Estimates of irrigation requirements throughout Germany under varying climatic conditions
As climate change brings about hotter and often drier summers, an improved understanding of how irrigation requirements vary according to climatic conditions is of increasing importance. Within Germany, temperate conditions have historically enabled most agriculture to be supplied solely by green wa...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2024-02-01
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| Series: | Agricultural Water Management |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0378377423005061 |
| _version_ | 1797365612296536064 |
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| author | Ian McNamara Martina Flörke Thorben Uschan Oscar M. Baez-Villanueva Frank Herrmann |
| author_facet | Ian McNamara Martina Flörke Thorben Uschan Oscar M. Baez-Villanueva Frank Herrmann |
| author_sort | Ian McNamara |
| collection | DOAJ |
| description | As climate change brings about hotter and often drier summers, an improved understanding of how irrigation requirements vary according to climatic conditions is of increasing importance. Within Germany, temperate conditions have historically enabled most agriculture to be supplied solely by green water, but recent crop yield reductions and crop failures have demonstrated its increased vulnerability to climatic conditions. The raster-based mGROWA hydrological water balance model was implemented over all agricultural areas in Germany for the period 1961–2020 at a high spatial (200 m) and temporal (daily) resolution. Grid-cells were each assigned one of 10 major crop classes, which account for 86.7 % of all agricultural areas in Germany, and effectively all irrigated areas. Using crop-specific irrigation rules that reflect actual practices, irrigation requirements were simulated for all crop areas. To investigate the relationship between climatic water balance over the crop growing season and irrigation requirements, the simulated annual irrigation requirements were compared with the standardised precipitation-evapotranspiration index (SPEI-6), calculated at the end of September. Through this comparison, irrigation requirements could be characterised for near-normal and dry conditions, and results were aggregated to the district level. Additionally, using district-level data on the areas with irrigation infrastructure, the actual water used for irrigation was estimated. The results highlight marked increases in irrigation requirements in dry conditions compared to near-normal conditions (median increase of 72 %), which are more pronounced over crops in silty soils than in sandy soils. The results also demonstrate how the increased irrigation requirements in dry years are in many cases higher than what is suggested by guidelines for irrigation management in Germany. This study provides important information for actors related to the agricultural sector and water management and is based on a robust and transferable framework to quantify how irrigation requirements vary according to climatic variability and local soil conditions. |
| first_indexed | 2024-03-08T16:52:22Z |
| format | Article |
| id | doaj.art-cf01cbdeaa924207a34d6e81c0d20ed3 |
| institution | Directory Open Access Journal |
| issn | 1873-2283 |
| language | English |
| last_indexed | 2024-03-08T16:52:22Z |
| publishDate | 2024-02-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Agricultural Water Management |
| spelling | doaj.art-cf01cbdeaa924207a34d6e81c0d20ed32024-01-05T04:22:56ZengElsevierAgricultural Water Management1873-22832024-02-01291108641Estimates of irrigation requirements throughout Germany under varying climatic conditionsIan McNamara0Martina Flörke1Thorben Uschan2Oscar M. Baez-Villanueva3Frank Herrmann4Institute of Bio- and Geosciences: Agrosphere (IBG-3), Forschungszentrum Jülich, Jülich 52425, Germany; Engineering Hydrology and Water Resources Management, Ruhr-Universität Bochum, Bochum 44801, Germany; Corresponding author at: Forschungszentrum Jülich, IBG-3, Jülich 52428, Germany.Engineering Hydrology and Water Resources Management, Ruhr-Universität Bochum, Bochum 44801, GermanyEngineering Hydrology and Water Resources Management, Ruhr-Universität Bochum, Bochum 44801, GermanyHydro-Climate Extremes Lab (H-CEL), Ghent University, Ghent, BelgiumInstitute of Bio- and Geosciences: Agrosphere (IBG-3), Forschungszentrum Jülich, Jülich 52425, GermanyAs climate change brings about hotter and often drier summers, an improved understanding of how irrigation requirements vary according to climatic conditions is of increasing importance. Within Germany, temperate conditions have historically enabled most agriculture to be supplied solely by green water, but recent crop yield reductions and crop failures have demonstrated its increased vulnerability to climatic conditions. The raster-based mGROWA hydrological water balance model was implemented over all agricultural areas in Germany for the period 1961–2020 at a high spatial (200 m) and temporal (daily) resolution. Grid-cells were each assigned one of 10 major crop classes, which account for 86.7 % of all agricultural areas in Germany, and effectively all irrigated areas. Using crop-specific irrigation rules that reflect actual practices, irrigation requirements were simulated for all crop areas. To investigate the relationship between climatic water balance over the crop growing season and irrigation requirements, the simulated annual irrigation requirements were compared with the standardised precipitation-evapotranspiration index (SPEI-6), calculated at the end of September. Through this comparison, irrigation requirements could be characterised for near-normal and dry conditions, and results were aggregated to the district level. Additionally, using district-level data on the areas with irrigation infrastructure, the actual water used for irrigation was estimated. The results highlight marked increases in irrigation requirements in dry conditions compared to near-normal conditions (median increase of 72 %), which are more pronounced over crops in silty soils than in sandy soils. The results also demonstrate how the increased irrigation requirements in dry years are in many cases higher than what is suggested by guidelines for irrigation management in Germany. This study provides important information for actors related to the agricultural sector and water management and is based on a robust and transferable framework to quantify how irrigation requirements vary according to climatic variability and local soil conditions.http://www.sciencedirect.com/science/article/pii/S0378377423005061Crop water requirementsMGROWADroughtSPEIWater resources management |
| spellingShingle | Ian McNamara Martina Flörke Thorben Uschan Oscar M. Baez-Villanueva Frank Herrmann Estimates of irrigation requirements throughout Germany under varying climatic conditions Agricultural Water Management Crop water requirements MGROWA Drought SPEI Water resources management |
| title | Estimates of irrigation requirements throughout Germany under varying climatic conditions |
| title_full | Estimates of irrigation requirements throughout Germany under varying climatic conditions |
| title_fullStr | Estimates of irrigation requirements throughout Germany under varying climatic conditions |
| title_full_unstemmed | Estimates of irrigation requirements throughout Germany under varying climatic conditions |
| title_short | Estimates of irrigation requirements throughout Germany under varying climatic conditions |
| title_sort | estimates of irrigation requirements throughout germany under varying climatic conditions |
| topic | Crop water requirements MGROWA Drought SPEI Water resources management |
| url | http://www.sciencedirect.com/science/article/pii/S0378377423005061 |
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