Prediction is essentially a step in EIA that projects the baseline environmental setting into the future. with or without project. For such predictions, Environmental status of the post project scenario of some of the already completed projects provides a ready and reliable information base for predicting real project related impacts. A 30 km stretch of Raghogarh and Gadher forests have a section of existing HBJ pipeline passing through it. The initial 30 km route of proposed pipeline follows this alignment of existing HBJ pipeline. Studies were undertaken in this 30 km stretch of existing pipeline to evaluate the environmental impacts of the project on forest stand, vegetation composition and wetland ecology. An assessment of secondary impacts of existing HBJ pipeline on regeneration of forest, land use and ecology of the adjacent forest area was also made.

Observations on different parameter in this area of existing pipeline would provide predictive trends in EIA. To evaluate the environmental impacts of existing pipeline on vegetation along the pipeline, 15X15 meter quadrat was laid at every 300 meter point in a 30 km long and 30 meter wide area of the existing pipeline. In each of these quadrats all the trees were identified and enumerated. An assessment of forest regeneration was made by enumerating all the seedlings and saplings with GBH less than 10 cm in each quadrat. For observing trends of recruitment, plant species with a GBH range of 10 to 20 cm were also enumerated in each quadrat. An estimation of shrub, weed and grass cover was also made in the existing pipeline area through random point sampling. Efforts were made to quantify the biotic pressure in these areas using cattle dung, lopping and wood cutting as indicators of biotic disturbances in the areas under existing pipeline. Direct and indirect evidences of wild animals were also collected from the area to assess the use of available habitat along the existing pipeline route.

In order to visualise the resultant changes in the forest ecosystem along the pipeline route, observations on all the parameters were repeated in the adjoining forest areas to determine the baseline status of the forest prior to project implementation.