What key elements are determined in hydrographic surveys of lakes and rivers?

In hydrographic surveys of lakes and rivers, the primary focus is on specific physical characteristics of the water body itself, which includes the determination of shorelines, soundings, and bottom characteristics. Shorelines are crucial for understanding the boundary of the water body and how it interacts with the surrounding land. Soundings refer to the measurement of water depth at various points, which is essential for navigation, construction, and ecological studies. Bottom characteristics involve assessing the substrate material at the bed of the water body, which can affect various factors such as habitat suitability for aquatic life and sediment transport dynamics.

While aspects such as water quality, environmental hazards, fish populations, and flood risk assessments are important in broader environmental and ecological studies, they do not fall under the primary objectives of hydrographic surveys. These surveys are primarily aimed at generating accurate bathymetric data and understanding physical attributes rather than biological or environmental conditions.