Walking through mountainous areas, you may have spotted many natural springs. Springs are an important part of the hydrological cycle and interestingly can be classified into different types. The word spring comes from German word ‘springer,’ which means ‘to leap from the ground’. The ground water discharges through springs occurs in areas where the upper surface of the zone of saturation intersects the ground surface. In simple terms natural springs are points on the earth surface through which ground water emerges and flows. Springs can be classified in several categories base on their morphological characteristics. K. Bryan of U.S Geological Survey gave a classification of natural springs based on which G’nY presents five different kinds of springs found in India
Depression springs are formed in unconfined aquifers when the topography intersects the water table, usually due to the surface stream incision. As these springs are formed because of earth’s gravitational pull they are named depression or gravity springs. These are usually found along hillside and cliffs.
Depression springs are most common in the Himalayas. The Dangala spring located near Dangala village, Tehri district of Uttarakhand is one such example. It emerges at the base of a ridge trending from north east to south west. Similarly, Malagiri Dhara in village Lungchok Kamarey, South Sikkim, is also a type of depression spring at an elevation of 975 meters.
The geological setting of Umbari village in Satara of Maharashtra results in a contact spring. The contact plane between a permeable and impermeable rock intersects the ground surface in such a way that the ground water is deflected to the surface making it a contact spring .The residents of Umbari who are the direct beneficiary of this spring water, meet their day to day needs by using this water. Similarly Myora of Nainital, Uttarakhand also falls into this category
Fracture spring has waters flowing from joints or other fractures in contrast to the numerous small opening from which a filtration spring flows. Fracture spring occurs when a system of interconnected minor faults leads the groundwater to the surface. An ideal example is the spring of Mundani of Uttarakhand. Two villages Channan and Mundadi are located on the opposite sides of a valley running in the north-south direction. Both the ridges on which the villages are located are entirely made up of a dipping sequence of quartzite’s, slates and phyllites. The entire rock sequence dips 40° towards north east. A fracture zone trending north-south cuts across the rock sequence leading to the emergence of natural springs along it.
The term ‘karst’ is derived from a Slavic word that means barren, stony ground. It is also the name of a region in Slovenia near the border with Italy that is well known for its sinkholes and springs. Geologists have adopted karst as the term for all such terrain. Karst spring represents a natural exit for ground water to the surface through the hydrologicaly active fissures of karst mass. The spring in karst landscape appears more frequently in the places of contact between the carbonate masses and the impermeable layers. In the south east Kashmir Valley, numerous natural springs rise from Triassic Limestone, Permo-Carboniferous Panjal Traps, Quaternary Karewas (lacustrine deposits) and recent alluvium. To name a few, Karsts springs are seen in Achabalnag, Andernag and Martandnag. These natural springs are also recharged by the Bringi stream and Liddar stream. Anantnag district of south Kashmir is actually famous as a land of countless springs
Igneous spring, also called hot spring, is a natural spring with water at a temperature substantially higher than the air temperature of the nearby region. Most igneous springs discharge groundwater that is heated by thin intrusions of magma. Some igneous springs, however, are not related to volcanic activity. In such cases, the water is heated by convective circulation – groundwater percolates downward reaching depths of a kilometer or more where the temperature of rocks is high because of the normal temperature gradient of the earth’s crust – about 30°C (54 °F) per kilometer in the first 10 km (6 miles). Known as one of the most famous natural springs in India, Tattapani in Surguja district of Madhya Pradesh is a hot water spring.
With increasing population pressure, India touted to surpass China by 2022, water is soon to become a scarcer commodity. This would adversely affect our natural springs with insufficient recharge of ground water. Conservation and recharge measures are thus imperative to maintain the beauty of India’s various springs.