What method can be used to measure topography?

The method of using GPS, laser, or optical instruments is effective for measuring topography because these tools provide precise data regarding the elevation and layout of the land. GPS technology allows for accurate positioning and can capture elevation data, which is crucial for understanding the land's contours. Laser instruments, such as laser levels or total stations, offer high precision in measuring distances and angles, making it easier to create detailed topographical maps. Optical instruments, like theodolites, are also essential for measuring horizontal and vertical angles, which contribute to a comprehensive understanding of the terrain.

In contrast, the other methods lack the precision or comprehensiveness necessary for accurate topographical measurement. A compass is primarily used for navigation and direction-finding rather than detailed topographical analysis. Water level measurement can provide some information about elevation differences but is limited in scope and detail. Visual inspection only allows for a general understanding of the landscape but does not yield the measurements needed for accurate topographical studies. Each of these methods may have their use cases, but for the complex needs of topography measurement, GPS, laser, or optical instruments are unparalleled in accuracy and detail.