Hydrology is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and environmental watershed sustainability. A practitioner of hydrology is called a hydrologist. Hydrologists are scientists studying earth or environmental science, civil or environmental engineering, and physical geography. Using various analytical methods and scientific techniques, they collect and analyze data to help solve water related problems such as environmental preservation, natural disasters, and water management.
The Rhine is one of the major European rivers. The river begins in the Swiss canton of Graubünden in the southeastern Swiss Alps. It forms part of the Swiss-Liechtenstein, Swiss-Austrian, Swiss-German borders. After that the Rhine defines much of the Franco-German border, after which it flows in a mostly northerly direction through the German Rhineland. Finally in Germany the Rhine turns into a predominantly westerly direction and flows into the Netherlands where it eventually empties into the North Sea. It digs an area of 9,973 sq km and its name derives from the Celtic Rēnos. There are also two German states named after the river, North Rhine-Westphalia and Rhineland-Palatinate.
The geography of Switzerland encompasses the geographical features of Switzerland, a mountainous and landlocked country located in Western and Central Europe. Switzerland's natural landscape is marked by its numerous lakes and mountains. It is surrounded by 5 countries: Austria and Liechtenstein to the east, France to the west, Italy to the south and Germany to the north. Switzerland has a maximum north–south length of 220 kilometres (140 mi) and an east–west length of about 350 kilometres (220 mi).
The main chain of the Alps, also called the Alpine divide is the central line of mountains that forms the drainage divide of the range. Main chains of mountain ranges are traditionally designated in this way, and generally include the highest peaks of a range. The Alps are something of an unusual case in that several significant groups of mountains are separated from the main chain by sizable distances. Among these groups are the Dauphine Alps, the Eastern and Western Graians, the entire Bernese Alps, the Tödi, Albula and Silvretta groups, the Ortler and Adamello ranges, and the Dolomites of South Tyrol, as well as the lower Alps of Vorarlberg, Bavaria, and Salzburg.
The Alps form part of a Cenozoic orogenic belt of mountain chains, called the Alpide belt, that stretches through southern Europe and Asia from the Atlantic all the way to the Himalayas. This belt of mountain chains was formed during the Alpine orogeny. A gap in these mountain chains in central Europe separates the Alps from the Carpathians to the east. Orogeny took place continuously and tectonic subsidence has produced the gaps in between.
A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the drainage divide, made up of a succession of elevated features, such as ridges and hills. A basin may consist of smaller basins that merge at river confluences, forming a hierarchical pattern.
The water cycle, also known as the hydrologic cycle or the hydrological cycle, is a biogeochemical cycle that describes the continuous movement of water on, above and below the surface of the Earth. The mass of water on Earth remains fairly constant over time but the partitioning of the water into the major reservoirs of ice, fresh water, saline water and atmospheric water is variable depending on a wide range of climatic variables. The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the atmosphere, by the physical processes of evaporation, transpiration, condensation, precipitation, infiltration, surface runoff, and subsurface flow. In doing so, the water goes through different forms: liquid, solid (ice) and vapor. The ocean plays a key role in the water cycle as it is the source of 86% of global evaporation.
Surface-water hydrology is the sub-field of hydrology concerned with above-earth water, in contrast to groundwater hydrology that deals with water below the surface of the Earth. Its applications include rainfall and runoff, the routes that surface water takes, and the occurrence of floods and droughts. Surface-water hydrology is used to predict the effects of water constructions such as dams and canals. It considers the layout of the watershed, geology, soils, vegetation, nutrients, energy and wildlife. Modelled aspects include precipitation, the interception of rain water by vegetation or artificial structures, evaporation, the runoff function and the soil-surface system itself.
In hydrology, discharge is the volumetric flow rate of water that is transported through a given cross-sectional area. It includes any suspended solids, dissolved chemicals, or biologic material in addition to the water itself. Terms may vary between disciplines. For example, a fluvial hydrologist studying natural river systems may define discharge as streamflow, whereas an engineer operating a reservoir system may equate it with outflow, contrasted with inflow.
The main European watershed is the drainage divide ("watershed") which separates the basins of the rivers that empty into the Atlantic Ocean, the North Sea and the Baltic Sea from those that feed the Mediterranean Sea, the Adriatic Sea and the Black Sea. It stretches from the tip of the Iberian Peninsula at Gibraltar in the southwest to the endorheic basin of the Caspian Sea in Russia in the northeast.
The Alps form a large mountain range dominating Central Europe, including parts of Italy, France, Switzerland, Liechtenstein, Austria, Slovenia, Germany and possibly Hungary.
The law of water balance states that the inflows to any water system or area is equal to its outflows plus change in storage during a time interval. In hydrology, a water balance equation can be used to describe the flow of water in and out of a system. A system can be one of several hydrological or water domains, such as a column of soil, a drainage basin, an irrigation area or a city. Water balance can also refer to the ways in which an organism maintains water in dry or hot conditions. It is often discussed in reference to plants or arthropods, which have a variety of water retention mechanisms, including a lipid waxy coating that has limited permeability.
A perennial stream is a stream that has continuous flow of surface water throughout the year in at least parts of its catchment during seasons of normal rainfall, as opposed to one whose flow is intermittent. In the absence of irregular, prolonged or extreme drought, a perennial stream is a watercourse, or segment, element or emerging body of water which continually delivers groundwater. For example, an artificial disruption of stream, variability in flow or stream selection associated with the activity in hydropower installations, do not affect this status. Perennial streams do not include stagnant water, reservoirs, cutoff lakes and ponds that persist throughout the year. All other streams, or parts of them, should be considered seasonal rivers or lakes. The stream can cycle from intermittent to perpetual through multiple iterations.
The Witenwasserenstock is a peak between the Swiss cantons of Valais and Uri, located in the Lepontine Alps. Close to the summit lies the tripoint border between the cantons of Valais, Uri and Ticino and the triple watershed of the Rhine, Po and Rhône basins.
The following outline is provided as an overview of and topical guide to hydrology:
DPHM-RS is a semi-distributed hydrologic model developed at University of Alberta, Canada.
The Po is the longest river in Italy. It flows eastward across northern Italy starting from the Cottian Alps. The river's length is either 652 km (405 mi) or 682 km (424 mi), if the Maira, a right bank tributary, is included. The headwaters of the Po are a spring seeping from a stony hillside at Pian del Re, a flat place at the head of the Val Po under the northwest face of Monviso. The Po then extends along the 45th parallel north before ending at a delta projecting into the Adriatic Sea near Venice.
