Yesterday (February 2) was World Wetlands Day. Wetlands are natural ecosystem involving fresh water, brackish or salt water. Wetlands, however do not contain ocean by definition.
Yesterday, I watched a video on Twitter that explained how concretizing recharge zone affects groundwater storage. Recharge zone is the area containing gravelly and/or coarse sand that conducts water readily. In mountainous valley like Kathmandu, the surrounding mountains make the recharge zone.
The central portion of the Kathmandu Valley consists of about 200 m thick layer of clayey soil. Water does not readily infiltrate in this zone. Roads and concrete structures in this part have increased urban flooding. In ancient and medieval times several ponds had been constructed to prevent urban flooding. But most of these have been depleted, encroached or altered.
The recharge zone has also gone through a huge change. “Development” is rampant. People are shifting towards the hills because of the increased population and advanced technology.
These areas have not been completely concretized. But with more people reaching the area, concretization will be inevitable. The Shivapuri-Nagarjun National Park aims to preserve the watershed in the northern part but it might not be enough.
The scarcity of drinking water in the Kathmandu Valley is something politicians have always cashed upon. The scarcity is going to create even more problems.
Similarly, disasters are going to be more frequent. Landslides and urban flooding will create more troubles. Our “development” activities have not considered these problems yet. Development could actually be destruction.
Problem is, those who talk about these geological and ecological problems and suggest sustainable development plans are often labelled as being against development. Unless common people understand the science behind mountains, groundwater, and urban planning, it is impossible to attain sustainable development.
#science-and-society #urbanization #water #wetlands-day