“Exploration for Hidden Water” by Mohammad Karaji—The Oldest Textbook on Hydrology?

Abstract

Reviewing a classical Persian book on ground‐water problems of the 11th century, it is shown that Ground‐water hydrology developed absolutely independently of geology. The Arabic‐Persian scientists of that time knew about the hydrologic cycle and the existence of different types of water underground; and they knew that the quality of water depends on the character of the rocks through which ground water flows. Techniques of developing ground‐water resources in the Middle East, i.e., the digging of wells and qanats, were of such a high standard that they are still in use today. Generally, it can be stated that the oriental scientists of the Middle Ages knew of the basic principles of hydrology. Thus they were far ahead of their contemporaries in Europe.

The millennium-old hydrogeology textbook The Extraction of Hidden Waters by the Persian mathematician and engineer Abubakr Mohammad Karaji (953 CE–1029 CE)

“…This book was about practical hydrology in this period. Although it has been mentioned that the book was written by him as a means of earning a living (Nadji and Voigt, 1972), we speculate that the topic was of great practical interest in the arid area of the Persian Plateau. It is also very likely that this topic was of interest to Karaji personally, and he certainly knew it was vitally important.…”

“…In an interesting article, Nadji and Voigt (1972) presented a glimpse into the book. They stated that, based on this 11thcentury book, the basics of the hydrologic cycle and components of underground water quality were already known by Arab and Persian scientists of that time.…”

“…They mentioned that the techniques of wells and qanat digging, which were developed for groundwater exploitation in the Middle East, were of such a high standard that they are still in use today. Prompted by Nadji and Voigt (1972), Davis (1973) put Karaji's work into a broader scientific context, explaining the lack of appreciation, value and awareness of Middle Eastern science and scientists in general.…”

“…Also, Rashed (1994) In the later years of his life, Karaji returned to the central plateau of his Persian homeland (e.g. Nadji and Voigt, 1972;Lewis, 2001) and wrote the book Inbat al-miyah alkhafiya (The Extraction of Hidden Waters). This book was about practical hydrology in this period.…”

The millennium old hydrogeology textbook The Extraction of Hidden Waters by the Persian mathematician and engineer Abubakr Mohammad Karaji (c. 953–c. 1029)

“…As it will be mentioned, in the extracts of Karaji's preface to his book, he notes that to provide people with a good water supply would be a most beneficial work. The book is considered "the oldest textbook on hydrology" (Nadji and Voigt, 1972). Figure 1 shows a statue of Abubakr Mohammad Karaji at the Water Museum of Sa'dabad Museum Complex in Tehran, Iran.…”