Rain brings happiness to everyone on earth. Clouds that move across the sky contain huge amounts of tiny water droplets and ice crystals. Not all clouds bring rain. Only under ideal conditions clouds condense into rain.
Rain water is very good for plants as it contains lot of nutrients and is free of salts and other harmful elements. Though rain absorbs gases from atmosphere, it is pure till it reaches the ground. Rainwater is soft water and hence it doesn’t form scales on surfaces or utensils. It also lathers well with soaps and detergents. Once rain water reaches the ground, it gets contaminated with chemicals and other water pollutants that are present on the ground.
Rain with more than normal amounts of chemicals constituents is called acid rain. Acid rains occur only in the most industrialized regions. It is mainly caused by the presence of harmful gases released into the environment by factories, power plants, automobiles etc. The two major pollutants causing acid deposition are sulfur dioxide (SO2) and nitric oxide (NOx). These chemicals become acids when they enter the air and react with water vapor. When it rains, it brings sulfuric acid (H2SO4) and nitric acid (HNO3) to earth either as wet or dry precipitations. A wet precipitation leads to acid rains and a dry one leads to particulates of acids. While normal rain has a pH in the order of 5-6 on the scale, acidic rains tend to a pH of 3-4. Acid rain causes acidification of lakes and streams and contributes to the damage of trees at high elevations.
Rain water harvesting is done in many regions across the globe in order to save the precious resource. There are many methods in which rain water can be harvested. Depending on the type of house and available structures like well, bore wells etc appropriate water harvesting methods are followed.