall. It pointed out quarrying alongside the highway as the most worrying activity. The anthropogenic activities I the study area continue without any inhibition…” due to the lack of stringent laws or non-implementation of the laws. “There are 28 stone quarries within the area affecting road, human settlement and environment, which require immediate attention of the government,” it stated.
“It is ironic that though there had been some scientific research on landslides by various agencies since decades back no scientific remedial measures recommended by them was taken up although most of the recommendations were affordable.
There seemed to be no will from the government to invest in the scientific inputs for slope stability, apart from traditional stabilizing methods of constructing retaining walls and gabion along the road sides during or after the slides.” Medziphema-Kohima segment, it stated, demands urgent attention.
“The present study shows that scientific inputs are beneficial… Therefore separate annual fund allocation should be made to yield the benefit of scientific technology on landslides mitigation and stabilization support by strong and favourable legislations.”
Six district headquarters, namely - Phek, Mokokchung, Kohima, Wokha, Dimapur, Zunheboto came under the ambit of the Geological Hazard Studies of Townships. It is said to be the first phase of the project.
The basic objective of the project is to indentify, delineate and classify natural hazard and other related phenomenon and prepare hazard zonation map accordingly for the towns earmarked. A total area of 360 square kilometers was mapped. It identified “41 landslides/rockslides, 5 debris avalanche, 38 palaeo slides, 40 slide susceptible zones, 52 bank erosion, 50 soil erosion, 12 flooded, 10 water logging, 25 rock fall, 20 soil creep, 6 waste disposal, 2 lighting, 2 hailstorm, 26 quarry, 271 water wells and 71 natural springs” which were termed as ‘geological hazards’. All the six townships are being affected or under threat from one or the other geo-hazards like earthquakes, water contamination etc, it stated.
