CLIMATIC RISK ZONING OF DOUBLE CROPPING SUPER RICE CULTIVATION IN HUNAN PROVINCE

Based on meteorological data including daily sunshine duration, temperature and precipitation from 97 meteorological stations in Hunan province during the period of 1981—2010, in combination with the field experiment in different places at different sowing dates, the precise climatic risk zoning of double cropping super rice cultivation has been studied by using the spatial interpolation method and other Geographical Information System(GIS)technologies. Three key climatic factors were selected including chilling in May, high temperature heat damage during July to early August and low temperature damage in autumn in this study. Furthermore, based on the analysis of climatic conditions suitable for double cropping super rice cultivation and climatic disasters, 8-22 ℃ active accumulated temperature, sunshine duration from late March to October, climatic risk index of the low temperature in autumn, and climatic risk index of chilling in May were selected as key climatic factors to study the precise agro-meteorological regionalization of double cropping super rice in Hunan province. The results showed that: the high-yielding zones of double cropping super rice in Hunan were mainly located in Zhuzhou, Hengyang, Yongzhou and Chenzhou City, the moderate-yielding zones were primarily located in the east and north reaches of Dongting Lake,together with most of Changsha, Zhuzhou and Xiangtan City, and other regions in Hunan were not suitable for double cropping super rice. These findings can provide valuable information for the large-scale cultivation of double cropping super rice in Hunan province.

Climate Change Impacts on Central China and Adaptation Measures

In Central China,the obvious climate change has happened along with global warming.Based on the observational analysis,the climate change has significant efects,both positive and negative,in every field within the study area,and with the harmful efects far more prevalent.Under the scenario A1B,it is reported that temperature,precipitation,days of heat waves and extreme precipitation intensity will increase at respective rates of 0.38 C per decade,12.6 mm per decade,6.4 d and 47 mm per decade in the 21st century.It is widely believed that these climate changes in the future will result in some apparent impacts on agro-ecosystems,water resources,wetland ecosystem,forest ecosystem,human health,energy sectors and other sensitive fields in Central China.Due to the limited scientific knowledge and researches,there are still some shortages in the climate change assessment methodologies and many uncertainties in the climate prediction results.Therefore,it is urgent and essential to increase the studies of the regional climate change adaptation,extend the research fields,and enhance the studies in the extreme weather and climate events to reduce the uncertainties of the climate change assessments.