基于格点数据的中国喜凉作物有效积温区划

Effective accumulated temperature compartment of the chimonophilous crop in China based on grid data

为了解全球升温背景下中国农业热量资源的变化,基于格点数据使用5日滑动平均、最小二乘法、多元回归插值法、旋转经验正交函数(REOF)对中国≥5℃有效积温进行分析。结果表明,(1)中国≥5℃有效积温整体呈升高趋势。南北方升高速率不一致,以秦岭为界,南方地区有效积温升幅较大;北方地区升幅相对较小,但不排除个别地区如塔里木盆地及阿拉善高原升幅较大;青藏高原和横断山脉升幅最小;秦岭及大巴山等地有效积温表现出下降趋势。(2)中国东部地区各有效积温界限北界均有北移趋势,4000℃·d积温等值线在长江中下游地区北移最明显(向北最大移动1.6纬距),四川盆地和塔里木盆地有效积温界限呈外扩趋势。(3)≥5℃有效积温起始日期多分布在3、4月份,持续时间6个月及以下的格点占比最多;自20世纪80年代后,起始时间有明显提前趋势,持续时间有延长趋势。(4)REOF将≥5℃有效积温分为8个区域,其中Ⅰ、Ⅱ区为第一模态正负2个高值区,Ⅳ、Ⅴ区为第三模态正负2个高值区,第Ⅶ、Ⅷ区是具有相同特征的区域,且第Ⅰ、Ⅲ、Ⅳ、Ⅷ区及第Ⅱ区东中部与中国综合农业区划结果相似。

To figure out the change of agricultural heat resource in China under the context of global warming,the sliding mean temperature of five days,least square method,multiple linear regression and rotated empirical orthogonal function(REOF)were used to analyze the effective accumulated temperature(≥5℃).The result showed that the effective accumulated temperature(≥5℃)was rising as a whole.The rising rate was inconsistent between north and south.The overall increase in the north of the Qinling Mountains was relatively small,but the increase was larger in some areas such as Tarim Basin and Alashan Plateau.The overall increase in the south of the Qinling Mountains was relatively larger.The Tibetan Plateau and the Hengduan Mountains had the smallest increases.The effective accumulated temperature showed a decreasing trend in Qinling Mountains,Daba Mountain and some of the mountains.The north boundary of each effective accumulated temperature tended to move northward,and the accumulated temperature contours of 4000℃·d had the most obvious northward movement in the middle and lower reaches of the Yangtze River.The effective accumulated temperature boundary of Sichuan Basin and Tarim Basin was expanding.The starting date of effective accumulated temperature(≥5℃)mostly occurred in March and April,and the duration was usually six months or less.However,the effective accumulated temperature started in advance and its duration showed an increasing tendency since the 1980s.The effective accumulated temperature was spatially and temporally partitioned by REOF and divided into eight regions.It was found that the 1st,3rd,4th,8th subregions were similar to the traditional chinese comprehensive agricultural regionalization.