张承地区气温与降水时空演变规律探讨

The Spatio-temporal Variability of Temperature and Precipitation in Zhangjiakou-Chengde Area

气候变化影响农业、水资源、生态系统与生物多样性等诸多领域,制约社会经济发展,尤其对人类生存环境产生不利影响。为此,以地处农牧业交错带的张家口与承德两地为研究对象,利用Arcgis软件中的空间分析工具对研究区1951-2016年的气温与降水数据进行时空演变分析。结果表明:张承地区的高温区出现在位于承德东南的兴隆南部,低温区主要分布在围场县的塞罕坝、张北县西部及蔚县东南部山区。研究时段,气温呈显著上升趋势,特别是春夏两季增温明显。降水量空间上亦呈现东南向西北倾斜特征,但东西差异更明显。研究时段,降水量呈递减趋势,且降水年际变化及季节变化等均较大。作为半干旱区与半湿润区分界的400mm等降水量线通过研究区的西北部,400mm等降水量线年际变化幅度较大,这势必对当地生态环境及人类的生存与发展产生诸多不利影响。

Global environment is already suffering the effects of climate change, such as agriculture, water resources, ecosystem and biodiversity, which has handicapped social and economic development, especially endangered human existence environment. Therefore, the temperature and precipitation data are analyzed using spatial analysis tools of Arcgis from 1951 to 2016 in Zhangjiakou-Chengde area. The major results could be summarized as follows： 1） The annual mean temperature climbed at a speed of 0.38 degrees Celsius per decade in the study area. And four season temperature shows the increasing trend, especially in spring and summer. While annual precipitation shows a downward trend at a speed of 3.05 mm/10 a. Average annual precipitation for the 476.2 mm mainly concentrates in the summer and fall, which period accounts for 82.44%. In short, Zhangjiakou-Chengde area has a continental monsoon climate with four distinct seasons, but with time the temperature is rising and the precipitation is falling. 2） In terms of spatial distribution, the temperature decreases gradually from southeast to northwest in study area, while the Bashang region is significantly lower than other area. The high temperature zone appears in the southern part of Xinglong in Chengde, and the low temperature areas are mainly located in Saihanba of Weichang County, the western regions of Zhangbei county, and the southeast mountains of Yuxian county. Similarly, the spatial trend of precipitation decreases gradually from southeast to northwest, but there is distinctive difference between the east and the west. Especially, the significant difference exists in Bashang region. The isohyet 400 mm, which is an important geography boundary between semi-arid region and semi-humid region winds through northwest area. Lack and large variability of precipitation, especially the erratic fluctuation of isohyet 400 mm would endanger regional ecological environment security and human survival, and therefore might have an adverse effect on Beijing and Tianjin area.