Today about 2.4 billion people in rural and urban areas do not have access to adequate sanitation services. Within 20 years, it is expected that an additional 2 billion will live in towns and cities, mainly in developing countries, demanding sanitation. Still over 90% of sewage in developing countries is discharged untreated, polluting rivers, lakes and coastal areas. Conventional sanitation co...

This issue contains peer-reviewed papers from a workshop on Closed Ecological Systems: Earth and Space Applications at the 35th COSPAR General Assembly in Paris, France, convened in July 2004. The contributions reflected the wide range of international work in the field, especially Europe, Russia, Japan, and the United States. The papers are arranged according to four main themes: 1) Methods of...

A framework is built, wherein hydrological/water quality model is used to measure watershed sustainability. For this framework, watershed sustainability has been defined and quantified by defining social, environmental and biodiversity indicators. By providing weightage to these indicators, a “River Basin Sustainability Index” is built. The watershed sustainability is then calculated based on t...

On considère un graphe G = (S,A), où S est l’ensemble des sommets de G et A ⊂ ( S 2 ) l’ensemble de ses arêtes. On suppose que le graphe G est connexe, ie. que toute paire {s, t} de sommets de S peut être reliée par un chemin d’arêtes {s, r1}, {r1, r2}, . . . , {rp, t} de A. On appelle graphe couvrant de G tout graphe dont l’ensemble des sommets est S, dont l’ensemble des arêtes est contenu dan...

Alternative agricultural systems that emphasize ecological and community resilience provide a bridge between traditional agriculture and natural resourcemanagement. These can be referred to as agri-ecological systems and include systems such as Organic Agriculture, Biodynamics, Community Supported Agriculture (CSA), Permaculture, Farmers Markets and Community Gardens. This paper reports on curr...