On the basis of hydrochemical and biological studies, a trophic gradient has been established between the inshore and the offshore areas of the Dal lake. The inshore areas receive large quantities of raw sewage and agricultural runoff as a result of which high nutrient concentration of water and the presence of dense phytoplankton populations have been registered at these sites.

The four recent major earthquakes of the Himalayan Convergence Zone, viz., the Kangra earthquake of 1905, the Bihar-Nepal earthquake of 1934, and the two Assam earthquakes of 1897 and 1950 were assigned magnitudes greater than 8 by Richter. Although estimates of areas vary, it is agreed that an extended rupture with its long dimension parallel to the local strike of the Himalaya was involved in each case.

Calculated loading rates of trace metals into the three environmental compartments demonstrate that human activities now have major impacts on the global and regional cycles of most of the trace elements. There is significant contamination of freshwater resources and an accelerating accumulation of toxic metals in the human food chain.

An integrated approach to energy planning, when applied to large hydroelectric projects, requires that the energy-opportunity cost of the land submerged under the reservoir be incorporated into the planning methodology.

The effect on the charring temperature of arsenic in blood with wall and platform atomisations of a number of matrix modifiers, such as cobalt, copper, nickel and palladium, has been studied. Based on this study, a nitric acid de-proteinisation-nickel matrix modification-graphite platform-in-furnace atomic absorption spectrometric method was developed for the determination of nanogram per millilitre levels of arsenic in whole blood samples after a systematic evaluation of the temperature programme of the atomiser. The method of standard additions is mandatory.

The Kandy lake, situated in the heart of Sri Lanka's second largest city with a population of nearly 120,000, has been monitored to probe the extent of heavy metal pollution. Although the lake is a source of drinking water to the city, a large number of effluent canals drain into the lake carrying a continuous flow of industrial and domestic waste matter. A total of 66 surface water samples were analyzed for their Fe2+, total Fe, total V, SO 4 2− , Cd2+, and Pb2+ contents.

There are few controlled data with which to assess the conservation role of corridors connecting refuges. If corridors were used sufficiently, they could alleviate threats from inbreeding depression and demographic stochasticity. For species that require more resources than are available in single refuges, a network of refuges connected by corridors may allow persistence.

Two drinking water lakes of Hyderabad - Osman Sagar and Mir Alam, were studied for their chemistry for two years (1977-78). Mir Alam, the older of the two, showed higher silicate content. Dissolved component formed 91-27% of the total silicate content in these lakes.

A great concern over genotoxic potential of environmental chemicals has been expressed in recent years. Endosulfan a polycyclic chlorinated hydrocarbon of cyclodien group, is a well known insecticide. It is widely used in agriculture and, in some countries, in public health.

The mid-canal of Kandy, a 8-km effluent canal that runs through the city, collects massive quantities of domestic, municipal, and agricultural waste products. In this study, 37 samples from canal water and 13 from nearby drinking water wells were analyzed for their total Pb, Cd, V, Fe, and ferrous ion content. The following average values for the canal water were recorded: Pb, 269 μg/liter; Cd, 138 μg/liter; V, 18 μg/liter; total Fe, 4 mg/liter. These values indicate the relative levels of metal input from the effluent sources of the city of Kandy, the second largest city in Sri Lanka.