EAPS 312Capstone Environmental Science

Lab #3 Urban EnvironmentsAlthough many people do not think of buildings, cities, and urban areas as environments, they are indeed environments. They consist of abiotic and biotic factors that interact to shape the landscape and determine the quality of the environment. Traffic flow in a downtown area may add to the air and noise pollution. The amount of traffic at any given time of day, type of traffic (e.g., cars, busses, trucks, pedestrians), and controlled timing of traffic may affect the urban environment. Temperature and other weather conditions may be influenced by the surrounding buildings, roads, and traffic. Urban “heat islands” occur when the air in urban areas is 6-8F warmer than the surrounding rural areas. Determining the urban factors that contribute to “heat islands” and making changes to these sources will reduce the pollution level and energy costs in urban areas. Some causes of the “heat island” effect are dark-colored surfaces and reduced vegetation. Darker surfaces absorb more of the sun’s energy, thus warming the surrounding air. Vegetation generally provides shade from the sun and cools the surrounding air. Runoff from rain and snow melt occurs more rapidly in urban areas and contains more impurities because of construction, traffic, and businesses. Litter is often found in urban areas. Key factors contributing to urban litter are the number of people in the area and the time of day.

This lab activity will provide some practice for you in using scientific equipment and procedures for measuring specific parameters that are indicators of the quality of the urban environment.

Think about it:

How might buildings impact weather conditions in urban environments?

How might the time of day impact noise levels in an urban environment?

What areas of downtown Lafayette might have the worst noise and air pollution levels?

Lab 3 Page L3-1

EAPS 312Capstone Environmental Science

Investigating Urban Environments

Your group will be assigned one of the downtown dilemmas (scenario) to provide a context for your investigation of the urban environment. Based on the scenario and the equipment available your group will design a protocol or procedure for determining the quality of the urban environment. Your group will complete the investigation planning sheet before starting your investigation. After conducting your investigation your group will complete the written report, which requires a data table and graph, form for the city council. Your group will hand in both documents. An aerial photograph and topographical map of downtown Lafayette may be found in the Appendix.

Urban Heat Islands. Although climatologists have been investigating urban heat islands for a long time, city governments are now interested in and concerned about the health and environmental impact of urban heat islands. This increased interest in heat-related health and environmental issues has prompted many cities to investigate the local impact of urban heat islands and to develop strategies for reducing their heat island impact. Urban heat islands, particularly during the summer, can affect a community's environment and quality of life:

Increased energy consumption: Higher temperatures in summer increase energy demand for cooling. One study estimates that the heat island effect is responsible for 5–10% of peak electricity demand for cooling buildings in cities.

Elevated emissions of air pollutants and greenhouse gases: Increasing energy demand generally results in greater emissions of air pollutants and greenhouse gas emissions from power plants. Higher air temperatures also promote the formation of ground-level ozone.

Compromised human health and comfort: Warmer days and nights, along with higher air pollution levels, can contribute to general discomfort, respiratory difficulties, heat cramps and exhaustion, non-fatal heat stroke, and heat-related mortality.

Impaired water quality: Hot pavement and rooftop surfaces transfer their excess heat to stormwater, which then drains into storm sewers and raises water temperatures as it is released into streams, rivers, ponds, and lakes.

The city council is concerned about the phenomenon of urban "heat islands" occurring in Lafayette and wants to reduce the “heat islands” effect. As the Lafayette City engineer, your job is to investigate the factors that currently affect the cities temperature. What are some factors that your team needs to consider? How will you measure these factors? What solutions can you come up with to remedy the potential problem? You are to prepare a recommendation for the city council.

Lab 3 Page L3-2

EAPS 312Capstone Environmental Science

Calculating Albedo1. Set the meter to measure in either Lux or FC, because you are interested in a ratio the unit

does not matter. What does matter is that you measure using the same unit each time.

Lux is the SI (International Symbol) unit of luminanceFC (foot-candle) is the non-SI unit of luminance

2. Using the Range button select one of the 3 ranges (FC= 20, 200, 2000; Lux=200, 2000, 20000). You may have to change the range depending on the amount of solar energy.

3. Remove the protective cover from the sensor. Be sure and replace the cover after each measurement to protect the sensor. Hold the sensor about 1 foot from the surface you are measuring.

4. You will take 2 readings. First measure the incidence light or incoming solar energy by holding the meter horizontal (parallel) to the surface with the sensor pointing toward the light source (sun). Next turn the sensor so it is pointing toward the surface and take the second reading, you are now measuring the reflective light. Be sure to not block the sensor.

5. To calculate the albedo you divide the reflective light by the incidence light:

Albedo = Reflective light to convert to a percentage multiply by 100 Incidence light

For example: The florescent lights in my office measured 507 lux (incidence light) and the floor measured 87 lux (reflective light). The floors albedo is:

87 lux/507 lux = 0.17 albedo

In other words the floor is reflecting 0.17 (17%) and absorbed 0.83 (83%) of the light.

Rerouting Traffic: Noise Pollution? The traditional definition of noise is “unwanted or disturbing sound.”  Sound becomes unwanted when it interferes with normal activities such as sleeping, conversation, or disrupts or diminishes one’s quality of life.  The fact that you can’t see, taste or smell noise may help explain why it has not received as much attention as other types of pollution.  The persistent and escalating sources of sound can become annoying.  This “annoyance” can have major consequences to one’s overall health.  Health problems related to noise include stress related illnesses, high blood pressure, hearing loss, and sleep disruption.  An individual exposed to 45 decibels of noise cannot sleep. At 120 decibels the ear registers pain, but hearing damage begins at about 85 decibels. The duration of the exposure is also important. Pursuant to the Noise Control Act of 1972 and the Quiet Communities Act of 1978 the Environmental Protection Agency (EPA) has authority to investigate and study noise pollution, disseminate information to the public regarding noise pollution and its health effects, and respond to inquiries on matters related to noise.

Lab 3 Page L3-3

EAPS 312Capstone Environmental Science

Due to upcoming road construction on South Street, traffic will be redirected down side streets in the downtown area. The city engineer and city council members have received complaints from residents and business owners about the proposed rerouting. They are concerned that the increased traffic, noise levels, will be both unsafe and bad for business. As members of the city engineering staff, you have been sent out to evaluate the merit of these complaints. What are some factors that your team needs to consider? How will you measure these factors? What solutions can you come up with to remedy the potential problem? You are to prepare a recommendation for the rerouting of traffic for the city council.

Measuring Noise

Noise is measured in decibels. The decibel scale is logarithmic; each 10-decibel increase represents a tenfold increase in noise intensity, roughly a doubling of loudness. Thus, 30 decibels is 10 times more intense than 20 decibels and sounds twice as loud; 40 decibels is 100 times more intense than 20 and sounds 4 times as loud. Distance diminishes the effective decibel level reaching the ear. Thus, moderate auto traffic at a distance of 100 ft (30 m) rates about 50 decibels. To a driver with a car window open or a pedestrian on the sidewalk, the same traffic rates about 70 decibels; that is, it sounds 4 times louder.

Vehicle Emissions. The Clean Air Act requires the Environmental Protection Agency (EPA) to set National Ambient Air Quality Standards for pollutants considered harmful to public health and the environment. The EPA is concerned that the increased traffic flow in downtown Lafayette is impacting air quality. The EPA is considering requiring vehicle emission testing as a means for improving air quality. The city of Lafayette has asked the city engineer to conduct a preliminary study to determine if the air quality in the downtown area is being impacted by vehicle emissions. Using the standard car exhaust emissions and traffic counts the city engineer can extrapolate the amount of HC, NOx, CO2, and CO emissions in the air. Note: this is a rough estimate and

Lab 3 Page L3-4

OSHA Permissible Noise Exposure

Note: If you have a Smartphone you can download the following free apps from the Play Store: Sound Meter: measures noise levels in decibels, recording the high and low levels (range) Vibrometer: measures ground vibrations, if you wish to investigate how traffic shakes the

ground Stopwatch &Timer: measures time

Duration(Hours)

Decibel Level(Time-weighted Average)

8 906 924 953 972 1001 105

1/2 1101/4 or less 115

Standard Car Exhaust EmissionsHydrocarbons (HC) 0.25 g/mileNitrogen oxides (NOx) 0.4 g/mileCarbon monoxide (CO) 3.4 g/mileCarbon dioxide (CO2) 0.4 g/mile

EAPS 312Capstone Environmental Science

does not take into consideration such factors as the type of vehicle or the year of the vehicle.

What are some factors that your team needs to consider? How will you measure these factors? What solutions can you come up with to remedy the potential problem? You are to prepare a recommendation for the city council.

Air Quality and Lichens

Lichens, which consist of a symbiotic relationship between a fungus and an alga, are found living in almost all environments, including urban environments. They are sensitive to atmospheric pollution, including nitrogen and sulfur emissions, as well as toxic lead and mercury emissions. This sensitivity makes them a valuable biological indicator of air quality. Although lichens are difficult to identify at the species level, their general shape may be used to monitor air quality. The three general categories are:

Crustose lichens (top image) form a crust on the substrate (e.g., bark, brick, cement, soil, and wood) they are attached. They are firmly attached and cannot be easily removed.

Foliose lichens (middle image) are leafy with the leaf lobes often parallel to the surface of the substrate. They are loosely attached to the substrate and can easily be removed.

Fruticose lichens (bottom image) are three dimensional, often growing perpendicular to the substrate. They often look like little bushes growing on the substrate.

In general, the air quality of an area may be determined by the presence or absence of crustose, foliose, and fruticose lichens using the following system:

No lichens = very poor air qualityCrustose lichens only = poor air qualityCrustose and foliose lichens = moderate to good quality airFruticose, foliose, and crustose lichens = very good air quality

Lab 3 Page L3-5

Note: If you have a Smartphone you can download a free Stopwatch &Timer app from the Play Store

EAPS 312Capstone Environmental Science

What are some factors that your team needs to consider when looking for and counting lichens? How will you measure these factors? What surfaces will you sample? Where will you sample? You are to prepare a recommendation for the city council.

Reflection Questions

Form an Earth systems perspective, what event(s) and Earth spheres did your urban investigation focus on and how did these events and Earth spheres relate or interact?

The Next Generation Science Standards (NGSS) emphasize engaging all students in science practices. The NGSS argues that “engaging in the practices of science helps students understand how scientific knowledge develops; such direct involvement gives them an appreciation of the wide range of approaches that are used to investigate, model, and explain the world.” Explain how this lab investigation supports this statement, models the need to engage students in science practices.

Lab 3 Page L3-6

NGSSScience Practices for K-12 Classrooms

1. Asking questions2. Developing and using models3. Planning and carrying out investigations4. Analyzing and interpreting data5. Using mathematics and computational

thinking6. Constructing explanations7. Engaging in argument from evidence8. Obtaining, evaluating, and

communicating information

EAPS 312Capstone Environmental Science

Investigation Planning Guide

Names(s) Date

What is the problem: What we already know about the problem:

Investigation question:

Why we think this is important to investigate:

In most investigations we are interested in how one particular variable changes in response to variations in one or more other variables. This particular variable that we focus on and measure is called the dependent variable. The other variables we measure, whose changes cause variations in the dependent variable, are called the independent variables. Other variables that could affect the dependent variable but which we keep constant in our investigation are called the controlled variables.

What is the dependent variable in our investigation?(The responding variable)

What are the independent variable(s) in our investigation?(The variable we change)

What are the controlled variable(s) in our investigation?(The variables we keep the same)

Lab 3 Page L3-7

EAPS 312Capstone Environmental Science

Prediction. What we think will happen.

Explanation. The reasons for our prediction.

Procedure for conducting the investigation:

How will the results be used to answer the question?

Lab 3 Page L3-8

EAPS 312Capstone Environmental Science

Data Collection Page(Record and organize your data here)

Lab 3 Page L3-9

EAPS 312Capstone Environmental Science

Downtown BriefA written report to the city council

Names: Date:

Guiding question(s):

Summary of Investigation Procedures:

Results and Findings(Includes data table and graph)

Lab 3 Page L3-10

EAPS 312Capstone Environmental Science

Discussion of Findings:

Recommendations:

Lab 3 Page L3-11

EAPS 312Capstone Environmental Science

Lab 3 Page L3-12

EAPS 312Capstone Environmental Science

Lab 3 Page L3-13