ISPRS, Vol.34, Part 2W2, “Dynamic and Multi-Dimensional GIS", Bangkok, May 23-25, 2001 
ISPRS, Vol.34 
Another source for elevation data is not in large scale. It derives 
from the digital China National Topographical Database 
1:250,000. From the elevation line layer, a DEM was created by 
using Arclnfo7.2.1 (www.esri.com). The result for the area of 
Dongbeiwang is shown in Fig.3. The DEM enables the analysis 
of slope aspect, exposition, inclination etc.. For the information 
system of Dongbeiwang, it will mainly be used for visualization of 
maps and 3D-views of the area. If a more detailed DEM is 
needed for the study region it could be created by using the 
elevation information of the 1:10,000 maps mentioned above. 
3D Scenel-Viet*« 1 
farm questionnaire is in process to evaluate the farm economics 
and soil profiles were investigated. Additional soil analyses are 
done in several fields in the township. The data of the project 
database enables the use of existing plant growth, soil (water) 
and greenhouse gas emission models as well as the economic- 
ecological modeling of farms. The key data of our project are 
and will be stored in a GIS based project database by using 
ACCESS or DBF tables and ArcView (Bareth et al. 2000). Using 
the organized folder system (Fig.4) it is possible to link the result 
tables of each sub-project to a GIS field map (Fig.5) for analysis, 
query or display. More information about the project database is 
available on our project homepage (www.uni-hohenheim- 
,de/chinaproject/georg2.htm). 
Even so meetings with the township officials were organized, it 
was impossible to collect official data about agriculture in the 
township. Therefore, the economic sub-project is working on a 
farm survey. The only statistical data, which were available, are 
about the Haidian district in the statistical Yearbook of Beijing. 
We are still trying to get official data, but there will be little 
chance to improve the situation. 
CONCLUSIONS AND PERSPECTIVES 
Fig.3: DEM of the area north of Beijing 
Finally, general data about agriculture for the township of 
Dongbeiwang are needed. Most of these data will derive from 
the field experiment of the Sino-German Project (www.uni- 
hohenheim.de/chinaproject). The main experiment is about 
different fertilizer and irrigation treatments in wheat/maize 
rotation. Furthermore, there are experiments with vegetables. A 
weather station provides various climate data for the township. A 
The set up of a GIS in large scale in China for environmental 
modeling is very difficult and sensitive because of data 
restriction and policy for spatial as well as for statistical data. 
Therefore, independent data sources like commercial satellite 
image distributors and own investigations are most important. 
Additional field surveys have to be done to ensure and evaluate 
the quality of the spatial data sources. The additional DGPS, soil 
and land use field surveys are essential to establish a large 
scale GIS for environmental modeling on field level and to create 
scenarios for sustainable agriculture on township level. The next 
steps are further field surveys to enlarge the available data of 
the GIS for the township of Dongbeiwang and the integration of 
available models to create different scenarios of sustainable 
agriculture. 
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Fig.5: ArcView 
REFERENCES 
Bareth, G., 2C 
Sensing Data 
2001, Bangkok 
Bareth, G., Yu 
2000, Establish 
Research Proje