Physical controls and ENSO event influence on weathering in the Panama Canal Watershed

Abstract

Recent empirical studies have documented the importance of tropical mountainous rivers on global silicate weathering and suspended sediment transport. Such field studies are typically based on limited temporal data, leaving uncertainty in the strength of observed relationships with controlling parameters over the long term. A deficiency of long-term data also prevents determination of the impact that multi-year or decadal climate patterns, such as the El Niño Southern Oscillation (ENSO), might have on weathering fluxes. Here we analyze an 18-year hydrochemical dataset for eight subbasins of the Panama Canal Watershed of high-temporal frequency collected between 1998 and 2015 to address these knowledge gaps. We identified a strongly positive covariance of both cation (Ca 2+ , Mg 2+ , K + , na +) and suspended sediment yields with precipitation and extent of forest cover, whereas we observed negative relationships with temperature and mosaic landcover. We also confirmed a statistical relationship between seasonality, ENSO, and river discharge, with significantly higher values occurring during La Niña events. These findings emphasize the importance that long-term datasets have on identifying short-term influences on chemical and physical weathering rates, especially, in ENSO-influenced regions.

Using compartmental models and Particle Swarm Optimization to assess Dengue basic reproduction number R0 for the Republic of Panama in the 1999-2022 period

“…With the ongoing global warming trend [22] , areas with the highest hatching rate of mosquito eggs are likely to shift, thereby requiring a shift in control efforts aimed at these vectors. In particular, the temperature shifts associated with El Niño-Southern Oscillation and La Niña can have a negative impact on the Central and South American regions, making it an important consideration in the study of vector-borne diseases and the development of effective control strategies [23] . These fluctuations in precipitation could result in a heightened number of Dengue cases during years of increased rainfall, and could also lead to Dengue outbreaks of unprecedented aggression [22] , [24] .…”

“…The evaluation of the dynamics of Dengue outbreaks in the Republic of Panama is a crucial step forward in the use of compartmental models for disease control, as it provides insights into the intricacies of the disease transmission process, which will aid in the formulation of evidence-based strategies to mitigate the impact of Dengue outbreaks. By accurately parameterizing an epidemiological model, decision-makers will be better equipped to respond to Dengue outbreaks in an informed and effective manner, ultimately reducing their negative impact on public health and society [23] , [24] . The objective of this study was to gain a thorough understanding of the dynamics of Dengue transmission in the Republic of Panama by utilizing compartmental models over the period of 1999 to 2022.…”

Spatial controls on riverbed sediment chemistry in three anthropogenically modified tropical mountainous watersheds

“…Tropical small mountainous rivers deliver a disproportionate amount of sediment to the global ocean (Milliman and Syvitski, 1992). Their characteristic steep slopes often result in "flashy" hydrographs, with large amounts of water and sediment delivered during intense aperiodic precipitation events, such as monsoonal activity or tropical cyclones (Milliman and Syvitski, 1992;Goldsmith et al, 2008;Smith et al 2020). More recently, anthropogenic activities such as deforestation (Vanacker et al, 2003;Syvitski et al 2005;Warne et al, 2005), agriculture (Kao and Milliman, 2008;Ramos-Scharrón and Thomaz, 2017) and unpaved roads (Kao and Liu, 2002;Scharrón, 2010;Ramos-Scharrón, 2018) have been shown to increase both erosion and sediment delivery in these systems.…”