Slope and Gradient Calculation

21 questions

Question 1Question

During a mapwork exercise on a topographical map with a scale of 1:100,0001 : 100,000, a student identifies a river bed at an elevation of 120 m120\text{ m} and a hilltop trigonometric station at an elevation of 320 m320\text{ m}. If the map distance between these two points is 4 cm4\text{ cm}, what is the average gradient of the slope?

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Answer: 1 in 201 \text{ in } 20

Answer

The average gradient of the slope is 1 in 201 \text{ in } 20.
The slope gradient is calculated by taking the ratio of Vertical Interval (VI) to Horizontal Equivalent (HE). The vertical rise between the river bed and the trigonometric station is 320 m120 m=200 m320\text{ m} - 120\text{ m} = 200\text{ m}. Using the map scale of 1:100,0001 : 100,000, a map distance of 4 cm4\text{ cm} corresponds to 400,000 cm400,000\text{ cm} or 4,000 m4,000\text{ m} on ground. Dividing 200 m200\text{ m} by 4,000 m4,000\text{ m} yields 120\frac{1}{20}, which is expressed as 1 in 201 \text{ in } 20.

Step-by-Step Solution

1
Calculate the Vertical Interval (VI)
VI=320 m120 m=200 m\text{VI} = 320\text{ m} - 120\text{ m} = 200\text{ m}
Vertical interval is the difference in height between the higher point and the lower point.
2
Calculate the Horizontal Equivalent (HE) in real-world meters using the map scale
HE=4 cm×100,000=400,000 cm=4,000 m\text{HE} = 4\text{ cm} \times 100,000 = 400,000\text{ cm} = 4,000\text{ m}
To find actual ground distance, multiply the map distance by the scale denominator and convert centimeters to meters.
3
Compute the gradient ratio
Gradient=VIHE=200 m4,000 m=120=1 in 20\text{Gradient} = \frac{\text{VI}}{\text{HE}} = \frac{200\text{ m}}{4,000\text{ m}} = \frac{1}{20} = 1 \text{ in } 20
Gradient is expressed as a ratio of vertical rise to horizontal distance.

Key Concept

Calculation of slope gradient from topographic map elevation points and representative fraction scale
Question 2Question

Match each topographic map elevation scenario to its corresponding calculated slope gradient ratio (1 in N1 \text{ in } N). Which of the following correct pairs match each map measurement scenario on the left with its computed gradient ratio on the right?

Click a left item, then click its matching right item

Items

Elevation difference of 80 m80\text{ m} between two points separated by 4 cm4\text{ cm} on a 1:50,0001 : 50,000 map scale
Elevation difference of 150 m150\text{ m} between two points separated by 3 cm3\text{ cm} on a 1:100,0001 : 100,000 map scale
Elevation difference of 200 m200\text{ m} between two points separated by 2 cm2\text{ cm} on a 1:25,0001 : 25,000 map scale
Elevation difference of 60 m60\text{ m} between two points separated by 6 cm6\text{ cm} on a 1:50,0001 : 50,000 map scale

Matches

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Answer

The correct matches pair each scenario with its gradient ratio as follows: the 80 m80\text{ m} elevation difference over 4 cm4\text{ cm} (1:50,0001:50,000) matches 1 in 251 \text{ in } 25; the 150 m150\text{ m} elevation difference over 3 cm3\text{ cm} (1:100,0001:100,000) matches 1 in 201 \text{ in } 20; the 200 m200\text{ m} elevation difference over 2 cm2\text{ cm} (1:25,0001:25,000) matches 1 in 2.51 \text{ in } 2.5; and the 60 m60\text{ m} elevation difference over 6 cm6\text{ cm} (1:50,0001:50,000) matches 1 in 501 \text{ in } 50.
Each elevation difference (VI) is divided by the true ground distance (HE) converted to meters. For scenario 1: 4 cm×50,000/100=2,000 m4\text{ cm} \times 50,000 / 100 = 2,000\text{ m}, leading to 80/2,000=1/2580 / 2,000 = 1 / 25. For scenario 2: 3 cm×100,000/100=3,000 m3\text{ cm} \times 100,000 / 100 = 3,000\text{ m}, giving 150/3,000=1/20150 / 3,000 = 1 / 20. For scenario 3: 2 cm×25,000/100=500 m2\text{ cm} \times 25,000 / 100 = 500\text{ m}, giving 200/500=1/2.5200 / 500 = 1 / 2.5. For scenario 4: 6 cm×50,000/100=3,000 m6\text{ cm} \times 50,000 / 100 = 3,000\text{ m}, yielding 60/3,000=1/5060 / 3,000 = 1 / 50.

Step-by-Step Solution

1
Recall the gradient formula for topographic maps
Gradient formula is Gradient=Vertical Interval (VI)Horizontal Equivalent (HE)\text{Gradient} = \frac{\text{Vertical Interval (VI)}}{\text{Horizontal Equivalent (HE)}}, where both VI and HE must be expressed in the same units (meters).
Gradient is a dimensionless ratio comparing vertical rise to horizontal ground distance.
2
Calculate Horizontal Equivalent (HE) for each scenario
Scenario 1: HE=4 cm×50,000=200,000 cm=2,000 m\text{HE} = 4\text{ cm} \times 50,000 = 200,000\text{ cm} = 2,000\text{ m}. Scenario 2: HE=3 cm×100,000=300,000 cm=3,000 m\text{HE} = 3\text{ cm} \times 100,000 = 300,000\text{ cm} = 3,000\text{ m}. Scenario 3: HE=2 cm×25,000=50,000 cm=500 m\text{HE} = 2\text{ cm} \times 25,000 = 50,000\text{ cm} = 500\text{ m}. Scenario 4: HE=6 cm×50,000=300,000 cm=3,000 m\text{HE} = 6\text{ cm} \times 50,000 = 300,000\text{ cm} = 3,000\text{ m}.
Map distance must be converted to actual ground distance using the representative fraction scale.
3
Compute the gradient ratio (VI / HE) for each item and pair with the correct ratio
Item 1: 802000=125\frac{80}{2000} = \frac{1}{25} (1 in 251 \text{ in } 25). Item 2: 1503000=120\frac{150}{3000} = \frac{1}{20} (1 in 201 \text{ in } 20). Item 3: 200500=12.5\frac{200}{500} = \frac{1}{2.5} (1 in 2.51 \text{ in } 2.5). Item 4: 603000=150\frac{60}{3000} = \frac{1}{50} (1 in 501 \text{ in } 50).
Simplifying each fraction to unit numerator format (1/N1 / N) yields the standard gradient ratio expression.

Key Concept

Slope and Gradient Calculation
Question 3Question

A proposed road route on a topographical map drawn to a scale of 1:20,0001 : 20,000 connects a river confluence at an elevation of 140 m140\text{ m} to a hilltop beacon at an elevation of 340 m340\text{ m}. If the distance measured along the route on the map is 8 cm8\text{ cm}, what is the average gradient of the slope along this route?

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Answer: 1 in 81 \text{ in } 8

Answer

The average gradient of the slope is 1 in 81 \text{ in } 8.
The slope gradient is determined by dividing the Vertical Interval by the Horizontal Equivalent. Subtracting the starting height (140 m140\text{ m}) from the beacon height (340 m340\text{ m}) gives a Vertical Interval of 200 m200\text{ m}. Converting the 8 cm8\text{ cm} map distance using the scale of 1:20,0001 : 20,000 yields a Horizontal Equivalent of 1,600 m1,600\text{ m}. Dividing 200 m200\text{ m} by 1,600 m1,600\text{ m} reduces to 18\frac{1}{8}, which gives 1 in 81 \text{ in } 8.

Step-by-Step Solution

1
Calculate the Vertical Interval (VI)
VI=340 m140 m=200 m\text{VI} = 340\text{ m} - 140\text{ m} = 200\text{ m}
Vertical Interval is the difference in elevation between the highest and lowest points of the slope segment.
2
Calculate the Horizontal Equivalent (HE) in meters
HE=8 cm×20,000=160,000 cm=1,600 m\text{HE} = 8\text{ cm} \times 20,000 = 160,000\text{ cm} = 1,600\text{ m}
Convert map distance to ground distance using the representative fraction scale (1 cm1\text{ cm} on map = 20,000 cm=200 m20,000\text{ cm} = 200\text{ m} on ground).
3
Compute the gradient ratio
Gradient=VIHE=200 m1,600 m=18\text{Gradient} = \frac{\text{VI}}{\text{HE}} = \frac{200\text{ m}}{1,600\text{ m}} = \frac{1}{8}
Gradient is expressed as a ratio of 1 unit vertical rise to NN units horizontal distance (1 in N1 \text{ in } N).

Key Concept

Calculation of slope gradient from topographical map scale and contour elevation values.
Estimated Time:1m 30s
Question 4Question

Match each set of elevation and ground distance measurements to its corresponding slope gradient ratio.

Click a left item, then click its matching right item

Items

Vertical Interval of 50 m50\text{ m} across a Horizontal Equivalent of 1 km1\text{ km}
Vertical Interval of 100 m100\text{ m} across a Horizontal Equivalent of 500 m500\text{ m}
Vertical Interval of 200 m200\text{ m} across a Horizontal Equivalent of 2 km2\text{ km}
Vertical Interval of 40 m40\text{ m} across a Horizontal Equivalent of 2 km2\text{ km}

Matches

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Answer

The measurements correctly match their gradient ratios as follows: 50 m/1,000 m50\text{ m} / 1,000\text{ m} matches 1 in 201 \text{ in } 20; 100 m/500 m100\text{ m} / 500\text{ m} matches 1 in 51 \text{ in } 5; 200 m/2,000 m200\text{ m} / 2,000\text{ m} matches 1 in 101 \text{ in } 10; and 40 m/2,000 m40\text{ m} / 2,000\text{ m} matches 1 in 501 \text{ in } 50.
Each pair is matched by ensuring both the Vertical Interval and Horizontal Equivalent are in meters, applying Gradient=V.I.H.E.\text{Gradient} = \frac{\text{V.I.}}{\text{H.E.}}, and reducing the fraction to 1 in N1 \text{ in } N form.

Step-by-Step Solution

1
Convert all Horizontal Equivalent values into meters so that units match the Vertical Interval.
1 km=1,000 m1\text{ km} = 1,000\text{ m} and 2 km=2,000 m2\text{ km} = 2,000\text{ m}.
Gradient calculation requires both vertical and horizontal measurements to be in identical linear units.
2
Apply the slope gradient formula: Gradient=Vertical Interval (V.I.)Horizontal Equivalent (H.E.)\text{Gradient} = \frac{\text{Vertical Interval (V.I.)}}{\text{Horizontal Equivalent (H.E.)}}.
Form fractions for each pair: 501000\frac{50}{1000}, 100500\frac{100}{500}, 2002000\frac{200}{2000}, and 402000\frac{40}{2000}.
Establishes the ratio between vertical rise and horizontal distance.
3
Simplify each fraction to unit numerator format (1 in N1 \text{ in } N).
Ratios simplify to 1 in 201 \text{ in } 20, 1 in 51 \text{ in } 5, 1 in 101 \text{ in } 10, and 1 in 501 \text{ in } 50.
Standard expression of slope gradient in geography mapwork.

Key Concept

Calculating slope gradient using Vertical Interval (V.I.) divided by Horizontal Equivalent (H.E.) in uniform units.
Question 5Question

On a topographical map, Point X is situated at an elevation of 200 m200\text{ m} and Point Y is situated at an elevation of 500 m500\text{ m}. If the horizontal ground distance between the two points is 6 km6\text{ km}, what is the gradient of the slope from Point X to Point Y expressed as a ratio?

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Answer: 1:201 : 20

Answer

The gradient of the slope between Point X and Point Y is 1:201 : 20.
The correct ratio 1:201 : 20 is obtained by subtracting the lower elevation (200 m200\text{ m}) from the higher elevation (500 m500\text{ m}) to obtain a vertical interval of 300 m300\text{ m}, converting the horizontal distance of 6 km6\text{ km} into 6,000 m6,000\text{ m}, and simplifying the fraction 3006000\frac{300}{6000} to 120\frac{1}{20}.

Step-by-Step Solution

1
Calculate the Vertical Interval (VI)
VI=500 m200 m=300 m\text{VI} = 500\text{ m} - 200\text{ m} = 300\text{ m}
Vertical interval is the difference in elevation between the higher and lower points.
2
Convert the Horizontal Equivalent (HE) to the same units as VI
HE=6 km×1,000=6,000 m\text{HE} = 6\text{ km} \times 1,000 = 6,000\text{ m}
Both vertical difference and horizontal distance must be expressed in identical units (meters).
3
Compute the slope gradient as a ratio
Gradient=VIHE=300 m6,000 m=120=1:20\text{Gradient} = \frac{\text{VI}}{\text{HE}} = \frac{300\text{ m}}{6,000\text{ m}} = \frac{1}{20} = 1 : 20
Gradient is calculated by dividing Vertical Interval by Horizontal Equivalent and simplifying to a ratio of 1 in N.

Key Concept

Calculating topographic gradient using Vertical Interval (VI) and Horizontal Equivalent (HE)
Estimated Time:45s
Question 6Question

A topographic map with an original scale of 1:50,0001 : 50,000 is reduced to half its linear size. On the reduced map, the measured distance between Point X (elevation 750 m750\text{ m}) and Point Y along a slope is 5.0 cm5.0\text{ cm}. If Point Y lies 88 contour intervals below Point X on a map with a contour interval of 25 m25\text{ m}, what is the gradient between Point X and Point Y expressed as a ratio?

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Answer: 1 in 251 \text{ in } 25

Answer

The gradient between Point X and Point Y is 1 in 251 \text{ in } 25.
The gradient expressed as 1 in 251 \text{ in } 25 is correct because reducing a 1:50,0001 : 50,000 map to half its linear size yields a scale of 1:100,0001 : 100,000. At this scale, 5.0 cm5.0\text{ cm} corresponds to a Horizontal Equivalent (HE) of 5,000 m5,000\text{ m}. With 88 contour intervals at 25 m25\text{ m} each, the Vertical Interval (VI) is 200 m200\text{ m}. Dividing VI by HE gives 2005,000=125\frac{200}{5,000} = \frac{1}{25}.

Step-by-Step Solution

1
Determine the new map scale after linear reduction
New Scale = 1:100,0001 : 100,000
Reducing a map to half its linear size doubles the scale denominator (50,000×2=100,00050,000 \times 2 = 100,000).
2
Calculate the Horizontal Equivalent (HE) ground distance
HE=5.0 cm×100,000=500,000 cm=5,000 m\text{HE} = 5.0\text{ cm} \times 100,000 = 500,000\text{ cm} = 5,000\text{ m}
Multiply map distance by the new scale factor and convert centimeters to meters.
3
Calculate the Vertical Interval (VI) between Point X and Point Y
VI=8×25 m=200 m\text{VI} = 8 \times 25\text{ m} = 200\text{ m}
Multiply the number of contour intervals by the contour interval value.
4
Compute the gradient ratio
Gradient=VIHE=200 m5,000 m=125\text{Gradient} = \frac{\text{VI}}{\text{HE}} = \frac{200\text{ m}}{5,000\text{ m}} = \frac{1}{25} or 1 in 251 \text{ in } 25
Divide Vertical Interval by Horizontal Equivalent in identical units to find the simple ratio.

Key Concept

Topographic Gradient and Map Scale Reduction
Estimated Time:3m 0s
Question 7Question

On a topographical map drawn to a scale of 1:50,0001 : 50,000, Point X is situated at an elevation of 150 m150\text{ m} and Point Y is situated at an elevation of 400 m400\text{ m}. If the straight-line distance between Point X and Point Y measured on the map is 5 cm5\text{ cm}, what is the slope gradient between the two points expressed as a percentage?

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Answer: 10%10\%

Answer

The slope gradient between Point X and Point Y expressed as a percentage is 10%10\%.
To find the gradient percentage, first calculate the Vertical Interval (VI): 400 m150 m=250 m400\text{ m} - 150\text{ m} = 250\text{ m}. Next, calculate the Horizontal Equivalent (HE): 5 cm×50,000=250,000 cm=2,500 m5\text{ cm} \times 50,000 = 250,000\text{ cm} = 2,500\text{ m}. Expressing VI over HE gives 250 m2,500 m=110\frac{250\text{ m}}{2,500\text{ m}} = \frac{1}{10}. Converting this fraction to a percentage gives 1/10×100%=10%1/10 \times 100\% = 10\%.

Step-by-Step Solution

1
Calculate the Vertical Interval (VI)
VI=400 m150 m=250 m\text{VI} = 400\text{ m} - 150\text{ m} = 250\text{ m}
The Vertical Interval is the difference in elevation between the higher point and lower point.
2
Calculate the Horizontal Equivalent (HE) in meters
HE=5 cm×50,000=250,000 cm=2,500 m\text{HE} = 5\text{ cm} \times 50,000 = 250,000\text{ cm} = 2,500\text{ m}
Multiply the map distance by the scale denominator to find ground distance, then convert centimeters to meters.
3
Compute the slope gradient as a fraction and convert to percentage
Gradient=VIHE=250 m2,500 m=0.10=10%\text{Gradient} = \frac{\text{VI}}{\text{HE}} = \frac{250\text{ m}}{2,500\text{ m}} = 0.10 = 10\%
Gradient percentage is calculated by dividing Vertical Interval by Horizontal Equivalent in identical units and multiplying by 100%100\%.

Key Concept

Slope and Gradient Calculation
Estimated Time:2m 0s
Question 8Question

On a topographical map drawn to a scale of 1:25,0001 : 25,000, two hilltop stations, Station A and Station B, are separated by a map distance of 16 cm16\text{ cm}. If Station A is situated at an elevation of 580 m580\text{ m} above sea level and Station B is at an elevation of 180 m180\text{ m}, what is the gradient of the slope between the two stations expressed as the value NN in the ratio 1:N1 : N?

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Answer: 10

Answer

The denominator NN in the slope gradient ratio 1:N1 : N is 1010 (representing a gradient ratio of 1:101 : 10).
To calculate the gradient expressed as 1:N1 : N, determine the Vertical Interval (VI =580 m180 m=400 m= 580\text{ m} - 180\text{ m} = 400\text{ m}) and the Horizontal Equivalent (HE =16 cm×25,000=400,000 cm=4,000 m= 16\text{ cm} \times 25,000 = 400,000\text{ cm} = 4,000\text{ m}). Dividing VI by HE gives 400 m4,000 m=110\frac{400\text{ m}}{4,000\text{ m}} = \frac{1}{10}, which corresponds to a gradient of 1:101 : 10, making N=10N = 10.

Step-by-Step Solution

1
Determine the Vertical Interval (VI)
\text{VI} = 580\text{ m} - 180\text{ m} = 400\text{ m}
The Vertical Interval is the vertical height difference between the two specified elevations.
2
Calculate the Horizontal Equivalent (HE) on the ground
\text{HE} = 16\text{ cm} \times 25,000 = 400,000\text{ cm} = 4,000\text{ m}
Multiply the map distance by the scale denominator to find the ground distance, then divide by 100 to convert centimeters to meters.
3
Calculate the gradient ratio
\text{Gradient} = \frac{\text{VI}}{\text{HE}} = \frac{400\text{ m}}{4,000\text{ m}} = \frac{1}{10} = 1 : 10
Gradient is calculated as Vertical Interval divided by Horizontal Equivalent, simplified to a fraction with a numerator of 1.

Key Concept

Calculation of slope gradient using vertical interval, map distance, and representative fraction scale
Estimated Time:1m 30s
Question 9Question

Match each set of topographic relief measurements to its corresponding slope gradient ratio (1 in N1 \text{ in } N).

Click a left item, then click its matching right item

Items

Vertical Interval of 20 m20\text{ m} across a Horizontal Distance of 200 m200\text{ m}
Vertical Interval of 50 m50\text{ m} across a Horizontal Distance of 1,000 m1,000\text{ m}
Vertical Interval of 100 m100\text{ m} across a Horizontal Distance of 500 m500\text{ m}
Vertical Interval of 10 m10\text{ m} across a Horizontal Distance of 500 m500\text{ m}

Matches

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Answer

Vertical Interval 20 m20\text{ m} / Distance 200 m200\text{ m} matches 1 in 101 \text{ in } 10; Vertical Interval 50 m50\text{ m} / Distance 1,000 m1,000\text{ m} matches 1 in 201 \text{ in } 20; Vertical Interval 100 m100\text{ m} / Distance 500 m500\text{ m} matches 1 in 51 \text{ in } 5; Vertical Interval 10 m10\text{ m} / Distance 500 m500\text{ m} matches 1 in 501 \text{ in } 50.
Each slope measurement set correctly matches its calculated gradient ratio by applying the standard formula Gradient=VIHE\text{Gradient} = \frac{\text{VI}}{\text{HE}} and reducing the resulting fraction to a 1 in N1 \text{ in } N form.

Step-by-Step Solution

1
Recall the fundamental gradient formula
Gradient = Vertical Interval (VI)Horizontal Equivalent (HE)\frac{\text{Vertical Interval (VI)}}{\text{Horizontal Equivalent (HE)}}
Gradient measures the ratio of vertical elevation change to horizontal ground distance.
2
Calculate the ratio for the first measurement set (20 m20\text{ m} VI and 200 m200\text{ m} HE)
20200=110=1 in 10\frac{20}{200} = \frac{1}{10} = 1 \text{ in } 10
Dividing both numerator and denominator by 20 simplifies the fraction to 1 in 10.
3
Calculate the ratio for the second measurement set (50 m50\text{ m} VI and 1,000 m1,000\text{ m} HE)
501000=120=1 in 20\frac{50}{1000} = \frac{1}{20} = 1 \text{ in } 20
Dividing both numerator and denominator by 50 simplifies the fraction to 1 in 20.
4
Calculate the ratio for the third measurement set (100 m100\text{ m} VI and 500 m500\text{ m} HE)
100500=15=1 in 5\frac{100}{500} = \frac{1}{5} = 1 \text{ in } 5
Dividing both numerator and denominator by 100 simplifies the fraction to 1 in 5.
5
Calculate the ratio for the fourth measurement set (10 m10\text{ m} VI and 500 m500\text{ m} HE)
10500=150=1 in 50\frac{10}{500} = \frac{1}{50} = 1 \text{ in } 50
Dividing both numerator and denominator by 10 simplifies the fraction to 1 in 50.

Key Concept

Slope and Gradient Calculation
Question 10Question

Match each topographic relief profile scenario to its corresponding calculated slope gradient expressed both as a ratio (1 in N1 \text{ in } N) and as a percentage gradient.

Click a left item, then click its matching right item

Items

Trigonometric beacon at 450 m450\text{ m} to river confluence at 150 m150\text{ m}; map distance is 6 cm6\text{ cm} on a scale of 1:50,0001:50,000.
Valley floor at elevation 180 m180\text{ m} rising to a plateau rim at 420 m420\text{ m}; map distance is 2.4 cm2.4\text{ cm} on a scale of 1:25,0001:25,000.
Proposed railway track passing from elevation 100 m100\text{ m} to 220 m220\text{ m}; map distance is 12 cm12\text{ cm} on a scale of 1:50,0001:50,000.
Scarp face intersecting 55 consecutive contour lines of interval 25 m25\text{ m}; map distance across the scarp is 0.8 cm0.8\text{ cm} on a scale of 1:50,0001:50,000.

Matches

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Answer

Trigonometric beacon to river confluence matches 1 in 101 \text{ in } 10 (10%10\%); Valley floor to plateau rim matches 1 in 2.51 \text{ in } 2.5 (40%40\%); Proposed railway track matches 1 in 501 \text{ in } 50 (2%2\%); Scarp face across 5 contour lines matches 1 in 41 \text{ in } 4 (25%25\%).
Each topographic scenario correctly pairs with its calculated gradient ratio and percentage by computing the exact Vertical Interval (difference in height) and Horizontal Equivalent (ground distance derived from map scale).

Step-by-Step Solution

1
Calculate the Vertical Interval (VI) for each scenario
Scenario 1: 450150=300 m450 - 150 = 300\text{ m}. Scenario 2: 420180=240 m420 - 180 = 240\text{ m}. Scenario 3: 220100=120 m220 - 100 = 120\text{ m}. Scenario 4: (51)×25=100 m(5-1) \times 25 = 100\text{ m}.
VI represents the difference in height between two points.
2
Calculate the Horizontal Equivalent (HE) in meters for each scenario
Scenario 1: 6 cm×500 m/cm=3,000 m6\text{ cm} \times 500\text{ m/cm} = 3,000\text{ m}. Scenario 2: 2.4 cm×250 m/cm=600 m2.4\text{ cm} \times 250\text{ m/cm} = 600\text{ m}. Scenario 3: 12 cm×500 m/cm=6,000 m12\text{ cm} \times 500\text{ m/cm} = 6,000\text{ m}. Scenario 4: 0.8 cm×500 m/cm=400 m0.8\text{ cm} \times 500\text{ m/cm} = 400\text{ m}.
Convert map distance to ground distance using the representative fraction scale.
3
Compute the slope gradient ratio (VI / HE) and express as 1 in N and percentage
Scenario 1: 300/3000=1/10=1 in 10300 / 3000 = 1/10 = 1 \text{ in } 10 (10%10\%). Scenario 2: 240/600=1/2.5=1 in 2.5240 / 600 = 1/2.5 = 1 \text{ in } 2.5 (40%40\%). Scenario 3: 120/6000=1/50=1 in 50120 / 6000 = 1/50 = 1 \text{ in } 50 (2%2\%). Scenario 4: 100/400=1/4=1 in 4100 / 400 = 1/4 = 1 \text{ in } 4 (25%25\%).
Gradient is calculated as VI / HE, yielding both ratio 1 in N and percentage slope (VI/HE * 100%).

Key Concept

Slope and Gradient Calculation
Question 11Question

On a topographical map with a scale of 1:50,0001 : 50,000, Point X lies on a hilltop at an elevation of 420 m420\text{ m}, while Point Y sits near a stream bed at an elevation of 170 m170\text{ m}. If the measured distance between Point X and Point Y on the map is 12.5 cm12.5\text{ cm}, calculate the slope gradient between the two points. Express your answer as the value of NN in the standard gradient ratio 1:N1 : N (or 1 in N1 \text{ in } N). What is the value of NN?

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Answer: 25

Answer

The denominator N in the gradient ratio 1 : N is 25.
The vertical interval (V.I.) between the hilltop at 420 m420\text{ m} and the stream at 170 m170\text{ m} is 250 m250\text{ m}. The horizontal equivalent (H.E.) on the ground is calculated by multiplying the map distance of 12.5 cm12.5\text{ cm} by the map scale factor of 50,00050,000, which gives 625,000 cm625,000\text{ cm} (6,250 m6,250\text{ m}). Dividing V.I. by H.E. yields 250/6,250=1/25250 / 6,250 = 1 / 25. Thus, the gradient ratio is 1:251 : 25, making N=25N = 25.

Step-by-Step Solution

1
Calculate Vertical Interval (V.I.)
V.I. = 420 m - 170 m = 250 m
Vertical interval is the difference in height between the highest and lowest points.
2
Convert map distance to ground distance to determine Horizontal Equivalent (H.E.) in meters
H.E. = 12.5 cm × 50,000 = 625,000 cm = 6,250 m
Horizontal equivalent must be in the same units as the vertical interval before computing ratio.
3
Divide V.I. by H.E. to express the gradient as a ratio 1 : N
Gradient = 250 / 6,250 = 1 / 25
Simplifying the fraction V.I. / H.E. yields 1 / 25, giving N = 25.

Key Concept

Slope and Gradient Calculation
Question 12Question

Four survey transects were evaluated on a topographical map drawn to a scale of 1:50,0001 : 50,000. Match each transect scenario on the left with its corresponding calculated slope gradient ratio on the right.

Click a left item, then click its matching right item

Items

Transect P: Vertical interval of 100 m100\text{ m} across a map distance of 5 cm5\text{ cm}
Transect Q: Vertical interval of 250 m250\text{ m} across a map distance of 2 cm2\text{ cm}
Transect R: Vertical interval of 60 m60\text{ m} across a map distance of 6 cm6\text{ cm}
Transect S: Vertical interval of 150 m150\text{ m} across a map distance of 3 cm3\text{ cm}

Matches

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Answer

Transect P matches 1 in 251 \text{ in } 25; Transect Q matches 1 in 41 \text{ in } 4; Transect R matches 1 in 501 \text{ in } 50; Transect S matches 1 in 101 \text{ in } 10.
Each scenario is correctly matched by converting map distance to real-world ground distance (HE) using the 1:50,0001 : 50,000 scale multiplier (1 cm=500 m1\text{ cm} = 500\text{ m}) and then computing rise over run (VI / HE).

Step-by-Step Solution

1
Convert map distances to Horizontal Equivalent (HE) in meters for each transect using the map scale ratio (1:50,0001 : 50,000, where 1 cm=500 m1\text{ cm} = 500\text{ m}).
Transect P HE: 5 cm×500 m/cm=2,500 m5\text{ cm} \times 500\text{ m/cm} = 2,500\text{ m}; Transect Q HE: 2 cm×500 m/cm=1,000 m2\text{ cm} \times 500\text{ m/cm} = 1,000\text{ m}; Transect R HE: 6 cm×500 m/cm=3,000 m6\text{ cm} \times 500\text{ m/cm} = 3,000\text{ m}; Transect S HE: 3 cm×500 m/cm=1,500 m3\text{ cm} \times 500\text{ m/cm} = 1,500\text{ m}.
Gradient calculation requires both Vertical Interval (VI) and Horizontal Equivalent (HE) to be in identical linear measurement units.
2
Calculate the slope gradient for each transect using the formula Gradient=VIHE\text{Gradient} = \frac{\text{VI}}{\text{HE}} and simplify to ratio form (1 in N1 \text{ in } N).
Transect P: 100 m2,500 m=125=1 in 25\frac{100\text{ m}}{2,500\text{ m}} = \frac{1}{25} = 1 \text{ in } 25; Transect Q: 250 m1,000 m=14=1 in 4\frac{250\text{ m}}{1,000\text{ m}} = \frac{1}{4} = 1 \text{ in } 4; Transect R: 60 m3,000 m=150=1 in 50\frac{60\text{ m}}{3,000\text{ m}} = \frac{1}{50} = 1 \text{ in } 50; Transect S: 150 m1,500 m=110=1 in 10\frac{150\text{ m}}{1,500\text{ m}} = \frac{1}{10} = 1 \text{ in } 10.
Expressing VIHE\frac{\text{VI}}{\text{HE}} as a unit fraction yields the standard ratio representation used in topographic map reading.

Key Concept

Slope gradient is the ratio of vertical elevation change (Vertical Interval) to ground horizontal distance (Horizontal Equivalent), expressed as a fraction or ratio 1 in N1 \text{ in } N.
Question 13Question

On a topographical map drawn to a scale of 1:25,0001 : 25,000, Point P is situated at a trigonometric station with an elevation of 520 m520\text{ m}, while Point Q lies at a stream confluence at an elevation of 370 m370\text{ m}. The measured straight-line distance between Point P and Point Q on the map is 15 cm15\text{ cm}. What is the slope gradient between Point P and Point Q, expressed as the denominator NN in the ratio 1 in N1 \text{ in } N?

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Answer: 25

Answer

The denominator NN of the slope gradient ratio (1 in N1 \text{ in } N) is 25.
The Vertical Interval (VI) between Point P and Point Q is 520 m370 m=150 m520\text{ m} - 370\text{ m} = 150\text{ m}. Using the map scale of 1:25,0001 : 25,000, the Horizontal Equivalent (HE) is 15 cm×25,000=375,000 cm=3,750 m15\text{ cm} \times 25,000 = 375,000\text{ cm} = 3,750\text{ m}. Dividing the VI by the HE gives 1503,750=125\frac{150}{3,750} = \frac{1}{25}. Therefore, the gradient expressed as a ratio is 1 in 251 \text{ in } 25, and the denominator NN is 25.

Step-by-Step Solution

1
Determine the Vertical Interval (VI)
VI=520 m370 m=150 m\text{VI} = 520\text{ m} - 370\text{ m} = 150\text{ m}
Vertical Interval is the difference in elevation between the higher and lower points.
2
Calculate the Horizontal Equivalent (HE) in ground units (meters)
HE=15 cm×25,000=375,000 cm=3,750 m\text{HE} = 15\text{ cm} \times 25,000 = 375,000\text{ cm} = 3,750\text{ m}
Horizontal Equivalent is obtained by converting the measured map distance to actual ground distance using the representative fraction scale.
3
Compute the Gradient Ratio
Gradient=VIHE=150 m3,750 m=125\text{Gradient} = \frac{\text{VI}}{\text{HE}} = \frac{150\text{ m}}{3,750\text{ m}} = \frac{1}{25}
Gradient is the ratio of Vertical Interval to Horizontal Equivalent, both expressed in identical units.

Key Concept

Slope and Gradient Calculation using Representative Fraction Map Scale
Estimated Time:1m 30s
Question 14Question

Match each topographic map slope calculation scenario on the left with its corresponding calculated gradient representation on the right.

Click a left item, then click its matching right item

Items

A vertical rise of 50 m50\text{ m} measured across a map distance of 4 cm4\text{ cm} on a map scale of 1:25,0001 : 25,000
An elevation change from 120 m120\text{ m} to 320 m320\text{ m} along a road measuring 5 cm5\text{ cm} on a 1:50,0001 : 50,000 topographical map
A hill slope rising 150 m150\text{ m} across a map line of 6 cm6\text{ cm} drawn to a scale of 1:25,0001 : 25,000
A terrain transect crossing 44 contour intervals of 20 m20\text{ m} each, spanning a map distance of 4 cm4\text{ cm} at 1:100,0001 : 100,000 scale

Matches

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Answer

The correct pairings are: (1) A vertical rise of 50 m across 4 cm on a 1:25,000 map matches 1 in 20 (5.0%); (2) An elevation change from 120 m to 320 m over 5 cm on a 1:50,000 map matches 1 in 12.5 (8.0%); (3) A rise of 150 m over 6 cm on a 1:25,000 map matches 1 in 10 (10.0%); (4) Crossing 4 contour intervals of 20 m across 4 cm at 1:100,000 scale matches 1 in 50 (2.0%).
Each scenario is accurately paired by converting the map distance to actual ground distance in meters using the given scale, determining the vertical interval, and computing the gradient as a ratio (1 in N) and percentage.

Step-by-Step Solution

1
Convert the map distance for each scenario into the ground horizontal distance (Horizontal Equivalent, HE) in meters using the designated map scale.
Scenario 1: 4 cm×25,000/100=1,000 m4\text{ cm} \times 25,000 / 100 = 1,000\text{ m}. Scenario 2: 5 cm×50,000/100=2,500 m5\text{ cm} \times 50,000 / 100 = 2,500\text{ m}. Scenario 3: 6 cm×25,000/100=1,500 m6\text{ cm} \times 25,000 / 100 = 1,500\text{ m}. Scenario 4: 4 cm×100,000/100=4,000 m4\text{ cm} \times 100,000 / 100 = 4,000\text{ m}.
Map scale Representative Fractions convert map measurements to real ground horizontal distances, which must be expressed in meters to match the unit of Vertical Interval.
2
Calculate the total height difference (Vertical Interval, VI) in meters for each terrain scenario.
Scenario 1: VI=50 m\text{VI} = 50\text{ m}. Scenario 2: VI=320 m120 m=200 m\text{VI} = 320\text{ m} - 120\text{ m} = 200\text{ m}. Scenario 3: VI=150 m\text{VI} = 150\text{ m}. Scenario 4: VI=4 intervals×20 m=80 m\text{VI} = 4 \text{ intervals} \times 20\text{ m} = 80\text{ m}.
Vertical Interval represents the net vertical relief difference between the start and end points of the transect.
3
Compute the gradient ratio (VI / HE) and express it both as a simple ratio (1 in N) and as a percentage slope.
Scenario 1: 501,000=1201 in 20\frac{50}{1,000} = \frac{1}{20} \rightarrow 1 \text{ in } 20 (5.0%5.0\%). Scenario 2: 2002,500=112.51 in 12.5\frac{200}{2,500} = \frac{1}{12.5} \rightarrow 1 \text{ in } 12.5 (8.0%8.0\%). Scenario 3: 1501,500=1101 in 10\frac{150}{1,500} = \frac{1}{10} \rightarrow 1 \text{ in } 10 (10.0%10.0\%). Scenario 4: 804,000=1501 in 50\frac{80}{4,000} = \frac{1}{50} \rightarrow 1 \text{ in } 50 (2.0%2.0\%).
Gradient formula is Gradient=Vertical Interval (VI)Horizontal Equivalent (HE)\text{Gradient} = \frac{\text{Vertical Interval (VI)}}{\text{Horizontal Equivalent (HE)}}.

Key Concept

Slope and Gradient Calculation from Topographical Maps
Estimated Time:3m 0s
Question 15Question

On a topographical map drawn to a scale of 1:40,0001 : 40,000, a communications cable line is planned between Trigonometrical Station PP at an elevation of 680 m680\text{ m} and Spot Height QQ at an elevation of 200 m200\text{ m}. If the straight-line distance measured between PP and QQ on the map is 12 cm12\text{ cm}, what is the average gradient of the slope between these two points expressed as a percentage?

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Answer: 10%10\%

Answer

The average gradient of the slope expressed as a percentage is 10%10\%.
The slope gradient is calculated by dividing the Vertical Interval (480 m480\text{ m}) by the Horizontal Equivalent (4,800 m4,800\text{ m}). Multiplying the ratio 4804,800=0.10\frac{480}{4,800} = 0.10 by 100100 yields 10%10\%.

Step-by-Step Solution

1
Calculate the Vertical Interval (VI)
VI=680 m200 m=480 m\text{VI} = 680\text{ m} - 200\text{ m} = 480\text{ m}
Vertical Interval is the difference in elevation between the two points.
2
Calculate the Horizontal Equivalent (HE) in meters
Ground distance=12 cm×40,000=480,000 cm=4,800 m\text{Ground distance} = 12\text{ cm} \times 40,000 = 480,000\text{ cm} = 4,800\text{ m}
Multiply the map distance by the scale factor and convert from centimeters to meters (100 cm=1 m100\text{ cm} = 1\text{ m}).
3
Compute the slope gradient as a percentage
Gradient (%)=(VIHE)×100=(480 m4,800 m)×100=10%\text{Gradient (\%)} = \left( \frac{\text{VI}}{\text{HE}} \right) \times 100 = \left( \frac{480\text{ m}}{4,800\text{ m}} \right) \times 100 = 10\%
Gradient percentage is defined as the ratio of Vertical Interval to Horizontal Equivalent multiplied by 100.

Key Concept

Slope and Gradient Calculation on Topographic Maps
Question 16Question

On a topographical map with a scale of 1:20,0001 : 20,000, a proposed electric transmission line extends from Point KK situated on a ridge contour of 650 m650\text{ m} to Point LL located near a stream contour of 450 m450\text{ m}. If the measured distance between Point KK and Point LL on the map is 8.0 cm8.0\text{ cm}, what is the gradient of the slope between these two points?

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Answer: 1 in 81 \text{ in } 8

Answer

The gradient between Point KK and Point LL is 1 in 81 \text{ in } 8.
The slope gradient is calculated using the formula Gradient=Vertical IntervalHorizontal Equivalent\text{Gradient} = \frac{\text{Vertical Interval}}{\text{Horizontal Equivalent}}. The Vertical Interval is 650 m450 m=200 m650\text{ m} - 450\text{ m} = 200\text{ m}. The Horizontal Equivalent is calculated by multiplying the map measurement (8.0 cm8.0\text{ cm}) by the representative fraction scale factor (20,00020,000), yielding 160,000 cm160,000\text{ cm}, which converts to 1,600 m1,600\text{ m}. Placing these in the gradient ratio yields 2001,600=18\frac{200}{1,600} = \frac{1}{8}, expressed as 1 in 81 \text{ in } 8.

Step-by-Step Solution

1
Calculate the Vertical Interval (VI)
VI=650 m450 m=200 m\text{VI} = 650\text{ m} - 450\text{ m} = 200\text{ m}
The Vertical Interval is the difference in elevation between the highest and lowest contour points.
2
Calculate the Horizontal Equivalent (HE) in ground units
HE=8.0 cm×20,000=160,000 cm=1,600 m\text{HE} = 8.0\text{ cm} \times 20,000 = 160,000\text{ cm} = 1,600\text{ m}
Map distance must be multiplied by the scale factor and converted into meters to match the Vertical Interval unit.
3
Compute the slope gradient ratio
Gradient=VIHE=200 m1,600 m=18\text{Gradient} = \frac{\text{VI}}{\text{HE}} = \frac{200\text{ m}}{1,600\text{ m}} = \frac{1}{8}
Gradient is expressed as the ratio of Vertical Interval to Horizontal Equivalent.

Key Concept

Slope and Gradient Calculation from Topographic Maps
Estimated Time:2m 0s
Question 17Question

Match each slope measurement scenario on the left with its corresponding calculated gradient on the right.

Click a left item, then click its matching right item

Items

Vertical Interval =80 m= 80\text{ m}, Horizontal Equivalent =1.6 km= 1.6\text{ km}
Vertical Interval =150 m= 150\text{ m}, Horizontal Equivalent =600 m= 600\text{ m}
Vertical Interval =50 m= 50\text{ m}, Horizontal Equivalent =2.5 km= 2.5\text{ km}
Vertical Interval =200 m= 200\text{ m}, Horizontal Equivalent =1 km= 1\text{ km}

Matches

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Answer

Vertical Interval = 80 m, HE = 1.6 km matches 1 in 20 (5%); VI = 150 m, HE = 600 m matches 1 in 4 (25%); VI = 50 m, HE = 2.5 km matches 1 in 50 (2%); VI = 200 m, HE = 1 km matches 1 in 5 (20%).
Each scenario is correctly matched by converting all horizontal distances into meters and calculating the simplified ratio VI / HE, expressed as both a ratio (1 in N) and a percentage.

Step-by-Step Solution

1
Convert all Horizontal Equivalent (HE) distances given in kilometers to meters so that units match the Vertical Interval (VI).
1.6 km=1,600 m1.6\text{ km} = 1,600\text{ m}, 2.5 km=2,500 m2.5\text{ km} = 2,500\text{ m}, and 1 km=1,000 m1\text{ km} = 1,000\text{ m}.
Both Vertical Interval and Horizontal Equivalent must be in the same units of measurement before calculating the ratio.
2
Apply the gradient formula Gradient=Vertical Interval (VI)Horizontal Equivalent (HE)\text{Gradient} = \frac{\text{Vertical Interval (VI)}}{\text{Horizontal Equivalent (HE)}} to each scenario.
Scenario 1: 801600=120\frac{80}{1600} = \frac{1}{20}; Scenario 2: 150600=14\frac{150}{600} = \frac{1}{4}; Scenario 3: 502500=150\frac{50}{2500} = \frac{1}{50}; Scenario 4: 2001000=15\frac{200}{1000} = \frac{1}{5}.
Dividing vertical rise by horizontal distance yields the simplified slope fraction.
3
Express each simplified fraction in standard ratio (1 in N1 \text{ in } N) and percentage formats.
120=1 in 20 (5%)\frac{1}{20} = 1\text{ in } 20\ (5\%), 14=1 in 4 (25%)\frac{1}{4} = 1\text{ in } 4\ (25\%), 150=1 in 50 (2%)\frac{1}{50} = 1\text{ in } 50\ (2\%), 15=1 in 5 (20%)\frac{1}{5} = 1\text{ in } 5\ (20\%).
This allows matching the calculated values directly to the corresponding choices on the right.

Key Concept

Slope and gradient calculation using Vertical Interval (VI) and Horizontal Equivalent (HE) with unit unification.
Question 18Question

A topographical map extract drawn to a scale of 1:100,0001 : 100,000 shows a footbridge over a stream at an elevation of 250 m250\text{ m} and a forest observation tower situated on a hilltop at an elevation contour of 450 m450\text{ m}. If the straight-line distance between the bridge and the tower measured on the map is 4 cm4\text{ cm}, what is the average gradient of the slope between these two locations?

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Answer: 1 in 201\text{ in } 20

Answer

The gradient between the two points is 1 in 201\text{ in } 20.
The gradient of a slope is computed as the Vertical Interval (VI) divided by the Horizontal Equivalent (HE). The vertical interval is 450 m250 m=200 m450\text{ m} - 250\text{ m} = 200\text{ m}. Using the map scale of 1:100,0001 : 100,000, a map distance of 4 cm4\text{ cm} equals 400,000 cm400,000\text{ cm} or 4,000 m4,000\text{ m} on the ground. Dividing 200 m200\text{ m} by 4,000 m4,000\text{ m} simplifies to 120\frac{1}{20}, expressed as 1 in 201\text{ in } 20.

Step-by-Step Solution

1
Calculate the Vertical Interval (VI)
VI=450 m250 m=200 m\text{VI} = 450\text{ m} - 250\text{ m} = 200\text{ m}
Vertical interval is the difference in elevation between the two points.
2
Calculate the Horizontal Equivalent (HE) in meters
HE=4 cm×100,000=400,000 cm=4,000 m\text{HE} = 4\text{ cm} \times 100,000 = 400,000\text{ cm} = 4,000\text{ m}
Multiply map distance by the scale factor to get real-world distance, then convert centimeters to meters.
3
Calculate the slope gradient
Gradient=VIHE=200 m4,000 m=120\text{Gradient} = \frac{\text{VI}}{\text{HE}} = \frac{200\text{ m}}{4,000\text{ m}} = \frac{1}{20}
Gradient is expressed as the ratio of Vertical Interval to Horizontal Equivalent in identical measurement units.

Key Concept

Slope gradient determination using Vertical Interval (VI) and Horizontal Equivalent (HE)
Estimated Time:1m 30s
Question 19Question

A field surveyor analyzing a topographical map with a scale of 1:50,0001 : 50,000 measures a straight line distance of 4 cm4\text{ cm} along a road connecting Hilltop Village at an elevation of 350 m350\text{ m} and Valley Junction at an elevation of 150 m150\text{ m}. What is the gradient of the road between these two settlements?

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Answer: 1 in 101 \text{ in } 10

Answer

The gradient of the road is 1 in 101 \text{ in } 10.
The gradient is determined by dividing Vertical Interval (VI) by Horizontal Equivalent (HE). With a VI of 200 m200\text{ m} (350 m150 m350\text{ m} - 150\text{ m}) and a ground distance HE of 2,000 m2,000\text{ m} (4 cm×50,000=200,000 cm=2,000 m4\text{ cm} \times 50,000 = 200,000\text{ cm} = 2,000\text{ m}), the ratio 2002,000\frac{200}{2,000} simplifies to 110\frac{1}{10} or 1 in 101 \text{ in } 10.

Step-by-Step Solution

1
Calculate the Vertical Interval (VI)
VI=350 m150 m=200 m\text{VI} = 350\text{ m} - 150\text{ m} = 200\text{ m}
Vertical Interval is the difference in elevation between the two points.
2
Calculate the Horizontal Equivalent (HE) in meters
HE=4 cm×50,000=200,000 cm=2,000 m\text{HE} = 4\text{ cm} \times 50,000 = 200,000\text{ cm} = 2,000\text{ m}
Horizontal Equivalent is the actual ground distance converted to the same unit as VI.
3
Compute the slope gradient ratio
Gradient=VIHE=200 m2,000 m=110\text{Gradient} = \frac{\text{VI}}{\text{HE}} = \frac{200\text{ m}}{2,000\text{ m}} = \frac{1}{10} or 1 in 101 \text{ in } 10
Gradient is defined as the ratio of Vertical Interval to Horizontal Equivalent.

Key Concept

Topographic Slope and Gradient Calculation
Question 20Question

On a topographical map with a scale of 1:60,0001 : 60,000, a railway track connects Hill Station XX at an elevation of 460 m460\text{ m} to Junction YY at an elevation of 340 m340\text{ m}. If the distance between the two points measured along the map is 5 cm5\text{ cm}, what is the average gradient of the slope between Station XX and Junction YY?

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Answer: 1 in 251 \text{ in } 25

Answer

The average gradient between Station X and Junction Y is 1 in 251 \text{ in } 25.
The vertical interval between the two stations is 460 m340 m=120 m460\text{ m} - 340\text{ m} = 120\text{ m}. Using the map scale of 1:60,0001 : 60,000, a map distance of 5 cm5\text{ cm} represents a ground horizontal distance of 5×60,000 cm=300,000 cm=3,000 m5 \times 60,000\text{ cm} = 300,000\text{ cm} = 3,000\text{ m}. Dividing the vertical interval by the horizontal equivalent gives 1203000=125\frac{120}{3000} = \frac{1}{25}, which is expressed as 1 in 251 \text{ in } 25.

Step-by-Step Solution

1
Calculate the Vertical Interval (VI)
VI=460 m340 m=120 m\text{VI} = 460\text{ m} - 340\text{ m} = 120\text{ m}
The Vertical Interval is the absolute difference in elevation between the two points.
2
Calculate the Horizontal Equivalent (HE) in meters
HE=5 cm×60,000=300,000 cm=3,000 m\text{HE} = 5\text{ cm} \times 60,000 = 300,000\text{ cm} = 3,000\text{ m}
Convert the measured map distance to ground distance using the representative fraction scale, then convert centimeters to meters.
3
Calculate the gradient ratio
Gradient=VIHE=120 m3,000 m=125 or 1 in 25\text{Gradient} = \frac{\text{VI}}{\text{HE}} = \frac{120\text{ m}}{3,000\text{ m}} = \frac{1}{25} \text{ or } 1 \text{ in } 25
Express the ratio of Vertical Interval to Horizontal Equivalent in standard 1 in N1 \text{ in } N form by dividing both values by the vertical interval.

Key Concept

Topographic Gradient Calculation
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