This picture is a "contour topographic map of an area". Look at the picture and answer the following questions. (18 point) (1) describes the terrain features in the graphic area. (4 points)

(1) The illustrated area belongs to basin topography, with an altitude of 300- 1500m, and the height changes greatly. (2 points)

The terrain is high around and low in the middle. (2 points)

② First to the south, then to the southeast. (4 points) (Answer 2 points from north to south)

(3) Scheme A: Disadvantages-small reservoir area and water storage capacity (2 points), advantages-less submerged land, small engineering quantity and small population migration scale; (4 points, 2 points for any answer)

Scheme B: Advantages-large reservoir area and water storage capacity (2 points), disadvantages-large flooded land (or many flooded towns), large engineering quantity and large population migration scale. (4 points, 2 points for any answer)

④D(2 points). Reason: The contour lines near Ding are dense and the mountain slope is large (2 points).

Test and analysis: (1) Topographic features mainly describe the main topographic types and topographic distribution features. (2) The river flows from high to low, and the flow direction is judged by the navigation mark. (3) The opening test shows that AB is a canyon, so it is reasonable to analyze the advantages and disadvantages of reservoir construction mainly from the aspects of engineering quantity, water storage capacity, submerged land and resettlement. (4) Landslides mostly occur on steep slopes, so the contour line in part D in the figure is the densest, indicating that the slope is large and landslides are easy to occur.

Comments: The key to solve this problem is to master graphic information and general methods to describe terrain characteristics; Main factors affecting reservoir construction, etc.