Annexure IV: Report by Dr. V N Nayak, DOS Marine Biology, Karwar

Land slide scenario in Karwar
Dr. V. N. Nayak, 
Chairman, Dept of Studies in Marine Biology, Kodibag, Karwar

Opinion

In following lines I forward my preliminary observations as seen on 14.10.09 :

The primary cause has been unprecedented heavy downpour in a very short period preventing immediate drain leading to creation of pressure on loose soil component. In addition anthropogenic activities also have contributed largely in each of the places visited.

I. Sankrubag-Binga hillock

1. There has been large scale quarrying activity wherein frequent powerful blasts are made to break the rocks. This has caused large scale vibration loosening the boulders, and also root system of the plants that binds the soil. As most of the slides are around the quarry this could be one of the major causes.
2. While constructing the high way the hillock is cut vertically and therefore the water pressure on the rocks and soil must have made the hillock part to slide downwards.
3. Heavy traffic of loaded Lorries also adds to the vibration and might have contributed to the impact.

II. Baithkol hillock

1. Soil quarrying for construction of road along the southern border to transport boulders to break water has made an impact on the slope.
2. A road constructed to approach the drying place and vertical cut to expand the area of fish drying places loosened the soil  

III. Kadwad Region :

1. The entire top portion of hillock is devoid of any large trees.
2. The major component of the hillock is loose soil with hardly any granite beds.
3. When there is high tide there is increase in the water level at the base of the hillock preventing the easy seepage of water
4. It is said that the dam water was released during the same time thus increasing the water-reverse pressure.
5. There has been large scale soil quarrying along the first slide making vertical cuts.
6. Water flow from the hillock in the form of seepage and rain drain was prevented by long term encroachments.
7. Houses were constructed on the slope of hillock by leveling the soft soil and without any protective measures for possible land slide
8. Railway track running by the side of the hillock not only creates vibration, it echoes in view of other hills around.
9. The track platform prevented easy drain of water during floods.

Immediate action suggested in Kadwad

1. Western portion of the hillock between two slide points is still intact mainly due to little forest created by protected trees. This portion is highly vulnerable in the near future in view of the open hillock. There is a need to survey and rehabilitate them.
2. Making proper rain drain and slopes to prevent further slide.

Move to Annexure III

Move to Annexure V