Which of the following is a key environmental consideration in hydraulic engineering?

Water table management is a vital environmental consideration in hydraulic engineering because it directly affects both the availability and quality of groundwater resources. Proper management of the water table involves monitoring changes in groundwater levels and ensuring that water is extracted sustainably to avoid depletion. Additionally, fluctuations in the water table can influence surface water bodies, impacting ecosystems, agricultural practices, and urban development. Understanding and managing the interactions between surface water and groundwater is crucial for maintaining ecological balance and preventing issues such as land subsidence, salinization, and disruption of natural habitats.

The other options, while important in their respective contexts, do not directly address environmental impacts in the same way. Soil density measurement focuses on the physical properties of soil rather than its water management. Material elasticity and thermal expansion of materials are concerned with engineering design and construction materials rather than environmental considerations. Thus, these aspects are more related to structural integrity and performance than to environmental sustainability in hydraulic contexts.