It is possible to produce environmental assessments in an efficient, economical manner by the careful advance specification of future information needs, the collection of the pertinent data into a single set of sectoral reports, and subsequent analysis of the information on a case-by-case basis as individual projects arise. The procedure for this, in six main steps, can be as follows:

A development scenario is produced that is a description of the chronological sequence of economic, industrial, and agricultural, activities. The scenario is studied to identify potential issues and conflicts. A list of basic questions and more specific sub-questions that follow from the issues and conflicts is then derived. The data to answer those questions are then collected and organized into sectoral reports. Later, as each assessment need arises, these sectoral reports will be found to contain the information that is required. Finally, the assessment is produced from the sectoral reports and leads to a decision on which action is taken.

The mechanics of the above procedure include: surveys of a wide range of information sources, each survey using sources which are appropriate to the step that is being taken; use of a standing core assessment group; use of common base-maps and formats; and well-planned interdisciplinary meetings.

As well as producing assessments at short notice, the procedure can be expected to provide priorities for research, and eventually to lead to due insertion of environmental considerations into national planning during the planning stage itself.

The trauma and loss which we experience from flooding is a measure of the effectiveness of a society's leaders, for the results of land and flood management configurations can be predicted. Floodplain Management (FM) is the only approach that can control excessive runoff and tides in the long term. It is a system for turning flood-plains to needed uses— ‘open’ uses such as farms and parks—and for either floodproofing buildings in flood zones or keeping them out of the floodplain.

FM tends in most situations, and indeed in general, to be more economic and less socially costly than other flood-management formats. It allows lands to play more appropriate roles, generally does not fight natural water-cycles, decreases at-risk populations, deals effectively with flood hazards, tends not to destabilize soil and biological systems, and does not require great commitments to maintain.

Unfortunately the structural approach is often preferred, and an important, perhaps pivoting, reason is that it is part of a system of largess used by governmental leaders to aid financial constituencies. Political reform is accordingly required.

FM tools include citizen intervention; regulation; property rights purchase; flood-control structures; relocation of settlements; weather forecasting, warning, and modification; governmental loan and guarantee activities; government flood insurance; private and governmental disaster aid; banking regulations; farm preservation, erosion control, and water-quality management; parks, refuges, scenic streams, and open spaces; coordination of ‘delivery’ of services; trust, cooperative, and other private arrangements; legal redress; and special planning and executive devices, each of which is considered briefly.

During the last decade or so, the use of systems analysis and the application of computer technology for planning water resources development and management processes have increased significantly in many developed countries. The progress in most Third World countries, however, has not been commensurate and leaves much to be desired. Water management in recent years has become increasingly complex, and there is every indication that it will continue to do so in the future. Therefore, it is essential to utilize all the techniques which are available in order that the appropriate strategies and viable alternatives can be properly analysed, and the consequences of possible policy-decisions can be evaluated.

Systems analysis, if used properly, can significantly improve the management process; but whether, in spite of its great potential, it will actually be used for these purposes in Third-World countries, is another question, though it seems more likely to be adopted in those that are really developing than in the others.

Few models fail because technical expertise or state-of-the-art computer technology is inadequate, of because they are improperly implemented from a technical standpoint; they fail more often because too much concentration is placed on the technical issues and not enough on the managerial ones.

There seems no room for doubt that systems analysis has now advanced sufficiently to be of decisive use in water management for developing countries. This paper outlines the principal reasons as to why such a situation has developed, and what steps can be taken to increase the use of systems analysis for more rational and effective management of the often limited water resources that are available to Third World countries. Admittedly, some of our current models in this field are rather crude and liable to be dependent on the experience and judgement of the analysts; but in the final analysis, the issue is very definitely on the side of having a model—even a crude one—rather than on having no model at all.

The paper discusses certain microbiological, biological, and chemical, aspects of pollution in Lake Naini Tal, U.P., India, which is characterized by heavy input of domestic sewage and other organic pollutants. The most probable number (MPN) for coliform Bacteria varied from 0.59 × 105 to 3.61 × 105 per 100 ml, being highest in the monsoon season and lowest in spring. The water was alkaline in reaction throughout the period of study. The concentrations of dissolved oxygen showed high values near the surface and low ones in the bottom waters. BOD values always exceeded 6.0 mg/1. The concentrations of NO3−N and P04−P varied from 0.100 to 0.750 mg/1 and 0.018 to 0.153 mg/1, respectively. These concentrations are sufficient to cause blooming of certain phytoplankters on occasion. The values of NH3–N fluctuated from 0.033 to 0.422 mg/1, being highest in winter and lowest in the monsoon months. Among the metallic ions, the values of Pb and Mn were higher than permissible limits.

The bottom sediments of the Lake were also found to produce toxic gases such as CH4, H2S, and NH3. Most of the carp fishes, such as Cyprinus carpio specularis, Tor tor, and Schizothorax spp., were found to be infected with Saprolegnia or other Fungi, or with trematodes. Certain phytoplankters (such as species of Microcystis, Anabaena, etc.), zooplankters (such as species of Bursaria, Spirostomum, Phillodina, etc.), and macrobenthos (including Tubifex tubifex, Limnodrilus sp., Chironomus plumosas, etc.), were found to be abundant. Macrobenthic species were absent from the profundal zone of the Lake, which showed all the important characteristics of a polluted water-body.

Many of the lowland streams of Hong Kong are grossly polluted, and most are polluted to some extent. This Situation has been allowed to develop, despite warnings to the Government as far back as 1968—mainly because, although legislation existed to control effluent discharges into streams, it was spread in at least fifteen different Ordinances and was seldom enforced. New legislation is now being enacted, but it is questionable whether or not this legislation will be any more effective than was the old.

In the short term, stream pollution is destined to become even worse than it is at present, and there are conflicting views as to the long-term prospects for Hong Kong streams. The optimistic foresee gradual improvement after an initial five-years' period of legislative machinery and Government expenditure. The less-optimistic foresee little relief in terms of industrial effluent discharges unless Government policy towards existing dischargers is changed, little relief also in terms of agricultural discharges unless drastic steps are taken to curb them or effectively treat their effluents, and merely a shifting of the problems of sewage discharges from the streams to the sea via partial treatment facilities.

In the City of Gloucester, Massachusetts, 30% of the Soft-shell Clam (Mya arenaria) beds in a tidal inlet known as the Annisquam River are not harvestable owing to the discharges of untreated sewage from the surrounding area. A large proportion of the total area of the clam-flats has been closed to clamming because of exceedingly high levels of coliform Bacteria in the clams and in the water. These polluted areas represent a ‘loss’ of resources for the community, and they were surveyed in 1980 to determine the number and value of Clams which could have been harvested if only the sewage discharges had been controlled.

In the productive areas of the closed-to-fishing flats, which totaled 25.9 ha, the densities of Clams larger than 2.5 mm were found to be statistically the same on the 9 flats sampled and averaged 122.3 per m2. The average number of legally harvestable Clams (those with shells more than 51 mm in length) was 23.3 per m2, and the total yield that could have been harvested in 1980 was estimated at 6 × 106 Clams. Assuming that only 50–60% of the Clams would actually have been harvested in a year (i.e. 3.2 × 106 animals), the local community lost $332,400 in retail sales alone for lack of adequate sewage treatment facilities. Locally, 70% of the harvest goes into the restaurant trade where a bushel (35.2 1), which contains some 1,600 animals, retails for $210, and 30% is sold fresh at $64 per bushel.

A survey of vegetation around an aluminium factory in Renukoot, Mirzapur, U.P., India, was made in the course of a study of the polluting effects on plants of gaseous hydrogen fluoride. These ‘pollugenic’ effects were analyzed by examining the chlorotic and necrotic symptoms of injury on the leaf surfaces, the plants then being classified into three categories on the basis of their sensitivity.

The study revealed the absence, from the vicinity of the factory, of certain plant species which are normally present in the surrounding unpolluted areas. The tree species were the first to be affected, followed by shrubs, grasses, and finally forbs. These differences in response could be attributed in part to differences between the ambient air and ground-level concentrations of the pollutant. The concentrations in the ambient air, being higher than those at ground-level, were responsible for the greater impact on trees, with less on shrubs and grasses, and least on forbs, this being in part a function of the exposure-height of the plant species.

The gradual improvement noted in the performance of the plants and the number of their species at increasing distances from the aluminium factory, was consequent on the gradual decrease in the concentration of the polluting hydrogen fluoride. Such a trend is clearly evident in the north-east direction, where the pollutant fallout was directed by the prevailingly southwesterly winds.