GEOG S1 GI Flashcards
What is a hypothesis (GI)?
The main focus of a GI can be expressed in the form of a hypothesis. A hypothesis is basically an idea which can be tested through the investigation. A well-written hypothesis is measurable and often contains independent and dependent variables.
What is an independent variable?
An independent variable refers to a factor that causes a change in another factor.
What is an dependent variable?
A dependent variable refers to a factor that changes in response to some other factor.
What is data?
Data are facts which are collected for reference or analysis, and from which conclusions can be drawn. They can be classified into primary and sec data.
Pri data refers to og data collected first-hand through fieldwork. The sources used would be fieldwork. Some examples are recordings, sketches, photographs, surveys and interviews.
Sec data refers to data that has alr been collected by someone else. The sources would be published materials. Some examples are books, news articles, maps, websites and reports.
What are ways to collect primary data?
Field sketching, field photography, sampling, water quality testing, measuring turbidity, measuring DO, measuring pH.
What is field sketching and what are its advantages/disadvantages?
A field sketch is essentially a pictorial form of note-taking of a landscape. Unlike taking a photograph, drawing a field sketch can help you to identify important features in the landscape and leave out things that are less important.
Field sketching develops the ability to observe and record important information by taking time to view and understand the landscape that is being sketched. Moreover, field sketching allows you to add notes directly onto the sketch.
However, F.S. requires more time than taking photographs. Moreover, one field sketch cannot show changes over time.
How to do a field sketch?
- Identify the focus and purpose of your sketch.
- Create a title for your sketch.
- Draw a clear outline box and divide it into **equal horizontal and vertical sections (foreground, middle ground, background, left, right, middle)
- Identify relevant details to be included in the sketch
- Begin your sketch with the furthest frame (bg) down to the nearest frame (fg).
- Label key features and annotate (additional details of activities taking place around there) your sketch.
- Consider scale by taking note of prominent objects/features.
- Note the date, time, weather conditions and location.
What is field photography and what are its advantages/disadvantages?
Multiple photographs can be taken of a feature from different angles. Moreover, most cameras now can take wide-angle shots -> larger scale photos.
However, field photography will capture everything, including unnecessary details. Moreover, one single photograph cannot show changes over time.
How to take field photography?
- The main feature you intend to capture should stand out clearly in the photograph and should fill up most of the photograph – it should not appear too small.
- Provide an indication of the scale of the features in your photograph by including people or common objects (e.g. a lamp post) in the photograph.
- Use a frame (see example below) to help you position items in the photograph into 9 horizontal and vertical sections, so that you can easily locate features in the photograph when giving descriptions and interpretations later.
- Record data such as date, time, location and field notes.
- Crop, label, and annotate using editing software.
What is sampling?
Sampling is the process of selecting a small group from a population and obtaining data about it, in order to estimate the characteristics of the entire population.
A population is a group that has characteristics that fit the investigation. e.g. a class of secondary one students
A sample consists of members selected from the population. e.g. all boys in a class of secondary one students.
Why do we do sampling?
-> saves time & energy - impossible to obtain data about the entire population directly
-> data collected can make conclusions about the entire population
What are the 3 water quality indicators that are often measured when testing water quality?
pH, DO, Turbidity.
What is pH and how is it measured?
pH is a measure of how acidic or alkaline water is. The pH of water can be affected by various factors, such as acid rain, wastewater discharges, runoff from mines and the type of rock found naturally in an area. Most aquatic animals are adapted to a specific pH level. If the pH of the water they are living in varies above or below this level, they may die, stop reproducing, or move elsewhere if possible.
pH is measured on a scale that ranges from a value of 0 (i.e. very acidic) to 14 (i.e. very alkaline), with 7 being neutral.
Most aquatic animals survive best in water that has a pH value of 6.5–8.0. If pH falls below 4.8 or rises above 9.2, the survival of many fishes will be at risk.
- Fill the test tube to the 10 ml line with water taken from the water body.
- Drop 1 pH test tablet into the test tube.
- Cap the test tube and invert it repeatedly until the tablet has completely disintegrated.
- Compare the colour of the water sample in the test tube with the pH colour chart to determine the pH level.
- Record the pH level to the nearest 0.5.
What is DO and how to measure it?
Dissolved oxygen is the amount of oxygen gas that has dissolved into a given amount of water. In order for water to support aquatic animals, it must contain at least a certain amount of dissolved oxygen, since aquatic animals require oxygen to survive.
The concentration of dissolved oxygen in water is determined by various factors. Temperature can affect the concentration as cold water can hold more dissolved oxygen than warm water. In addition, the concentration of dissolved oxygen increases during the day as aquatic plants are able to photosynthesise, but falls gradually overnight. High levels of bacteria or large amounts of rotting plants may cause the concentration of dissolved oxygen to decrease.
The unit of measurement for dissolved oxygen is parts per million (ppm) or milligrams per litre (mg/l). Water that has a dissolved oxygen concentration of 7–9 ppm is able to support aquatic life the best. However, if dissolved oxygen concentration falls below 4 ppm, the survival of many fishes will be at risk.
- Fill the white plastic cylindrical container with water taken from the water body.
- Immerse the small glass vial into the water inside the container in order to fill it up.
- Carefully take the vial out of the container and ensure that it remains completely full.
- Drop 2 dissolved oxygen test tablets into the vial.
- Screw the cap on the vial and make sure that there are no air bubbles inside.
- Shake the vial for 4 minutes until the tablets have completely dissolved.
- Wait 5 more minutes for the colour to develop.
- Compare the colour of the water sample in the vial with the dissolved oxygen chart)to determine its dissolved oxygen concentration.
- Record the dissolved oxygen concentration data in ppm.
What is turbidity and how is it measured?
Turbidity is a measure of how clear water is. Water that has a high turbidity level is murky and difficult to see through, because it contains a large amount of suspended particles such as clay, silt, dead plant matter and even microscopic organisms. Turbidity should not be confused with colour, since dark-coloured water can still be clear and not murky.
High turbidity levels may be caused by soil erosion, runoff after heavy rain, growth of algae or disturbance of sediment by boats or aquatic animals. As a result, the amount of sunlight that is able to enter the water is reduced – this makes it harder for aquatic plants to photosynthesise, thus lowering the amount of dissolved oxygen in the water. In addition, fish will also be affected by the suspended particles, which can clog their gills, reduce their resistance to diseases, and impact their ability to grow and reproduce.
The unit of measurement for turbidity is the Jackson Turbidity Unit (JTU). Water that has a turbidity level of around 20–40 JTU is likely to support aquatic life the best.
- Ensure that the white plastic cylindrical container has a Secchi disc sticker pasted on its inside bottom.
- Fill the container with water taken from the water body.
- Compare the appearance of the Secchi disc in the container with the turbidity chart to determine the turbidity level of the water sample.
- Record the turbidity data in JTU.
How should secondary data be collected?
Refer to several sources such as books, journals, newspapers, wedsites.
