Final answer:
Urbanisation increases surface runoff due to impervious surfaces, enhances soil erosion by removing vegetation, and causes higher levels of water pollution from industrial waste and agricultural runoff, affecting the drainage basin systems.
Step-by-step explanation:
Urbanisation significantly alters the characteristics of drainage basin systems. The increase in impervious surfaces such as roads and buildings in urban areas diminishes the land's ability to absorb rainfall, leading to higher levels of surface runoff. This escalation can result in flash flooding, as the drainage system is overwhelmed by the rapid influx of water.
Moreover, urbanisation often leads to the removal of vegetation, which exacerbates soil erosion, reduces groundwater recharge, and contributes to higher levels of pollution in water bodies. The use of lands for industrial and agricultural activities introduces pollutants like industrial waste and agricultural runoff, contaminating water supplies and affecting the quality of drinking water.
This urban impact on water resources is a critical issue that needs sustainable urban planning and better water resource management.