Based on wire icing observation data at 18 icing meteorological stations and conventional meteorological observation data at 91 meteorological stations of Shanxi Province, the meteorological estimation model of designed wire icing thickness was built by using stepwise regression analysis in different climatic regions, respectively. Then, the designed wire icing thickness at each station under 30-year, 50-year and 100-year return periods was estimated by regression models. And on this basis, combined with DEM data and wire icing observation data in the process of power grid operation and maintenance, the designed wire icing thickness was corrected by terrain, and it in easily icing areas was modified according to operating experience of power grid, the spatial distribution and division of wire icing thickness were obtained in Shanxi Province. The results are as follows: (1) The designed wire icing thickness in Shanxi Province was closely related to air temperature, relative humidity, wind speed and water vapor pressure, it was also related to precipitation and sunshine duration in alpine region, and the influence of meteorological conditions on continuous previous three days on icing thickness was obvious, while that in hilly and plain region was closely related to meteorological conditions on the day and previous day or two days. (2) The regional meteorological estimation model had a good effect on simulating wire icing thickness in each region of Shanxi Province, and the deviation was about 2 mm at Wutai Mountain station before the relocating, while that was less than 1.2 mm in other areas. (3) The results after the terrain correction could perform more reasonably the spatial distribution characteristics of wire icing thickness under different return periods in Shanxi Province. The wire icing thickness decreased with the decrease of latitude, the medium and heavy icing thickness mainly distributed in high elevation areas of Hengshan, Wutai, Guancen, Lvliang, Taiyue and Taihang Mountains, while the icing thickness was thin relatively along the Yellow River and in basin, and that in basin was the thinnest. (4) After the modification of operating experience in easily icing areas of power grid, the wire icing thickness could show more accurately the real situation of icing in local micro-terrain areas, which had practical reference value to electricity department.

Based on dynamic downscaling simulation data of temperature and precipitation by the regional climate model version 4 (RegCM4) from National Climate Center under the representative concentration pathways 4.5 (RCP4.5) and RCP8.5 scenarios, the simulation ability of RegCM4 was tested in baseline period (1986-2005). And on this basis, the climate change was analyzed in North China in future of the 21st century. The results show that RegCM4 had a better performance in simulating air temperature and precipitation in North China in baseline period. The change of surface air temperature, precipitation, consecutive dry days (CDD) and strong precipitation (R95p) under RCP4.5 and RCP8.5 scenarios will increase gradually in North China in future of the 21st century, but their changes under RCP4.5 scenario will be obviously less than those under RCP8.5 scenario. Under the higher emission scenario of RCP8.5, the annual mean air temperature will rise 1.77, 3.44 and 5.82 ℃ in near term (2021-2035), medium term (2046-2065) and long term (2080-2098) of the 21st century, the annual mean precipitation will increase 8.1%, 14% and 19.3%, CDD will reduce 3, 3 and 12 d, and R95p will increase 30.8%, 41.9% and 69.8%, respectively. In space, the mean air temperature in the whole year, winter and summer in North China will rise consistently in future of the 21st century, and the warming in summer will be the most, while the mean precipitation in the whole year, winter and summer will increase in most regions, and the increase of precipitation in winter will be the most. Meanwhile, CDD will decrease except in Shanxi and Beijing-Tianjin-Hebei areas in near term and medium term, while R95p will increase, which indicated that the drought events will reduce and the extreme precipitation will increase in the 21st century.