User:S1937772/sandbox

Background:
The rainy season in Niger is from June to September, and peaks in September. Heavy rains have caused floods. Since 2000, the floods in Niger have continued to intensify, seriously threatening the property and life safety of people on the southwestern part of Niger and on the banks of the Niger River.

Cause:

 * Wetland degradation. The ecology of the Niger River is destroyed, and land are degraded.  There are no plants to conserve water, and floods are easy to occur every year during the rainy season.
 * Global climate change. Increased seasonal rainstorms (various extreme weather effects).
 * Cities in Nigel are unreasonable in planning and cannot adapt to the rapidly growing population changes. The drainage system is approaching saturation, and many towns even lack drainage networks. Because of the rapid population growth, local residents are free to build houses without planning and organization. The dumping of garbage on the streets causes the surface runoff to be easily blocked due to heavy rain.
 * The upstream dam discharge water is unreasonable, and a large amount of water is released during the rainstorm season. The water volume downstream of the river channel increases and the water level of the river rises.