川西北高原畜牧业界限温度日期及资源的变化特征

利用川西高原31个气象观测站1961~2012年的观测资料,采用线性趋势法、Mann-Kendall突变检测法和Morlet小波分析方法,详细分析了川西北高原畜牧业界限温度0℃初日、5℃终日及0℃初日至5℃终日之间畜牧气候资源的变化特征。结果表明:(1)川西北高原稳定通过0℃初日及5℃终日在区域上有很大差异,主要受海拔高度、纬度的影响。(2)畜牧气候资源的年际变化总体呈增加趋势,但区域变化不均;(3)各要素年代际变化不同,积温在各个年代都比前一年代增加,而日照时数则呈现出一增两减一增的趋势,降水量的年代际变化型式与日照相反,呈现一减两增一减的趋势;(4)各因素突变特征明显,突变的时间主要出现在20世纪80年代,不同因素的突变类型不同;(5)畜牧业气候资源存在明显的周期性变化,各要素变化周期长短不一致,尤其是降水量以4a左右的短周期振荡为主。

CHARACTERISTICS OF CHANGES IN THE DATE OF BOUNDARY TEMPERATURE AND CLIMATIC RESOURCES FOR ANIMAL HUSBANDRY ON THE NORTHWEST SICHUAN PLATEAU

Ranging extensively with a complex terrain and a great altitude difference, it shows an extremely great difference in climatic resources in the Northwest Sichuan plateau. In this area, the main feature of climate is plenty of sunshine and slightly low temperature and lesser precipitation, so the major industries are economically primarily supported by animal husbandry. The beginning date and the ending date of limited boundary temperature of livestock represent the effective period of pasture growth, and the climate resource from beginning date to ending date represent how much quantity of climate resources can be used effectively by animal husbandry. Therefore, the two parameters play a very important role in animal husbandry. The global climate changes, featured by temperature increases, will inexorably affect changes in the farming and animal husbandry environment. As shown by a great many research statistics, climate warming leads to increased frequency extreme climatic events, thereby constituting a severe threat to agriculture, animal husbandry and ecological safety. Employing the linear trend method, the Mann Kendall trend test and the Morlet wavelet analysis, this paper explicates in detail the change characteristics of climate resources elements for livestock such as beginning date of 0℃ and ending date of 5℃ and others, based on the observation data gathered by 31 weather stations from 1961 to 2012. The result shows that : (1) the start date of 0℃ and end date of 5℃ differs greatly from area to area, due primarily to the impact of elevation and altitude; (2) Inter annual changes in livestock climatic resources shows increasing trend overall, but regional variations are uneven; (3) different parameters demonstrate different inter annual changes, evidenced by that fact that accumulated temperature is on the increase year on year, while decadal changing trends of sunshine times are characterized by an increase (one decade) and two decrease (two decades ) and an increase (one decade); but rainfall has an decadal change pattern contrary to that of sunshine times, which features a decrease (one decade) and two increase (two decades) and one decrease (one decade) pattern; (4) the various parameters pointed to a distinct mutation characteristics, with mutation time occurred primarily over the 1980s; different parameters feature different types of mutation; (5) the climatic resources for animal husbandry have a distinct periodic trend of change; different parameters vary in periodic length; in especial, rainfall is dominated by a short periodic oscillation (approx.4 a). In general, beginning date of 0℃ is advanced and ending date of 5℃ is postponed in the observed area. So this change feature implies that the average temperature and accumulated temperature from beginning date to ending date of livestock limited temperature increased. The increase in interval temperature and accumulated temperature helps extend the effective period of growth of pasture. Pasture species with a longer effective period of growth may be introduced appropriately to promote pasture yield. This plan is very beneficial to the development of animal husbandry. Although sunshine hours develop a minimal decreasing trend, the situation will not exert a substantial impact on the growth and yield of pasture.