Establishment And Its Applications Of The 1:200,000 Soil Database In Jiangsu Province

This paper selects Jiangsu province which have southern typical red soil, yellow brown soil and brown soil resources in China as a studied area, uses the data of the second country general detailed soil survey, supported by the ARC/INFO, MapObject and VB software, finally establishes the soil database of Jiangsu at middle scale (1:200000). Based on the soil database of Jiangsu, many correlative studies are carried out. The results show that the study on establishment and applications of the 1:20000 soil database in Jiangsu is valuable. The basic datum of the soil database of Jiangsu is composed of spatial and attribute datum. 11 original maps of 11 areas (Nanjing, Changzhou, Zhenjiang, Wuxi, Suzhou, Nantong, Yangzhou, Huaiyin, Yancheng, Xuzhou and Lianyungang) in the whole province are stored in the way of the spatial datum in which there are many geographic features such as rivers, lakes and soil. Classifications of the soil are based on the classification of the original soil group. Based on the classification of the original soil map, this paper classifies 4 grades: soil group, soil subgroup, soil genus and soil species, the whole spatial datum includes 9769 spots with 13 soil groups, 43 subgroups and 228 soil species in Jiangsu at the scale of 1:200000. The soil attribute datum includes the soil physical properties (for example soil particle distribution, organic matter, total nitrogen, total phosphorus, rapidly available phosphorus, total potassium and available potassium etc) and chemical properties (for example: CEC, exchangeable calcium, exchangeable potassium, exchangeable magnesium and total iron etc). The soil database of Jiangsu is very affluent in attribute data and it has 455 soil profiles from 11areas of Jiangsu. The original maps of the 11 studying areas can't inosculate well; the same situation happen between the classifications and names of the soils and also between the classification and unit of the soil attribute datum. The spatial datum of the soil database are connected technically consulting the other soil databases in this paper, classifies and names of the soils are researched by experts. In this paper the code of soil spatial datum and attribute datum are standardized in the database, so the soil spatial datum can be related to the soil attribute datum by standardized code, in this study the codes of regions are established and added to the soil attribute datum.The soil database of Jiangsu manages the attribute datum and spatial datum uniformly and establishes the contact between them. This soil database provides many powerful functions, including the output of thematic map; querying function such as query from map to table, from table to map and from table to table; the analytical function; also data managing and updating function. The function of outputting thematic map has three intentions: transmitting geographical information, showing important geographical relation and interpreting analytical content. It is the map with specifically request or notion such as Jiangsu's soil map and Jiangsu's pH map. Querying function is very important to GIS workers, which has many inquiring ways such as instantly inquiring and browsing datum. Data analytical function is one of the greatly important functions for GIS, which can display the properties to be used to create output in the process of analysis. These properties are specific to the active view. We can view and change the following properties: the spatial extent for output themes; the cell size or resolution for output grid themes; the area within the extent that analysis should take place in; These properties are only used for operations found in the Analysis menu. Data managing and updating function means data reedit, for example input of up to date datum. The systematic design of database is fulfilled with the support of MapObject and VB.In the study of the soil condition character of Jiangsu, we find that the area with 6.5-8.5 scale in soil pH is more than 80000 km2 and suits crop growth, acidic soils mostly distribute in t...