Rapidly multiplying population of the Indian subcontinent has put a tremendous pressure on the resources and environment. Each area has its characteristic problem in terms of environmental degradation. The fertile area between the Godavari and Krishna rivers in Andhra Pradesh is known as the rice bowl of A.P. It is facing the perils of natural and man made environmental hazards. In order to understand the gravity of situation, it is essential to know something about the geography and geomorphology of the area.
The coastal belt of Andhra Pradesh extends over 1034 Km from Ichchapuram in the north (border with Orissa) to Pulikat Lake in south (border with Tamilnadu). Ten districts of Andhra Pradesh, viz. Srikakulam, Vizianagaram, Visakhapatnam, West Godavari, East Godavari, Krishna, Guntur, Prakasam, Nellore and Chitoor fall in the arcuate coastal tract. They cover an area of 20,000 Sq. Km. The width of the coast varies from less than five kilometers to 80 km. The ground rises westward, ultimately leading to the Eastern Ghats. The coastal plain is widest in parts of Guntur, Krishna, East Godavari and West Godavari districts. Godavari and Krishna rivers form major deltas. The area between the two major rivers is traversed by the distributaries of these river systems. Kolleru on the north and Pulikat on the south are the two major lakes. These are in fact remnants of earlier lagoons. Kolleru is a fresh water lake and Pulikat Lake's water is saline. The fertile fields end up towards east and are taken over by several lagoons, mangrove swamps and salt marsh. The coast is narrow and rocky in Srikakulam'Uppada area. The deltas of Krishna and Godavari project 37 and 35 km respectively from the coast.
The maritime districts of Andhra Pradesh represent a unique environment as they fall in the interface between the marine and river borne environment. During the months of October and November each year cyclones play havoc on these districts. The cyclonic storms bring in flash floods in their wake thus doubling the misery and hardship. The sea offers plenty of vocation like fishing to the residents of the coasts. The cyclones shatter their lives.
The knowledge and interpretation of geomorphology and geology of any area plays a vital role in assessing the nature and extent of damage caused by the nature over a period of time. While attempting to work out the details of the natural damage through the millennia the earth scientist works like a forensic expert. Geological Survey of India (GSI) has extensively worked on the coastal geology in Andhra Pradesh. Their studies published recently have lucidly brought out the environmental hazards the fertile coasts are facing and their remedy too. The seacoast of Andhra Pradesh as already mentioned is quite wide. Ground rises gradually from zero level at the sea to almost 180 meters westwards. The marks of earlier shoreline on the ground, called strand lines, indicate that the sea has been receding there. The sea-level was at least 18 meters higher than where it is today at the deltas of Krishna, Godavari, Penner and Eleru rivers. This is confirmed by dating the age of the marine sediments found at higher elevations than the present shoreline. These sediments are more than 6500 years old. The marine and fluviatile landforms respond differently to natural agencies. Landforms like tidal flat, salt flat; mangrove swamps etc are more prone to flood hazards. In case a mantle of clay is present in these landforms, it holds water. Thus results water logging in the post flood period.
Canals, and drains in this area are often encroached by humans and the flow of water is restricted. Rainy season complicates the situation and a huge tract gets water logged. Chebrolu'Garikepalem stretch is one of the examples. Similarly in Bhadrachalam area in Godavari valley a number of canals and smaller streams are choked due to growth of weeds and continuous silting. Come monsoon and the beautiful looking streams or canals become menacing for the population. A better management, regular cleaning and dredging of all waterways can ease the situation considerably
Saltwater incursion is another hazard felt by the population of the coasts. Mostly it is due to ignorance of people and negligence of authorities. Excessive withdrawal of fresh water from the underground resource causes salt water to creep in. Being heavier it settles down and then it is almost impossible to remove. Instead of growing Paddy, people have taken to Prawn farming in the area. The latter involves less labor and gives more profit. Naturally society is attracted towards such recourse. The saline water required for Prawn tanks is handy. It is said ignorance is bliss. What the farmers do not realize is this seawater once brought inland for Prawn farms percolates to subsurface. They start blaming the Government for not doing anything about the salinity in their drinking water. Unless regulated, this practice can lead to large areas turning saline. The salinity does not remain subsurface. By capillary action the salts travel to surface and render the fertile areas barren.
Erosion of the coasts is yet another hazard faced by the population residing along Visakhapatnam coast. Unlike Godavari' Krishna segment, here the coast is rocky. There are engineering solutions to this problem. Construction of jetties, seawalls, breakers etc can control the process considerably. Erosion has to be controlled because the precious land is lost in the process and at times the habitation is also endangered.
Compared to other states Andhra Pradesh is developing fast. A number of industries like sugar mill, rice and paper mill saw mills etc have come up in the coastal districts. The indiscriminate discharge of effluents, wastes etc has added to the woes of the pollution along the coasts and at several places even the free flow of the streams is hampered by the muck. Only a serious effort by the authorities concerned can check the malpractice. The ash dumps of Visakhapatnam Thermal Station at the apex of Krishna delta are turning the delta hazardous. Department of Science and Technology, Government of India has already developed the technique of making bricks from fly ash. The progressive state of Andhra Pradesh should adopt the new technology and convert the waste ash to gold (bricks).
Despite cyclones the granary of Andhra Pradesh has all the scope to develop in to one of the best in the Country. The norms laid by the Coastal Regulation Zone Authorities for development of such zones needs to be strictly followed. It is high time that scientists, engineers and the society of the coastal districts join hands for conserving the ecosystem and achieve sustainable development of the Rice Bowl of Andhra.