秦巴山区地表太阳辐射的时空动态及农业气候区划研究

运用GIS空间分析，研究了秦巴山区1960—2015年地表太阳辐射的时空动态。结果表明：① 秦巴山区地表太阳辐射量年平均值为4 482.77 MJ/m²，呈现由南向东北、西北递增的态势；年际变异系数为8.85%，呈现由西南向东北递减的态势。② 地表太阳辐射量年际变化呈明显下降趋势，年平均递减率为?10.17 MJ/m²，1970—1992年下降尤为明显；空间上呈现西北局部不显著的微增和东部普遍显著性的减少。③ 年内地表太阳辐射量呈单峰型，最大值在7月，最小值在12月，空间上由南向西北、东北递增；7月年递减率为?0.49 MJ/m²，以西南剑阁县、北川县和东南保康县递减明显；12月年递减率为?0.715 MJ/m²，以汉滨区递减最快；④ 结合降水量和≥10℃积温，将秦巴山区分为5个农业气候区。秦巴山区地表太阳辐射量呈“北高南低的纬向变化，高纬东西分异”，年内递减区表现为“夏季纬向变化，冬季涡旋状”的空间差异。因此，区域内部地表太阳辐射量空间差异大，利用光能资源助力农业扶贫，应体现区域差异。

Spatio-temporal Dynamics of Surface Solar Radiation and Agroclimatic Zoning in the Qinling-Bashan Mountains

Revealing the spatiotemporal dynamics of surface solar radiation in Qinling-Bashan Mountains is helpful to the utilization of regional solar energy resources and to agricultural production. In this article, using GIS spatial analysis, the spatiotemporal dynamics of surface solar radiation in Qinling-Bashan Mountains from 1960 to 2015 were studied to reveal distribution law, which laid a foundation for the study of agroclimatic zoning. The results showed that: 1) The annual average of surface solar radiation is 4 482.77 MJ/m² in Qinling-Bashan Mountains, showing an increasing trend from south to northeast and northwest; the interannual variation coefficient is 8.85%, showing a decreasing trend from southwest to northeast. 2) With an average interannual decline rate of -10.17 MJ/m². The interannual variation of surface solar radiation temporally showed a significant downward trend, especially in 1970-1992, and spatially showed non-significantly slight increase in part of the northwest and significantly general decrease in the East. 3) The innerannual surface solar radiation showed a single peak pattern, with the maximum in July and the minimum in December. It spatially increased from south to northwest and northeast. The annual decline rate is -0.49 MJ/m² in July, obviously declining in Jiange County and Beichuan County in the southwest and Baokang County in the southeast. The annual decline rate is -0.715 MJ/m² in December, with fastest declining in Hanbin District. 4) According to precipitation and ≥10℃ accumulated temperature, the Qinling-Bashan Mountains are divided into five agroclimatic zonings. The surface solar radiation in Qinba mountain area is “longitudinal variation of high in the north and low in the south, differentiation between the east to the west in high latitudes”. Regional differences should be reflected in the use of light resources to help the poverty alleviation in agriculture.