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Estimation of winter wheat yield using machine learning from airborne hyperspectral data
Švik, Marian ; Pikl, Miroslav ; Janoutová, Růžena ; Veselá, Barbora ; Slezák, Lukáš ; Klem, Karel ; Homolová, Lucie
Methods based on optical remote sensing allow nowadays to assess crop conditions over larger areas. The assessment of crop conditions and potential estimation of crop yields in the early growth\nstages can help farmers to better target their management practice such as application of fertilizers. In this study we analysed airborne hyperspectral images acquired several times during the growing season over two experimental sites in the Czech Republic (Ivanovice and Lukavec). The field experiments on winter wheat included 12 levels of fertilisation (combination of organic and mineral fertilisers). Such an experiment design and the possibility of combining the data from two sites together increased the variability in our wheat yield dataset, which varied between 2.8 and 10.0 t/ha. Further, we used a machine learning method – namely gaussian process regression from the ARTMO toolbox to train two variants of models: a) combining the spectral data from both sites and from the multiple acquisition days and b) combining the spectral data from both sites for individual acquisition days.The results showed that it was feasible to predict wheat yield already at the beginning of April with R2 > 0.85. This promising result, however, requires more thorough validation and therefore we plan to include more data from other sites in the next steps.
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Effects of urbanization on the landscape of a Modern City in Ghana: A case study of sunyani
Boateng, K. A. ; Mensah, Caleb ; Agyei, Thomas ; Švik, Marian
Changes in land use through urbanization and agriculture are the key anthropogenic effects of climate change. Thus, the preservation of natural environment of urban areas is essential for conserving water and soil, while still adjusting the microclimatic variables (temperature, precipitation, relative humidity, etc.) and stabilizing the natural ecological system from destruction. It has been observed that most parts of city's green vegetation have been lost due to housing developments and commercial activities. This study was carried out to assess the effect of the change in land use on a modern city like Sunyani, by observing the significant changes in vegetation cover from LANDSAT TM imagery over a 31-year period (1986 – 2017). From the study, there was significant decline of vegetation cover from 1986 to 1999, and no significant change from 1999 to 2017. There were also significant changes in the built-up areas from 1986 to 1999 and no significant change from 1999 to 2017. Adoption of sustainable and environmentally friendly technologies that maintain open green vegetation is recommended for future city planning.
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Effects of urbanization on the landscape of a Modern City in Ghana: A case study of sunyani
Boateng, K. A. ; Mensah, Caleb ; Agyei, Thomas ; Švik, Marian
According to the fifth assessment report of the Intergovernmental Panel on Climate Change, changes in land use through urbanization and agriculture are the key anthropogenic effects of climate change. Thus, the preservation of natural environment of urban areas is essential for conserving water and soil, while still adjusting the microclimatic variables (temperature, precipitation, relative humidity, etc.) and stabilizing the natural ecological system from destruction. It has been observed that most parts of city's green vegetation have been lost due to housing developments and commercial activities. This study was carried out to assess the effect of the change in land use on a modern city like Sunyani, by observing the significant changes in vegetation cover from LANDSAT TM imagery over a 31-year period (1986-2017). From the study, there was significant decline of vegetation cover from 1986 to 1999, and no significant change from 1999 to 2017. There were also significant changes in the built-up areas from 1986 to 1999 and no significant change from 1999 to 2017. Adoption of sustainable and environmentally friendly technologies that maintain open green vegetation is recommended for future city planning.
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