Several problems of geography in senior high school

1: When choosing the reservoir construction scheme, we should consider the reservoir site, dam site and whether it is necessary to emigrate after the reservoir is completed. Regardless of geological conditions, two factors should be considered: first, there must be a basin or depression for water storage in this area, and the contour line of this terrain is pocket-shaped, with a wide hinterland and a large reservoir capacity; Second, the dam should be built near the contour line of the closed section and the narrowest part of the canyon, so as to reduce the engineering quantity, save investment and ensure the safety of the dam.

Example:

Longyangxia Reservoir of Three Gorges Reservoir Xin 'anjiang Reservoir

2:

According to the different forms of settlement expansion, it can be divided into three types: ① Group (or block) village. Houses are relatively concentrated, and the plane shape is nearly round or irregular polygon. Many houses are naturally formed around road intersections, springs or temples, and are located in plains and basins. (2) banded (or columnar) villages. Villages along rivers, valleys, traffic lines or highlands to avoid floods, sometimes several villages are connected end to end to form beaded settlements; ③ Huancun Village. Mountain settlements along the foothills and along the hutang area are often distributed in a ring shape, which is actually a strip or beaded settlement. Scattered villages, also known as scattered villages, have scattered houses and the spacing varies from place to place. Settlement form is influenced by many factors such as nature, social economy, customs and culture, and different rural settlement forms reflect the relationship between human production, life and surrounding environment.

3:

Classification of rural residential areas refers to the classification of rural residential areas according to certain principles or standards. Rural settlements are closely related to the surrounding environment. There are obvious differences in internal composition, structure and layout (such as economic function, village form, architectural form and structure, etc.). Rural settlements in different regions have different types of settlements. According to the economic structure, it can be divided into rural areas (agricultural settlements), mountain villages (forestry settlements), pastoral villages, fishing villages, central villages and rural market towns with more township enterprises and handicrafts, or villages with more than two kinds of economic activities. In agricultural and forest areas, settlements are usually fixed. According to its morphological characteristics, it can be divided into point settlements (also known as scattered villages or scattered villages), linear settlements (road villages and street villages) and block settlements (also known as reunion villages, group villages or collective villages). In pastoral areas, besides settled settlements, there are seasonal settlements and nomadic tent settlements; In the river of water town, there is a boat, and the home is in Zhouzhi. The purpose of settlement classification is to understand and master the basic characteristics and distribution laws of different types of settlements, so as to adopt different village renovation measures and scientifically formulate village plans, coordinate the relationship between village distribution and environment, and serve village construction.

4. Yunnan-Guizhou Plateau forms karst landform.

There are several reasons:

The conditions for the formation principle to promote karst development are: 1, dense limestone with near-surface joints; 2. moderate to heavy rain; 3. The groundwater circulation is smooth.

According to its development and evolution, karst landform can be divided into the following six types. 1) Surface water dissolves along the joint surface or fracture surface in limestone, forming a karst ditch (or karst trough), and the limestone originally distributed in layers is divided into stone pillars or stalagmites by the karst ditch. 2) Surface water permeates and dissolves downward along limestone cracks, and when the depth exceeds 100 meters, a sinkhole is formed ... 3) The groundwater falling from the sinkhole flows laterally to the aquifer, forming a karst cave. 4) With the formation of underground caves, the surface collapses, and those with large collapse depth and small area are called collapse funnels, while those with small depth and large area are called collapse ponds. 5) Long-term joint action of groundwater dissolution and collapse forms slopes and valleys and natural bridges. 6) When the ground rises, the original caves and underground rivers are taken out of the ground and turned into dry valleys and stone forests, and the dissolution of groundwater continues under the old caves and underground rivers.

The stone forest in Lunan, Yunnan Province is the product of the first stage (ditch-dissolving stage), and the natural scenery here is particularly charming because of the touching legend of Ashima girl.