## 5 Conclusions  
The approach of assessing agricultural drought by the DISS index, developed at the Institute of Geodesy and Cartography, which is the fusion of meteorological and satellite data, combines, in one formula, both types of information, hence considering the variability in the environmental conditions expressed by HTC. HTC has been assumed as an atmospheric drought indicator; however, this study brought a better understanding of the relationship between water deficit characterized by the HTC index and the reaction of vegetation to the water deficit expressed by TCI calculated from MODIS data.  
The DISS model is significant for its ability to derive drought information for local governments across different time scales. This information is important for decision-making at the local, regional, and national levels across multiple sectors such as agriculture, water resources, insurance, energy, and public health. The choice of the time scale for drought assessment (from 30 to 50 days, as presented) depends on the needs of the private and public sectors. Such information is important from an economic point of view; hence, satellite-based drought maps should start to be included as part of crop condition assessment systems at the farm level.  
This study revealed that the percentage of drought area in the NUTS 2 regions detected by the DISS index corresponds to the level of yield reduction, especially for high yield reduction in the most important parts of the season of cereal growth (May-June). The central and western parts of Poland are usually heavily affected by the occurrence of drought and the longest drought duration, which is critical for the development of cereals. High yield reductions (i.e., over 30%) are clearly related, to a large extent, to drought for most of the growing season. Information on the areas where yield reduction occurs can serve as an indication for farmers on which crop they should grow, but also what kind of drought mitigation measures should be performed.  
The DISS drought index should also have great importance in implementing adaptation and mitigation activities for agricultural areas related to the occurrence of drought. The model was validated only for Poland, applying data about the yield reduction. The spatial distribution of DISS was 1 km\({}^{2}\), which is very important for the agriculture sector. In the future, the model will be tested for the global scale with the use of gridded meteorological data from models. Strong discussions are taking place in regional governments regarding the building of irrigation systems and the provision of capacity for local retention. Local retention is very important, as Poland is exposed to climate changes when drought frequently occurs.  
K.D.-[PERSON] conceived and designed the experiments and wrote the paper; [PERSON] performed the statistical analyses; [PERSON] analyzed the data and contributed to writing the paper; [PERSON] processed the satellite data; [PERSON] prepared the satellite maps; [PERSON] analyzed maps in the GIS environment; and [PERSON] contributed to the final map preparation. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding. The study was funded by the budget planned for the statutory activity of the Institute of Geodesy and Cartography 2017-2018 (Task No. 2, topic No. S/02.03).  
The authors thank [PERSON] for preparing meteorological data (verification, interpolation) from the open public Meteorological Data Base and [PERSON] for support in processing the meteorological data, as well as the Institute of Meteorology and Water Management (IMGW-PIB) for sharing public meteorological data.  
The authors declare no conflict of interest.