Most precipitated water infiltrates and travels through shallow soils and deeper groundwater aquifers before ultimately emerging in rivers. The predominant flow paths differ under dry (for example, top hillslope) and wet (for example, bottom hillslope) conditions. Under dry conditions, low flow from deeper groundwater enriched in geogenic solutes such as Ca and Si (from soil and rock weathering) predominantly feeds the river, often with low water inputs leading to potentially disconnected water puddles (light and dark blue areas from shallow soil and deeper groundwater, respectively). Under wet conditions, rivers are fed more by surface runoff (sometimes carrying sediments) and shallow soil water enriched with biogenic carbon and nutrients (for example, C, N and P, from biogeochemical transformation of organic matter).
