Why can droughts occur in Hainan despite its heavy rainfall?

Although Hainan experiences heavy annual rainfall, droughts can still occur due to the uneven distribution of precipitation across both different seasons and different geographic areas of the island.1

While the eastern regions receive higher average annual precipitation, the western coastal areas receive significantly less, falling below 60 inches (1,500 mm). Furthermore, because the climate is monsoonal, the rainfall is concentrated during specific times of the year, leading to seasonal water shortages. To mitigate these challenges, the province has constructed numerous large, medium, and small-sized reservoirs to manage water resources across the island.1