In coupled “source-to-sink” systems, spatial differences in hydrology and geomorphology influence how processes in the source are recorded in the sink. The catchment of the tropical Cauca River (source) in the northern (Colombian) Andes, and its associated Mojana lowland sedimentary basin (sink), are a model system in which to explore the relationship between climate processes that control runoff and erosion in the upper catchment, and sediment deposition in the lower basin that occurs through avulsion events and seasonal wetland flooding. This study employed historical climate and hydrologic data from the Cauca River watershed and its associated sedimentary basin, along with topographic data and satellite imagery. We discovered that the Cauca River catchment and its associated Mojana Basin are governed by different patterns of intra- and inter-annual climate variability. Biannual passage of the Intertropical Convergence Zone (ITCZ) over the watershed, annual incursion of the Choco Jet, and sub-decadal variability of the El Niño Southern Oscillation (ENSO) all modulate runoff and sediment fluxes that ultimately become fluvial deposits (e.g., crevasse splays, channel and floodplain sediments). Fluctuations in wetland water levels and area, preserved as lacustrine and marsh deposits, are influenced primarily by annual variations in rainfall that are controlled by the yearly northernmost extent of the ITCZ. Long-term erosion in the Cauca River catchment is controlled largely by active tectonism in the northern Central Cordillera. Avulsion events on the Cauca River in 2010 and 2011 occurred as a consequence of levee failure during a period of high runoff associated with the negative phase of the El Niño Southern Oscillation (ENSO) along with higher cross-floodplain than down-valley slopes in the basin.

在耦合的“源到汇”系统中，水文和地貌的空间差异会影响在汇中记录源过程的方式。北部（哥伦比亚）安第斯山脉热带高加索河（源头）及其相关的莫哈纳低地沉积盆地（下沉）的集水区是一个模型系统，其中探讨了控制上游径流和侵蚀的气候过程之间的关系流域水土流失和季节性湿地洪水在下游盆地造成的沉积物和沉积物沉积。这项研究采用了来自高加索河流域及其相关沉积盆地的历史气候和水文数据，以及地形数据和卫星图像。我们发现，高加索河流域及其相关的莫哈纳盆地受年内和年际气候变化的不同模式支配。流域上的热带辐合带（ITCZ）每年两次通过，Choco Jet的年度侵入以及厄尔尼诺南方涛动（ENSO）的年代际变化都调节了径流和沉积物通量，这些通量和沉积物通量最终变成了河流沉积物（例如，裂缝径流，河道和洪泛区沉积物）。保留为湖水和沼泽沉积物的湿地水位和面积的波动主要受ITCZ年度最北端控制的年降水量变化的影响。高加索河流域的长期侵蚀主要受中部北部中部活跃的构造作用控制。