Land use change and management


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4.1.Land use change and management Exercise02









    1. Land use change and management


Geographical features presented in Figure 1. Delineation of the region based on landscape type and ranks for usability status exist in working directory of gisserver//GIS//CDB features called CentralAsia.

Table 1. Alphabetic order of GIS layers in Central Asian feature

#

Layer name

Shape type

Description



ADMCAC

Polygon

Administrative boundary of Central Asian countries in province wise scale



Capital

Point

Capital of Central Asian countries



Center

Point

Cities located in centers of provinces



Cities

Polygon

Cities including located in districts with areal description



City

Point

Cities including located in districts with point description



Evrasia

Polygon

Regional delineation of Evrasia



Grid

Polyline

Grids with parallels and meridians



Irrigated_Land

Polygon

Irrigated land of Central Asia extracted by MODIS images



Lake

Polygon

Main lakes



Land_Type

Polygon

Delineation of land types such as forest, steppes, desserts and so on



Landscape

Polygon

Landscape types such as depression, plain, plateau and mountain areas



Province

Polyline

Boundary of provinces presented with polylines



Railway

Polyline

Main railways



Rainfall

Polygon

Categorized rainfall presented with filled isolines



Region

Polygon

Overall boundary of the region



Relief

Polygon

Categorized filled horizontals of relief



Reservoir

Polygon

Main Reservoirs



River

Polyline

Main rivers with streams



State

Polygon

Administrative boundary of Central Asian countries

In this exercise, GIS base functions such as conversion tools of polygon to raster, polyline density, point density, Euclidean distance and weighted overlay which are able to run using QGIS will be used to evaluate land suitability assessment in Central Asia.

  1. Install QGIS if you do not have in your system!

  • Press windows icon in keyboard and write cmd.exe and press ENTER, command line window will appear

  • Use command line and write: cd gisserver/softs/gis/QGIS_R_installer/ and press ENTER

  • Write a next line: install.bat and ENTER, it calls install.bat window for both R and QGIS installation:

    • 1 – Install QGIS

    • 2 – Install QGIS Plugins

    • 3 – Install R-Packegts

    • 0 – Exit

  • Please write 1 to install QGIS and fallow to accept installing windows to complete installation

  • Do the same and write 2 to install QGIS Plugins, fallow and complete installation

  1. Opening QGIS project

  1. Press windows icon in keyboard and write QGIS Desktop  press enter to open project  save project in the working directory D://CDB/CentralAsia/project folder  write name as “rasterize”

  1. Rasterize_polygons_into_raster_using_attributes'>Rasterize polygons into raster using attributes

  1. Select D://CDB/CentralAsia/shape folder from Browser Panel and existing features appear

  2. Double click on  Landscape.shp to enter layer into Layers Panel

Rasterize vector data

  1. Click on Raster  Conversion  Rasterize (Vector to Raster). The tool dialog will appear.

  2. Set it up like this:



  1. Repeat steps from 3 to 5 in order to convert each features of “Land_Type”, “Relief” and “Rainfall” into raster module.



  1. Rasterize points into raster using Grid interpolation method

  1. Go to main menu and Click Raster  Analysis Grid (Interpolation)


  2. Fill Grid (Interpolation) window as follow and click OK to finalize operation:

    1. Input file: click and dropdown Input file array select City shape file

    2. Mark Z field section and select ZPOP_THOUS field from attributes

    3. Mark algorithm section and select a method “Inverse distance to a power


  3. In order to reclassify continues raster into discrete use Raster Calculator  Look at the further steps through 18-19 and classify into 8 classes:

(( "Popdensity@1" <= 10 ) * 1 + ( ( "Popdensity@1" >= 11 ) AND ( "Popdensity@1" <= 20 ) ) * 2 + ( ("Popdensity@1">= 21 ) AND ("Popdensity@1"<= 30 ) ) * 3 + ( ("Popdensity@1">= 31 ) AND ("Popdensity@1" <= 40 ) ) * 4 + ( ("Popdensity@1" >= 41 ) AND ("Popdensity@1"<= 50 ) ) * 5 + ( ("Popdensity@1">= 51 ) AND ("Popdensity@1" <= 60 ) ) * 6 + ( ("Popdensity@1">= 61 ) AND ("Popdensity@1" <= 90 ) ) * 7 + ("Popdensity@1" >= 91 ) * 8)

  1. Rasterize polylines into raster and reclassification

  1. Click VectorGeometry ToolsExtract nodes: in order to convert River networks as polylines into points extracting by nodes for further estimation of density.


  2. Dropdown Input layer section and select  River shape file.

  3. Click Node’s section and select  Create temporary layer




  1. Click Plugins Manage and Install Plugins… from main menu to activate required function for instance Heatmap



  1. Write  Heatmap into search panel in Plugins window  select Heatmap function  and click Upgrade all button

Note: Installed button provides you functions that installed plugins!



  1. Go to main menu and click Raster  and select Heatmap



  1. Fill as follow the Heat Plugin window:

    1. Input point layer: select  Nodes as temporary shape file of River network

    2. In the Output raster section select a path to the working directory where raster catalog located in CDB/CentralAsia/raster/ and write a name of new raster filename as RiverDens, respectively.

    3. In the Output format section select GeoTIFF

    4. In the Radius section write as 100 000 meaning we will suppose lands around 50 km radius potentially arable lands

  2. Click OK from plugin window when you fill all sections same as like instruction or below the picture.



  1. Click RasterRaster Calculator…



  1. Enter the expression as follow to reclassify River density continues raster into 8 classes: (( "RiverDens@1" <= 10 ) * 1 + ( ( "RiverDens@1" >= 11 ) AND ( "RiverDens@1" <= 30 ) ) * 2 + ( ( "RiverDens@1" >= 31 ) AND ( "RiverDens@1" <= 60 ) ) * 3 + ( ( "RiverDens@1" >= 61 ) AND ( "RiverDens@1" <= 90 ) ) * 4 + ( ( "RiverDens@1" >= 91 ) AND ( "RiverDens@1" <= 120 ) ) * 5 + ( ( "RiverDens@1" >= 121 ) AND ( "RiverDens@1" <= 150 ) ) * 6 + ( ( "RiverDens@1" >= 151 ) AND ( "RiverDens@1" <= 200 ) ) * 7 + ( "RiverDens@1" >= 201 ) * 8)







Figure 1. Delineation of the region based on landscape type and ranks for usability status

  1. Click Processing and select Toolbox from main menu and Processing Toolbox will appear

  2. Write “density” into the searching section of Processing Toolbox in order to find a density extention


  3. Double click on  Kernel density estimation  from SAGA geoalgorithms Raster Creation Tools section




Table 2

Category by ranking

Landscape

Land type

Relief

Rainfall

Categorize Irrigated land

1

2

3



4

5

6



7

8

9



10


  • Depression

  • Plain

  • Plateau

  • Hills

  • Foothills

  • Mountain valley

  • Mountains

  • High mountains



  • Coniferous forests

  • Deciduous forests

  • Wooded steppe

  • Steppes and semidese

  • Semi-deserts

  • Deserts

  • Salt deserts

  • Mountain deserts

  • Alpine meadows

0-50

50-100


100-200

200-500


500-1000

1000-2000

2000-3500


<50

50-100


100-200

200-500


500-1000

1000-2000



2000-3500


Criteria to select most suitable lands



Irrigated agro-ecosystem / potential area of out-scaling raised bed technology

Similarity criteria

Land use

Irrigated land

Slope, degree

0-5

Water availability/source

Sufficient water resources

Soil (texture), clay content, %

10-75 physical clay

Soil salinity, %

< 8 dS m-1







Rainfed agro-ecosystem / potential area of for out-scaling conservation agriculture

Similarity criteria

Precipitation

300-600

Slope, degree

<7

Land use

Cropland

Soil (texture), clay content, %

20-75 physical clay







Mountain agro-ecosystem / potential area for out-scaling pasture environment

Similarity criteria

Slope, degree

>7

Precipitation

>500

Altitude, m

>800

Land use

Exclude inconvenient areas (rocks, gullies etc.

Soil depth, cm

>50







Rangelands agro-ecosystem / potential area for out-scaling pasture improvement

Similarity criteria

Land use

Rangelands, pasture

Slope, degree

>12

Degradation degree

Areas with week, medium to strong degradation as well as the Bareland areas

Livestock density per ha

Areas with high and moderate livestock density

Watering points/ha

Data not available

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