Inbat al-miyah al-khafiya is an excellent manual on the supplies of hydraulic water; it was written by Abu Bakr Muhammed Al-Karaji. Besides its main interest in hydrology, it contains a discussion of many topics related to the geography of the globe, various remarks on soil types and nature, as well as paying great attention to surveying techniques.
Al-Karaji was quite familiar with the basic hydrological, geological, and engineering principles associated with groundwater. He displayed comprehensive skills regarding the classification of soils, how to search for fresh water, and the different types and hydraulic characteristics of aquifers. He explained how to use a certain number of surveying instruments and described the details of how to construct and service a canal providing water in harsh places.
The book is an original contribution in other aspects of geology concerned with the advanced knowledge of groundwater during the 10th century in the Islamic lands. Relying on his own studies and researches, Al-Karaji revealed a technical understanding of groundwater theory; as such, his contribution in this field is the oldest known text discussing the drilling of wells to search for water from ground levels. He succeeded in recording each phase in his book individually, including practical information on the construction of irrigation systems in the form of canals.
According to Al-Karaji, the book begins with assertion of the subject of the book then to study Earth, types and tastes of waters that are to be found, how to find them, and how to clean contaminated water. It goes on to discuss springs, wells, drilling, the measurement of water and dealing with dams.
During the Islamic era, canals became one of the most effective methods for providing water in regions that did not have direct access to any source of water. This technique originated in northern Iran in Ancient Times; in time, this system of supplying water over a long distance was in widespread use in the Muslim world in the Medieval period and up to Modern Times.
A part of the book is dedicated to describe how to survey the slope of canals, its effects, and how to work under difficult circumstances. One of the discussions is digging wells through non unified rocks and how to use timber to protect the workers and the work area.
In conclusion, Al-Karaji pioneered work with geological structures in his use of plant growths as indicators and locators of groundwater reservoirs. The reception and authentication of Al-Karaji's treatise in history of science should strengthen his value as this book was only translated into French in 1973, and Italian in 2007; however, there are no complete English or German translations.
References
www-history.mcs.st-and.ac.uk
www.muslimheritage.com