Assessing the function of controlled drainage using satellite data

BcA. Teshome Yetmgeta Manyazewal, BA

Master's thesis

Abstract:

The amount of available water to plants is a crucial parameter in determining the yields of crops grown on agricultural land. The controlled drainage systems providing subsurface irrigation can reduce the water shortage part of the vegetation season. The conversion of the existing drainage systems in which the water level in the system can be controlled is now being researched in the Czech Republic. One of the pilot localities is in Strašov, Pardubice Region. The thesis is focused on the application of the remote sensing method for evaluation of the condition of the grown crop by comparing the normalized difference vegetation indexes (NDVI) for areas affected and unaffected by the controlled drainage. The functionality of the controlled drainage system was evaluated based on the assumption that plants' response to solar radiation reflects their water stress status. Plants highly absorb red and reflect near-infrared (NIR) bands when they are in good status. The satellite imageries were downloaded from the Land Viewer, Earth observing system (EOS). In each part of the area (affected/unaffected by controlled drainage), 10 sampling polygons were defined and the NDVI values were compared for the vegetation season from April to October 2020. The vegetation season was selected to reduce the impact of soil reflectance. Suitable dates for which the NDVI values could be compared were selected and NDVI data for these dates were then statistically evaluated by analysis of variance. For the periods when the precipitation did not meet the plants’ requirements, the plants grown on the area affected by controlled drainage showed significantly higher NDVI values than plant grown on the unaffected area. The NDVI differences between the areas diminished in the period with sufficient precipitation. Later during the season when the regulation was set out of operation, the NDVI values of the two areas were similar and did not significantly differ from each other. The results support the conclusion that the NDVI analysis from the satellite data can provide information assessing the function of the controlled drainage system in the agricultural field. To prove the technique further, data for more vegetation seasons for more than one experimental sites needs to be evaluated.

Keywords

Controlled drainage system, Normalized difference vegetation index, Satellite imagery, Drainage, Drainage system, Vegetation index, Remote sensing

Language used: English

Date on which the thesis was submitted / produced: 14. 4. 2022

Thesis defence

• Supervisor: Ing. Kamila Báťková, Ph.D.

Czech University of Life Sciences Prague

Faculty of Agrobiology, Food and Natural Resources

Master programme / field:
Natural Resources and Environment / Natural Resources and Environment