Robert E. Horton
Encyclopedia
Robert Elmer Horton was an American
ecologist
and soil scientist
, considered by many to be the father of modern hydrology
.
Born in Parma, Michigan
, he earned his B.S.
from Albion College
in 1897. After his graduation, he went to work for his uncle, George Rafter, a prominent civil engineer
. Rafter had commissioned a weir
study, the results of which Horton analyzed and summarized. In 1900, he was appointed New York
District Engineer of the United States Geological Survey
.
During his studies of New York streams, Horton determined that the degree to which rain
fall could reach the aquifer
depended on a certain property of the soil, which he called infiltration capacity. He analyzed and separated the water cycle
into the processes of infiltration, evaporation
, interception
, transpiration
, overland flow
, etc. Horton was the first to demarcate and label these now-familiar stages of the cycle.
Horton is well-known for his study of maximum runoff and flood
generation. His concept of maximum possible rainfall, limiting the effect of rainfall in specific regions, has had a major effect on meteorology
. His studies of overland flow aided in the understanding of soil erosion and provided a scientific basis for soil conservation
efforts.
Having realized early in his career that the physical character of terrain played a large role in determining runoff patterns, he resolved to isolate the physical factors affecting runoff and flood discharge. He believed these to include drainage density
, channel slope, overland flow length, and other less important factors. However, late in his career, he began to advocate a very different mechanism of "hydrophysical" geomorphology
, which he believed better explained his prior observations.
Horton detailed his theory in a landmark paper published in 1945, only a month before his death, in the Bulletin of the Geological Society of America
. He summarized his conclusions with four laws: the law of stream numbers, the law of stream lengths, the limits of infiltration capacity, and the runoff-detention-storage relation. His results demonstrate that the salient factor in aqueous soil erosion is the minimum length of overland flow necessary to produce enough runoff to effect erosion. This seminal work may be considered the founding of modern stream chemistry modeling, since it was the first comprehensive set of mathematical model
s to link basin hydrology with a water pollutant, namely sediment. the terminology Horton overland flow
is named after his accomplishments in hydrology.
Horton is the namesake of the Robert E. Horton Medal, awarded by the American Geophysical Union
to recognize outstanding contributions to the field of hydrological geophysics
.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
ecologist
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
and soil scientist
Soil science
Soil science is the study of soil as a natural resource on the surface of the earth including soil formation, classification and mapping; physical, chemical, biological, and fertility properties of soils; and these properties in relation to the use and management of soils.Sometimes terms which...
, considered by many to be the father of modern hydrology
Hydrology
Hydrology is the study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability...
.
Born in Parma, Michigan
Parma, Michigan
Parma is a village in Jackson County in the U.S. state of Michigan. The population was 907 at the 2000 census. This was an increase from 875, the population in 1990, and this marks the first time the village of Parma had more than 900 people....
, he earned his B.S.
Bachelor of Science
A Bachelor of Science is an undergraduate academic degree awarded for completed courses that generally last three to five years .-Australia:In Australia, the BSc is a 3 year degree, offered from 1st year on...
from Albion College
Albion College
Albion College is a private liberal arts college located in Albion, Michigan. Related to the United Methodist Church, it was founded in 1835 and was the first private college in Michigan to have a chapter of Phi Beta Kappa. It has a student population of about 1500.The school's sports teams are...
in 1897. After his graduation, he went to work for his uncle, George Rafter, a prominent civil engineer
Civil engineering
Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including works like roads, bridges, canals, dams, and buildings...
. Rafter had commissioned a weir
Weir
A weir is a small overflow dam used to alter the flow characteristics of a river or stream. In most cases weirs take the form of a barrier across the river that causes water to pool behind the structure , but allows water to flow over the top...
study, the results of which Horton analyzed and summarized. In 1900, he was appointed New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...
District Engineer of the United States Geological Survey
United States Geological Survey
The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization has four major science disciplines, concerning biology,...
.
During his studies of New York streams, Horton determined that the degree to which rain
Rain
Rain is liquid precipitation, as opposed to non-liquid kinds of precipitation such as snow, hail and sleet. Rain requires the presence of a thick layer of the atmosphere to have temperatures above the melting point of water near and above the Earth's surface...
fall could reach the aquifer
Aquifer
An aquifer is a wet underground layer of water-bearing permeable rock or unconsolidated materials from which groundwater can be usefully extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology...
depended on a certain property of the soil, which he called infiltration capacity. He analyzed and separated the water cycle
Water cycle
The water cycle, also known as the hydrologic cycle or H2O cycle, describes the continuous movement of water on, above and below the surface of the Earth. Water can change states among liquid, vapor, and solid at various places in the water cycle...
into the processes of infiltration, evaporation
Evaporation
Evaporation is a type of vaporization of a liquid that occurs only on the surface of a liquid. The other type of vaporization is boiling, which, instead, occurs on the entire mass of the liquid....
, interception
Interception (water)
Interception refers to precipitation that does not reach the soil, but is instead intercepted by the leaves and branches of plants and the forest floor. It occurs in the canopy , and in the forest floor or litter layer...
, transpiration
Transpiration
Transpiration is a process similar to evaporation. It is a part of the water cycle, and it is the loss of water vapor from parts of plants , especially in leaves but also in stems, flowers and roots. Leaf surfaces are dotted with openings which are collectively called stomata, and in most plants...
, overland flow
Horton overland flow
In soil science, Horton overland flow describes the tendency of water to flow horizontally across land surfaces when rainfall has exceeded infiltration capacity and depression storage capacity. It is named after Robert E...
, etc. Horton was the first to demarcate and label these now-familiar stages of the cycle.
Horton is well-known for his study of maximum runoff and flood
Flood
A flood is an overflow of an expanse of water that submerges land. The EU Floods directive defines a flood as a temporary covering by water of land not normally covered by water...
generation. His concept of maximum possible rainfall, limiting the effect of rainfall in specific regions, has had a major effect on meteorology
Meteorology
Meteorology is the interdisciplinary scientific study of the atmosphere. Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the 18th century. The 19th century saw breakthroughs occur after observing networks developed across several countries...
. His studies of overland flow aided in the understanding of soil erosion and provided a scientific basis for soil conservation
Soil conservation
Soil conservation is a set of management strategies for prevention of soil being eroded from the Earth’s surface or becoming chemically altered by overuse, acidification, salinization or other chemical soil contamination...
efforts.
Having realized early in his career that the physical character of terrain played a large role in determining runoff patterns, he resolved to isolate the physical factors affecting runoff and flood discharge. He believed these to include drainage density
Drainage density
Drainage density is the total length of all the streams and rivers in a drainage basin divided by the total area of the drainage basin. It is a measure of how well or how poorly a watershed is drained by stream channels...
, channel slope, overland flow length, and other less important factors. However, late in his career, he began to advocate a very different mechanism of "hydrophysical" geomorphology
Geomorphology
Geomorphology is the scientific study of landforms and the processes that shape them...
, which he believed better explained his prior observations.
Horton detailed his theory in a landmark paper published in 1945, only a month before his death, in the Bulletin of the Geological Society of America
Geological Society of America
The Geological Society of America is a nonprofit organization dedicated to the advancement of the geosciences. The society was founded in New York in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hitchcock, John R. Proctor and Edward Orton and has been headquartered at 3300 Penrose...
. He summarized his conclusions with four laws: the law of stream numbers, the law of stream lengths, the limits of infiltration capacity, and the runoff-detention-storage relation. His results demonstrate that the salient factor in aqueous soil erosion is the minimum length of overland flow necessary to produce enough runoff to effect erosion. This seminal work may be considered the founding of modern stream chemistry modeling, since it was the first comprehensive set of mathematical model
Mathematical model
A mathematical model is a description of a system using mathematical concepts and language. The process of developing a mathematical model is termed mathematical modeling. Mathematical models are used not only in the natural sciences and engineering disciplines A mathematical model is a...
s to link basin hydrology with a water pollutant, namely sediment. the terminology Horton overland flow
Horton overland flow
In soil science, Horton overland flow describes the tendency of water to flow horizontally across land surfaces when rainfall has exceeded infiltration capacity and depression storage capacity. It is named after Robert E...
is named after his accomplishments in hydrology.
Horton is the namesake of the Robert E. Horton Medal, awarded by the American Geophysical Union
American Geophysical Union
The American Geophysical Union is a nonprofit organization of geophysicists, consisting of over 50,000 members from over 135 countries. AGU's activities are focused on the organization and dissemination of scientific information in the interdisciplinary and international field of geophysics...
to recognize outstanding contributions to the field of hydrological geophysics
Geophysics
Geophysics is the physics of the Earth and its environment in space; also the study of the Earth using quantitative physical methods. The term geophysics sometimes refers only to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and...
.
See also
- Surface runoffSurface runoffSurface runoff is the water flow that occurs when soil is infiltrated to full capacity and excess water from rain, meltwater, or other sources flows over the land. This is a major component of the water cycle. Runoff that occurs on surfaces before reaching a channel is also called a nonpoint source...
- Extensions of Horton Formulas (Italian Wikipedia)