a) Remote sensing techniques refer to the use of various devices and instruments to gather information about the Earth’s surface from a distance, without direct physical contact. These techniques involve the use of sensors that detect and measure various aspects of the environment, such as light, heat, and electromagnetic radiation, to create images or data that can be used to study and analyze the Earth’s surface.
Resolution in remote sensing refers to the level of detail or accuracy with which a sensor can detect and distinguish between different features or objects on the Earth’s surface. There are various types of resolution in remote sensing, including:
- Spatial resolution: This refers to the size of the smallest feature or object that can be detected by a sensor. Higher spatial resolution means that smaller features can be detected and distinguished.
- Spectral resolution: This refers to the number and width of the bands of electromagnetic radiation that a sensor can detect. Higher spectral resolution means that more detailed information about the composition and properties of the Earth’s surface can be obtained.
- Radiometric resolution: This refers to the sensitivity of a sensor to differences in the intensity or brightness of the electromagnetic radiation that it detects. Higher radiometric resolution means that more subtle differences in the Earth’s surface can be detected.
Some of the various types of remote sensing techniques include aerial photography, multispectral imaging, radar imaging, LiDAR, and thermal imaging.
b) The hydrological cycle, also known as the water cycle, refers to the continuous movement of water between the Earth’s surface, atmosphere, and oceans. This cycle involves processes such as evaporation, precipitation, transpiration, infiltration, and runoff, and is driven by the energy from the sun.
The hydrological cycle is essential for supporting life on Earth, as it regulates the distribution of water and nutrients, and helps to maintain the Earth’s climate and weather patterns. The cycle also plays a critical role in shaping the Earth’s landscape, as water erosion and deposition can create features such as rivers, lakes, and canyons.
Understanding the hydrological cycle is important for managing water resources, predicting and mitigating the impacts of floods and droughts, and maintaining the ecological health of aquatic and terrestrial ecosystems. Climate change and human activities such as land use changes and water extraction can also affect the hydrological cycle, highlighting the need for continued research and monitoring of this vital process.