River Rehabilitation

A century ago, Nahr Beirut was a riparian river which flowed from a mountainous valley to a coastal plain, the Beirut Peninsula, before entering the Mediterranean Sea. After being for centuries the distant edge of Beirut, Nahr Beirut today is the central spine of the Metropolitan Area, coinciding with a major transport corridor linking the coast with the hinterland. In 1968, the river was converted from a riparian river to a concrete canal and eventually, it mutated into an open sewer. The highway built on its right bank completed this conversion into an infrastructural conduit of sewage and transport. Informed by the notions of infrastructural landscape, the thesis investigates Nahr Beirut through an urban and ecological analysis, and proposes measures for restoring the river, creating public space and enhancing the quality and management of water. In doing so, Nahr Beirut acts as a cultural catalyst which addresses citywide concerns of water supply, urban fragmentation and lack of public space. An overall plan addresses the ecological continuity of the river, flood mitigation, water management and treatment cycles. The plan proposes new navigational paths along the restored corridor, and sequences of public instances which respond to specific physical, infrastructural and urban conditions. Smaller scale proposals include public nodes and a series of land formation strategies that respond to the environmental and infrastructural situations. Advancing that rivers as infrastructural landscapes can become urban, social and ecological structures which sustain amid political and aesthetic fluctuations, the thesis posits Nahr Beirut as a new cultural and ecological spine in the city, which mediates its infrastructural functions with its civic and environmental roles.

The Clarion River is a major tributary of the Allegheny River in northwestern Pennsylvania. Abundant water and close access to forest resources fueled the rise of a heavy industry base along the upper Clarion River in the late 1800s, which at its height in the early 1900s included eight tanneries, eleven wood chemical plants, and a large paper mill. The Clarion River was the sink for the effluents from these industries which were discharged directly into river with no or minimal treatment. Cumulative effluent loading from the Clarion River’s main industries was estimated to exceed 25 million gallons daily in the early 1900s. In this presentation I gauge the relative impacts of these different industries on the environment of the Clarion River and show how the ebb and flow of industries set the stage for the eventual recovery of the river.

Introduction
It is indisputable that cities have been comprised essential place today throughout the world. By the industrial development particularly, the world is becoming increasingly urbanized. In 1900, only 160 million people, one tenth of the world’s population were living in the cities. By the 2000s, more than half of the world has been living in urban areas. As Boone (2006, p.36) states, “the future of the world is urban, and the problems that cities and their environments face must therefore be addressed”. While the urban population throughout the world grows, and the climate change is been lived, the effects of urbanization on water resources and rivers are increasing. The current problems with urban rivers in general are closely concerned with achieving eco-efficiency of urban water system and rivers.
Cities are playing a vital role in our societies. In difficult economic times, more than ever before, it is essential to re-invest in our cities’ infrastructure and environmental improvement. After being neglected for decades, since the second half of the 20th century, with more attention given to sustainability of resources, an awareness has grown of the vital role of urban rivers as a resource for humans and a lifeline for cities. As a result of the problems associated with urban rivers cannot be isolated from the water system; a new approach was developed for the last decades, one that is integrative, taking the problem of rivers within the water system. Aiming to create sustainable cities, there is a concentration on the development of many transformation projects including urban waters.
In this regard, the paper aims to better understand the challenges on urban rivers in the meaning of its integration to urban water system. To be able to clarify the challenges, the discussion extends into the old and emerging paradigms. The discussion is supported by major practices on rivers and comparative analysis on them conducted. Evaluating Porsuk River as a case, Turkey in accordance with the contemporary context, provides a framework on the dynamics of new approaches in Turkey as a final outcome. Before it, urbanization and water as a starting point is being addressed below.

A century ago, Nahr Beirut was a riparian river which flowed from a mountainous valley to a coastal plain, the Beirut Peninsula, before entering the Mediterranean Sea. After being for centuries the distant edge of Beirut, Nahr Beirut today is the central spine of the Metropolitan Area, coinciding with a major transport corridor linking the coast with the hinterland. In 1968, the river was converted from a riparian river to a concrete canal and eventually, it mutated into an open sewer. The highway built on its right bank completed this conversion into an infrastructural conduit of sewage and transport. Informed by the notions of infrastructural landscape in Kathy Poole's article, Infrastructure in the ecological city, the thesis investigates Nahr Beirut through an urban and ecological analysis, and proposes measures for restoring the river, creating public space and enhancing the quality and management of water. In doing so, Nahr Beirut acts as a cultural catalyst which addresse...

River engineering in the Rhine delta and water pollution have been major threats for the ecological functioning of the river in The Netherlands. To mitigate effects of river engineering, secondary channel construction in the forelands along the existing distributaries is considered to be an important measure for river restoration. These areas are the remnants of the former Rhine floodplain and the only area where habitat restoration is possible due to the river functions assigned. Secondary channel construction in the area called ‘Gamerensche Waarden’ was taken as an example to show effects of habitat restoration on the macroinvertebrate fauna. Totally 322 macroinvertebrate taxa were found during the monitoring period. During the first 3 years species richness in the area increased rapidly due to colonization processes in the channels following habitat development. After that period total number of taxa found in the channels stabilized at around 170. A clear positive relationship was demonstrated between habitat quality and species richness. Furthermore, the density of exotic species in the secondary channels was less than in the groyne fields of the main channel. The relatively low number of taxa in polluted habitats could be explained by the presence of the PCB 28 congener. Copyright © 2007 John Wiley & Sons, Ltd.