K. Manikandan , S. Natarajan , R. Sivasamy , M. Sankar , K. S. Dadhwal

Abstract

Soil resources of the coastal region of Cuddalore district of Tamilnadu were evaluated to assess the productivity rating for field crops, pastures, agroforestry, forestry and other tree crops. The soil resources were inventoried using remote sensing approach. The IRS 1D PAN merged LISS III data at 1:50,000 scale was used for pre-field interpretations. The soils mapped were evaluated for its productivity for agricultural, pasture, agroforestry, forestry and other tree crops. The texture of the soils varied from sandy to clayey due to the coastal sand dune landforms (72%). Loam (Arasanatham, Srinivasapuram and Mangadu series) and clay soil (Kondal series) occupied 16 and 3%, respectively which falls under alluvium landform. The mean pH of the soils ranged from 6.79 to 8.29. The neutral soil phase (6.5 to 7.5) was recorded in Mahabalipuram, Vandiyampalayam, Padugai, Pulavanur and Arasanatham series which occupied 58% (4905 ha) of the study area. The remaining soil series exhibited alkaline pH ranging from 7.85 to 8.29 (3688 ha; 42%). The study revealed that 71, 16 and 3 % of the area falls under Entisols, Inceptisols and Veritsols, respectively.

Keywords

Coastal Lands, Remote Sensing, Productivity Rating, Soil Resource Inventory

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K. Manikandan , S. Natarajan , R. Sivasamy , M. Sankar , K. S. Dadhwal

Abstract

This research work was aimed to study the spatial and temporal changes in groundwater quality of the coastal region of Cuddalore district, Tamil Nadu. The study was conducted during 2006 for which the coastal area was divided in to three zones based on 1.5 km spatial distance from sea. The groundwater was collected from 27 representative shallow wells for the whole year with three-month interval representing different seasons. The water samples collected were characterized for its chemical composition as well as electro-che mical properties. Based on the chemical composition, different quality parameters were arrived. The results revealed that 88 per cent of the wells recorded for slightly alkaline p^H ranging from 7.6 to 7.9 with electrical conductivity varying froml.l to 4.0 dS m^-1. The sodium and magnesium hazard was higher in most of the wells. Seawater intrusion is the key factor, which decides the quality of groundwater in this coastal zone. Natural rainfall is the next most important factor which balances the negative effects of seawater intrusion. In total, the grolIDdwater quality of this coastal zone was poor during swnm.er and optimum during monsoon and post monsoon seasons which necessitates that sufficient care may be taken when using this water for agricuJtura1/agroforestry/fOrestry/other land use purposes.

Keywords

Ground Water Quality, Coastal Region. Seawater Intrusion, Spatial Variation. Temporal Variation

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