**Explanation:**

**Topographical Surveys**

Topographical surveys are carried out to depict the natural and man-made features of a specific area. These surveys provide detailed information about the terrain, elevation, and physical characteristics of the land. They are commonly used in various fields such as civil engineering, urban planning, and environmental assessment.

**Purpose of Topographical Surveys**

The primary purpose of topographical surveys is to accurately represent the physical features of an area. This includes mountains, rivers, water bodies, wooded areas, and other cultural details. These surveys are essential for the planning and design of infrastructure projects, land development, and resource management.

**Techniques Used in Topographical Surveys**

Topographical surveys involve the use of various techniques and instruments to gather accurate data about the terrain and its features. These techniques may include:

1. **Global Positioning System (GPS):** GPS technology is used to determine precise coordinates and elevations of different points on the ground.

2. **Total Station:** A total station is a surveying instrument that combines the functions of a theodolite and an electronic distance measuring (EDM) device. It is used to measure angles and distances between points.

3. **LiDAR (Light Detection and Ranging):** LiDAR is a remote sensing technology that uses laser pulses to measure distances. It is capable of generating highly detailed 3D maps of the land surface.

4. **Aerial Photography:** Aerial photography involves capturing images of the land from an elevated position, usually from an aircraft or drone. These images can be used to create accurate topographic maps.

**Conclusion**

Topographical surveys are essential for understanding the physical characteristics of an area. They provide valuable information about mountains, rivers, water bodies, wooded areas, and other cultural details. These surveys are crucial for the planning and development of various projects, ensuring that they are designed and implemented in a manner that is compatible with the natural and man-made features of the land. Therefore, the correct answer is option C - topographical surveys.