Final answer:
Run-off is the part of precipitation that does not soak into the ground and can carry pollutants from areas like industrial sites and suburban lawns to water bodies, causing water pollution. Point sources and nonpoint sources are two ways through which pollutants enter water systems. Measures such as preserving wetlands and reducing fertilizer use can help mitigate run-off pollution.
Step-by-step explanation:
Understanding Run-off and Its Impact on Water Pollution
Run-off refers to the precipitation that falls over the land but is not absorbed by the soil. When there is increased industrialization and suburban expansion, the resultant run-off can carry pollutants from various sources—like fertilizers on lawns, oil spills on roads, and heavy metals from industrial waste—directly into the water bodies. This contributes to water pollution, which is detrimental to marine life and human health.
Run-off can be categorized into two main sources: point sources and nonpoint sources. Point sources are easy to identify and originate from specific locations, while nonpoint sources are more diffuse and can cover large areas. Urban areas might lack appropriate sewage systems, causing untreated or partially treated sewage to enter water systems during heavy rainfall, exacerbating the problem. Efforts to preserve wetlands and reduce the use of fertilizers are measures that help mitigate the adverse effects of run-off.