India releases Water Body census

 Highlights:

• The photograph of the water bodies along with the latitude and longitude was captured by a mobile app developed for this purpose.  
• 24,24,540 water bodies have been enumerated in the country, out of which 97.1% (23,55,055) are in rural areas and only 2.9% (69,485) are in urban areas. 
• 59.5% (14,42,993) of water bodies are ponds, followed by tanks (15.7%, i.e 3,81,805), reservoirs (12.1%, i.e 2,92,280), Water conservation schemes/percolation tanks/check dams (9.3%, i.e 2,26,217), lakes (0.9%, i.e 22,361) and others (2.5%, i.e 58,884).
• West Bengal has highest number of ponds & reservoirs, whereas Andhra Pradesh has highest number of tanks, Tamil Nadu has highest number of lakes and Maharashtra is the leading state for water conservation scheme. 
• A major proportion of water bodies i.e., 83.7% (20,30,040) are in use whereas remaining 16.3% (3,94,500) are not in use on account of drying up, construction, siltation, destroyed beyond repair, salinity and other reasons. 
• Most of the water bodies are used in pisciculture, followed by irrigation, ground water recharge and domestic/drinking purpose. 

Read the report: https://cdnbbsr.s3waas.gov.in/s3a70dc40477bc2adceef4d2c90f47eb82/uploads/2023/04/2023040672.pdf

Primer on atmospheric water harvesting technologies

Indian Prime Minister Modi was reported enquiring whether a turbine could be used to harvest water from moisture in the air and oxygen too, thus serving as a three-in-one machine. Three components of the system , Wind mills, Atmospheric water generator, Water splitting to produce Oxygen, Hydrogen are well known.

Here we look at review paper on atmospheric water harvesting technologies.

The scope of this paper is to review different types of sustainable water harvesting methods from the atmospheric fogs and dew. In this paper, we report upon the water collection performance of various fog collectors around the world. We also review technical aspects of fog collector feasibility studies and the efficiency improvements. Modern fog harvesting innovations are often bioinspired technology. Fog harvesting technology is obviously limited by global fog occurrence. In contrast, dew water harvester is available everywhere but requires a cooled condensing surface. In this review, the dew water collection systems is divided into three categories: i) dew water harvesting using radiative cooling surface, ii) solar-regenerated desiccant system and iii) active condensation technology. The key target in all these approaches is the development of an atmospheric water collector that can produce water regardless of the humidity level, geographical location, low in cost and can be made using local materials.

Download paper: https://academic.oup.com/ijlct/article/15/2/253/5718410