Sediment and water discharge assessment on santiago and pánuco rivers (central mexico): the importance of topographic and climatic factors

Abstract

This study explores the main factors controlling sediment and water discharge in the antiago and ánuco Rivers, the two largest rivers of central exico. Both antiago and ánuco Rivers are sourced in the Central Plateau of exico and flow in an opposite direction. antiago River flows over a tectonically active margin draining to the Pacific Ocean, and ánuco River flows into the passive margin of the Gulf of exico. Mean annual and monthly values of suspended sediment load and water discharge spanning around 50 years were used to evaluate sediment load and water discharge in these two rivers. Our findings indicated that antiago River delivers to the ocean around 45% more sediment than ánuco River. However, we found that antiago River has about half the water discharge of ánuco River. The high river gradient along antiago River is likely to enhance the net erosion and sediment transport capacity. Water discharge at ánuco Basin is higher than in antiago Basin because the annual rainfall is higher for the former. The difference in sediment and water discharge for both rivers are also related to iño Southern Oscillation events. Our results indicated that water discharge in antiago River increases during iño and a iña events. In contrast, ánuco River is mostly affected by a iña events.

Key words:

• sediment and water discharge
• climate
• El Niño Southern Oscillation
• river gradient
• tectonic control
• Santiago River
• Pánuco River
• central Mexico

Acknowledgements

This research was possible by the funds of DGAPA‐PAPIIT (Ref. IB100812‐2) assigned to the first author and the DGAPA Postdoctoral Scholarship assigned to the second author. The authors thank Dr Oscar Escolero and Oscar Mario Salas for facilitating the data from the gauge stations located at Santiago and Pánuco Rivers. They also thank Dr Moshe Inbar and an anonymous reviewer for their comments.