Life Line Of Nagaland Endangered

Robert Lanky *

National Highway-39 is the life line of Nagaland and Manipur. The 74 Km long stretch of NH-39 which ascends from Chumukedima (Altitude 495 feet to Zakhama, Altitude 5245 feet) passes through a geologically unstable area where hill slopes are subjected to subsidence upheavals, aggravated by frequent tremors, causing large scale land slide (since it is a seismically active zone). " The maintenance of the road becomes more complex because of quarrying and due to the clay soil, which loses strength on contact with water and cracks when dry". Said an expert on roads.

The road Dimapur-Kohima-Mao-Maram(DKMM) takes off from Numaligarh and connects Assam with Nagaland and Manipur. Part of NH-39 from Dimapur to Maram is being maintained by Border Road Organisation (Project Sewak). Tragedy with NH-39 are endless. Sometimes it is subjected to bandhs due to illegal extortion, agitations and road blocks etc by various organisations for meeting their demands by state government. But, most of the time it is closed due to landslides. The road is subject to landslides especially during the monsoon period. Initially on this highway, frequency and magnitude of the land slides was very minor and generally neglected. But in last few years it has increased due to quarrying specially during monsoons.

Few years back in 2003, then The Prime Minister of India Mr Atal Behari Vajpayee travelled along this 70 Km stretch, which can hardly be called a National Highway had 'bumpy ride' since his helicopter could not take off due to bad weather. Then, The PM said: " Speaking of roads in Nagaland, I have to say that, I had a first hand experience. Mother nature wanted me to take the road from Dimapur to Kohima.

I was told that, of all the roads in the state, this is the best. If this is the best, it is difficult to imagine how bad is the worst"? During his visit he announced that, the 'Golden Quadrilateral', will be extended to Kohima, and the centre will spend Rs 400 crore on converting this stretch of NH-39 into a four-lane highway. He also announced another Rs 40 crore to the state for building roads, but not before laying one condition : " The roads must be of good quality-much better than the existing roads".

Many a times blame game have been in practice between maintenance agency and PWD/Govt. Various organisations had also criticised the agencies responsible to maintain this highway in the states of Nagaland and Manipur. A 'Study' was also carried out by a reputed institute (Central Road Research Institute - CRRI). In their investigation the institute had given many reasons for frequent landslides on NH-39. Among all, one of the prominent reasons was 'QUARRYING' and its effects at various landslides area on road NH-39. As per CRRI; there are many causes of landslides : These are sinking of roads, breaking up of roads, quarrying, lack of vegetation, rainfall and all of which are existing along the NH-39 stretch.

Disturbance caused by quarrying is one of the major factors which upsets the balance of forces within a slope by changing the structure of loose rocks and soil and eventually triggers landslides. Probable causes of the landslides on this stretch has been enumerated by CRRI in detail as : Weak geological formation, High rain fall, High weathering and erosion, Deforestation, Inadequate protection measures, Cohesive soil (silty clayey), Quarrying and Non functional roads, Successive failure (co controlled), Cultivation field with irrigation etc.

To look into the details of quarrying on NH-39 which is causing maximum damage to the road, self with one of my colleagues who has got expertise in the field of road construction surveyed the stretch. During the survey at various places between Dimapur - Kohima illegal quarry sites have been found, which are responsible for disturbing as well as exposing the soil strata. Over a period of time these quarries have led the slopes in becoming unstable, leaving the area prone to landslides. In addition quarrying have caused the following problems too :
* Land Degradation in the form of alternation of land structure due to excavation.
* Disturbing of natural surface drainage patterns. Heavy induction of water beneath the road material layers.
* Degradation of forest and decrease in bio-diversity. Mining/Quarrying either open cast or underground destroys landscape and forest eco system.
* Air and Noise pollution-common environmental problem in all mines and quarries, especially during open cast in formation.
* Surface and Ground water pollution –Water balance is affected due to the changes in the surface hydrology, soil texture and terrestrial vegetation.
* Abandoned Quarries- Become a continuous source of degradation of the slopes, accident prone areas and have serious environmental and socio- economic impacts.

To assess the effect of quarrying on NH-39 the CRRI from year 2000-2009 has carried two studies at various landslide location at villages Lalmitti, Jotsoma, Kohima and Mao Gate from Kms stone no 162 -221. A detailed report by the CRRI was submitted to the state government and to the agency responsible for maintenance of NH-39.

The highlights of report was :
* Uphill slope : Stone quarrying was observed on many uphill slopes and the quarry locations have become degraded due to subsidence, and is an area for impounding of rain water.
* Downhill slope : The rock surface is highly weathered and gives impression of being sheared/crushed/pulverized.
* Effects on Mountains and their constituents: The rocks are highly weathered with presence of large number of cracks and joints and large and small scale faults and thrusts, thus making them weak. Such soil once reclaimed or disturbed due to quarrying forms a honey comb structure and poses difficulty in consolidating itself.
* Climate and Rainfall : Area experience sub moderate to cool temp varying from 8º to 40º C. Average yearly rainfall is 2000 to 2500 mm with maximum rainfall during month of May -October.
* Land Use Cultivation : Improper land use practices such as heavy tilling agricultural practices and settlement patterns have contributed to creep and withdrawal of toe support in many cases. Due to deforestation and impounding JHOOM CULTIVATION, subsurface flow increase manifold, which increases the angle of repose of hill slope and contributes instability to hill slope. Water contents of soil changes from 2% to 16% due to prolonged rainfalls of varying intensity, which leads to the decrease in shear strength and increase in shear forces, resulting finally in sinkage or movement of hill slopes.
* Common Factor - It is noticed that most of these vulnerable slopes have gone through deforestation in the recent past, cultivation of seasonal crops and increase in settlements.
* Excessive and haphazard quarry : Quarry operation and development activities along the highway, Impounding Jhum cultivation, construction of approach roads and houses etc, has all led to occurrence of landslide. Blocking of surface drainage, loading of critical slopes and withdrawal to toe support promoting vulnerability of critical slopes.

The present state of the road is that, in last one year there have been extensive works on NH-39 with approx expenditure of Rs 25 crore, however, certain existing problems are nullifying the effort put in to bring up the road to the desired level of user satisfaction. Problems have been brought to the notice of concern monitoring agencies as well as to the knowledge of state government, but no concrete steps have been taken up to curb illegal activities like:
* Quarrying : Rampant quarrying is under progress between Kiruphema (Km 158 -159 ) at Lalmitti Area (Km 162) and Jotsama (Km 170-171) which is making the hill slope unstable besides blocking the drainage.
* Approach roads- So many approach roads have been constructed by cutting the hill side from Km 131 to 182(From all along the road side from Jharanapani to Kohima town. These roads have weakened the hill slopes tremendously.
* Washing Pits - At Km 148 and 171 (place between Pherima & Piphema and Jotsoma) are degrading the road surface.
* Unauthorised Construction: A number of unauthorised construction have recently come up from Km 131 to 181 (from villages like Jharnapani , Zubza, Jotsoma thus blocking the drainage and damaging the road surface.

After having gone through the CRRI report and first hand experience by survey in detail on NH-39 and also interaction with Border Roads Organisation officials, we could gather few remedial measures :
* The down ward movement of the slope has to be arrested by nullifying the destabilizing factors, in the form of construction of horizontal drains.
* Gabion walls with greater flexibility.
* Increase in number of culverts for cross drainage and compaction of loose soil along the slopes by forestation.

The remedial measures require immediate attention by the maintenance agency, and State Government which has got most important role to play if it want that the life line of Nagaland & Manipur to be safe and remain open throughout the year without endangering the lives of common man. The State Government should enforce a land lease act to ban quarrying along the road or shifting it to areas where it will not affect the stability of slopes considerably.

Govt should also identify common dumping space for overburden from various construction sites, as in general it is dumped along the road side. Restriction on Jhum cultivation be enforced on the uphill slopes. Restoration of tree and vegetation covers on the slopes in proximity of road (NH-39) should be taken up as 'Basic Mantra' for saving the road from degradation and valuable human life.
The landslide areas are frequent choke point and lead to disruption of traffic, inconvenience to public and colossal loss to effort put in by the maintenance agency year after year. Until, a coordinated effort by BRO and State Govt is taken up seriously life line of the state and lives of all of us will always be endangered. The road from Zubga to Kohima may just disappear one day, if stone quarrying near the road is not totally stopped.

STOP THE QUARRYING IMMEDIATELY.