广西自动气象站平行观测资料质量评估   总被引：1，自引：0，他引：1  

陆小玉  陈德诚  丘平珠 《气象研究与应用》2007,28(4):69-72

对广西2004年投入运行的39个自动气象站的自动观测资料与人工观测资料进行对比分析,形成了各个观测要素的质量评估,并对两种观测资料差异的原因进行了初步探讨。  相似文献   

胜利油田部分岸段岸滩演化和防护问题     

吴世迎  臧启运 《海洋科学进展》1997,(4)

本文在综合我所多年实地观测资料的基础上,讨论了黄河三角洲胜利油田所辖部分岸段岸滩演化和防护问题。认为岸滩演化主要受制于黄河尾闾变化和海动力的相互作用,预测了１９９６年汛期到来前黄河入海口由北汊１南侧人工改道后,岸滩发育的基本趋势和需要重视的问题。文章也讨论了防潮堤和有关海上设施的防护问题。  相似文献   

Effects of grain size distribution on mineralogical and chemical compositions: a case study from size‐fractional sediments of the Huanghe (Yellow River) and Changjiang (Yangtze River)     

Xiaojing Zhou  Anchun Li  Fuqing Jiang  Jian Lu 《Geological Journal》2015,50(4):414-433

The influence of hydrodynamics on the chemical composition of sediments is based on the uneven distribution of element abundances in different size fractions. In this study, 72 size‐fractional sediments from the Huanghe (Yellow River) and Changjiang (Yangtze River) riverbeds were measured with XRD, SEM, ICP‐AES and ICP‐MS. The analysis results show that the mineral and chemical characteristics change with grain size in the Huanghe and Changjiang sediments. According to the principal components analysis, three independent geochemical factors were found. The first factor elements, Zr, Hf, Th, U, Y, La and TiO₂ are influenced by the existence of heavy minerals. The second factor elements, Al₂O₃, alkalis, alkaline earth (excluding Ca and Sr) and most of the transitional metals are dominated by clay minerals. The third factor group includes Ca and Sr, which were controlled by calcium‐bearing mineral contents and chemical weathering intensities. The various grain size distributions greatly affect the mineralogical and chemical compositions of bulk sediments. Compared to other size fractions, the 5–6PHI size fractions of the Huanghe and Changjiang sediments have special mineralogical and chemical compositions, and intermediate volume percentages. Weight or volume percentage of each size fraction may be more suitable than mean grain‐size of the bulk sediment to elucidate the grain size effects. Chemical Index of Alteration (CIA) values increase steeply with decreasing grain size, while Weathering Index of Parker (WIP) values are relatively stable. Because of the big influence of the abundance of clay minerals on CIA values, it is questionable to use CIA as a proxy of weathering intensity. Considering the clay mineral effects, stability in values and heterogeneous material properties, WIP has the potential to indicate the chemical weathering intensity of sediments. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

渤海夏季底层氧亏损分布的年际差异分析     

李志成  魏皓  张海彦  赵化德  郑楠  宋贵生 《海洋与湖沼》2021,52(3):601-613

通过2014年和2019年观测资料分析了渤海夏季底层水体氧亏损空间分布的年际差异,同时首次揭示了黄河口东侧莱州湾 口区域的氧亏损现象,并利用三维物理生态耦合模式ROMS-CoSiNE探究了氧亏损分布年际差异的影响因素.2014年秦皇岛外氧亏损区(以溶解氧(dissolved oxygen,DO)饱和度小于70％为统计范...  相似文献   

典型天气形势与溪洛渡电站发电供求关系的影响          下载免费PDF全文

李艳  蔡芗宁  徐卫立  范晓青  吴星烨  柳晓庆 《气象科技》2022,50(3):420-427

本文利用2015—2017年溪洛渡电站逐日入库及出库流量、逐日电站出力资料、广东逐日用电负荷数据及NCEP逐日再分析资料，针对溪洛渡右岸电站汛期弃水严重、枯期水量不足，电站发电与广东用电需求存在矛盾的几种生产情景，划分为供不应求型、供过于求型和非典型供过于求型3种类型，选取典型个例分析不同类型对应的环流形势和天气成因，并提出今后溪洛渡电站调度的建议。结果表明：每年5、6月，广东常受副热带高压控制，用电需求较大，而宜宾以上流域大多受一致的偏西或西南暖湿气流控制，冷空气活动较弱，不利于产生大范围降水，使得溪洛渡电站发电能力与广东用电需求多呈供不应求型；7—9月，宜宾以上流域多受高原槽及切变线影响，有利于出现明显降水，电站具备满发能力，而华南一般有低涡切变或台风活动，有利于广东出现降水，由于不受副高控制且出现降水，广东用电需求降低，导致出现供过于求型；如广东在副热带高压控制之下，用电需求旺盛，但溪洛渡右岸具备满发能力而出现弃水的情景，往往是因为西南地区降水总体较强，其他水电站加大出力，而电网送出受限等多方面因素影响，导致电网对溪洛渡右岸的电能需求减少，即出现非典型供过于求型。在实际发电生产中可根据天气环流形势提前研判，更加有针对性地开展水库调度、优化电站运行，增加汛期水电电能的有效消纳以及水能资源充分利用。  相似文献