地理经纬双向过渡带和复杂地形下气候的过渡性和特异性 ——以宜昌市为例          下载免费PDF全文

毛成忠  肖湛臻  李芳  雷东洋  孟芳  覃金华  黄诚 《中低纬山地气象》2023,47(1):31-37

宜昌处在我国地形第二、第三级阶梯的过渡地带,又位于我国南北过渡带秦巴山地南麓的中低纬度过渡带,长江中上游结合部,山地河谷平原并存,地形复杂,垂直高差大。气候资料分析和文献调研表明,宜昌天气气候因特殊地理环境具有过渡性和特异性：（1）年平均气温主要随地形高度递减,年总降水量主要随纬度升高减小。（2）年暴雨日数、连阴雨天数,在中西部随纬度升高而递减,等值线近似纬向排列;东部随地形升高而递增,等值线近似经向排列。（3）山地平原过渡带地形的阻挡滞留、辐合抬升等对极端短时强降水有明显加强作用,这种作用在秦岭与黄淮过渡带、太行山与华北平原过渡带有相似的天气气候效应。（4）宜昌位于江淮梅雨的西界、华西秋雨的东界,具有天气气候“分水岭”特征。（5）宜昌是暴雨雨团、西南涡移动的主要通道之一。  相似文献   

基于DTW与K-means算法的河北场雨及雨型分区特征研究     

李雨欣  王瑛  马庆媛  刘天雪  司丽丽  俞海洋 《地球信息科学学报》2021,23(5):860-868

深入挖掘气象站点的观测降雨数据,研究区域降雨的雨型规律,对于洪涝灾害预警和减灾措施制订有重要意义。本文基于河北省2005—2017年3189个站点逐小时降雨观测数据,进行“场雨”的划定,进而提取历史上各场雨的累积雨量、时长指标。采用数据挖掘技术中的DTW相似性算法进行场雨雨型的自动归类,将场雨分成Ⅰ—Ⅶ共7种雨型,包括峰值在前、中、后期的3种单峰型降雨,以及3种双峰型降雨和均匀型降雨,结果显示：河北降雨过程以Ⅰ型前期单峰值降雨、Ⅲ型中期单峰值降雨居多,二者占总降雨场次的70%以上,但空间分布上存在差异;通过K-means聚类,将河北地区分成3个雨型区：① 区, Ⅰ型和Ⅲ型降雨为主,分布在燕山丘陵气候区、冀东平原气候区和山前平原气候区。② 区,Ⅲ型、Ⅰ型、Ⅵ型、Ⅶ型降雨并重,在冀北高原气候区,承德市南部等分散分布。③ 区,Ⅲ型降雨为主,主要分布在石家庄市南部、邯郸市、邢台市大部分地区。本文将DTW相似性算法和K-means聚类方法相结合的数据挖掘技术,可以在未来的气象大数据分析中得到更多的应用。  相似文献   

乐山地区酸性降水特征、规律及防治对策     

周骏一  刘国  马小梅  李晓  贾疏源  钟国华  王能峰 《地质灾害与环境保护》2004,15(3):31-34

酸雨已成为世界性问题之一．它给人们造成了巨大的危害和损失。研究乐山酸雨污染形成机理、特征、变化规律以及防治对策,对于乐山这个优秀旅游城市来说．具有非常重要的意义。  相似文献   

1994年江淮地区首次区域性春季暴雨诊断分析     

王亦平  徐良谋  王肖成 《成都信息工程学院学报》1996,(4)

分析了１９９４年４月１９～２０日春季暴雨主要是由对流层中低层低涡和地面静止锋共同作用的结果，侧重于对低空急流的形成与变动和熵平衡方程的诊断分析，能量场与该次暴雨有很好的相关性  相似文献   

Converting tropical rain forest to forest plantation in sabah,malaysia. Part I. Dynamics and net losses of nutrients in control catchment streams     

H. Grip  A. Malmer  F. K. Wong 《水文研究》1994,8(3):179-194

Streamwatcr chemistry was monitored for five years in six streams in a paired catchment experiment in Mendolong, Sabah, Malaysia, including controls in rain forest and secondary vegetation after the [Borneo fire] of 1982–3 and comparing the effects of different ways of establishing forest plantations with Acacia mangium. Three catchments were covered with selectively logged lowland hill dipterocarp forest (W4-W6) and three (W1-W3) with secondary vegetation after forest fires. The control catchments, W3 and W6 reported in this paper, had no treatments applied. Reference monitoring at all streams was for 25 months and the total period of study reported here is 64 months. The soils in the catchments were mainly Orthic Acrisol in W3 and Gleyic Podsol in W6 and a mix of both soil types in the other catchments. Element baseflow concentrations were generally low and not significantly different from stormflow concentrations for all streams during the reference period. Concentrations were also generally consistently low for the two control streams during the whole period of measurement. Chemical inputs as wet deposition were low as a result of a high input from local convection. The rain forest on the Podsol had a tight nutrient circulation indicated by small net losses of macronutrients. The Podsol was found to have poorer conditions for soil mineralization and more surficial runoff, resulting in higher loads of S, C and N in the organic phases, with higher organic C/N ratio, in the discharge. Nitrogen was found to accumulate in both catchments. An almost double accumulation of N in W3 was attributed to a larger biomass accumulation continuing after the forest fire 3–8 years earlier. On the other hand, the Acrisol in W3 had much larger net losses of S, Si, K, Ca, Mg and Na. Most of differences could be attributed to differences in weathering between the soils and local mineralogical differences.  相似文献   

Infiltration at the Tai rain forest (Ivory Coast): Measurements and modelling     

A. Wierda  A. W. L. Veen  R. W. A. Hutjes 《水文研究》1989,3(4):371-382

Infiltration experiments have been performed at three sites along a well-known catena under virgin tropical rain forest using a portable sprinkling infiltrometer. Experimentally determined infiltration curves are presented. Infiltration curves are also simulated on the basis of the Mein-Larson equation. The parameters for this model have been obtained from the infiltration curves (saturated conductivity) and simple soil moisture determinations (fillable porosity). The agreement between experimentally determined and modelled infiltration is reasonable, provided (a) saturated conductivity as derived from the experimental data is corrected, (b) a storage parameter, also derived from the experimental data, is added to the Mein-Larson model, and (c) the decline in soil porosity with depth is either small or occurs abruptly at shallow depth. Comparison of observed infiltration rates with rainfall intensity shows that Horton Overland Flow has to occur naturally at least on the middle and lower section of the catena. Despite the fact that most parameters can be estimated in principle from basic soil data, it remains advisable to obtain sprinkling infiltrometer field measurements, because of soil variability due to dynamic surface conditions, macroporosity, air entrapment, and irregularity of the wetting front.  相似文献   

模拟酸雨及施磷对水稻土中铅的淋溶特性影响   总被引：1，自引：1，他引：0  

陶春军  周涛发  李湘凌  陈永宁  陈兴仁  贾十军  陈富荣  袁峰 《现代地质》2008,22(6)

采用pH=3.0、pH=4.5与对照pH=5.6的3种模拟酸雨淋溶土柱的方法,研究酸雨及含磷酸雨淋溶下合肥市郊水稻土中铅的释放特征与规律。结果表明:经过相当于1 980 mm降水量的淋溶后,铅释放量总体上表现为随着酸雨强度增加累积淋溶量也增加的现象。酸雨作用下,施磷量越多土壤中铅的淋失总量越大。在酸雨及施磷条件下,大兴地区黄褐土中Pb较义城地区水稻土中易于淋失。  相似文献   

2015—2016年深圳地区强降水过程滴谱特征分析     

卢超  罗红艳  李磊  高瑞泉  陈元昭 《气象科技》2018,46(3):563-567

选取2015—2016年广东深圳地区的强降水过程为研究对象,降水过程按照天气条件划分为西风带型、西南季风型和热带气旋型,利用Parsivel激光雨滴谱仪和雨量筒测得的数据对广东深圳地区降水的微物理特征进行分析,结果表明：在不同降水量级的情况下,激光雨滴谱仪与雨量筒测得的分钟雨量都具有较好的对应关系,表明激光雨滴谱仪能够适应深圳地区多暴雨的环境;热带气旋带来的降水小粒径雨滴密度最大,大粒径雨滴密度最小,整个降水过程较为绵密;西南季风带来的降水小粒径雨滴密度最小,大粒径雨滴密度最大,整个降水显得很急促;西风带型降水的特征则介于前两者之间。  相似文献   

副高外围影响下遵义市区域性暴雨的高空形势场特征研究          下载免费PDF全文

杨熠  简茂球  谢和林 《中低纬山地气象》2018,42(6):15-21

利用常规观测资料和NCEP1°×1°再分析资料,发现2007-2016年6～8月有8次区域性暴雨天气过程是由副高东退、引导高空槽东移的大尺度背景条件下,配合低层系统造成的,将其分类后得到三种类型：低涡槽型、高空槽气旋旋转型和高空槽低涡切变型;对每种类型的高空形势进行合成分析,找出了暴雨落区与高空系统、物理量配置之间的关系。  相似文献   

那曲市历年冰雹日数变化特征及冰雹、雷暴环境条件分析     

达瓦泽仁  央美  王秀明  等. 《气象与环境科学》2018,41(4):84-91

利用那曲市7个国家气象观测站建站至2015年的冰雹日数资料,分析了那曲市冰雹日数时空分布特征及气候突变情况,并分析了2012—2016年色尼区单站冰雹日、雷雨日个例,揭示了色尼区冰雹、雷暴发生前的环境条件。结果表明:那曲市年平均冰雹日数呈减少趋势,减少趋势最明显的是申扎县,每10 a减少4. 9天,减少趋势最弱的为色尼区和班戈县,每10 a减少1. 9天,减少趋势均通过了0. 01的显著性检验;不同区域各代表站均显示减少趋势且出现突变现象;那曲市冰雹天气具有明显的季节特征,大多集中在6—9月;降雹时间多集中在14—20时,占全天的78%。对那曲市色尼区冰雹日和雷雨(无降雹)日个例分析表明,高原较强对流发生在0℃层高度低(多在1.5 km高度以下)、CAPE值小(多在500 J·kg~(-1)以下)、风垂直切变弱的环境下,与平原地区大冰雹环境差异显著,因而高原冰雹绝大部分为直径5 mm以下的小冰雹,严格意义上应称为霰;雷雨天气低层较雹日的更暖湿,其温度露点差略小于雹日的,露点比雹日的高,因而雹日抬升凝结高度高于雷雨日的。  相似文献