CN108053458A - A kind of watershed generalization figure based on GIS-Geographic Information System makes and methods of exhibiting - Google Patents

Abstract

The invention discloses a method for making and displaying a watershed generalization map based on a geographic information system. First, CAD application software is used to make an electronic map of rivers, lakes, key water conservancy projects, and hydrological survey station elements in the watershed; The map is imported into the desktop GIS, and is drawn in layers in different layers according to the characteristics of the elements and the types of points, lines, and surfaces; finally, the drawn generalized map base map is published to the server-side GIS to provide maps for Web-side development service to realize the display of generalized graphs. The invention can provide flood control dispatching decision makers with the water and rain information of the whole basin in real time, has strong expandability, practicability, and is convenient for updating, and has high popularization and application value.

Description

A Method of Making and Displaying Watershed Generalization Map Based on Geographic Information System

technical field

The invention relates to a method for making and displaying a generalized watershed map based on a geographic information system, and belongs to the field of flood control and disaster reduction.

Background technique

my country has a vast territory, numerous rivers, complex terrain, prominent monsoon climate characteristics, and concentrated annual precipitation, so it is a country with frequent floods and droughts. Flood and drought disasters cause great losses to people's lives and property every year, and become one of the main factors restricting national economic construction and sustainable development. According to historical statistics, a major flood occurs in my country on average in less than two years. Flood control scheduling is a task of resisting flood disasters, and the generalized watershed map is an important basis for flood control scheduling. The generalized map of the watershed provides technical means for scientific dispatching and lawful flood control for the dispatching of flood control in the river basin. The generalized diagram has a high value of popularization and application because of its concise and intuitive, rich in pictures and texts, and strong practicability.

At present, the generalized diagrams used by decision makers for flood control dispatching are mostly based on engineering drawing methods. Although the static diagrams produced can attach some important information of water conservancy projects to the diagrams, they also have certain defects:

1. The traditional generalized map is a static map, which cannot present the real-time hydrological characteristic information of the hydrological database on the generalized map;

2. The static generalized map cannot be displayed by watershed, and decision makers need to judge which watershed the monitoring point belongs to. At the intersection of some complex watersheds, it is easy to interfere with decision-making;

3. The combination of the generalization map and the web system is displayed in the form of a picture, and the zoom operation cannot be performed on the generalization map.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention provides a method for making and displaying a watershed generalization map based on a geographic information system. First, CAD application software is used to map elements of rivers, lakes, key water conservancy projects, and hydrometric stations in the watershed. Create an electronic map, and determine the shape and color of each element according to the importance, relative size and position of the elements in the watershed; then import the electronic map into the desktop GIS, and publish the map service; finally, based on the published map service, perform web-side Develop and display the generalized map, and attach real-time hydrological feature information to the generalized map, so that decision makers can keep abreast of the current drought and flood conditions in the watershed.

The present invention adopts the following technical solutions for solving the problems of the technologies described above:

On the one hand, the present invention provides a kind of watershed generalization map production method based on geographical information system, and the steps of this production method are as follows:

Step 1: Select elements of rivers, lakes, key water conservancy projects and hydrometric stations in the watershed, and use CAD software to make electronic CAD drawings;

Step 2: Import the electronic map into the desktop GIS, draw it in different layers according to the characteristics of the elements and the types of points, lines, and surfaces, and obtain the base map of the generalized map.

As a further technical solution of the present invention, the specific steps of step 1 are:

Step 1.1: Generalize the elements of rivers, lakes, key water conservancy projects and hydrometric stations in the watershed;

Step 1.2: Screen key water conservancy projects and hydrometric station elements in the watershed;

Step 1.3: Place the key water conservancy projects and hydrometric stations on the upper layer of the corresponding rivers, lakes or reservoirs. The river to which the station belongs is added to generate an electronic CAD drawing.

As a further technical solution of the present invention, the concrete steps of step 2 are:

Step 2.1: Select the coordinate system and determine the coordinate reference to ensure that the display range is consistent when multiple basemaps are switched;

Step 2.2: import the electronic CAD drawing made in step 1 into the ArcGIS desktop software, and draw the GIS base map layer by layer, wherein the uppermost layer is a point feature class, the middle layer is a line feature class, and the bottom layer is a surface feature class to ensure All elements can be displayed normally;

Step 2.3: According to different display scales, define the display scale of each layer and feature class to display different feature classes, so as to obtain the generalized map base map.

As a further technical solution of the present invention, in step 2.1, it is determined that the coordinate system established for use by the GPS global positioning system is used as a coordinate reference.

As a further technical solution of the present invention, draw water level station, tide station, rainfall station and pumping station element in the point element class of step 2.2, draw sluice element in the line element class, draw main river and its tributaries, flood storage area in the surface element class , lake, and reservoir features.

As a further technical solution of the present invention, when there are multiple elements in the same element class in step 2.2, use cartographic representation to solve the problem of different schemas used by different elements, and use a rule-based structure to symbolize the data. These structures Stored with the data in the geodatabase.

On the other hand, the present invention also provides a method for displaying a generalized map made by a method for making a generalized watershed map based on a geographic information system as described above, and publishes the base map of the drawn generalized map to the server GIS provides map services for web-side development and realizes the display of generalized maps.

As a further technical solution of the present invention, the specific steps of the display method are:

Step 3.1: Use ArcGIS for Desktop to connect to ArcGIS for Server, and publish the generalized map base map drawn by desktop GIS to the server GIS;

Step 3.2: Embed the generalized map basemap resource provided by ArcGIS for Server into the web page through the application program interface provided by ArcGIS;

Step 3.3: In the layer where the key water conservancy projects and hydrological stations feature classes are located in the basemap of the generalization map, query the specified stations, and pass the callback function to send the attribute data of the elements back to the background database to query the corresponding values of each element. Real-time water level, rainfall or tide level data are displayed on a generalized map for review by decision makers of flood control and drought control scheduling.

As a further technical solution of the present invention, the specific operation steps shown in the generalized diagram in step 3.3 are:

(1) Create the query task QueryTask object of the ArcGIS application program interface and initialize it, and set the query parameters of the generalized map;

(2) Attribute query, set the query condition and the format of the returned data, and construct the SQL query statement;

(3) Obtain the result, execute QueryTask, and query the real-time data of the station to the real-time water and rain database, and pass the function of obtaining the result to the QueryTask object as a callback function. After the query is completed, pass the result set to the callback function;

(4) Attribute binding, binding the data queried in the database to the corresponding station, as the attribute data of the station elements;

(5) To display the results, in the callback function, add the logic of the result display, and display the attribute data of the measuring station on the generalization map.

Compared with the prior art by adopting the above technical scheme, the present invention has the following technical effects: the method for making a watershed generalization map and display based on a geographic information system provided by the present invention first adopts CAD application software to map rivers, lakes, The elements of key water conservancy projects and hydrological survey stations are made into electronic maps; then the electronic maps are imported into the desktop GIS, and are drawn in layers in different layers according to the characteristics of the elements and the types of points, lines, and surfaces; finally, the drawn outline The base map of the generalized map is published to the server-side GIS to provide map services for web-side development and realize the display of the generalized map. This method can provide flood control decision makers with real-time water and rain information in the whole basin, and is scalable, practical and easy to update.

Description of drawings

Fig. 1 is the method flowchart of the embodiment of the present invention;

FIG. 2 is a schematic diagram showing a flowchart of an embodiment of the present invention.

Detailed ways

Below in conjunction with specific embodiment, further illustrate the present invention, should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention, after having read the present invention, those skilled in the art will understand various equivalent forms of the present invention All modifications fall within the scope defined by the appended claims of the present application.

As shown in Fig. 1, a kind of water basin generalization map making method based on geographical information system of the present invention comprises the following steps:

Step 1: Select elements of rivers, lakes, key water conservancy projects and hydrometric stations in the watershed, and use CAD application software to make electronic maps.

Use CAD software to create straight line, polygon, circle and ellipse basic graphic objects, and use these basic graphic objects to express oceans, rivers, lakes, key water conservancy projects and hydrometric station elements in a general way.

The specific steps for making an electronic diagram are:

Step 1.1: Generalize the elements of rivers, lakes, key water conservancy projects and hydrometric stations in the watershed, that is, ignore the shape of elements, pay attention to the relative size, position and relationship between elements, and generalize the key points in the watershed The location information of water conservancy projects and measuring stations and the relationship of related water conservancy projects. According to the actual geographical map of the watershed, select the main rivers and their tributaries, flood storage areas, lakes and reservoirs, and reconstruct the shape and relative position of these elements in the generalized map according to the actual shape, geographical location and size of these elements , size and connectivity. Among them, polygons are used to draw rivers, ellipses or circles are used to draw lakes and reservoirs, and semicircles or semi-ellipses are used to draw flood storage areas. The use of lines: solid lines represent embankments or banks; both banks of the river are dotted lines, representing underground culverts; there are no solid or dotted lines between intersecting or interconnected rivers, lakes, and reservoirs.

Step 1.2: Screen key water conservancy projects and hydrometric station elements in the watershed. Key water conservancy projects and hydrometric stations mainly include water level stations, tide stations, rainfall stations, sluice gates and pumping stations, and the diagrams refer to the "Flood Control and Drought Relief Diagrams" issued by the Ministry of Water Resources.

Step 1.3: Place key water conservancy projects and hydrometric stations on the upper layer of corresponding rivers, lakes or reservoirs. If the rivers to which key water conservancy projects and hydrometric stations belong are not drawn in the generalization map, add them. After the drawing is completed, an electronic CAD map is generated for the desktop GIS to draw the GIS base map.

Step 2: Import the electronic map into the desktop GIS, and draw it in layers in different layers according to the characteristics of the elements and the types of points, lines, and surfaces.

Desktop GIS is a software suite for designing, sharing, managing and publishing geographic information. ArcGIS for Desktop is a GIS software for editing, creating and analyzing geographic information, and can complete the work of drawing GIS base maps. Import the above-mentioned electronic CAD drawing into ArcGIS for Desktop and draw the GIS base map layer by layer.

The specific steps to make a GIS base map are as follows:

Step 2.1: Determine the coordinate datum. Multiple basemaps use the same coordinate system and the same display range, which can ensure that the map field of view and the coordinates of the center point are consistent when switching between different basemaps. For example, when we use the boundary of Jiangsu Province as the coordinate reference, when the base map of the generalized map and the base map of Jiangsu Province are switched, the field of view and display center point of the base map of Jiangsu Province are consistent with those of the generalized map. Here, the World Geodetic System 1984 (WGS84) coordinate system established for the GPS global positioning system is used as the coordinate reference.

Step 2.2: Import the electronic CAD map and draw the GIS base map layer by layer. In ArcGIS, points, lines, and areas represent different data types. When drawing, these three types of elements are divided into different feature classes for drawing. The stacking order is that the point feature class is placed on the top, followed by the line The feature class, and the bottom one is the polygon feature class. Water level station, tide station, rainfall station and pumping station can be drawn in the point feature class, sluice features can be drawn in the line feature class, and main rivers and their tributaries, flood storage areas, lakes and reservoirs can be drawn in the area feature class. Different elements use different schemas, and when there are multiple elements in the same feature class, cartographic expressions can be used to solve this problem, and the data can be symbolized flexibly using rule-based structures, which are stored together with the data in in a geographic database. A feature class can have multiple representations, allowing users to display the same data according to different application requirements without backing up additional data. In addition, representations can be edited individually for the appearance of each feature in a feature class.

Step 2.3: The display scale of each layer and feature class will be defined, and different elements will be displayed at different display scales.

A method for displaying a generalized map of a watershed based on a geographic information system in the present invention is as follows: publishing the base map of the drawn generalized map to the server GIS, providing map services for Web-side development, and realizing the display of the generalized map.

The specific steps to publish the GIS base map and display the generalized map are as follows:

Step 3.1: Use ArcGIS for Desktop to connect to ArcGIS for Server, and publish the generalized map base map drawn by desktop GIS to ArcGIS for Server;

Step 3.2: Embed the generalized map basemap resource provided by ArcGIS for Server into the web page through the application program interface provided by ArcGIS;

Step 3.3: In the GIS base map, include key water conservancy projects and hydrological station feature classes, and query the specified station in the layer where this class is located. And through the callback function, the element attribute data is sent back to the background database to query the real-time water level, rainfall or tide level data corresponding to each element, and displayed on the generalized map for viewing by flood control and drought control scheduling decision makers.

As shown in Figure 2, the specific operations shown in the generalization diagram include:

(1) Create and initialize the query task (QueryTask) object of the ArcGIS application program interface, and set the query parameters of the generalized map;

(2) Attribute query, set the query condition and the format of the returned data, and construct the SQL query statement;

(3) Obtain the result, execute QueryTask, and query the real-time data of the station to the real-time water and rain database, and pass the function of obtaining the result to the QueryTask object as a callback function. After the query is completed, pass the result set to the callback function;

(4) Attribute binding, which binds the data queried from the database to the corresponding station as the attribute data of the station elements.

(5) To display the results, in the callback function, add the logic of the result display, and display the attribute data of the measuring station on the generalization map.

The above is only a specific implementation mode in the present invention, but the scope of protection of the present invention is not limited thereto. Anyone familiar with the technology can understand the conceivable transformation or replacement within the technical scope disclosed in the present invention. All should be covered within the scope of the present invention, therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (9)

1. a method for making a river basin generalization map based on geographic information system, characterized in that, the steps of the method for making are as follows: Step 1: Select elements of rivers, lakes, key water conservancy projects and hydrometric stations in the watershed, and use CAD software to make electronic CAD drawings; Step 2: Import the electronic map into the desktop GIS, draw it in different layers according to the characteristics of the elements and the types of points, lines, and surfaces, and obtain the base map of the generalized map. 2. a kind of water basin generalization map making method based on geographic information system according to claim 1, is characterized in that, the concrete steps of step 1 are: Step 1.1: Generalize the elements of rivers, lakes, key water conservancy projects and hydrometric stations in the watershed; Step 1.2: Screen key water conservancy projects and hydrometric station elements in the watershed; Step 1.3: Place the key water conservancy projects and hydrometric stations on the upper layer of the corresponding rivers, lakes or reservoirs. The river to which the station belongs is added to generate an electronic CAD drawing. 3. a kind of water basin generalization map making method based on geographic information system according to claim 1, is characterized in that, the concrete steps of step 2 are: Step 2.1: Select the coordinate system and determine the coordinate reference to ensure that the display range is consistent when multiple basemaps are switched; Step 2.2: import the electronic CAD drawing made in step 1 into the ArcGIS desktop software, and draw the GIS base map layer by layer, wherein the uppermost layer is a point feature class, the middle layer is a line feature class, and the bottom layer is a surface feature class to ensure All elements can be displayed normally; Step 2.3: According to different display scales, define the display scale of each layer and feature class to display different feature classes, so as to obtain the generalized map base map. 4. A kind of water basin generalization map making method based on geographic information system according to claim 3, it is characterized in that, in step 2.1, the coordinate system determined to be used by the GPS global positioning system is used as the coordinate reference. 5. a kind of watershed generalization map making method based on geographic information system according to claim 3, is characterized in that, draws water level station, tide station, rainfall station and pumping station element, line element in the point feature class in step 2.2 The sluice features are drawn in the class, and the main rivers and their tributaries, flood storage areas, lakes and reservoirs are drawn in the area feature class. 6. a kind of water basin generalization map making method based on geographic information system according to claim 3, it is characterized in that, when there are multiple elements in the same feature class in step 2.2, solve the used of different elements with cartographic expression Schema different problems symbolize the data using rule-based structures that are stored with the data in the geodatabase. 7. as any one of claims 1 to 6, a method for displaying the generalized map based on the production method of the generalized map of the watershed based on the geographical information system is characterized in that, the generalized map base map that will be drawn is released Go to the server-side GIS to provide map services for web-side development and realize the display of generalized maps. 8. a kind of display method based on the water basin generalization map of geographical information system according to claim 7, is characterized in that, the concrete steps of this display method are: Step 3.1: Use ArcGIS for Desktop to connect to ArcGIS for Server, and publish the generalized map base map drawn by desktop GIS to the server GIS; Step 3.2: Embed the generalized map basemap resource provided by ArcGIS for Server into the web page through the application program interface provided by ArcGIS; Step 3.3: In the layer where the key water conservancy projects and hydrological stations feature classes are located in the basemap of the generalization map, query the specified stations, and pass the callback function to send the attribute data of the elements back to the background database to query the corresponding values of each element. Real-time water level, rainfall or tide level data are displayed on a generalized map for review by decision makers of flood control and drought control scheduling. 9. A kind of watershed generalized map display method based on geographic information system according to claim 8, characterized in that, the specific operation steps of generalized map display in step 3.3 are: (1) Create the query task QueryTask object of the ArcGIS application program interface and initialize it, and set the query parameters of the generalized map; (2) Attribute query, set the query condition and the format of the returned data, and construct the SQL query statement; (3) Obtain the result, execute QueryTask, and query the real-time data of the station to the real-time water and rain database, and pass the function of obtaining the result to the QueryTask object as a callback function. After the query is completed, pass the result set to the callback function; (4) Attribute binding, binding the data queried in the database to the corresponding station, as the attribute data of the station element; (5) To display the results, in the callback function, add the logic of the result display, and display the attribute data of the measuring station on the generalization map.