Slope = (elevation difference/horizontal distance) x 100%
When expressed as a percentage, i=h/l× 100%.
Subtitle answer:
1.49% =( 150-x)/50 * 100%
x=75.5
That is, it drops 75.5 meters at 50 meters.
Extended data:
There are four methods to express slope: percentage method, degree method, density method and fraction method, among which percentage method and degree method are more commonly used.
The gradient is expressed in degrees and calculated by inverse trigonometric function, and its formula is as follows:
Tanα (slope) = height difference/distance
So α (slope) =arc tan (elevation difference/distance)
In fact, the slope is simply the tan value of a right-angled adjacent angle (the angle of the ground).
According to the classification of slopes used in geomorphological detailed drawings by the Geomorphological Survey and Geomorphological Cartography Committee of the International Geographical Union, 0 ~ 0.5 is defined as plain, and > 0.5 ~ 2 is defined as micro-slope. 2 ~ 5 is gentle slope, > 5 ~15 is slope, >15 ~ 35 is steep slope, > 35 ~ 55 is steep slope and > 55 ~ 90 is straight wall.
Chinese mainland stipulates that people over the age of 25 cannot farm.
The northwest loess plateau15 and 25 are the lower limit and upper limit critical slope angles of slope water surface erosion respectively.
References:
Baidu encyclopedia-slope