FUNDAMENTALS
OF PHYSICAL GEOGRAPHY (2nd Edition)
CHAPTER 1:
Introduction to Physical Geography
CHAPTER 1:
Introduction to Physical Geography
(a). Introduction to Geography
Introduction
The main objective of this online textbook is to introduce
students to the exciting field of knowledge known as physical
geography. Physical geography is a discipline that is part of a
much larger area of understanding called geography.
Most individuals define geography as a field of study that deals with maps.
This definition is only partially correct. A better definition of geography may
be the study of natural and human
constructed phenomena relative to a spatial dimension.
The discipline of geography has a history that stretches over
many centuries. Over this time period, the study of geography has evolved and
developed into an important form of human scholarship. Examining the historical
evolution of geography as a discipline provides some important insights
concerning its character and methodology. These insights are also helpful in
gaining a better understanding of the nature of physical geography.
History of Geography and
Physical Geography
Some of the first truly geographical studies occurred more
than four thousand years ago. The main purpose of these early investigations
was to map features and places observed as explorers traveled to new lands. At
this time, Chinese, Egyptian, and Phoenician civilizations were beginning to
explore the places and spaces within and outside their homelands. The earliest
evidence of such explorations comes from the archaeological discovery of a
Babylonian clay tablet map that dates back to 2300 BC.
The early Greeks were the first civilization to practice a
form of geography that was more than mere map making or cartography.
Greek philosophers and scientist were also interested in learning about spatial
nature of human and physical features found on the Earth. One of the first
Greek geographers was Herodotus
(circa 484 - 425 BC). Herodotus wrote a number of volumes that described the
human and physical geography of the various regions of the Persian Empire.
The ancient Greeks were also interested in the form, size,
and geometry of the Earth. Aristotle
(circa 384 - 322 BC) hypothesized and scientifically demonstrated that the
Earth had a spherical shape. Evidence for this idea came from observations of
lunar eclipses. Lunar eclipses occur when the Earth casts its circular shadow
on to the moon's surface. The first individual to accurately calculate the
circumference of the Earth was the Greek geographer Eratosthenes
(circa 276 - 194 BC). Eratosthenes calculated the equatorial circumference to
be 40,233 kilometers using simple geometric relationships. This primitive
calculation was unusually accurate. Measurements of the Earth using modern
satellite technology have computed the circumference to be 40,072 kilometers.
Most of the Greek accomplishments in geography were passed on
to the Romans. Roman military commanders and administrators used this
information to guide the expansion of their Empire. The Romans also made several
important additions to geographical knowledge. Strabo (circa
64 BC - 20 AD) wrote a 17 volume series called "Geographia".
Strabo claimed to have traveled widely and recorded what he had seen and experienced
from a geographical perspective. In his series of books, Strabo describes the
cultural geographies of the various societies of people found from Britain to
as far east as India, and south to Ethiopia and as far north as Iceland. Strabo
also suggested a definition of geography that is quite complementary to the way
many human geographers define their discipline today. This definition suggests
that the aim of geography was to "describe the known parts of the inhabited world
... to write the assessment of the countries of the world [and] to treat the
differences between countries".
During the second century AD, Ptolemy (circa
100 - 178 AD) made a number of important contributions to geography. Ptolemy's
publication Geographike hyphegesis or "Guide to Geography" compiled
and summarize much of the Greek and Roman geographic information accumulated at
that time. Some of his other important contributions include the creation of
three different methods for projecting the Earth's surface on a map, the
calculation of coordinate locations for some eight thousand places on the
Earth, and development of the concepts of geographical latitude
and longitude
(Figure 1a-1).
Little academic progress in geography occurred after the
Roman period. For the most part, the Middle Ages (5th to 13th centuries AD)
were a time of intellectual stagnation. In Europe, the Vikings of Scandinavia
were the only group of people carrying out active exploration of new lands. In
the Middle East, Arab academics began translating the works of Greek and Roman
geographers starting in the 8th century and began exploring southwestern Asia
and Africa. Some of the important intellectuals in Arab geography were
Al-Idrisi, Ibn Battutah, and Ibn Khaldun. Al-Idrisi is best known for his skill
at making maps and for his work of descriptive geography Kitab nuzhat al-mushtaq fi ikhtiraq al-afaq or "The Pleasure Excursion of One Who Is Eager to
Traverse the Regions of the World". Ibn
Battutah and Ibn Khaldun are well known for writing about their extensive
travels of North Africa and the Middle East.
During the Renaissance (1400 to 1600 AD) numerous
journeys of geographical exploration were commissioned by a variety of nation
states in Europe. Most of these voyages were financed because of the potential
commercial returns from resource exploitation. The voyages also provided an
opportunity for scientific investigation and discovery. These voyages also
added many significant contributions to geographic knowledge (Figure 1a-2).
Important explorers of this period include Christopher Columbus,
Vasco da Gama, Ferdinand Magellan, Jacques Cartier, Sir Martin Frobisher, Sir Francis Drake, John and Sebastian Cabot,
and John Davis.
Also during the Renaissance, Martin Behaim created a spherical
globe depicting the Earth in its true three-dimensional form in 1492. Behaim's
invention was a significant advance over two-dimensional maps because it
created a more realistic depiction of the Earth's shape and surface
configuration.
Figure 1a-2: This map was constructed by Oliva
in 1560. It describes the known world at this time and suggests that North
America is part of Asia. Further exploration of the world would soon reject
this idea.
|
In the 17th century, Bernhardus
Varenius (1622-1650) published an important geographic reference
titled Geographia generalis (General Geography: 1650). In this
volume, Varenius used direct observations and primary measurements to present
some new ideas concerning geographic knowledge. This work continued to be a
standard geographic reference for about a 100 years. Varenius also suggested
that the discipline of geography could be subdivided into three distinct
branches. The first branch examines the form and dimensions of the Earth. The
second sub-discipline deals with tides, climatic variations over time and
space, and other variables that are influenced by the cyclical movements of the
Sun and moon. Together these two branches form the early beginning of what we
collectively now call physical geography. The last branch of geography examined
distinct regions on the Earth using comparative cultural studies. Today, this
area of knowledge is called cultural geography.
During the 18th century, the German philosopher Immanuel Kant
(1724-1804) proposed that human knowledge could be organized in three different
ways. One way of organizing knowledge was to classify its facts according to
the type of objects studied. Accordingly, zoology studies animals, botany
examines plants, and geology involves the investigation of rocks. The second
way one can study things is according to a temporal dimension. This field of
knowledge is of course called history. The last method of organizing knowledge
involves understanding facts relative to spatial relationships. This field of
knowledge is commonly known as geography. Kant also divided geography into a
number of sub-disciplines. He recognized the following six branches: Physical,
mathematical, moral, political, commercial, and theological geography.
Geographic knowledge saw strong growth in Europe and the
United States in the 1800s. This period also saw the emergence of a number of
societies interested in geographic issues. In Germany, Alexander
von Humboldt, Carl Ritter,
and Fredrich
Ratzel made substantial contributions to human and physical
geography. Humboldt's publication Kosmos
(1844) examines the geology and physical geography of the Earth. This work is
considered by many academics to be a milestone contribution to geographic
scholarship. Late in the 19th Century, Ratzel theorized that the distribution
and culture of the Earth's various human populations was strongly influenced by
the natural environment. The French geographer Paul
Vidal de la Blanche opposed this revolutionary idea. Instead, he
suggested that human beings were a dominant force shaping the form of the
environment. The idea that humans were modifying the physical environment was
also prevalent in the United States. In 1847, George
Perkins Marsh gave an address to the Agricultural Society of
Rutland County, Vermont. The subject of this speech was that human activity was
having a destructive impact on land, especially through deforestation and land
conversion. This speech also became the foundation for his book Man and Nature or The Earth as Modified by Human Action, first
published in 1864. In this publication, Marsh warned of the ecological
consequences of the continued development of the American frontier.
During the first 50 years of the 1900s, many academics in the
field of geography extended the various ideas presented in the previous century
to studies of small regions all over the world. Most of these studies used
descriptive field methods to test research questions. Starting in about 1950,
geographic research experienced a shift in methodology. Geographers began
adopting a more scientific approach that relied on quantitative techniques. The
quantitative
revolution was also associated with a change in the way in which
geographers studied the Earth and its phenomena. Researchers now began
investigating process rather than mere description of the event of interest.
Today, the quantitative approach is becoming even more prevalent due to
advances in computer and software technologies.
In 1964, William Pattison published an article in the Journal of Geography (1964, 63:
211-216) that suggested that modern Geography was now composed of the following
four academic traditions:
Spatial
Tradition - the investigation of the
phenomena of geography from a strictly spatial perspective.
Area
Studies Tradition - the geographical study of
an area on the Earth at either the local, regional, or global scale.
Earth
Science Tradition - the study of natural
phenomena from a spatial perspective. This tradition is best described as
theoretical physical geography.
Today, the academic traditions described by Pattison are
still dominant fields of geographical investigation. However, the frequency and
magnitude of human mediated environmental problems has been on a steady
increase since the publication of this notion. These increases are the result
of a growing human population and the consequent increase in the consumption of
natural resources. As a result, an increasing number of researchers in
geography are studying how humans modify the environment. A significant number
of these projects also develop strategies to reduce the negative impact of
human activities on nature. Some of the dominant themes in these studies
include: environmental degradation of the hydrosphere,
atmosphere,
lithosphere,
and biosphere;
resource use issues; natural hazards; environmental impact assessment; and the
effect of urbanization and land-use change on natural environments.
Considering all of the statements presented concerning the
history and development of geography, we are now ready to formulate a somewhat
coherent definition. This definition suggests that geography, in its simplest
form, is the field of knowledge that is concerned with how phenomena are spatially
organized. Physical geography attempts to determine why natural phenomena have
particular spatial patterns and orientation. This online textbook will focus
primarily on the Earth
Science Tradition. Some of the information that is covered in
this textbook also deals with the alterations of the environment because of
human interaction. These pieces of information belong in the Human-Land
Tradition of geography.
(b). Elements of Geography
In the previous section, we discovered that geography
consists of at least two different sub-fields of knowledge with similar
methodology: Physical
geography and human
geography. The following table also helps to make the
differences between these two types of geography more apparent. This table
describes some of the phenomena or elements studied by each of these sub-fields
of knowledge. Knowing what kinds of things are studied by geographers provides
us with a better understanding of the differences between physical and human
geography.
Table 1b-1: Some of the
phenomena studied in physical and human geography.
Physical Geography
|
Human Geography
|
Rocks
and Minerals
|
Population
|
Landforms
|
Settlements
|
Soils
|
Economic
Activities
|
Animals
|
Transportation
|
Plants
|
Recreational
Activities
|
Water
|
Religion
|
Atmosphere
|
Political
Systems
|
Rivers
and Other Water Bodies
|
Social
Traditions
|
Environment
|
Human
Migration
|
Climate
and Weather
|
Agricultural
Systems
|
Oceans
|
Urban
Systems
|
Geography is also a
discipline that integrates a wide variety of subject matter. Almost any area of
human knowledge can be examined from a spatial perspective. Figure 1b-1
describes some of the main subdisciplines within human and physical geography.
Physical geography's primary subdisplines study the Earth's atmosphere (meteorology
and climatology),
animal and plant life (biogeography),
physical landscape (geomorphology),
soils (pedology),
and waters (hydrology).
Some of the dominant areas of study in human geography include: human society
and culture (social and cultural geography), behavior (behavioral
geography), economics (economic geography), politics (political
geography), and urban systems (urban geography).
Figure 1b-1: Major subdisciplines of physical
and human geography.
|
The graphic model in Figure 1b-1 indicates that the
study of geography can also involve a holistic synthesis. Holistic synthesis
connects knowledge from a variety of academic fields in both human and physical
geography. For example, the study of the enhancement of the Earth's greenhouse
effect and the resulting global
warming requires a multidisciplinary approach for complete
understanding. The fields of climatology and meteorology are required to
understand the physical effects of adding addition greenhouse gases to the
atmosphere's radiation balance. The field of economic geography provides
information on how various forms of human economic activity contribute to the
emission of greenhouse gases through fossil fuel burning and land-use change.
Combining the knowledge of both of these academic areas gives us a more
comprehensive understanding of why this serious environmental problem occurs.
The holistic nature of geography is both a strength and a
weakness. Geography's strength comes from its ability to connect functional
interrelationships that are not normally noticed in narrowly defined fields of
knowledge. The most obvious weakness associated with the geographical approach
is related to the fact that holistic understanding is often too simple and
misses important details of cause and effect.
(c). Scope of Physical
Geography
We have now learned that physical geography examines and
investigates natural phenomena spatially. In the previous section, we
identified some of the key elements studied by physical geographers. Combining
these two items, we can now suggest that physical geography studies the spatial patterns of weather
and climate, soils, vegetation, animals, water in all its forms, and landforms. Physical
geography also examines the interrelationships of these phenomena to human
activities. This sub-field of geography is academically known as the Human-Land Tradition. This
area of geography has seen very keen interest and growth in the last few
decades because of the acceleration of human induced environmental degradation.
Thus, physical geography's scope is much broader than the simple spatial study
of nature. It also involves the investigation of how humans are influencing
nature.
Academics studying physical geography and other related earth
sciences are rarely generalists. Most are in fact highly specialized in their
fields of knowledge and tend to focus themselves in one of the following well
defined areas of understanding in physical geography:
Geomorphology - studies the
various landforms on the Earth's surface.
Pedology - is concerned with
the study of soils.
Biogeography - is the science
that investigates the spatial relationships of plants and animals.
Hydrology - is interested in
the study of water in all its forms.
Meteorology - studies the
circulation of the atmosphere over short time spans.
Climatology - studies the
effects of weather on life and examines the circulation of the atmosphere over
longer time spans.
The above fields of knowledge generally have a primary role in
introductory textbooks dealing with physical geography. Introductory physical
geography textbooks can also contain information from other related disciplines
including:
Geology - studies the
form of the Earth's surface and subsurface, and the processes that create and
modify it.
Ecology - the scientific study
of the interactions between organisms and their environment.
Oceanography - the science
that examines the biology, chemistry, physics, and geology of oceans.
Cartography - the technique of
making maps.
Astronomy - the science that
examines celestial bodies and the cosmos.
(d). Geography as an Environmental Science
Webster's 9th Collegiate Dictionary defines Environment "... as the complex of physical, chemical, and biotic factors (such as climate, soil, and living things) that act upon an organism or an ecological community and ultimately determines its form and survival".Both human and physical geography provide an important intellectual background for studying the environment. Many environmental studies/science programs offered by Universities and Colleges around the world rely on the information found in various geography courses to help educate their students about the state of the environment.
(e). History of Physical
Geography
The nature of understanding in physical geography has changed
over time. When investigating this change it becomes apparent that certain
universal ideas or forces had very important ramifications to the academic
study of physical geography. During the period from 1850 to 1950, there seems
to be four main ideas that had a strong influence on the discipline:
(1). Uniformitarianism - this
theory rejected the idea that catastrophic forces were responsible for the
current conditions on the Earth. It suggested instead that continuing
uniformity of existing processes were responsible for the present and past
conditions of this planet.
(2). Evolution - Charles Darwin's Origin of Species (1859)
suggested that natural selection determined which individuals would pass on
their genetic traits to future generations. As a result of this theory,
evolutionary explanations for a variety of natural phenomena were postulated by
scientists. The theories of uniformitarianism and evolution arose from a fundamental
change in the way humans explained the universe and nature. During the 16th,
17th, and 18th centuries scholars began refuting belief or myth based
explanations of the cosmos, and instead used science to help explain the
mysteries of nature. Belief based explanations of the cosmos are made
consistent with a larger framework of knowledge that focuses on some myth.
However, theories based on science questioned the accuracy of these beliefs.
(3). Exploration and Survey - much of
the world had not been explored before 1900. Thus, during this period all of
the fields of physical geography were actively involved with basic data
collection. This data collection included activities like determining the
elevation of land surfaces, classification and description of landforms, the
measurement of the volume of flow of rivers, measurement of various phenomena
associated to weather and climate, and the classification of soils, organisms,
biological communities and ecosystems.
(4). Conservation - beginning
in the 1850s a concern for the environment began to develop as a result of the
human development of once natural areas in the United States and Europe. One of
the earliest statements of these ideas came from George Perkins Marsh (1864) in
his book "Man in
Nature" or "Physical Geography as Modified by Human Action". This
book is often cited by scholars as the first significant academic contribution
to conservation and environmentalism.
After 1950, the following two forces largely determined the
nature of physical geography:
(1). The Quantitative
Revolution - measurement became the central focus of research in Physical
Geography. It was used primarily for hypothesis testing. With measurement came
mapping, models, statistics, mathematics, and hypothesis testing. The
quantitative revolution was also associated with a change in the way in which
physical geographers studied the Earth and its phenomena. Researchers now began
investigating process rather than mere description of the environment.
(2). The study of Human/Land
Relationships - the influence of human activity on the environment was
becoming very apparent after 1950. As a result, many researchers in physical
geography began studying the influence of humans on the environment. Some of
the dominant themes in these studies included: environmental degradation and
resource use; natural hazards and impact
assessment; and the effect of urbanization and land-use
change on natural environments.
(f). Future of Physical
Geography
The following list describes some of the important future
trends in physical geography research:
(1). Continued development of applied physical geography for
the analysis and correction of human-induced environmental problems. A student
of applied physical geography uses theoretical information from the field of
physical geography to manage and solve problems related to natural phenomena
found in the real world.
(2). Remote Sensing - Advances in
technology have caused the development of many new instruments for the
monitoring of the Earth's resources and environment from airborne and space
platforms. Also see section 2e. The most
familiar use of remote sensing technology is to monitor the Earth's weather for
forecasting. See the following links for examples of remotely sensed images:
o GOES
(3). Geographic Information Systems
- A geographic information system (GIS) merges information in a computer
database with spatial coordinates on a digital map. Geographic information
dystems are becoming increasingly more important for the management of
resources. Also see section 2f.
Tidak ada komentar:
Posting Komentar