It is not easy to answer this vast question because a lot of high-level scientific research has been done so far in the field of hydraulics.

Hydraulics is one of the oldest activities of human civilization, since it controls all uses of water. Since ancient times, traces of hydraulic structures (drainage canals of the Nile valley, 4000 years before the Christian era) have been found. But until the Renaissance and the clarification of the basic principles of mechanics, this activity remained an art without scientific bases. This did not prevent the old builders from building admirable works such as the Roman aqueducts or, under the impetus of Louis XIV at Versailles, the famous Marly machine. The further development of hydraulics is based essentially on the improvement of mathematical tools and on the notions of mechanics, which took off in the 17th century. Pascal (1623-1662) made a very important contribution to hydraulics by giving his definitive form to the theory of hydrostatics. Daniel Bernoulli (1700-1782), in his book Hydrodynamica, reviews most of the hydraulic problems of the time. We owe him the famous "Bernoulli theorem" which is constantly used in this science. From the seventeenth to the twentieth century, the development of hydraulics then accompanies the general progress of science and technology, with the masterly contributions of Leonhard Euler (1707-1783), Louis de Lagrange (1736-1813), Pierre du Buat (1734 -1809), Jean-Louis Marie Poiseuille (1799-1869), Adhémar Barré of Saint-Venant (1797-1886), William Froude (1818-1879), Henri Navier (1785-1836), Joseph Boussinesq (1842-1929) Osborne Reynolds (1842-1912), to name but a few of the main founders of modern hydraulics.

Regards

My personal opinion - Many of the water, watershed, stream and river studies and research takes years and decades of effort. That is why I would hesitate in responding for last 10 years only. Funding for many types of research has been reduced or cut. As suggested, significant work from my perspective may depend on what has been useful to me as a professional hydrologist. Field hydrology and watershed management were a large part of my career, research a small part. Several items I found very useful during my career were 1) experimental watershed studies and associated ecosystem studies by the US Forest Service researchers and others, 2) information collected and publications of US Geologic Survey from their network of real time and archived data of long term stream gauging stations, and 3) efforts compiled and developed by David Rosgen with early associates such as Luna Leopold, Red Wolman and others in the areas of stream classification, stabilization and restoration, channel morphology, sediment and hydrogeomorphology training (wildlandhydrology.com). Some may say his work and efforts fail to qualify as hard core research, but his work applied more to the work I was hired to do, so I would suggest much qualifies as applied research. Concerning Rosgen or Rosgen inspired stream restoration, I would guess at least a hundred million dollars have been invested by various entities in the last 20 years.

But I also found some instances of dated research papers has great meaning, but their importance and awareness had been lost through time. If any of this interests you about my opinion, if you take time to look through my researchgate papers, most of them include citations that I felt significant at the time. Likewise, if you find other papers of special interest to you, their citations are also useful insights into what the author(s) felt important.

I believe LiDAR is a significant remote sensing tool when applied to watershed and stream subjects. My guess is that prominent research and researchers have access to or compiled substantial hydrological records over significant time periods, and as a result, have developed and disseminated useful information in their field relative to resource management and society awareness.

Une réponse intéressante et très bien dite.