Study On Climatic Regionalization For Wine-grape In Shaanxi Province

Based on the climatic data (from 1991 to 2000) of reprentaticve 25 counties in Shaanxi province, mean temperature, extreme temperature, precipation, and insolation in different period (year, April to October, July, August, September) were studied. According to these indexes, sum of active temperature (∑T), sum of effective temperature, hydrothermal coefficient (K) and relative illumination rate (Sc) were computed.The climatic characteristics of Shaanxi province were appraised,the climatic factors of influential grapevine were analysed,and the program of climatic regions suitable for grapevine in Shaanxi province were advanced.The main results obtained as following:1. Shaanxi province has a varied topography and soil, different in microclimate. The climatology factors, temperature, precipation, and insolation are the basis of regionalization for grapevine, as they are obvious difference in time and space.2. The indexes for regionalization of grapevine in Shaanxi province:The first index: sum of active temperature,The secondary index: hydrothermal coefficient, relative light rate.(1) The standard of the first regionAccording to the sum of active temperature (∑T) of growing season(from 4 to 9), Shaanxi province was divided into 4 climatic regions (the first region):Ⅰ: Hot region, ∑T≥4300℃,Ⅱ: Warm region, 3800≤∑T<4300℃,Ⅲ: Moderate region, 3200≤∑T<3800℃,Ⅳ: Cool region, ∑T<3200℃From the heat, the four regions are the ideal areas for grapevine except specific regions.(2) The standard of the secondary regionAccording to hydrothermal coefficient (K, from 8 to 9) and relatvine light (Sc), every first region was divided into 3 sub-regions:A. High quality sub-region, K<1.0 and Sc≥50%,B. Good quality sub-region, 1.0≤ K≤1.5 and Sc>45%,C.Ordinary quality sub-region, K>1.5and Sc≤45%. 3. The draft of regionalization for grapevine in Shaanxi province:According to these indexes, the grapevine regions in Shaanxi province were divided into3 first regions and 12 sub-regions. The foundmental programs as following:ⅠA: Pucheng, Dali, Pucheng, Sanyuan.ⅠB: Hancheng, Fuping, Gaoling, Liquan, Qianxian. ⅠC: Tongguan, Huaxian, Huayin, Weinan, Lantian, Xi'an, Chang'an, Huxian, Xianyang, Xingping, Shangluo, Danfeng, Baihe, Xunyang, Ankang, Langao, Ziyang, Hanyin, Shiquan, Xixiang, Yangxian, Chenggu, Hanzhong, Mianxian, Baojixian.ⅡA: Jingyang.　ⅡB: Heyang, Chengcheng, Baishui, Yaoxian.ⅡC: Fengxiang, Baoji, Qishan, Meixian, Fufeng, Zhouzhi, Wugong, Lueyang, Ningqiang, Nanzheng, Zhengba, Pingli, Zheng'an, Zhashui, Shanyang, Shangnan, Luonan.ⅢA: None.ⅢB: Fugu, Shenmu, Yulin, Jiaxian, Hengshan, Mizhi, Zizhou, Suide, Wubu, Zichang, Qingjian, Yanchuan, Yan'an, Yanchang, Yichuan, Luochuan, Huangling, Chunhua, Yongshou.ⅢC: Longxian, Qianyang, Fengxian, Ningshan, Yijun, Tongchuan.ⅣA: Jingbian, Dingbian.ⅣB: Wuqi, Zhidan, Ansai, Ganquan, Fuxian, Huanglong, Binxian, Xunyi.ⅣC: Changwu, Linyou, Taibai, Liuba, Foping, Zhenping.In these regions, ⅠA, ⅡA and ⅣA are the most iddal areas for grapevine, ⅠB, ⅡB, ⅢB and ⅣB are suitable for grape,.There are microclimatic in certan areas in C regions, therefore, some zones may be suitable for producting grapevine and wine in specific regions, and which needs to be studied further.4. The region of protecting in winterJanuary is the coldest month in Shaanxi province. The mean temperature of ten years in January was compulated, and -15℃ was regarded as criterion, the regions in the north of Wuqi, Zhidan, Luochuan and Yichuan are the boundary for grapevine with winter protection.