陕西省降雨和风蚀气候侵蚀力时空分布特征

[目的]研究陕西省不同区域降雨侵蚀力和风蚀气候侵蚀力的时空分布特征、突变特征和周期特性等,为陕西水土流失防治和生态建设提供科学依据。[方法]利用陕西省96个气象站1981-2020年气象观测资料计算了全省降雨侵蚀力和风蚀气候侵蚀力,采用气候趋势分析、空间插值、M-K检验、小波分析等方法,分析了陕西省风蚀、水蚀气候侵蚀力时空分布特征、突变和周期特征等。[结果](1)全省1981-2020年降雨侵蚀力为2 719.6 MJ·mm/(hm^(2)·h),空间差异性较大,呈现南高北低的空间分布。陕西省风蚀气候侵蚀力为3.18,呈现北高南低的空间分布特征。(2)近40年陕西省降雨侵蚀力年际波动较大,呈现微弱上升趋势,但未通过显著性检验。全省降雨侵蚀力经历了先减小后增大的变化趋势,目前处于降雨侵蚀较大的年代。陕西省风蚀气候侵蚀力年际波动较大,但无显著变化趋势。风蚀气候侵蚀力近40年先增强后减弱,大部分地区风蚀气候侵蚀力在20世纪90年代最强,目前处于最弱的年代。(3)降雨侵蚀力主要以6-9月较大,最大值出现在7月,风蚀气候侵蚀力则以冬春两季较大,4月最大,二者具有明显的非同步性。(4)陕西省降雨侵蚀力存在2~4 a, 8 a和31~32 a共3个时间尺度的振荡周期,风蚀气候侵蚀力变化主要存在5~10 a和31~32 a两个时间尺度的振荡周期。2009年为降雨侵蚀力突变年份,降雨侵蚀力自此逐渐上升,突变前后降雨侵蚀力相差416.27 MJ·mm/(hm^(2)·h)。[结论]目前,陕西省大部分地区降雨侵蚀力均处于较强的时期,尤以陕北北部降雨侵蚀力距平最大,且陕北北部全省风蚀气候侵蚀力最强的区域,榆林东部风蚀气候侵蚀力近40年亦呈上升趋势,该地区风蚀水蚀气候侵蚀力的增长更应引起重视。

城市热岛下TMY的修订方法及其对建筑能耗的影响——以西安市为例

通过对西安建筑科技大学雁塔校区自测气象数据与气象局所建台站的实测气象数据进行对比分析,确定实测地与台站之间的城市热岛(UHI)强度;以台站长期观测记录数据为基准,利用"Morphing"变形方法,对建筑所在地的干球温度、相对湿度和太阳辐射等气象参数进行修订,生成UHI效应下的典型气象年(TMY);应用Energy Plus对办公建筑进行模拟,研究UHI对建筑能耗的影响。结果表明,在考虑UHI效应下,修订后的建筑负荷比修订前更接近实测地的建筑负荷。

Characteristics of Wind Speed Profiles under Complex Terrain Conditions in Loess Plateau

To reveal the changing characteristics of wind speed with altitude in under complex terrain conditions in Loess Plateau in Northern Shaanxi, based on the complete data of wind speed profiles of six wind towers in the region in a year, the diurnal, monthly, and seasonal variations of wind shear index of the wind towers as well as the changes of wind shear index with wind speed under complex terrain conditions were studied. The results showed that the wind shear index of each wind tower was positive, showing that wind speed tended to increase with the rising of altitude in most areas of Loess Plateau in Northern Shaanxi; terrain had obvious effects on wind speed profiles. The wind shear index of the wind towers was small during the day and large at night; the differences between day and night in the wind shear index of various wind towers were different; there were obvious seasonal variations in the wind shear index of the wind towers under different terrain conditions. With the increase of wind speed, the wind shear index of each wind tower increased firstly and then decreased, but the peaks of wind shear index of various wind towers ap- peared in different wind speed ranges. When wind speed varied from 3 to 12 m/s, wind shear index was larger than the comprehensive wind shear index of the wind towers, which is beneficial to the improvement of power generation of a wind power plant. Wind shear index can be used to assess wind resources of a wind power plant.

基于FloodArea模型的暴雨洪涝灾害风险预评估技术及效果检验

利用陕西气象站点逐小时降水实况、精细化格点预报、数字高程、土地利用、灾情等资料,应用水动力模型FloodArea对暴雨洪涝进行淹没模拟,在淹没水深和范围的基础上叠置承灾体属性,引入承灾体的灾损曲线,建立暴雨洪涝灾害风险预评估模型,并从数量占比和灾情占比两个角度,以县为单元进行验证,利用格点降水量预报对陕西6次大范围暴雨过程灾害风险进行预评估以及效果检验。结果表明:暴雨洪涝气象风险预估结果与实际受灾地区分布基本吻合,正确预报率73.2%,模拟结果可信度高,对于降水区域集中暴雨的风险预评估性能较分散性暴雨较高,漏报率相对低,但是空报率较高;建立的暴雨洪涝灾害风险预评估及效果检验流程,提高了气象服务的针对性,可以用于洪涝风险预评估的实际业务中,对暴雨洪涝风险管理提供技术支撑。