Science, Art, Litt, Science based Art & Science Communication
You must have been told a story in your school about a stupid person who tries to cut down the very branch he is sitting on. And if I say we are all now doing the same you will definitely be surprised. Some even protest and say you are not doing anything like that. But just keeping quiet when others are cutting the branch you are sitting on is unintelligent too! Don't you agree and start stopping the people who are doing this harm to you? I am sure you would.
Here we frequently hear about lakes, ponds and other water bodies getting dried up and people suffering as a result.
Our short-sighted activities are the reason for it - at least a part of what has been happening is man-made. Yes, we ourselves are destroying our water supply systems. Let me explain how.
Of course global warming, climate change and destroying green cover have some effect on the rainfall pattern in any given area. But we are also stopping whatever little rain water that is falling in our localities from reaching the water bodies thereby depleting them of their sustenance.
A catchment area or basin is land which is bounded by natural features such as hills or mountains from which all runoff water flows to a low point. This low point will be a dam, a location on a river, or the mouth of a river where the water enters a bay or the ocean. So catchment areas are the regions from which rainfall flows into a river, lake, or reservoir. They vary in size and make-up. Large catchment areas are bordered by mountain ranges and include major drainage networks of creeks and rivers. Large catchment areas are made up of hundreds of smaller 'sub-catchment' areas. These can be bordered by low hills and ridges and drained by only a small creek or gully.
In fact a catchment area is the life line of these water bodies. If we cut it, the water body's recharge capacity could diminish considerably and it naturally dies!
If we add pollutants to the catchment areas, the water bodies get polluted too making the water unusable.
What happens in one part of a catchment is likely to affect the well being of the rest of the catchment area, so there are many things you can do to minimise your impact on the system.
For instance, since storm water drains run straight into our waterways, heavy rainfall can wash sediments, rubbish and pollutants into the rivers and eventually into the ocean. This may impact negatively on aquatic life, coral reefs and seagrass beds. It can also affect people who use the water, for example, for irrigation or stock watering.
Sediments in waterways are particles of soils that have been washed from farms, construction and development sites, road stockpiles, sewage effluent and other sources. Large amounts of sediments in the water reduces the amount of light able to reach the river beds. That means aquatic plants don't have enough light to photosynthesise and die. If they die other life forms like insects, fish etc. that depend on them too perish.
Moreover, floods and cyclones are natural processes which can benefit the environment. Changes we make to our catchments can change the way they respond to flooding and cyclones.
Another issue that is bothering the scientists is people are covering every inch of road surface, foot-paths, lands surrounding their dwellings with concrete or tarmac. This stops water from percolating and harvesting and the scope for water absorption by the ground is highly getting disrupted as a result. This is one of the reason why the ground water levels are decreasing day by day.
And if hills and ridges around water bodies are flattened to use the land for commercial purposes the flooding will increase in urban areas. When a ridge is flattened to build a road or a complex of buildings it disrupts the natural flow of water and ultimately alters the drainage patterns of the area. This is the reason the area witnesses severe urban flooding, even with a short spell of rain. Cutting into ridges also means that an important watershed is being destroyed. Flattening a ridge, which itself is a rainwater storage site, will result in acute water shortage in the region. The green cover that usually covers ridges makes it easier for water to seep into the ground. With massive concretization, the area will be under severe water crunch as there is no way for water to enter the ground.
Now how can you help preserve the catchment areas for uninterrupted supply of pure water?
You can do many little things such as reducing water pollution and conserving water to reduce your impact on your catchment. Minimising erosion around your home and business will also reduce problems downstream. Tree planting and mulching prevents excess soil and nutrients getting into drains and creeks.
Then stop using the catchment areas for house and other commercial constructions. Don't block the catchment areas by throwing discarded material of your developmental activities.
Stop blocking every inch of land available. Leave some space for the water to go under ground. At least go for rain-water harvesting pits.
Don't cut the life line of these water bodies. If you do so, you are indirectly cutting your own life line!