when modeling phenomena in science and engineering, we begin with simplified, incomplete models. As we examine things in greater detail, these simple models become inadequate and must be replaced by more refined models.
Kokuniemi concert 2014-12-04 https://commons.wikimedia.org/wiki/File:Kokuniemi_concert_2014-12-04.jpg
Many programmers have to re-orient themselves from orthodox object-oriented development, and shift to a world in which data structures are transparent but the behavior – the transformation – is not.
For web applications, there are several open source stress and load testing tools available, including Grinder, JMeter, and Gatling.
in a graph database what you sketch on the whiteboard is typically what you store in the database.
People communicate in myriad ways. We have channels of information taking various forms such as encyclopedias, dictionaries, maps, photo albums, journals, letters, postcards, and more. Often, information exists in separate realms, and is difficult to combine. This, in turn, makes it difficult to create into rich and evolving forms.
People need an information tool(kit) that is easy to use. There needs to be little separation, or contortion, from working directly with the information we wish to remix and share.
We need to reward activities such as
- improvement of existing commonwealth resources,
- removing barriers to access
- providing usefulness and/or relevance.
This, while filtering and discouraging abusive behaviour.
Create an open source interface that abstracts the complexities of API/data management. Enable people of all skills and abilities to create graphs and composite views of information from many sources.
People will select information types and sources, and then connect the information on a canvas to create a composite display. These composites can be bundled and shared as well as embedded within other composite displays, in modular fashion.
The system might consist of modules to work with data. Generally speaking, there are at least three primary categories of modules.
Make request(s) for information, about the condition of information, and search for relevance.
Once information is located it may need to be modified, combined, filtered, etc.
Information may be rendered in at many stages of the process and in many forms, such as documents, tables, graphs, and multimedia output.
An attribute is a quality or characteristic of an object, observation, event, etc. Attributes can be recorded as fields in a database, columns in a spreadsheet, or through other structures and data formats. Attribute data can be classified into general types that generally align with statistical data types – i.e. category, numeric, etc.
Census block group
Census blocks are the smallest division of the U.S. census system, where information is collected from 100% of the households therein. Census blocks are clustered into groups, called block groups. Block groups form together in larger census tracts. This footprints of block groups and tracts are available, in TIGER line format, from the U.S. Census website.
COGO is short for coordinate geometry, and is a reference language describing the geometric properties of observed objects. These observations, often provided by land surveyors, can be converted to digital representations using basic geometry components such as lines or arcs. An early implementation of COGO was the Integrated Civil Engineering System (ICES) created at Massachusettes Institute of Technology.
Digital Elevation Model (DEM)
Digital Elevation Model data describe the Earth’s surface. The data can be structured as raster or vector format. The raster format represents the entire surface as a regularly spaced grid of points, while the vector format can contain only the number of points necessary to render the surface at a desired accuracy level. Each point, or node, in the data describe the elevation of the Earth’s surface at that particular place.
Geographic coordinates assign values to points on the Earth’s surface. The values can be combinations of up to three numbers, usually indicating latitude, longitude, and altitude. The coordinates are overlain on a surface representing the entire surface, or a subset, of Earth. Different shapes, called datums, can be used to represent the Earth’s surface. This produces variability in accuracy between points on different datums, where the same coordinates on two datums can be meters apart.
Georeferencing involves associating spatial or geographic locations (i.e. coordinates) with data or objects. This can include indicating locations of objects depicted in images, such as aerial photographs.
Map projection and datum
A map projection is a process whereby the spherical surface of the earth is unwrapped and flattened to display as a map. The projection is a mathematical process that assumes a generic shape for the surface of the Earth, such as a sphere or ellipsoid, and then transforms each point on the surface to a point on a two dimensional grid. A projection can be thought of, and is analogous to, the shadow between your hand and a wall when shining a flashlight on the side of your hand opposite to the wall. There are hypothetically unlimited ways that a surface can be projected, and each method introduces some distortion in the process – creating inaccuracies in the projected result.
Map scale describes a ratio of one map unit as it relates to real world units of the same measurement. E.g. how many real world inches are represented by one inch on a map.
Metadata are data about data. Metadata describes characteristics of data that are not directly indicated or inherent. This can include projection/datum information, data quality/lineage assessment, attribution, licensing, and derived characteristics such as number of geometries, spatial extents, distribution of values, etc.
When taking images, including aerial photographs, there are natural distortions that occur due to perspective and optics. With aerial photographs, distortions such as perspective/tilt, lense distortion, and topographical differences, can be corrected to produce a ‘flattened’ image. This process is called orthorectification and the resulting images can be more accurately used in conjunction with other spatial data for base layers, etc.
World water crisis
failure to meet basic human needs for water
we have knowledge of how to provide clean water and sanitation
have failded to do so for large percentage of Earth’s population
1.5-2 million preventable deaths per year
we contaminate fresh water
humans are changing climate at rates much faster than natural rates
will impact natural hydrologic cycle and water distribution systems
will affect water availability, quality, etc.
Human uses of water
irrigated agriculture (40% of world’s food)
all water comes out of natural ecosystems
humans move water across ecosystems.
i.e. out of natural water shed area
affecting species, causing extinction
ecosystems cross borders.
Colorado river basin
shared by seven states and Mexico
legal agreements, compacts, and treatee
Nile is shared by ten nations
Danube is shared by eighteen nations
water, politics, conflict
exponential growth has a tendency to get out of hand
economic growth (GNP)
CO2 concentration in atmosphere (greenhouse gasses)
exponential at first
peaks at some point
may recover, or stabilize
slow growth at first
peaks and levels off
some resources are non-renewable
oil (renewal process slower than is useful for humans, consumption outpaces)
water is, basically renewable
flow limited – hydrologic cycle
cannot use more than natural flow provides
e.g. Colorado river does not complete its natural course to the Gulf of California
e.g. solar energy – sun provides steady stream of energy
non-renewable stocks of water
e.g. ogalala aquifer
pumping faster than renewal process (slow geologic process)
as much as 40% of food grown worldwide is grown using fossil water
water is not profitable to move via tanker, as oil has proven
we don’t move water around too much
some large scale water infrastructure exists
California central valley
1,000 times more expensive than tap
economically feasable to bottle and distribute water
Book — Bottled and Sold: The Story Behind Our Obsession with Bottled Water by Peter H. Gleick
there is no known substitute for water, for most things
e.g. growing food, human life
We build infrastructure to store and use the total flow of renewable water
How much peak renewable should we use?
Peak non-renewable water
depletion of fossil water
farmers are shifting back to dry ground farming techniques as water becomes more costly to pump
The more water we use, the more economic benefit we get
essentially linear process
The more water we use, the less ecological value remains intact
Inverse curves, produce a point of optimal use
Non renewable water creates stock constraints
Renewable water sources create flow limits
Ecological limitations become more present
Move to sustainable water management and useful
Develop new supply
Traditionally: more drilling, dam building, aquaduct, etc.
we are running into constraints on traditional supply
no more dams or aquifers that make economic sense (in U.S.)
other places in world need traditional infrastructure — built to different standards
consider economic, ecological, social, and cultural costs
asset, not liability
use highly treated wastewater in appropriate areas
expensive but reliable
groundwater/surface water together
recharge groundwater aquifers
maintain to a better level, existing water infrastructure
improve efficiency of water use
we are not at the limits of efficiency
we are often at the end of available water supply
improve/enforce standards for water quality
use economics, water is an economic good
true valuation, pricing questions, equity issues
price/meter water properly
balance economics with human rights
improve/expand public participation in decision making
improve water institutions
21st century revitalization