Understanding and predicting process dynamics across a range of scales are fundamental challenges for basic hydrologic research and practical applications. This is particularly true when larger-scale processes, such as climate and weather, need to be translated to finer space-time scale process dynamics, such as soil moisture, channel hydraulics, and erosion and sediment transport. In this context, we pursue both modeling approaches and empirical observations and this presentation will illustrate both, highlighting latest research efforts. Specifically, we have developed a suite of integrated models simulating hydrologic and vegetation processes, flow dynamics, erosion, and sediment transport, tRIBS+VEGGIE-FEaST. The model aims to take advantage of the growing wealth of data representing watershed topography, vegetation, and soil, as well as urban environment, facilitating mechanistic exploration of (eco)hydrological factors and their feedback mechanisms. Research applications will demonstrate an urban flooding problem and a mechanistic attribution of non-uniqueness of upland soil erosion. Another example will focus on ecohydrology of Amazonian rainforests that experience seasonal droughts, while showing maximum rates of photosynthesis and evapotranspiration during these dry intervals. This presentation will discuss a hypothesis of “root niche separation” and highlight preliminary results from the on-going field monitoring campaign, its challenges and opportunities.