2.1 ENVIRONMENTAL IMPACT ASSESSMENT
Environmental Impact Assessment (EIA) is a procedure which provides an opportunity to identify the potential environmental and social consequences of the proposed developmental activity and also able to suggest strategies for mitigating those identified adverse effects right at the planning stage. This way the major contribution of EIA in environmental management may well be in reducing adverse impacts and making necessary alterations in the developmental proposals. The overall methodology used in the present study has been described in the following sequential sections.

2.2 CONSULTATION OF BACKGROUND INFORMATION
As a foremost requirement of the present study, detailed relevant Feasibility Reports prepared by M/s IOCL, Refineries & Pipelines Division, New Delhi were obtained and consulted. These reports were used throughout the field studies as a major reference material. Maps depicting routes of existing and proposed pipelines with various allied facilities en route provided by the IOCL were referred intensively during the field reconnaissance and intensive studies. These maps were of great help in locating sample points.

In addition to the background information and maps provided by the IOCL relevant toposheets of Survey of India in the scale of 1:50,000 and a hydrographic map (Scale 1:1,50,000) for the Gulf of Kutch were also used during the field studies. Information on Protected Areas (PAs), important wildlife habitats, floral and faunal diversity for all concerned areas were collected from he WII's National Wildlife Database. Simultaneously bibliographic search for published information was undertaken by consulting individuals/ libraries of concerned organizations viz. State Forest Department of Gujarat, Space Application Centre (SAC), Ahmedabad; Bombay Natural History Society (BNHS), Bombay and a number of other institutions.

2.3 MACRO LEVEL ASSESSMENT
The second step in the present study was the macro level assessment which involved the identification of protected areas (National Parks, Wildlife Sanctuaries) and ecological sensitive ecosystems/ wildlife habitats en route the existing and proposed pipelines. Broad ecologically sensitive ecosystems and wildlife habitats recognized en route the pipeline were viz. wetlands (rivers, lakes and village ponds), grasslands, forests (thorny woodland and open scrub) and man-made plantations as these are prime habitats for diverse terrestrial and aquatic flora and fauna. It was considered that the disturbances associated with the construction activities would be uniform all along the pipeline route; the impacts on ecologically sensitive areas en route would be more significant and therefore, need to be evaluated more carefully.

2.4 RAPID FIELD ASSESSMENT
The field study was conducted during May, 1994 in this section by an independent research team comprising scientists and researchers from WII and representative from the EIL.

The reconnaissance along the pipeline route included an assessment of overall land use pattern and the extent of ecologically sensitive areas. For this purpose 25 sample points in this section (total pipeline length - 141 km) along the pipeline route were visited. Surveyed sample points were largely randomly located and some additional points were included intentionally in view of their earlier identification as ecologically sensitive wildlife habitats on those locations. On an average a sample point was surveyed at least once every 5-6 km interval. At each sample point, data on the pipeline reference number, land use pattern and wildlife values (existing and potential) were recorded. The crucial wildlife habitats thus identified during the reconnaissance were revisited for intensive studies. Impact assessment methodologies used for the intensive studies were specific for each wildlife habitat category and are described below.

2.5 INTENSIVE STUDIES
Basedon the above three steps viz. consultation of background information, macro level assessment and rapid field assessment only wetlands were identified as ecologically important areas for the purpose of present study.

Intensive studies were undertaken in the above described major wildlife habitat categories using the methodologies outlined below separately for each of the category.

2.5.1 Wetlands :
Wetlands are areas transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or land is covered by shallow water (SAC, 1992). Wetlands thereby support a very wide array of ecologically important floral and faunal species some of which are rare, vulnerable and endangered. Conservation of these sensitive ecosystems is a must for the sustenance of life support systems. The pipeline crosses some of the major rivers along its course. Majority of these rivers were seasonal and hence, during the field survey in the month of May they were dry. At each river sample point short stretches upstream and downstream were walked in order to appreciate the river width, type of banks, river-bed, direct and indirect evidences of wildlife and moisture/ water availability. At each location local people were also interviewed for obtaining secondary information on wildlife values (fishes, crocodiles, turtles, birds, river characteristics, etc.) In case of lakes and village ponds a similar methodology as described in the case of rivers was applied.

2.6 EVALUATION AND ASSESSMENT CRITERIA FOR CONSERVATION SIGNIFICANCE
The assessment of how and why a species, a population, a community, a habitat and an ecosystem as a whole are threatened is crucial to rational decision making before the implementation of a major developmental project. Spellerberg (1992) has provided a set of ecological guidelines for determining priorities for nature conservation. Taking a clue from these guidelines a set of evaluation criteria for the assessment of conservation significance of various wildlife habitats/ ecosystems en route the proposed pipelines project has been evolved and described here.

(i) Legal status of wildlife habitats :
Under the Forest Conservation Act, 1980 and the Wildlife (Protection) Act, 1972, forests and wildlife areas have been provided varying level of protection, legal status and also provisions of different levels of uses. Accordingly five categories viz. National Park (NP),Wildlife Sanctuary (WLS), Reserved Forests (RF), Protected Forests (PF) and privately owned areas were recognised and conservation significant rating viz. 5, 4, 3, 2 and 1, respectively to them have been assigned. It is obvious in this case that a National Park has the highest conservation importance.

(ii) Extent of wildlife areas :
Size or actual extent of a wildlife area is critical because the capacity to support the range of diverse flora and fauna of an ecosystem would depend on the total area included for or available to conservation such values. Following evaluation criteria have been evolved with regard to the size of grassland, a forest and an open scrub. Categories of coastal and marine ecosystem and wetlands (rivers, lakes and village ponds) have been excluded from this particular evaluation criteria.

Similarly for various categories of wetland a separate criteria on the basis of their seasonality have been evolved. These criteria classes are: (a) Wetland having water only during the monsoon season of3-4 months, (b) Wetland having water during the greater part of the year except the dry summer season, and (c) Wetlands which are perennial. These wetlands have been assigned ranking values 1, 2 and 3, respectively. These values are in an increasing order of conservation significance.

(iii) Status of wildlife habitat ecosystem - Species diversity, biological productivity and present level of threat :
In view of a very large extent of proposed pipeline, and adoption of rapid assessment methods, it was not possible and desirable to present detailed inventories of flora and fauna for each area, assessment of overall species diversity and estimation of primary and secondary productivity. However, based on actual field observations, secondary data collection and professional judgment status value to each wildlife habitat was assigned as explained below:

In summary, a wildlife habitat/ an ecosystem can achieve the maximum score of 11 and a minimum of 3 by taking into account assigned values as per the above items (i), (ii) and (iii). Thus, a wildlife habitat/ ecosystem securing higher score by above criteria signifies a greater importance with respect to conservation. The explanation for the final evaluation criteria is presented in the following tabular statement.