Jack Dykinga / Colorado River Delta, with watercourse sculpted patterns eroded into the salt / silt flats near the Sea of Cortez, La Reserva del Golfo, Baja, Mexico

Luiz Claudio Marigo / Igarap / watercourse in the upland Amazon rainforest of Cuieiras Biological Reserve, Amazonas State, Northern Brazil.

Kerstin Hinze / Aerial view of crossing near Magdeburg of an artificial watercourse/ viaduct bridge crossing the Elbe River. Saxony-Anhalt, Germany, May 2012.

Luiz Claudio Marigo / A Quebrada, small watercourse in Paramo habitat, the Andean high altitude fields. Chingaza Natural National Park, municipality of La Calera, Cundinamarca Department, Colombia, 2011.

Luiz Claudio Marigo / Inflorescence / flowers of the "Bacaba" palm tree (Oenocarpus bataua) on the margin of an igarape / watercourse in the upland Amazon rainforest, Pará State, Northern Brazil.

Luiz Claudio Marigo / "Buçu" palm tree (Manicaria saccifera) near the watercourse of Cuieiras Biological Reserve, Amazonas State, Northern Brazil.

Luiz Claudio Marigo / The drought of 2007 was so severe in the Amazon Basin that this watercourse was "closed". Amazonas River, between Itacoatiara town and the mouth of Madeira River, Amazonas State, Northern Brazil.

Luiz Claudio Marigo / Aerial view of watercourse with its gallery rainforest completely destroyed to create pasture land for cattle, Rondônia State, Western Brazil.

Luiz Claudio Marigo / "Buriti" palm trees (Mauritia flexuosa) along a watercourse / igarapé near Manaus city, Amazonas State, Northern Brazil.

Cyril Ruoso / Vegetated watercourse, San Fernando Reserve, Peru

Jack Dykinga / Alluvial watercourse drying and cracking after winter El Nino rains with a trails of flowering Desert golds (Geraea canescens) at the base of the Amargosa Mountains, Death Valley National Park, Califo...

Bruce Thomson / Watercourse in rainforest with overhanging branches, Queensland Wet Tropics World Heritage Area, Cairns, Australia.