Which combination is identified as the three main human-caused sources of floods?

Which combination is identified as the three main human-caused sources of floods?

• A. Urbanization, Deforestation, and Agriculture
• B. Urbanization and Deforestation only
• C. Agriculture and Urbanization only
• D. Deforestation and Agriculture only

Answer: (A)

The key idea is how human activities change the way water moves across the landscape, increasing the likelihood and impact of floods. Urbanization introduces a lot of impervious surfaces like roads, roofs, and parking lots. Water can’t soak into concrete and asphalt, so rainfall becomes rapid surface runoff that overwhelming drains and can swell rivers quickly. Deforestation removes the trees and other vegetation that normally intercept rainfall, hold soil together with roots, and promote infiltration. With less interception and more exposed soil, rainfall runs off faster and more sediment is carried into waterways, reducing channel capacity and making floods more likely downstream. Agriculture alters land cover and drainage as fields are cleared, tilled, and sometimes drained or irrigated. These changes can disrupt natural water flow, increase runoff during storms, and contribute to soil erosion and sedimentation in rivers, which can reduce channel capacity and worsen flood conditions. Together, these human activities create conditions that amplify flood risk, which is why this combination is identified as the three main human-caused sources of floods.

The key idea is how human activities change the way water moves across the landscape, increasing the likelihood and impact of floods. Urbanization introduces a lot of impervious surfaces like roads, roofs, and parking lots. Water can’t soak into concrete and asphalt, so rainfall becomes rapid surface runoff that overwhelming drains and can swell rivers quickly.

Deforestation removes the trees and other vegetation that normally intercept rainfall, hold soil together with roots, and promote infiltration. With less interception and more exposed soil, rainfall runs off faster and more sediment is carried into waterways, reducing channel capacity and making floods more likely downstream.

Agriculture alters land cover and drainage as fields are cleared, tilled, and sometimes drained or irrigated. These changes can disrupt natural water flow, increase runoff during storms, and contribute to soil erosion and sedimentation in rivers, which can reduce channel capacity and worsen flood conditions.

Together, these human activities create conditions that amplify flood risk, which is why this combination is identified as the three main human-caused sources of floods.