Landslide Hazard Mitigation in Kozhikode district, Kerala

The project started in July 2003, aims to evolve landslide hazard zonation and suggest mitigation plans for implementation in the Kozhikode district of Kerala. The work is being carried out in two phases. In the first phase, the study area will be subjected to a rapid landslide zonation on scale 1: 50,000 in a GIS environment, categorizing the area into critical, highly unstable, moderately unstable, moderately stable and stable regions. Analysis of the terrain parameters viz. slope, relative relief, drainage pattern, drainage density, land use, geology, geomorphology and landslide population in the study area generated from the secondary data, remote sensing, air photo and field work will form basis for zonation. In the second phase, the critical and highly unstable categories which demand immediate mitigation measures shall be evaluated on 1: 12,500 scale through detailed field work. Site-specific mitigation measures thus evolved shall be communicated to the government and the concerned Panchayats or LSG for implementation. From the slope maps prepared , the areas falling in the slope category of 160 was considered for mapping of various terrain parameters. Landuse, drainage pattern and density, relative relief and landform maps are completed for further analysis

Landslide mitigation study in landslide prone areas of Pathanapuram taluk, Kollam district:

Terrain evaluation was carried out in the Edamon, Aryankavu and Tenmala villages of Pathanapuram taluk, Kollam district to identify landslide prone areas. Thematic maps related to terrain parameters such as slope, drainage, landuse, relative relief were prepared using GIS and conventional methods. Out of the total 360 sq. km, about 3.76 sq. km is found to be critical and 70.54 sq. km area has been identified as highly unstable. The moderately unstable area constitutes 151.24 sq. km and moderately stable and stable areas constitute 96.46 and 38.00 sq. km respectively. It implies that about 1.04% of the studyarea is falling in the critical zone and about 19.59% of the study area is falling in the highly unstable category. It means that about 20% of the study area needs careful handing as far as slope stability is concerned. Analysis indicate that places such as north flank of Nagamala, Tooval mala Tenmala-Ottakkal, west Thirthakaramala near Aryankavu, Peak 222 near Ambanadu Ar, Thunnattumala, Rishimala, Kalangamalateri, Karithod north, Minulli Ar etc may require special attention as far as vulnerability is concerned. Dewatering methods such as opening of stream-channels and poorly defined drainage channels (hollow sections), providing drainage to terraces, strengthening of toe and other slope-cut portions are suggested to stabilize critical and highly unstable slopes.