Miguel Castillo

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.