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Overview |
Crop Production |
Crop Pattern |
Crop Yield |
Irrigation |
Soil Management | Precision Farming |
Relevant Products |
Relevant Links
Bangladesh establishes a GIS-based agricultural and Land Resources Information System
Soil/Land Type Mapping Model
An ArcView GIS-based application has been developed to dynamically combine a user-specified digital elevation model (DEM) with the national (reconnaissance level) soil association layer to create a more detailed Soil/Inundation Land Type layer. The application is written in Avenue and uses the ArcView Spatial Analyst extension. It has been programmed to handle future updating of both the soil and the DEM layers.
The first step in the development of this application was to refine a previously generated 300-meter DEM by filling in areas of missing elevation with values taken from a 1,000-meter DEM. Then, an Avenue program was written to assign soil association and topographically derived "land type" designations to each 300-meter grid cell. In Bangladesh, the following inundation land type designations are used to specify a range of inundation depths based on the average peak water depth: highland, medium highland 1 and 2, medium lowland, lowland, and very lowland.
The output of this application is a new grid-based Soil/Inundation Land Type layer in which the number of many-to-one relationships between soil attributes and soil mapping units is greatly reduced. This new layer provides for a more explicit, accurate, and dynamic soil mapping capability.
Climatic Modeling
Much effort has been made to expand existing historical climatic data involving different types of data with recent records obtained from various institutions. Procedures have been developed to perform quality control and enhance database management and modeling capabilities. Meteorological station data is analyzed using the Agricultural Planning Tools (APT) calculator, and the resulting data is then used to create GIS surfaces showing important climatic properties related to plant growth by season as well as the variability of these properties (e.g., average starting date of the kharif growing season).
Hydrologic Modeling
On average, approximately 60 to 70 percent of Bangladesh is inundated by rising water table levels between July and September of each year. Previous AEZ assessments indicated that the year-to-year variation in inundation regime is affecting the long-term suitability and productivity of the land. The enhanced system now in place enables quantification of the year-to-year variation in extent, depth, and timing of inundation. This information will greatly improve the assessment of single crop and cropping pattern suitability in individual inundation land types.
Crop Suitability Model
The system also includes a component that permits the evaluation of crop suitability. First, individual crop suitability ratings are analyzed, and then suitabilities for various cropping patterns are rated using a database of known and potential cropping patterns (rotations). This suitability modeling takes into account individual crop characteristics, input/management levels, the soil's physical characteristics, hydrologic and climatic conditions, and seasonal variability.
Another primary goal of this project is the analysis of land use scenarios integrating the physical suitability for various cropping patterns and socioeconomic factors of agricultural production. Relevant socioeconomic and farming system databases are being constructed for this purpose.
The analysis will essentially involve three steps: the formulation of scenarios, with each scenario represented by a core model; the analysis of solutions of the core model using a linear programming solver based on multiobjective linear optimization; and the application of multicriteria analysis to the core model solutions to determine compromised solutions that adequately reflect the preferences of decision makers in real-life situations. Various software tools have been put in place for this application, and GIS plays a pivotal role in all aspects of this important work.
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