Razvoj sistema za podporo odločanju o izvajanju kmetijskih ukrepov za varovanje podzemne vode pred onesnaženjem z nitrati

Curk, Miha (author), Glavan, Matjaž (mentor), Rak, Gašper (comentor)

V nalogi je bil razvit sistem za podporo odločanju o izvajanju kmetijskih ukrepov za varovanje podzemne vode pred onesnaženjem z nitrati. Sistem sestavljajo 3 faze: analiza obstoječega stanja, vrednotenje učinkovitosti ukrepov ter optimizacija in umeščanje ukrepov. Preučevali smo vpliv različnih virov vhodnih (izmerjeni oz. izračunani podatki o fizikalnih lastnostih tal) in umeritvenih podatkov (pretoki rek, količina vode v tleh, kombinacija obojega) na delovanje 12 različic modela SWAT. Ugotovili smo, da vsi načini umerjanja modela niso primerni za vse situacije. Zgolj v nekaterih primerih je prišlo do razlik v modelnih rezultatih. Zaključujemo, da razlike med rezultati niso tako velike, da bi jasno pokazale na najboljšo možnost, zato je za umerjanje bolj smiselno uporabiti podatke, ki so lažje dostopni oz. na drug način primernejši v dani situaciji. Predlagani sistem za podporo odločanju smo preizkusili na ranljivih območjih Dravske in Krške kotline. Za vsako območje smo ovrednotili okoljski (izpiranje nitrata) in ekonomski (pokritje) učinek različnih kmetijskih praks; prvega z uporabo modela SWAT in drugega z izračunom pokritij. S simulacijo pričakovanih kmetijskih praks (obstoječe stanje) smo na vsakem območju ugotovili, kateri deli so bolj ranljivi in bi bilo zato na njih bolj smiselno zaostriti ukrepe za omilitev izpiranja nitrata. S primerjavo učinkov širšega nabora alternativnih kmetijskih praks smo ugotovili, katere so za posamezne talne tipe na območju najbolj primerne (tako okoljsko kot ekonomsko). Izkazalo se je, da univerzalno učinkovite prakse ne obstajajo: nekatere so bolj učinkovite v enih, druge v drugih primerih. Na podlagi informacije o učinkovitosti ukrepov smo v zadnji fazi kmetijske prakse razporedili na območje po treh kriterijih optimizacije: okoljske, ekonomske in kombinirane. Ugotovili smo, da so vse tri, celo ekonomska, izboljšale stanje z izpiranjem nitrata na celotnem območju, zato zaključujemo, da bi lahko z uporabo predlaganega sistema in umeščanjem ukrepov na podlagi njihove okoljske in ekonomske učinkovitosti na območju hkrati zmanjšali izpiranje nitrata s kmetijskih površin in povečali ekonomičnost kmetijske pridelave.

• Language: Slovenian
• Keywords: izpiranje nitrata, kmetijstvo, varovalni ukrepi, agroekonomika, model SWAT, podnebne spremembe, optimizacija rabe tal, lastnosti tal, vhodni podatki modela, kalibracija modela
• Work type: Doctoral dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: BF - Biotechnical Faculty
• Year: 2022
• PID: 20.500.12556/RUL-142629
• COBISS.SI-ID: 129817859
• Publication date in RUL: 17.11.2022

Secondary language

• Language: English
• Title: Developing a decision support system for implementation of agricultural measures for groundwater protection against pollution by nitrates

Abstract

This thesis developed a decision support system for implementation of agricultural measures for groundwater protection against pollution by nitrates. The system consists of 3 phases: analysis of the existing situation, evaluation of the effectiveness of measures, and optimization and placement of measures. Influence of different sources of input (measured or calculated soil hydraulic properties data) and calibration data (river discharge, amount of water in the soil, a combination of both) on the functioning of 12 versions of the SWAT model was studied. We found that not all model calibration methods are suitable for all situations. Only in some cases differences in the model results were confirmed. We conclude that the differences are not so large as to clearly indicate the best option, so it may be more prudent to use data that are easier to access or otherwise more appropriate in a given situation. The proposed decision support system was tested in vulnerable areas of the Drava and Krško basins by evaluation of the environmental and economic impact of different agricultural practices; the first by simulating nitrate leaching and the second by calculating the contribution margins. By simulating the expected agricultural practices, we determined which parts are more vulnerable and where it would make more sense to introduce stricter measures. By comparing the effects of a wider range of alternative agricultural practices, we determined which ones are most suitable for individual soil types in the area. It turned out that universally effective practices do not exist: some are more effective in some, others in other cases. Effective agricultural practices were allocated in both areas according to three optimization criteria: environmental, economic and combined. We found that all three, even the economic one, which maximizes the economic impact of agriculture, improved the nitrate leaching situation in the whole area, so we conclude that using the proposed system and placing measures based on both their environmental and economic effectiveness in the area can reduce nitrate leaching from agricultural land and increase the economy of agricultural production.

• Keywords: nitrate leaching, agriculture, mitigation measures, agroeconomy, SWAT model, climate change, land use optimization, soil properties, model input data, model calibration