Tỉ lệ xích là gì –


Many people are familiar with what maps look like, but not everyone understands how map ratios are calculated. In this article, we will delve into the concept of map ratios, providing a comprehensive explanation of how they are determined. So let’s dive in and discover more about this fascinating topic!

1. Calculating Map Ratios

When it comes to maps, almost all of them have a specific map ratio. However, not everyone comprehends the significance of this ratio. Below, we have compiled some information to help you gain a better understanding of what map ratios are all about.

1.1 What are Map Ratios?

Map ratio refers to the relationship between the measured distance on a map and the corresponding real-world distance. On each map, this ratio is displayed beneath the map’s title, allowing readers to gauge the scale at which the map has been reduced in relation to real-world objects. The map ratio is typically located in the bottom corner of the map and is used to measure various parameters, distances, and areas on the map. The larger the map ratio, the more detailed the map becomes.

1.2 Representing Map Ratios

Map ratios can be classified into two types, namely:

  • Scale Ratios: These are fractions with the numerator always equal to 1. The larger the denominator, the smaller the scale ratio, and vice versa.

  • Scale Bar: This is a measurement scale drawn as a ruler, with each segment of the ruler denoting a specific measurement value in the real world. For example, each 1cm segment on the ruler could represent 1km or 10km in the actual terrain. This is also applicable when determining the meaning of a map ratio such as 1:500.

Map ratios have a direct impact on the number of objects displayed on the map. The larger the map ratio, the more objects can be placed on the map. Different map ratios are categorized as follows:

  • Large: Ratios over 1:200,000
  • Medium: Ratios ranging from 1:200,000 to 1:1,000,000
  • Small: Ratios below 1:1,000,000

2. Measuring Real-World Distances Using Map Ratios or Scale Ratios

To measure distances in the field using ratios, follow the steps below:

  • Mark two points on the map that represent a distance of 1/1000 using a sheet of paper or a ruler.
  • Align the ruler along the pre-marked scale on the paper or ruler and read the distance on the ruler.
  • If you are measuring distances with a compass, it is easy to compare the distance with the scale ratio and then read the value. For more information, you can refer to our articles on “Internal Links” and “External Links.”

If you are using a scale ratio, follow the same steps for measuring distances.

3. Significance of Map Ratios When Calculating Map Ratios

All maps feature map ratios and corresponding applications, typically mentioned at the bottom or in a corner of the map. By referring to the map ratio, we can ascertain how much the distances on the map have been reduced compared to the actual size of the area being depicted.

The map ratio plays a vital role in how well geographical objects are represented on the map. The larger the ratio, the more detailed the map becomes. This principle applies when calculating the geographical map ratio for sixth-grade students.

Maps with ratios larger than 1:200,000 are considered large-scale maps. Maps with ratios ranging from 1:200,000 to 1:1,000,000 are categorized as medium-scale maps. Maps with ratios smaller than 1:1,000,000 are classified as small-scale maps.

These classifications have been standardized for all base maps and topographic maps, with ratios of 1:200, 1:500, 1:1,000, 1:5,000, and 1:10,000. These specific cases only apply to a particular type of map. The type and ratio will be explained in the Icon and Icon Explanation sections.

Each icon has a designated number, referred to as the icon number. The corresponding explanation will correspond to the icon number. An explanation may include more than one feature common to multiple icons. If any icon does not require an explanation, it will not be included in the explanation. The significance of a 1/1000 map ratio should also be noted.

The icons are divided into three types, which include:

  • Scale-drawn icons: These icons are drawn to the size of the object according to the map ratio.
  • Half-scale icons: These icons have one side scaled to the actual size of the object, while the other side represents conventions and is not drawn to the map ratio.
  • Non-scale icons: These icons are drawn in a general manner that does not accurately represent the size of the object. These icons are used when objects cannot be drawn to the exact scale for the map. In some cases, objects may be drawn to scale but require more conventional symbols at designated locations to enhance readability and orientation on the map.

The size and stroke thickness of icons are measured in millimeters. These icons do not indicate stroke thickness and are drawn with strokes ranging from 0.15mm to 0.20mm. These icons do not specify size and are drawn according to the shape and size of sample icons in this set. The fonts displayed on the topographic map will be selected from the vnfontdc.rsc font set, specifically designed within the famis software. The font style and size of these notes must adhere to the overall font style specified in the icon set. The text and numbers of the notes should be arranged parallel to the drawing frame, except for notes arranged along the direction of the object, such as road networks, rivers, streams, canals, and ditches. Noteworthy are the map ratios for sixth-grade students.

Boundary lines and map coordinates are represented on the map as coordinates with high accuracy, as prescribed. They are not shifted and must be prioritized during the compilation of topographic maps. The intersection of the grid with coordinates and the corners of the map frame will be marked on the map with coordinates.

Elements with topographic content are drawn to scale and positioned accurately. Especially for ratios such as 1:2000, 1:5000, 1:10000, some objects need to be represented with half-scaled icons or non-scaled icons. In the case of sixth-grade maps, these ratios will have certain parameters, and if drawn accurately, the icons will overlap. In such cases, you can move less important objects from 0.1mm to 0.3mm to clearly display each feature. Please note that boundaries of postal items will always be drawn accurately.

Topographic maps that apply a 1/500 map ratio are presented in three colors: black, dark brown, and brown. These colors render the topographic maps clearly enough to be printed or photographed for any usage needs.

4. Comparing the Calculation Methods of Detailed 1/500 and 1/2000 Map Ratios in Urban Planning

According to Articles 11(2) and 24(2) of the Construction Law, detailed urban planning comprises two types: detailed architectural planning at a 1/2000 ratio and detailed architectural planning. What does a 1:500 map ratio mean?

The classification is designed to meet the following specific objectives:

  • Detailed urban planning at a 1/2000 ratio is the implementation step following general urban planning. It serves as the basis for implementing, establishing, and managing detailed planning at a 1/500 ratio. Detailed urban planning at a 1/2000 ratio must be consistent with general planning and is established by local authorities. The meaning of 1cm on the map being equal to cm in real life will be specifically calculated.

  • Detailed urban planning at a 1/500 ratio is the specific implementation of planning at a 1/2000 ratio. It serves as the basis for investment project implementation, construction permit issuance, and construction investment management in accordance with the planning. Planning at a 1/500 ratio must be consistent with planning at a 1/2000 ratio. This is the responsibility of enterprises that prepare the planning. The planning costs are all included in the project cost, and the remaining part will be implemented by local authorities to serve construction management and permit issuance tasks.

We hope that this information on calculating map ratios has been helpful. If you have any further questions, feel free to consult us for free through our website

Kiến Thức Y Khoa

Xin chào các bạn, tôi là người sở hữu website Kiến Thức Y Khoa. Tôi sử dụng content AI và đã chỉnh sửa đề phù hợp với người đọc nhằm cung cấp thông tin lên website

Related Articles

Back to top button