Explanations:An arch dam is a type of dam that is curved in shape and is designed to withstand the pressure of water by transferring the load to the abutments (the sides of the valley). The curvature of the dam allows it to resist the horizontal thrust of the water, making it a highly efficient and strong structure. Arch dams are typically built in narrow canyons or valleys where the rock formations on the sides can provide the necessary support.
The Idukki Dam, located in the Idukki district of Kerala, India, is a notable example of an arch dam. It is one of the highest arch dams in Asia and is known for its unique design and engineering. The dam is situated between two mountains, Kuravanmala and Kurathimala, and is supported by the rock formations on both sides. The Idukki Dam is not only a significant hydroelectric power project but also a popular tourist attraction due to its scenic beauty and engineering marvel.
Other dams in Kerala, such as the Malampuzha Dam, are not arch dams. The Malampuzha Dam, located in Palakkad district, is a masonry dam and is primarily used for irrigation and drinking water supply. The Malankara Dam and Chulliar Dam are not located in Kerala and are not arch dams, which makes them incorrect options for this question.
Understanding the type and location of dams is crucial for various competitive examinations, especially those related to geography and general knowledge. The Idukki Dam stands out as a significant example of an arch dam in India, making it a key piece of information for students preparing for such exams.