Final answer:
Deforestation disrupts drainage basin systems by removing vegetation that intercepts rainfall and stabilizes soil, leading to increased runoff, erosion, and sediment discharge, as well as intensified flood frequency and duration.
Step-by-step explanation:
Deforestation significantly impacts drainage basin systems by disrupting the natural processes that regulate water flow and quality within a watershed. Forests play a crucial role in moderating the hydrological cycle; they intercept rainfall, reduce soil erosion, and enable gradual water infiltration into the soil, thereby stabilizing stream flows and minimizing flood risks. Trees and vegetation act as natural barriers, filtering water and preventing excess sediment from entering water bodies. When forests are cleared, the protective vegetative cover is lost, leading to higher surface runoff, reduced water quality, and increased soil erosion.
This can result in heightened flood frequency, longer flood durations, and greater sediment discharge into rivers and oceans, compromising the health of aquatic ecosystems such as coral reefs. Additionally, deforestation causes soil compaction and alters drainage regimes, potentially increasing flood volume, especially when associated with road construction and forest plantations not native to the region.