2021年1月23日发(作者：茄子的英语)
考题类型

一、名词术语解释（
English to English
，每题
3
分，共
15
分
）

二、

词汇翻译（
English to Chinese
，每题
1
分，共
15
分）

三、英译汉（每题
5
分，共
25
分）

四、汉译英（每题
5
分，共
25
分）

五、英文写作（
20
分）

参考资料

Information Systems

The function of an information system is to improve one's ability to make decisions.
An
information
system
is
that
chain
of
operations
that
takes
us
from
planning
the
observation and collection of data, to storage and analysis of the data, to the use of the
derived information in some decision-making process . This brings us to an important
concept:
a
map
is
a
kind
of
information
system.
A
map
is
a
collection
of
stored,
analyzed
data,
and
information
derived
from
this
collection
is
used
in
making
decisions.
To
be
useful,
a
map
must
be
able
to
convey
information
in
a
clear,
unambiguous fashion, to its intended users.
A geographic information system (GIS) is an information system that is designed to
work with data referenced by spatial or geographic coordinates. In other words, a GIS
is
both
a
database
system
with
specific
capabilities
for
spatially-referenced
data,
as
well a set of operations for working with the data . In a sense, a GIS may be thought
of as a higher- order map.
As
we
shall
see
later,
a
modern
GIS
also
stores
and
manipulates
non-spatial
data.
A
geographic information system can, of course, be either

manual or automated. Manual
geographic
information
systems
usually
comprise
several
data
elements
including
maps, sheets of transparent materials used as overlays, aerial and ground photographs,
statistical
reports
and
field
survey
reports.
These
sets
of
data
are
compiled
and
analyzed
with
such
instruments
as
stereo
viewers,
transfer
scopes
of
various
kinds,
and
mechanical
and
electronic
planimeters.
Manual
GISs
have
played
an
extremely
important role in resource management and planning activities. Furthermore, there are
still applications where a manual GIS approach is entirely appropriate. Although this
text
focuses
on
the
technology,
instrumentation,
and
utilization
of
geographic
information systems that are automated.
A Manual Geographic Information System
To introduce some of the language of geographic information systems with a simple
first example, let's examine an application of a simple manual GIS. This GIS arises
during
the
early
steps
in
developing
a
site
for
a
golf
course.
We
assume
for
this
discussion that a specific site is already under consideration. A planner has sought out
and
gathered
together
a
group
of
existing
datasets
for
the
site.
This
group
might
include
a
topographic
map,
a
blue-line
map
of
parcel
boundaries
from
the
local
municipal planning agency, and an aerial photograph of the site.
The topographic map depicts several kinds of information. Elevation on the site is
portrayed as a series of contour lines. These contour lines provide us with a limited
amount of information about the shape of the terrain.

The map from the local planning agency provides us with additional and different
kinds of information about the area. This map focuses principally on the infrastructure:
legal
descriptions
of
the
proposed
golf
course
property
boundaries,
existing
and
planned
roadways,
easements
of
different
kinds,
and
the
locations
of
existing
and
planned utilities.

The resulting database may have no simple relationship to a well-known geodetic
coordinate
system,
such
as
latitude
and
longitude.
However,
for
applications
that
cover a small area, this may not be a serious problem.

Types of GIS
Geographical variation, in the real worlds is infinitively complex. The closer you
look the more detail you see almost without limit. It would take an infinitively large
database to capture the real world precisely data must somehow be reduced to a finite
and manageable quantity by a process of generalization or abstraction. Geographical
variation must be represented in terms of discrete elements or objects. The rules used
to convert real geographical variation into discrete objects is the data model. Data
model is set of guidelines for the representation of the logical organization of the data
in a database.
Current GISs differ according the way in which they organize reality through the
data model. Each model tends to fit certain types of data and applications better than
others. The software available, the training of the key individuals and historical
precedent, also influences the data model chosen for a particular project or application.
There are two major choices of data model: raster and vector.
Raster model divides the entire study area into a regular grid of cells in specific
sequence. The conventional sequence is row by row from the top left corner. Each cell
contains a single value. It is space-filling since every location in the study area
corresponds to a cell in the raster. One set of cells and associated values is called as
layer or coverage. There maybe many layers in a database, e.g. soil type, elevation,
land use, land cover.
Vector model uses discrete line segments or points to identify locations. Discrete
objects (boundaries, streams, cities) are formed by connecting line segments. Vector
objects do not necessarily fill space, not all locations in space need to be referenced in
the area.
A raster model tells what occurs everywhere at each place in the area. A vector
model tells where everything occurs and gives a location for every object.
Conceptually the raster models are the simplest of the available data models.
Raster GIS
Consider a raster by coding each cell with a value that represents the rock type,
which appears in the majority of that cell areas, when finished every cell, will have a
coded value. There are several methods for creating raster databases. Direct entry of
each layer cell by cell is the simplest. Much raster data is already in digital form, as
images. Remote sensing generates images in the digital form. The type of values
contained in a raster depends on both the reality being coded and the GIS. Each pixel
or cell is assumed to have only one value.