Restoring River Connectivity: Prioritizing Passage Improvements for Diadromous Fishes and Lampreys

Physical obstructions are becoming increasingly recognized as major factors influencing the migrations, population structures, spawning success and recruitment of freshwater organisms. This paper presents a simple but effective method, intended for use by environmental managers, government agencies and conservation bodies, of rapidly assessing and prioritizing barriers to the migrations of diadromous fishes and lampreys for passage improvements. A prioritization matrix was developed using information on fish stock status, the passage efficiency of fishes at individual structures, the distance from the tidal limit and the passability of downstream barriers, and the quantity and quality of habitat upstream of each structure. Importantly, the 'Likelihood of access' was incorporated into the matrix to account for passage efficiency at downstream barriers. Barriers ranked as the highest priority for passage improvements were those characterized by poor fish stocks upstream, low passage efficiency, easy passage from downstream, and a large quantity and high quality of habitat upstream. Prioritization of migration barriers should ensure that access improvements are targeted to achieve optimum benefits.     

Assessing the environmental performance of urban wastewater systems using the INSA model: application to the Algés-Alcântara wastewater system, in Portugal

Although the application of complex integrated models to wastewater systems is useful, it is often difficult to implement and not always suitable for the design of new systems or for their rehabilitation. Integrated simple approaches that allow assessing the environmental performance of urban wastewater systems may be advantageous, especially during the initial phases of the system planning process. This paper presents an original, straightforward approach that can be used for planning, design and operation of urban wastewater systems. The INtegrated Simplified Approach (INSA) combines the concepts of performance indicators with mass balances and can be applied to wastewater systems as a management support tool, particularly in situations where there is lack of data, economic limitations or time constraints. The INSA was applied to the Algés-Alcantara wastewater system to evaluate its environmental performance and to simulate the individual or combined impact of the rehabilitation measures proposed, thus defining their priority. The results clearly indicate that, despite the investment already made upgrading the wastewater treatment plant (WWTP), the proposed interventions must be implemented to ensure an acceptable environmental performance of the system. In addition, the results demonstrate the significant pollution loads present in stormwater, frequently higher than the pollution loads discharged into receiving waters during dry weather.     

Gentrification and housing improvement: the case of Nürnberg

A revival of interest among professional people in central and inner city residence appears to have occurred in West Germany since the late 1970s. In recent years, a selective programme of central area rehabilitation has successfully wedded public and private funding in Nürnberg, with consequent displacement of low‐income tenants. The further spread of upgrading and social change appears to have been halted in parts of the inner city designated as Urban Renewal Areas, where the federal and local authorities are apparently intent on stabilising and improving the much‐neglected housing and environmental conditions of the poorest “guestworker” communities.     

苏州河河道曝气复氧探讨

经过六支流截污、综合调水等苏州河综合整治一期工程项目的实施，苏州河沿岸的污染源大部分已被截留，河水水质大有改善。但是，苏州河北新泾以下河段，由于沿江37座合流泵站雨季排江的冲击负荷，雨天苏州河水体仍有黑臭。向苏州河进行曝气复氧，能在较短的时间内提高水体的溶解氧水平，增强水体的净化功能，对解决突发性的冲击负荷所造成的水质恶化、消除水体黑臭、恢复苏州河水生生态系统，将起到重要的作用。     

Where the exception confirms the rule: The cyclones of 1982-1983 in French Polynesia

The island groups of French Polynesia, which had not experienced any really devastating cyclones since the beginning of the century, were hard hit several times between December 1982 and April 1983. This paper reviews the cost of damage from these cyclones and shows how lowered public awareness of the hazard in a low-frequency area combined with the special economic conditions prevailing in the Territory to make the total cost much higher than it need have been. Ways and means of rehabilitation are analyzed. The development of the thermal imbalance in the Pacific, which appears to have triggered this series of natural disasters, only seemingly exceptional, is briefly discussed.     

Pollution by halogenated aromatic compounds at Trissino: A case study of groundwater contamination and rehabilitation

An investigation is presented on industrial contamination by benzotrifluoride percolation into ground water used for drinking water, in a populated area of 20 km² at Trissino, north Italy, due to improper chemical waste disposal. Hydrogeological features of the situation are reported, as well as the emergency action taken, such as the surveys made and their analytical results. The epidemiology of the emergency is examined and rehabilitation measures are presented and discussed. Fortunately no major ecological or social disaster occurred, In part thanks to the speed and efficiency with which the affair was handled. It is notable that the authorities kept the public duly informed and thus retained their confidence.     

Adaptation of local building materials — a key to rapid housing development in Nigeria

There are some experts who are dealing with research on locally made materials for building in the Ministry of Housing and Works in Nigeria. It has been discovered in the Ministry that lateriate clays can be fired and used for building even two‐storey buildings depending on the firing and the pressure (Ogunbamwo, 1975). The Ministry has constructed a block of bungalows of low‐cost housing units with mud at Ikoyi, off Kingsway Road. No one will know that these houses are mud houses if not at closer inspection. Unfortunately, no effort has been made to continue or improve on this laudable adventure in Nigeria.     

The neighbourhood project for urban rehabilitation in France: a progress report

Serious social and environmental problems are encountered on many of the large post‐war estates of blocks of social housing (grands ensembles) surrounding French cities, as well as in many inner‐city districts. In 1981 the new Socialist administration set up a National Commission to foster grass‐roots schemes in order to improve housing and to attempt to tackle both the expressions and the causes of social problems. The resulting neighbourhood programme represents an innovative dialogue between the central State, the regions, local authorities and residents’ groups. Examination of a sample of projects from the provinces (Romans, Dreux, Les Minguettes) and the Paris region confirms that progress has been made by improving housing, open spaces and community facilities. Formidable problems of poverty, unemployment and racism remain on many estates.     

Proposals for rehabilitation and management of Isipingo lagoon and estuary,South Africa

The Isipingo lagoon and estuary, situated to the south of the Durban metropolitan area, on the east coast of South Africa, has been subjected to intense environmental degradation. Historical events, such as the building of a major airport and the development of an industrial township, have contributed to the reduction in water flow from 102 × 10⁶ m³/yr to 3 × 10⁶m³/yr between 1952 and 1969. Current environmental issues such as water quality, litter, noise, air pollution, and solid waste dumping are described. A rehabilitation and management program that seeks to address these issues is proposed. The main objectives of this program are: the improvement of the water flow, the improvement of the water quality, and the curtailment of the destruction of littoral zone elements. The rehabilitation proposal is summarized by means of a flow chart, which lists short-, medium-, and long-term actions and identifies parties and/or organizations responsible for implementing the actions. A two-tier management structure is proposed, with the first level comprising an environmental monitoring committee, consisting of organizations with scientific expertise who would function in a watchdog capacity, monitoring restoration efforts and intervening where actions are contrary to the objectives of the rehabilitation program. The second level would consist of an estuarine management committee, which would be responsible for evaluating the restoration program and modifying objectives where necessary.     

Mining taxation issues for the future

During the 1970s and 1980s the main concern of mining policies was to attract investment whilst at the same time balancing the interests of governments and companies. By the turn of the century a new spectrum of challenges faces governments and companies in the mining sector. The need for fiscal regimes to adapt to price cyclicity is to some extent superseded by the requirement that they adapt to a long-term decline of metal prices. The growing importance of environmental and community affairs in the mining sector will force governments to design coherent and comprehensive tax regulations to complement the wide range of initiatives being taken in these fields. Finally, the age-old problem of tax collection continues to raise its head in transition and developing economies.