Digital Agrohydrological Atlas for Southern Africa
Steve Lynch and R.E. Schulze, Computing Centre for Water Research
Agrohydrology seeks to evaluate the influence of available water on the agricultural potential of a region with the objective of promoting a high efficiency in the use of water. The advent of desktop Geographic Information Systems (GIS) has made it possible to develop a digital Agrohydrological atlas for Southern Africa. The atlas is available in two parts, viz. a digital version for use with a GIS package and a colour paper edition for use by people without access to a computer-based GIS package. The digital Agrohydrological atlas contains inter alia coverages and textual descriptions on rainfall, temperature and different crop production scenarios that have been created using detailed in-house research and algorithms from the research literature. It must be noted that this atlas is different from the conventional atlas in the sense that the maps are in a digital format which allows users to manipulate the spatial data and information to suit their own needs.
Optimal Management System of Stored Grain in GIS Environment
Zhu Zesheng and Sun Ling, Jiang Su Academy of Agriculture Sciences
In recent years, scientific management of stored grain has been being a very important research direction in the field of agricultural engineering. However, how to design and implement optimal or high efficiently management system of stored grain in practice has been being a very complex and difficult problem. Although there were a number of papers which discussed the problems how to construct and implement the management model of stored grain related to the above system, the solutions to those problems are usually not satisfactory. The major reason resulting in the situation can be further disused as follows:
- A number of managed objects in the management system of stored grain are usually influenced by various complex geographical factors.
- Some important physical variable in those objects such as the temperature and moisture to describe some physical behaviors of those objects have obvious information.
However, our research shown that an advanced and satisfactory optimal management system of stored grain can be implemented in the GIS environment such as ArcView Version 2.1. This paper presented our new method for designing and implementing the optimal management system of stored grain in the environment and our new advances in the research of stored grain management. First, the general principle and basic method of designing basic model of the management system were discussed. Secondly, the basic GIS environment provided by ArcView Version 2.1 and how to implement the above basic model in it were investigated respectively. thirdly, some key techniques which were used to implement the management model of stored grain in ArcView Version 2.1 environment were discussed, which includes how to develop the customizing ARCHIVE Version 2.1 environment related to the management system by the Avenue. Otherwise , we discussed in this paper some important experiences how to apply an object-oriented method for building complex model of management system of stored grain and how to apply ArcView Version 2.1, VISUAL BASIC 4.00 and VISUAL C++2.0 to develop and implement the model. In practical implementation of the system, we found that ArcView Version 2.1 and VISUAL BASIC 4.0 provided very satisfactory user interface for our system. On the other hand, ArcView Version 2.1 completed also some complex computation about graphical coverage. In the process to develop and implement our system, VISUAL C++ 2.0 was used to design various complex objects and to complete various complex numeric computation and simulation operation. In summary, our current research and achievements had shown that ArcView Version 2.1 with its Avenue is one of the most efficient and flexible environments for developing the optimal management system of stored grain.
Variable Rate Agriculture: A problem that is ideally suited to a GIS based solution
A. J. Romanelli, GIS Solutions, Inc.
Variable rate technology (i.e. VRT or precision farming) is a technology which allows farms to apply varying amounts of fertilizer to a field depending on soil needs. The keys to VRT are properly determining the amount of nutrient to be applied, and applying that amount in its proper location. Using GIS both of the needs of VRT can be served. First the application map analysis of various input parameters (soil tests, yield data, environmental concerns, etc.) can be produced using a GIS based system, and secondly the nutrients may be applied using a GIS based system. In GIS terminology the former translates into spatial interpolation (kriging) and overlay analysis, and the latter to point-in-polygon analysis. A system has been developed which allows both processes to be achieved, and supplies the user with several additional benefits (i.e. accountability and planning).
Back to Paper Presentation Abstracts