Explanations:Water harvesting is a critical practice in arid and semi-arid regions like Rajasthan, where water scarcity is a significant issue. Traditional water harvesting structures have been developed over centuries to ensure a steady supply of water for drinking, irrigation, and other domestic uses. One such structure is the Tankas, which are underground tanks used to store rainwater for drinking purposes.
Tankas are typically constructed in homes and are designed to collect rainwater from rooftops. The water is then filtered and stored in these underground tanks, which are usually made of masonry and lined with lime or cement to prevent seepage. The stored water is used during the dry season when surface water sources are scarce. This system is highly efficient in conserving water and ensuring a clean and reliable source of drinking water for the community.
Other water harvesting structures in Rajasthan include Khadins, which are large earthen embankments that collect and store rainwater. Khadins are typically built on the lower slopes of hills and are used to irrigate fields and provide water for livestock. Unlike Tankas, Khadins are not underground structures but are built on the surface to collect and store water.
Ponds, on the other hand, are surface water bodies that can be used for water storage but are not specific to Rajasthan's traditional water harvesting systems. They are more commonly found in regions with higher rainfall and are used for various purposes, including irrigation, fishing, and livestock watering.
Kuls are water channels used in the Himalayan region, particularly in Jammu and Kashmir, to divert and store water. They are not specific to Rajasthan and are not underground tanks. Kuls are typically constructed to channel water from natural springs or streams to fields for irrigation purposes.
In summary, Tankas are the correct answer as they are the underground tanks used in Rajasthan to store rainwater for drinking purposes. They are an integral part of the region's traditional water harvesting systems and play a crucial role in ensuring water security in the arid and semi-arid regions of Rajasthan.