Rice Planting Suitability Zoning In Heilongjiang Province Under The Background Of Climate Warming

This paper applies the daily mean temperature of growing season,≥10℃accumulated temperature, precipitation, sunshine duration, relative humidity and other meteorological datum of Heilongjiang province from1981to2010, and use trend analysis and Kriging spatial interpolation methods to study the time variation and space distribution characteristics of five agricultural climate index; use SPSS19.0software to analysis rice yield in Heilongjiang province from1981to2010with meteorological factor correlation analysis and principal component analysis, to seek for the main factors affecting the rice yield and its weight coefficient; By introducing the terrain factor to agricultural climate resources spatial analysis, the paper gets agricultural climate resources spatial distribution maps, overlaying these zoning maps, a suitability and planting rice map of Heilongjiang province is obtained. Then the main conclusions are drawn as follows:(1) Average sunshine duration of the growing season is1255.47h, its linear trend line and average line perfectly coincide; the daily mean temperature of the growing season in Heilongjiang province from1981to2010shows a fluctuation rise trend over time, the daily mean temperature is17.63℃, at a0.422℃/10a growth rate;≥10℃accumulated temperature also has a significant increase trend, at a83.947℃/10a, and≥10℃accumulated temperature is2645.39℃; annual average precipitation of the growing season is526.55mm, on a declining trend, at a18.66mm/10a decline rate, it shows a volatile trend over time; average relative humidity of the growing season is66.36%, assumes a fluctuate declining trend.(2) Except the Greater Khingan Mountains that has relatively short sunshine duration, others show a distribution that gradually decreases from the west to the east. For the spatial distribution aspect, average temperature of the growing season and80%guaranteed rate of≥10℃accumulated temperature in Heilongjiang province overall assumes the obvious latitude zonal distribution, gradually reducing from the south to the north. Compared with the accumulated temperature zone division of Heilongjiang province in the1990s, every accumulated temperature zone roughly extends a northward and eastward zone:the first zone increased slightly; the second, third, fourth, fifth has an obvious northward trend, and the area also has an increase, covering the original parts of the third, fourth, fifth, sixth zones; The sixth zone is significantly reduced. Precipitation and relative humidity is relatively concentrated, assuming much more in central region, eastern region is less than parts of the western characters, and precipitation of most of the province in the growing season is between400and600mm, the is commonly between60and70%, no.significant regional differences.(3) There was a positive correlation between rice yield and sunshine duration, annual average temperature,≥10℃accumulated temperature in Heilongjiang province from1981to2010.But precipitation and relative humidity have a negative correlation.≥10℃accumulated temperature has a significantly positive correlation. Analysis results show that the impact climatic factors from1981to2010in Heilongjiang province on rice are:≥10℃accumulated temperature, precipitation, annual average temperature, relative humidity, sunshine duration.(4) Rice yield suitability and planting regionalization in Heilongjiang province presents a clear regional difference. The highly suitable mainly distributes in south and central regions in Harbin, heat and water resources are extremely rich; the suitable mainly distributes in the central and parts of the Three River Plain, heat and water resources can meet rice fertility conditions; the less suitable scatters in southwest, the central, north and parts of east regions, where large amounts of differences are on heat and water resources, matching degree not good enough. Rice yield restricts to factors of climate; the not suitable concentrates in the Heihe river in northern regions, where precipitation is sufficient but heat resources are in shortage, not suitable for rice planting; the most unsuitable locates in the Greater Khingan Mountains which is the most northern region in the province and the country, where has the low temperature, less water and complex terrain, highly inaptitude for growing rice.