I.A.G. A.I.G. International Association of Geomorphologists Association Internationale des Géomorphologues NEWS

The first meeting of the IAG Working Group on Large Rivers started with two full days of papers in Goiânia, Go, Brazil, followed by a seven-day field excursion in the basin of the Araguaia. The 777308km² basin of the Araguaia-Tocantins system discharges to the Atlantic Ocean, mainly via the channel south of the Marajo Island near the mouth of the Amazon. It is the fourth largest river basin in South America. The symposium was efficiently organised by the Institute of Social and Environmental Studies (IESA) of the Federal University of Goiás. The chief local organisers were E. Latrubesse, J.C. Stevaux, S. De Castros S. and A. Borges De Campos.

The papers presented fell into two groups: a collection of case studies on rivers in South and Central America and assorted papers on rivers outside this region. A striking proportion of both the oral and poster presentations of the first group dealt with the Amazon and the Paraná Basins, and were given mainly by graduate students from Brazilian universities. The exchange of ideas and information with these young geomorphologists was a characteristic feature of the meeting. Two other studies, on the Rio Térraba of Costa Rica (T. Bullard) and the Bio Bio River of Chile (A. Duyvestein and O. Link), reminded the participants of the nature of tectonics-related steep gradient streams.

Papers from outside the region discussed basins in the Polish Carpathians (T. Kalicki and M. Pietrzak), the Mississippi-Atchafalaya system (J. Mossa), flood hazards in Japan and Bangladesh (S. Kubo), and the Cooper Creek in Australia (G. Nanson). L. Starkel reviewed the regimes of large rivers in the Quaternary. A. Gupta presented an introductory discussion on the nature of large rivers and the problems of their management. The meeting also included a seminar on the management of the Araguaia, reflecting some concern about present and future environmental changes.

Regarding fieldwork, about 2500 km were covered by bus and boat in one week. The areas visited included the upper Araguaia basin with its characteristic geomorphological problems, the Emas National Park, the Bananal Plain, and the forested lower reaches of the Araguaia. The help and kindness received from CENAQUA-IBAMA (especially regarding the use of their base camp, thanks to V.H. Cantarelli and his colleagues) and the Brazilian Geological Survey (CPRM) was invaluable.

Apart from geomorphology in the field and wonderful ecological experiences such as the sight of Araguaia dolphins somersaulting in the sun, the conference provided an excellent opportunity for building contacts with local researchers which was one of the prime reasons for the meeting. Incidentally, a local television station perceived an IAG field trip as news, and at least one senior colleague appeared on the screen waving his arms on a point bar.

Avijit Gupta