Describe a drainage basin and identify features of a river's course, including its profile and valley shape, based on provided figures.

Hey 赞美地图, good to see you again. Here are the answers to your questions: 3.1.1 A drainage basin is an area of land where all precipitation that falls within it drains into a common outlet, such as a river, lake, or ocean. It is separated from adjacent basins by a watershed. 3.1.2 FIGURE A is a(n) plan view of a river. 3.1.3 FIGURE A is not provided in the image, so the direction of the river's flow cannot be determined. 3.1.4 Since FIGURE A is not provided, a reason for the flow direction cannot be given. 3.1.5 The river profile in FIGURE B is a longitudinal river profile (or graded river profile). 3.1.6 The profile shows a concave shape, with a steep gradient in the upper course and a gentler gradient towards the lower course. This shape indicates the river is attempting to achieve a state of equilibrium between erosion and deposition along its length. 3.1.7 A cross-section of the upper course of the river would typically be a V-shaped valley. The type of erosion that characterizes the upper course is vertical erosion (or downward erosion). Send me the next one 📸