Final answer:
Areas with high river drainage near landmasses are known as drainage basins, which can form fertile deltas or unique estuaries. These regions support agriculture and provide crucial water resources.
Step-by-step explanation:
Areas that are near landmasses and have high river drainage are typically referred to as drainage basins. These are regions that are drained by a river or stream, and all precipitation that falls within the basin ultimately feeds into that river system, unless it evaporates or seeps into the ground.
These drainage basins are important for a variety of ecological and human activities. Particularly, when a river discharges into an ocean or lake, and the water flow slows down, sediments can accumulate to form deltas which are often very fertile and become prime agricultural land. Alternatively, in areas with less silt or higher ocean currents, estuaries are formed where salt and fresh water mix, creating unique ecological environments.
Aside from their importance in agriculture, rivers are also vital for providing water resources, both for irrigation and consumption by cities. High river drainage into specific areas thus has significant environmental and socio-economic implications, supporting diverse ecosystems and human populations through the provision of fertile soils, fresh water, and fishery resources.