Base Maps

(Origina Dir:data/Basemap/data/global/grid-country/compare/GMT(comparison chart between grid and country))

Contents: Countries | Region | River Basin | Topography | Area of Grid Cells / Drainage Area


Countries

Refered from Mr. Saruhashi's Master Thesis...(In Japanese, URLs are modified.)

 国境データは,ESRI(Environmental Systems Research Institute)によって作成された,DCW(Digital Chart of the World)である.これは,豪州・カナダ・英国および米国において作成されたDMA(United Stated Defense Mapping Agency)向けのONC(Operational Navigation Chart)に基づいて,ESRIが作成した,1:1,000,000のベクトルベースマップである.詳細はESRIのWebページを参照.これを,ARC/Infoの機能によりグリッドサイズ0.5度にラスター変換してデータを用いた.この0.5度ラスターデータは,国毎にその国内のグリッドがWRI CD-ROMにおける国番号に対応した番号で表記されるようにしたので,以下ではこれを”国番号データ”と呼ぶことにする.
 この国番号データをグローバルに図化した結果,国境データの対象とする年次においては分離・独立していない国が,WRI CD-ROMに収録されるまでには分離・独立を果たし,新たに国境線が生じている部分があることが判明した.そこで,この国番号データをテキスト表示して,印刷地図を参照にしながら国境を定め,CD-ROMに対応した国番号を挿入するといった手作業による修正を加えることにした.

Data

Script to count # of grids of each countries...

setenv COUNTRY_CODE_LIST_FILE 'country_code.txt'
setenv RESULT_FILE 'result.txt'
\rm -f $RESULT_FILE

setenv COUNTRY_LIST `awk '{printf("%s ", $1); }' < ${COUNTRY_CODE_LIST_FILE}`

foreach COUNTRY_CODE ( $COUNTRY_LIST ) 
	setenv LINE `grep "^ *${COUNTRY_CODE} " ${COUNTRY_CODE_LIST_FILE} `
	setenv COUNTRY_NAME ` echo $LINE | awk '{ print $2}'`
	setenv REGION_CODE  ` echo $LINE | awk '{ print $3}'`

	setenv NUM_GRIDS  `../bin/asc_calc ${COUNTRY_MAP_FILE} 'where' \\
	  'this' '==' $COUNTRY_CODE count`

	echo $COUNTRY_CODE $COUNTRY_NAME $REGION_CODE $NUM_GRIDS | \
	  awk '{printf("%-5d%30s%5d%8d\n", $1,$2,$3,$4)}' >> $RESULT_FILE
end

Figures

Comparison of area of each countries calculated by above dataset and FAO country statistics:


Programs and Scripts

countgrid.f
Make a country-statistics list containing 'Code','Country Name', 'Number of Grids from country-map file (*.asc)'
 
countgrid_one.f
Get country code from command line, and output the number of grids with that code
 

Region

Data

There are some ways how to divide world into several 'regions'. Pattenr 1 to 3 were used in originally, then No. 4 was added. No.4 was used in Oki et al.(2001).

ver RegionList Map Notes
1 region_code.txt region_code.asc Divide South American Continent to into 'Central America'(3) and 'South America'(2). Region '7' is former Soviet Union (no data).
2 region_code2.txt region_code2.asc SOUTH_AMERICA = 'CENTRAL_AMERICA' + 'SOUTH_AMERICA'(see Pattern '1')
3 region_code3.txt region_code3.asc Following region separation by SEI.
4 region_code4.txt region_code4.asc Basically same as pattern '2'. But following points are different: [1] East of Ob River in Russia are classified into Asia, [2] North of Panama and Island countries in gulf are classified int North America and [3] Papua New Guinea Island is classified into Oceania.

Figures

  1. Version 1
  2. Version 4

Programs

count_region.f, count_region2.f, count_region3.f
Calculates number of grids of each regions
 
make_region4.c
From region_code.asc to region_code4.asc. And outputsregion_code4.txt. Common libraries common.h, common.c are needed.
 

Basin classification

Data

Figures


DEM

2003.2.8. : Error Correction : Antarctica Data (But their still exists a strange data in original GTOPO30, now asking this issue to USGS...

0.5 deg global DEM is created from 30-sec grid DEM GTOPO30 by USGS. Calculation method is simple averaging. There are two versions. One is simply averaged and another is made by omitting cells without valid river discharge data ("masked" version).

Calculation method :

Data

Figures


Area of each 0.5 by 0.5 deg grids

Using equation in Oki and Kanae(1997) (in Japanese). Unit is km2.

Reference (in Japanese) : 沖・鼎(1997):回転楕円体を考慮した地球表面の緯度経度直交格子内面積の算定.水文水資源学会誌,10,371-374

Data

Figures

Grid Cell Area
Drainage Area

Program

  1. common.c (a file containing calculation function)
  2. calc_area.c (program for output grid_area.asc)

Compressed Data(zip)