• Definition of Environmental Science:
• An integrated, multidisciplinary academic discipline that analyzes the systemic interactions and energy/matter flows between the environment's physical, chemical, and biological components, alongside human impacts on natural ecosystems. (Correct answer: Option 4)

• CPCB Regulatory Norms (2015): Under the Environment (Protection) Rules and Central Pollution Control Board guidelines for thermal power plants, condenser cooling water discharge must not exceed 10°C above the ambient temperature of the intake water body ($\Delta T \le 10^\circ\text{C}$).
• Ecological Protection: Limiting thermal discharge protects aquatic flora and fauna from acute thermal shock, elevated metabolic strain, and depleted dissolved oxygen (DO) levels in receiving rivers, lakes, or estuaries.

Correct option: (1) 10°C

• Watershed & Land Management: Effective agricultural management determines land capability, zoning, slope stabilization, and conservation tillage practices, directly mitigating non-point source water contamination.
• Sediment & Agrochemical Control: Implementing vegetated buffer strips, cover crops, and proper contour farming prevents surface soil erosion, fertilizer runoff (nitrates and phosphates), and pesticide leaching into adjacent waterways.

Correct option: (1) By giving an idea about the use of land management

• Sedimentation & Stream Geometry: Accelerated soil erosion deposits heavy silt and sediment into natural riverbeds and watercourses, elevating river beds and creating wider, shallower channels.
• Solar Absorption & Thermal Pollution: Shallow water bodies with larger surface area and elevated turbidity absorb significantly higher solar radiation, causing water temperatures to rise unnaturally above baseline ecological limits.

Correct option: (4) By making natural water bodies to rise beyond their normal level