Data Set Citation:
When using this data, please cite the data package:
Osawa T , Kadoya T , and Kohyama K.
5- and 10-km mesh datasets of agricultural land use based on governmental statistics for 1970–2005.
ERDP-2015-02.3.1 (https://db.cger.nies.go.jp/JaLTER/metacat/metacat/ERDP-2015-02.3.1/default)
General Information:
Title:5- and 10-km mesh datasets of agricultural land use based on governmental statistics for 1970–2005.
Identifier:ERDP-2015-02.3.1
Abstract:
Land use data serve as an essential part of large-scale ecological research, such as landscape ecology and macroecological studies. For agricultural fields in Japan, existing time series statistical records can be used to convert map data according to a map of municipality units. In this data paper, we determined the areas of agricultural land use in Japan from 1970 to 2005, excluding small islands, at spatial resolutions of 5- and 10-km mesh grid units, which are often referred to as the Five-fold Mesh and Japanese Second-order Mesh, respectively. The elements considered included total farmland, paddy fields, dry farmland, and orchards. In 2005, we included abandoned agricultural areas because the related data were available in the agricultural statistical records. The source data came from the Census for Agriculture, Forestry and Fisheries conducted by the Ministry of Agriculture, Forestry and Fisheries, Japan. The Datum was the Japanese Geodetic Datum 2000 (JGD2000). All of the datasets have open data licenses under the rules of the Creative Commons CC-BY 4.0 International (https://creativecommons.org/licenses/by/4.0/legalcode).
Keywords:
  • agricultural abandonment
  • agriculture
  • five-fold mesh
  • land cover
  • land use
  • open data
  • second-order mesh
  • standard mesh
  • time-series records
Data Table, Image, and Other Data Details:
Metadata download: Ecological Metadata Language (EML) File
Data Table:2nd_mesh ( View Metadata | Download File download)
Data Table:5km_mesh ( View Metadata | Download File download)

Involved Parties

Data Set Owners:
Individual: Takeshi Osawa
Organization:National Institute for Agro-Environmental Sciences, Japan
Phone:
+81.78.803.8148 (voice)
Phone:
+81.78.803.8199 (fax)
Email Address:
arosawa@gmail.com
Individual: Taku Kadoya
Organization:National Institute for Environmental Studies, Japan
Individual: Kazunori Kohyama
Organization:National Institute for Agro-Environmental Sciences, Japan
Data Set Contacts:
Individual: Takeshi Osawa
Organization:National Institute for Agro-Environmental Sciences, Japan
Phone:
+81.78.803.8148 (voice)
Phone:
+81.78.803.8199 (fax)
Email Address:
arosawa@gmail.com

Data Set Characteristics

Geographic Region:
Geographic Description:All of Japan, excluding small islands
Bounding Coordinates:
West:  122.90625  degrees
East:  148.90625  degrees
North:  45.562507  degrees
South:  24.021185  degrees
Time Period:
Begin:
1970
End:
2005

Sampling, Processing and Quality Control Methods

Step by Step Procedures
Step 1:
Description:

This study employed agricultural statistical data from the CAFF dataset, which the Ministry of Agriculture, Forestry and Fisheries of Japan compiles every 5 years. We used the eight datasets obtained from 1970 to 2005. The CAFF data were derived from “e-Stat,” which is the website portal used for Japanese government statistical information (Ministry of Internal Affairs and Communications). We obtained the CAFF datasets from the Ministry of Agriculture, Forestry and Fisheries website because this website integrated several raw datasets into prefectural units (CAFF 2005). The CAFF dataset includes statistical data related to agricultural land area, e.g., total farmland and a breakdown of farmland into categories such as paddy fields and dry farmland, as well as some more detailed categories such as bean and wheat fields (Ministry of Agriculture, Forestry and Fisheries). These records were summarized using hamlet units, which included old municipality units, i.e., one old municipality unit consists of several hamlet units. We aggregated the hamlet units into municipality units using the hamlet records for 2000. The number of hamlet units has gradually decreased as farmers retire, with the greatest number of hamlets existing in 1970 when the period from 1970 to 2005 is considered. The hamlets that have vanished could not be attached to municipalities because the records for old hamlet units were never digitized. Consequently, the area of farmland from the records for 1970 to 1995 was underestimated because we used the hamlet units existing in 2000. In this data paper, we could not use the more detailed crop categories such as beans and wheat, as in Kohyama et al. (2003), because of the masking of locations. If a hamlet had fewer than four farmers, the records were masked to protect the farmers’ personal information (Ministry of Agriculture, Forestry and Fisheries); thus, several values were underestimated. Kohyama et al. (2003) could only use data for 1970–1995 and could not include data from 2000 for the same reason. Use of the larger categories, such as dry farmland, which pools the more detailed categories, allowed us to alleviate much of the underestimation. To convert the municipality units into Second-order and 5-km mesh units, we divided the municipality units into 100-m (i.e., 1 ha) mesh units, and reconstructed the Second-order and 5-km meshes, which contained 10,000 and 2,500 100-m meshes, respectively. When we divided the municipality units into 100-m mesh units, we partitioned both the total farmland and abandoned agricultural areas equally. If one mesh unit included two or more municipality units, we assigned the mesh unit to the dominant municipality, i.e., the municipality that represented the largest portion of the mesh area. We assumed that the proportions of total farmland and abandoned areas were distributed equally in the 100-m mesh grid within the same municipality. This is the concise conversion technique used by Kohyama et al. (2003). Subsequently, we reconstructed Second-order and 5-km mesh units using 100 × 100-m meshes and summed the areas for all agricultural land use areas. We ignored the numerical error that might occur by dividing the municipality units into the 100-m mesh units because the Second-order and 5-km mesh sizes were sufficiently larger than the 100-m mesh units. We used small 100-m mesh units rather than 1-km grids as the minimum area for reconstructing the Second-order Mesh units because the smallest municipality unit was 1.27 km2 (Ministry of Agriculture, Forestry and Fisheries), and the 1-km mesh did not meet our accuracy requirement. We did not create 1-km mesh data for the same reason. Creating 1-km mesh data using the same methods as the Second-order and 5-km meshes, would have resulted in many neighboring meshes having identical values without a more detailed source dataset, which is only available for purchase from the Association of Agriculture and Forestry Statistics (http://www.aafs.or.jp) (Kohyama et al. 2003). We reconstructed the Second-order and 5-km meshes and calculated the areas of total farmland, paddy fields, other farmland, and orchards in each Second-order Mesh unit. For 2005, we also calculated the abandoned agricultural area because these areas were clearly reported in 2005 (Ministry of Agriculture, Forestry and Fisheries). The records for 1970 to 2000 were based on the Tokyo Datum. A difference of about 400 m exists between the Tokyo Datum and the Japanese Geodetic Datum 2000 (JGD2000), which is the current standard datum in Japan (Matsumura et al. 2004; Geospatial Information Authority). To make the conversion, we divided the Tokyo Datum mesh according to JGD2000 mesh using the “Intersect” function in a geographic information system (GIS ; ArcGIS, ESRI, California, USA), and then dissolved the resulting mesh into the JGD2000 mesh using the “Dissolve” function in a GIS. Although several methods were available for converting the Datum, we used this method because of its simplicity. Additionally, we believe that any errors in the Second-order and 5-km meshes caused by this conversion were quite small.

Citation:  
Title:Generation of Agricultural Statistics Mesh Data Using Digital National Land Information
(ja) 国土数値情報を利用した農業統計データのメッシュ化
Author(s):
Individual: Kazunori Kohyama (ja) 神山和則
Author(s):
Individual: Masayuki Hojito (ja) 賓示戸雅之
Author(s):
Individual: Hiroyuki Sasaki (ja) 佐々木寛幸
Author(s):
Individual: Hirotake Miyaji (ja) 宮路広武
Publication Date:2003
ARTICLE:
Journal:Japanese Journal of Soil Science and Plant Nutrition / 日本土壌肥料学雜誌
Volume:74
Issue:4
Page Range:415-424
Citation:  
Title:Concept of the New Japanese Geodetic System
(ja) 新たな測地基準系の概念
Author(s):
Individual: Shouichi Matsumura (ja) 松村正一
Author(s):
Individual: Masaki Murakami (ja) 村上真幸
Author(s):
Individual: Tetsuro Imakiire (ja) 今給黎哲郎
Publication Date:2004
ARTICLE:
Journal:Bulletin of the Geographical Survey Institute
Volume:51
Page Range:1-9

Data Set Usage Rights

Creative Commons attribution license CC-BY 4.0 International (https://creativecommons.org/licenses/by/4.0/legalcode)
Access Control:
Auth System:JaLTER
Order:allowFirst
Allow: [read] public
Metadata download: Ecological Metadata Language (EML) File