National Institute of Hydrology (NIH)

Groundwater conditions in the multi-aquifer system in the delta, were studied through an integrated approach using hydrochemical, hydrogeological and isotopic techniques. This study was taken up because of the reported seawater intrusion into the groundwater system of this agriculturally rich region.

It attempts at compiling information on various component processes of hydrology and their interaction. The report has been divided into nine chapters dealing with different aspects of hydrology.

Like other sciences, the science of water too was well developed in ancient India. The report regrets that at present sufficient attention is not paid to our ancient Indian sciences. The study of Sanskrit literature indicates valuable references to hydrology and important concepts of modern hydrology are scattered in various verses of Vedas, Puranas, Meghmala, Mayurchitraka, Vrhat Sanhita and various other ancient Indian works. 

Some of the key references are as follows –

• In vedic age, Indians had developed the concept that water gets divided into minute particles due to the effect of sun rays and wind. At various places in the Puranas it is alluded that water cannot be created or destroyed and that only its state is changed through various phases of hydrological cycle.
• Evaporation, condensation, cloud formation, precipitation and its measurement were well understood in India in vedic and puranic times.
• Effect of yajna, forests, reservoirs etc., on the causation of rainfall, classification of clouds, their colour, rainfall capacity etc, forecasting of rainfall on the basis of natural phenomenon like colour of sky, clouds, wind direction, lightning, and the activities of animals was well developed in ancient India well before 10th century BC.
• Contrivances to measure rainfall were developed during the time of Kautilya (4th century BC) which had the same principle as that of modern hydrology except the fact that weight measure (of drone, paia etc.,) were adopted instead of modern linear measurement of rainfall.
• Scientific facts like arid region of Tibetan rain shadow area and no rainfall by polar winds was discussed in the puranas. The knowledge of monsoon winds and height of clouds along with the division of atmosphere was well developed in vedic age.
• The technique of knowing the slope of an area by means of a flowing river and dimensions of meandering rivers along with velocity of flow were developed.
• In ancient times, Indians had well developed concepts of groundwater occurrence, distribution and utilization. Literature also reveals that hydrologic indicators such as physiographic features, termite mounds, soils, flora, fauna, rocks and minerals were used to detect the presence of groundwater.
• Variation in the height of water table with place, hot and cold springs, ground water utilization by means of wells, well construction methods and equipment are fully described in chapter 54 of Vrhat Sanhita (Bruhat Samhita) named as ‘Dakargala’. The fact that sun rays, winds, humidity, vegetation etc are the major causes of evapotranspiration was well realized.
• Varamihira in as early as 550 AD presented a simple method for obtaining potable water from a contaminated source of water. Various plant materials along with the sun heating, aeration, quenching of water with fire heated stones, gold, silver, iron or sand were used. The change in the quality of water with the months of year and suitability of water from different sources for various uses were described.
• Efficient water use, lining of canals, construction of dams, tanks, essential requirements for the construction of good tanks, bank protection methods, spillways and other minor aspects were given due consideration in ancient times in India.
• Well organized water pricing system was prevalent during the times of Kautilya.
• Various references are available in the Vedas alluding the importance of efficient water use so as to reduce the intensity of water scarcity and drought.

This “Learning Package on Hydrology” by the National Institute of Hydrology deals with the basic scientific concepts underlying hydrology. In a general sense the package deals with elements of the hydrologic cycle and explains the processes of rainfall, runoff and evapotranspiration and their interaction.  

This document, an outcome of the joint efforts of NIH and CGWB gives a detailed outline emphasizing the gaps, focal areas of research, immediate measures to be taken up to provide arsenic safe potable water to the people in the arsenic vulnerable areas, other activities to be initiated for attaining a logical conclusion of the arsenic problem and also to develop a roadmap delineating as to how the suggested activities could be initiated, coordinated, undertaken, including framing out a budget estimate to fulfill those activities.

The study by National Institute of Hydrology attempts to model seawater intrusion using FEFLOW, an interactive finite element simulation system in the coastal area of Bardez taluka in North Goa and evaluate the impact of increasing groundwater development on the phenomenon. Coastal tracts of Goa are rapidly being transformed into settlement areas and the poor water supply facilities have encouraged people to develop their own sources of water by digging or boring wells.

This study by the National Institute of Hydrology deals with simulation of soil moisture movement and determination of groundwater recharge from rainfall in Barchi watershed in the hard rock region of Karnataka using the numerical model, Soil Water Infiltration and Movement (SWIM).

The India Water Portal is pleased to announce to its users, that a comprehensive archive of over two hundred and fifty technical research reports of the National Institute of Hydrology (NIH), Roorkee, have now been made available on the portal, and in the public domain for the first time.

The study determines rates of sedimentation and estimates the useful life of Dal-Nagin lake situated in Srinagar, Jammu and Kashmir using radiometric techniques. In spite of various ecological problems the lake is the largest freshwater lake in India. It has four major sub-basins viz., Hazratbal, Bod Dal, Garibal and Nagin. The lake is fraught with the problem of growth of underwater weeds and increasing rate of sedimentation.

The study deals with the development of an operation policy for the Tawa dam. It adopts rule-curve based policy for conservation regulation of the dam developed for three levels viz. upper rule level, middle rule level (critical for irrigation) and lower rule level (critical for water supply and upstream use). The generated simulation model developed by the Water Resources System Group at the National Institute of Hydrology is used to simulate the system operation and to refine the rule curves.

The study deals with flood plain mapping in a part of Yamuna basin between Gangoh and New Delhi. A flood is a markedly high stage of flow in a river and may inundate adjoining lands, which is called the floodplain of a river. So, floodplain is land inundated by a flood of given frequency. Alternately it is also defined as flat land between valley walls.