Define "ineffective rainfall."

Ineffective rainfall refers to precipitation that does not contribute to surface runoff or groundwater recharge. This type of rainfall can occur for several reasons, such as being absorbed by dry soil that cannot retain moisture or evaporating before it can reach any water bodies. Essentially, this rainfall fails to provide the intended benefits of replenishing water supplies or supporting ecosystems.

In contrast, effective rainfall would enhance soil moisture levels, contributing to agriculture or replenishing aquifers. Other options suggest scenarios where rainfall has beneficial impacts, either for groundwater recharge or agricultural productivity, which do not align with the concept of ineffective rainfall.