What do you understand by the term ‘Basin Morphometry ’ ? Narrate the techniques used in areal and relief properties of the drainage basin.

Basin Morphometry:-

Basin morphometry refers to the quantitative measurement and analysis of the physical characteristics and dimensions of a drainage basin, which is an area of land drained by a single river system and its tributaries. These measurements provide valuable insights into the hydrological and geomorphic processes that shape the landscape within the basin. By studying basin morphometry, researchers can better understand the relationship between the basin's physical attributes and its hydrological behaviour, erosion patterns, sediment transport, and other environmental processes.

Techniques for Measuring Areal and Relief Properties:

Areal properties involve the quantitative assessment of various characteristics of the basin's plan view, such as its size, shape, and land use. Relief properties, on the other hand, pertain to the elevation and slope variations within the basin. Here are some common techniques used to measure these properties:

Areal Properties:

1. Area and Perimeter: The basic areal properties of a drainage basin include its total area (often measured in square kilometres or square miles) and perimeter (the length of the basin's boundary).

2. Shape Factors: Shape factors like the elongation ratio (length-to-width ratio) or the compactness coefficient (ratio of the basin's area to the area of a circle with the same perimeter) provide insights into the basin's form.

3. Drainage Density: This metric represents the total length of streams within the basin per unit area. High drainage density indicates a high concentration of streams and a well-dissected landscape.

4. Stream Ordering: Horton's stream order system categorizes streams within a basin into different orders based on their hierarchical position within the drainage network. Higher-order streams are formed by the confluence of lower-order streams.

Relief Properties:

1. Elevation: Using digital elevation models (DEMs) derived from satellite data or LiDAR (Light Detection and Ranging) technology, researchers can determine the elevation of various points within the basin. This data is used to create elevation profiles and maps.

2. Slope Analysis: Slope is calculated by dividing the change in elevation between two points by the horizontal distance between them. Slope maps provide insights into the topographic variations across the basin.

3. Hypsometric Curve: The hypsometric curve illustrates the proportion of a basin's area at various elevations. It can reveal the stage of development of the drainage basin and the degree of erosion it has experienced.

4. Relief Ratio: This is the ratio of the difference in elevation between the highest and lowest points in the basin to the basin's length. It indicates the steepness of the basin's relief.

5. Longitudinal Profiles: These profiles show the variation in elevation along the main channel of the river as it flows from the headwaters to the mouth. They help identify areas of rapid and gradual descent.

By combining data from these techniques, researchers can create comprehensive morphometric analyses of drainage basins, which are useful for understanding hydrological processes, sediment transport dynamics, flood behaviour, erosion patterns, and the overall geomorphic evolution of the landscape.