Water and Soil Quality Analysis of Selected Areas of Sunderban and Mapping Using GIS Technique

Abstract

Mangrove ecosystem of Sunderbans is dynamic, fragile and comprised of a complex network of estuaries, tidal inlets, tidal creeks and large number of islands. Due to temporal and spatial variations in water and soil qualities, monitoring programs help to understand quality of natural ecosystems. The present investigation was undertaken to assess seasonal and spatial variations in pH, electrical conductivity, total dissolved solids, hardness, turbidity, sodium and potassium of water. Similarly, soil samples were also checked for pH, electrical conductivity, total dissolved solids, water holding capacity, organic carbon, organic matter and calcium carbonate. The results of the various parameters significantly fluctuated over different seasons. The surface water of the study area was brackish to brine. All parameters except turbidity have shown highest concentration in monsoon. Overall, the concentration of water quality parameters were governed by flushing of rainfall, river water flow, seawater intrusion,  runoff from agricultural fields and oil from spill. The high percentage of organic matter and calcium carbonate content might beattributedto decomposition of plant-animal residues in mangrove area. Mud content in the study area was higher because of high organic matter in the soil while the high water holding capacity directs that soil was clayey in texture. It is advisable that continuous baseline, monitoring studies for water and soil quality analysis is carried out with scientific approach to conserve the mangrove ecosystem. Monitoring programs using remote sensing and GIS can be used to tackle the threats at all levels efficiently.