Responses of Soybean Water Supply and Requirement to Future Climate Conditions in Heilongjiang Province

Understanding future changes in water supply and requirement under climate change is of great significance for long-term resource management agricultural planning. In this study, daily minimum temperature (Tmin), maximum (Tmax), solar radiation (Rad), precipitation 26 meteorological stations RCP4.5 RCP8.5 MIRCO5 the period 2021–2080 were downscaled by LARS-WG model, average relative humidity (RH) was estimated using method recommended FAO-56, reference crop evapotranspiration (ET0), (ETc), irrigation (Ir), effective (Pe), coupling degree ETc Pe (CD) soybean during growth calculated CROPWAT model Heilongjiang Province, China. The spatial temporal distribution these variables factors analyzed, response to explored. result showed that Tmin, Tmax, Rad increased 0.2656 0.5368 °C, 0.3509 0.5897 0.0830 0.0465 MJ/m², respectively, while RH decreased 0.0920% 0.0870% per decade from 2021 2080. annual ET0, ETc, Pe, Ir 542.89, 414.35, 354.10, 102.44 mm, they 1.92%, 1.64%, 2.33%, ?2.12% RCP8.5, respectively. ranges CD 0.66–0.95 0.66–0.96, with an value 0.84 2021–2080. Spatially, a general trend increasing first then decreasing west east. addition, 9.55, 7.16, 8.77 mm decade, 0.65 decade. Under overall This study provides basis resources policy