The Environmental Setting

The state of Gujarat [lat. 20°01' to 24°07'N] and [Long.68°04' to 74°04' E], covers an area of 195,984 sq. km and accounts for six percent of the total geographical area of the country.

Demography

According to the 1991 census, Gujrat had a population of 4.13 crores. The population density was 211 per sq. km. The decadal rate of population growth during 1981-91 was 21.19. The total population is estimated to be 4.85 crores in July 2000 and expected to grow to 5.55 crores by 2010.

Urbanization

The urban population in Gujrat was 34.5% in 1991. It is estimated to grow to 38.8% by 2001 and 44.46% by 2021.

Geological History

The geological evolution of Gujarat began with the breaking up of the Gondwanaland. Its subsequent geological history is related to the northward drift of the Indian sub-continent and breaking up of the western continental margin.

The important rock formations of the State are metamorphosed quartzites, slates and limestones in Aravallis, sandstone in Kachchh and in the north-eastern part of Saurashtra and as outcrops in parts of Wadhwan and Sabarkantha, basaltic flows in the Saurshtra Peninsula, tertiary rocks along the coastal region of Surat, Bharuch and south-east of Saurashtra and Kachchh, gypsiferous clay in the Dwaraka beds and large alluvial tract from Surat to Banaskantha.

Climatic conditions

Located on the Tropic of Cancer, the State falls in the sub-tropical climatic zone and has a varied climate and can be divided into five climatic regions [Annexure-IV].

Seasons

The various seasons of the year are monsoon (June to October), winter (November to February) and summer (March to June). The temperature varies between 8⁰ C to 45⁰ C.

Rainfall and Humidity

Gujarat receives its rainfall from the south-west monsoon [June to September], its maximum intensity being in the months of July and August. The annual rainfall varies between 300mm in the North and Northwest gradually increasing to 2500 mm in the South.

The relative humidity in all parts of the State is low. Winds are generally light to moderate, increasing in intensity during the late summer and monsoon seasons.

Isohyte Map of Gujarat

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Physiograpic Zones of Gujarat

Mainland Gujarat

Mainland Gujarat, consists of the eastern rocky highlands [alt. 300 to 1000 meters], the extensions of the mountains of western India, and the western alluvial plains including the coastal plains [alt. 25 to 75 meters].

Saurashtra Peninsula

The peninsula of Saurashtra forms a rocky tableland [alt.300-600meters] fringed by coastal plains, with a central part made up of an undulating plain broken by hills and considerably dissected by various rivers that flow in all directions. The eastern fringe of Saurashtra is a low-lying ground marking the site of the former sea connection between the Gulfs of Kachchh and Khambhat. An elevated strip of ground connecting the highlands of Rajkot and Girnar forms the major water divide of Saurashtra.

Kachchh

The Kachchh region consists of [a] the Ranns, salt-encrusted wasteland rising only a few meters above sea-level, and inundated during monsoon, divided into the Great Rann to the north and the Little Rann to the east [b], the Banni plains between the Great Rann and the rocky mainland, [c], hilly region with the island belt of four rocky projections rising above the Rann, [d], the Kachchh mainland [e], the southern coastal plains.

Physiographic regions of Gujarat

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Drainage system

The rivers Banas, Sabarmati, Mahi, Narmada and Tapi are the important drainage lines of the Gujarat plain draining into the Gulf of Khambatt while the rivers Bhadar, Ojat and Shetrunji are those of the Kathiawar peninsula draining into the Arabian sea. There are few seasonal and small rivers draining into the Gulf of Kachchh.

Drainage map of Gujarat

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Geo-hydrology

On the mainland, the hilly tracts in the northeast, east and south provide an erratic groundwater scenario. Groundwater accumulates only in the secondary porosity zone i.e. zone of weathering, joint planes, cracks and fissures. Water table in these rocky areas varies from 4 to 10 meter below the ground level and is mostly unconfined.

The alluvial plains provide better conditions for the storage of groundwater. The junction between the eastern hill areas and the well-demarcated alluvial plains is the principal site for recharge of groundwater.

In Saurashtra and Kachchh, the areas of sandstone and alluvial cover yield moderate quantities of water while the basalt areas hold good amount of water. Here, the Zones of weathering between successive lava flow also act as aquifers.

Coastal and marine environment

The Arabian Sea and the Gulfs of Khambhat and Kachchh wash the shores of the State. The State has a coastline of 1,659 km. Tidal and saline flats generally characterize the coast of Gujarat. The coast of Kachchh, both on the west and on the South, is surrounded by 10-13 km wide marshy zone.

There are innumerable creeks dotting the coastline of Gujarat. They are shallow and have mostly got silted up.

The Gulf of Kachchh, [7,350 sq km] is aligned in an east-west orientation. Its depth extends from less than 20 m at the head (eastern end) to about 60m at the mouth (western end). The coastal geomorphology is marked by a number of islands, coral reefs, marshy islands, mangroves, sandy stretches, creeks and bays.

The Gulf of Khambhat, [3,120 sq km] is aligned in a north-south orientation. It is marked by the huge interaction of saline and freshwaters, providing it the characteristics of an extended estuarine system. It is a high-energy regime, with large quantities of sediment transport, extensive mudbanks and rapid changes in the coastal geomorphology.

The southern coast of mainland Gujarat is generally sandy.

Wetlands

Gujarat is rich in wetland resources in the form of lakes, salt marshes, creeks, mudflats, and estuaries, swamps, mangrove swamps and man-made wetlands like reservoirs. The [79] major wetlands cover an area of five lakh ha.

Soils

Deep black and coastal alluvium soils are predominant in South Gujarat, medium black is prevalent in middle Gujarat, grey brown and coastal alluvial soils are in north and north-west while the Saurashtra peninsula has calcareous medium black and to some extent coastal alluvial soils.

Only about 28% of the total geographical area of the State have soil of over 150 cm depth, while about 15% have soil of 100-150 cm depth. In terms of its texture, loamy soils cover about 37% of the State while 40% is clayey and 7% is sandy.

The Bhal region has a type of soil that is clayey in texture preventing percolation of water making large parts marshy during monsoon and extensively saline.

Soil Types of Gujarat

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Ecosystem Diversity

Gujarat is endowed with a great diversity of ecosystems ranging from deserts, scrublands, grasslands, deciduous forests, wetlands, mangroves, coral reefs, estuaries and gulfs. Some of these like the ranns and the coral reefs are the habitat for a variety of plants and animals including several rare and endangered species.

Some Endangered species of Gujarat
Mammals Caraca Desert cat Ratel Long –eared hedge hog Common Dolphin Four-Horned Antelope	*Birds* Lesser Florican Great Indian Bustard Indian skimmer Sarus crane Dalmatian pelican	Reptiles Green Turtle Banded geeks Painted frog Sping tailed ligual	Plants Andho – khimps Karandia Gokhru Guggal Dhavo

Genetic diversity

A large variety of crops are cultivated in the state. It has 11 varieties of indigenous breeds of livestock both of buffaloes and cattle

Indigenous breeds of cattle and buffaloes of Guajrat
Cattle Gir Kankrej Dangi Murah	Buffaloe Surati Mehsani Jafrabadi

Endemism

Gujarat is the only abode of the Asiatic lions and the Asiatic wild ass and the banded Gecko.

Indigenous knowledge

About 29 tribes consisting of about 15% of the population have a large depository of knowledge relating to some 1200 plant species including some 750 medicinal plants.

Biodiversity

Some Important medicinal plants of Gujarat
Khair Gum Saledi Resin Bhilama Behda	KalmeghD4FFD9 Shatavari Musli Amla Kadayo Harda

Gujarat is rich in biodiversity. Recorded in its four bio-geographic zones are 4320 species of

plants and 2728 species of animals. Plants of the higher order found in the State represent nearly 13% of the country's flora. Of the country's fauna, 14% of fish species, 9% of amphibians, 19% of reptiles, 37% of birds and 25% of mammals have been recorded in Gujarat. Environmental factors explain the State's varied plants and animal wealth.

Eco regions

Based on topography, soils, climate and hydrology, Gujarat can be divided into eight ecoregions [ Annexure-V].

Disaster prone

Natural calamities are recurring phenomena in Gujarat. Some 37 talukas of the state experience drought every two years, while 55 talukas would experience below normal rainfall during 40-50% years, while 91 talukas are likely to have inadequate rainfall once in four years. The ecological consequence of such abnormal rainfall pattern is obvious. The State has more than its share of cyclones and other serious natural calamities. Large areas of the State lie within earthquake prone zones of high seismic activity.

Though environmental setting would explain some of the problems most of them are man made, as the following pages would demonstrate.

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