Analysis of water use efficiency and its dynamics in Shandong Province during 2011 -2020

In order to further enhance the water use efficiency (WUE), four WUE indicators as well as the data envelopment analysis (DEA)model and Malmquist index were combined to evaluate the WUE of 16 cities in Shandong Province during 2011 - 2020. The results showed that the WUE in Shandong Province was overall higher than that of China, but its development was unbalanced in different cities of the province. The agricultural, industrial and comprehensive water use levels in Jiaodong Peninsula were the highest among Shandong Province (especially Tsingtao City), followed by central Shandong Province, then southern Shandong Province, and northwestern Shandong Province ranked lowest (especially Binzhou and Liaocheng cities). The DEA was effective for 8 cities (Jinan, Tsingtao, Zibo, Yantai, Jining, Weihai, Rizhao and Heze)in terms of scale and technology; whereas the other 8 cities could not achieve the DEA effectiveness, among which Liaocheng City had the lowest WUE over the whole province. Furthermore, the total factor productivity (TFP)change index of Shandong Province has increased by 8.2% on average from 2011 to 2020, suggesting that the WUE in Shandong Province showed an upward trend mainly due to the increase in the technological progress. Particularly, the TFP index has increased by more than 10% in Tsingtao, Yantai and Weihai cities. However, it has overall declined since 2014 over the whole province, which even dropped to less than one during 2019 -2020. Therefore, the WUE of Shandong Province needs to be improved urgently in the near future. In order to ensure the sustainable utilization of water resources and the high-quality development of economic society, it is suggested that the investment in science and technology should be strengthened and the technological innovation should be promoted in Shandong Province. In addition, it is necessary to reasonably control the production scale in northwestern and southern Shandong Province and to promote the use of unconventional water resources

Analysis of spatial and temporal characteristics of chlorophyll-a concentration and red tide monitoring in Bohai Sea

Affected by intense human activities, Bohai Sea, the largest inland sea of China, has being suffered from serious water pollution, e.g., exacerbated water eutrophication, frequent red tide outbreaks, causing major damages to marine ecology/environment, public health, and economy. Based on MODIS data during 2014-2015, the spatial and temporal characteristics of surface layer chlorophyll-a concentration has been analyzed and then, the red tide has been monitored for Bohai Sea. The results showed that surface layer chlorophyll-a concentration was overall higher from May to October, which reached its peak in May. Spatially, chlorophyll-a concentration decreased from the coastal area to the offshore, which was higher in Qinhuangdao offshore area, Laizhou Bay, Bohai Bay and Liaodong Bay. According to the chlorophyll-a concentration threshold of 16 mg/m3 and ERGB composite, the red tide information has been successfully extracted. In the Qinhuangdao offshore area with the frequent occurrence and worst-hit area of red tide in Bohai Sea, red tide happened in May and its dispersion area reached its maximum in late May. The distribution of red tide agreed with the location of two bottom hypoxia zones in Bohai sea, suggesting that red tide outbreaks may play an important role in the formation and development of bottom hypoxia zone. The results for this study will provide scientific foundation for the red tide prediction and control of Bohai Sea

胶东半岛大沽河流域径流变化特征

大沽河是胶东半岛最大的河流,被称为青岛市的"母亲河",近年来受气候变化与人类活动的共同影响,河川径流量急剧减少,河道断流形势严峻。基于1964—2008年大沽河3个水文站点(南村、产芝水库和尹府水库)的径流资料以及青岛气象站点的气象资料,初步探讨了大沽河流域径流的年际年内特征、变化趋势及其原因。结果表明:大沽河年径流存在明显的年代际特征,45 a间有一定下降趋势,特别是20世纪80年代以来,南村站河道常出现全年断流现象;3个水文站均于60年代初发生了突变,而且尹府水库站的年径流还存在显著的准4 a的变化周期;南村站径流的季节特征及变化趋势均比较显著,年径流量的89.8%集中在汛期,汛期径流量及..

流域-河口-近海系统氮、磷营养盐输移研究综述

综述了流域-河口-近海系统氮、磷营养盐的主要来源、营养盐输移的影响因素等方面的研究,介绍了当前营养盐输移研究的主要方法,并概括了氮、磷营养盐在流域-河口-近海系统的整体性研究. 在此基础上,提出了该领域研究存在的主要问题及未来展望,强调了将流域、河口与近海系统作为一个整体,并充分发挥分布式模型的优势开展营养盐输移研究的重要

Variation of Runoff Volume in the Dagu River Basin in the Jiaodong Peninsula

大沽河是胶东半岛最大的河流,被称为青岛市的"母亲河",近年来受气候变化与人类活动的共同影响,河川径流量急剧减少,河道断流形势严峻。基于1964—2008年大沽河3个水文站点(南村、产芝水库和尹府水库)的径流资料以及青岛气象站点的气象资料,初步探讨了大沽河流域径流的年际年内特征、变化趋势及其原因。结果表明:大沽河年径流存在明显的年代际特征,45 a间有一定下降趋势,特别是20世纪80年代以来,南村站河道常出现全年断流现象;3个水文站均于60年代初发生了突变,而且尹府水库站的年径流还存在显著的准4 a的变化周期;南村站径流的季节特征及变化趋势均比较显著,年径流量的89.8%集中在汛期,汛期径流量及..

流域-河口-近海系统氮、磷营养盐输移研究综述

综述了流域-河口-近海系统氮、磷营养盐的主要来源、营养盐输移的影响因素等方面的研究,介绍了当前营养盐输移研究的主要方法,并概括了氮、磷营养盐在流域-河口-近海系统的整体性研究。在此基础上,提出了该领域研究存在的主要问题及未来展望,强调了将流域、河口与近海系统作为一个整体,并充分发挥分布式模型的优势开展营养盐输移研究的重要性。

Trends of Extreme Precipitation Events Over Shandong Province From 1961 to 2008

利用山东省1961～2008年逐日降水资料,采用百分位值法定义了极端降水事件的阈值,然后统计出极端降水事件的频次、降水量、强度和年最大日降水量,并对其空间分布和时间趋势进行分析。结果表明,山东省极端降水事件阈值的空间分布存在明显的地域差异,总体上以泰山为中心向周边逐渐减小;频次的空间差异较小,基本在18 d/a左右;极端降水量、强度和年最大日降水量的空间特征基本相似,总体呈自东南向西北递减的态势,且高值中心均分布于泰山一带。48 a来,除降水强度,极端降水事件的其他3个指标呈弱减少趋势,并于1965年左右发生了突变现象;相对中西部,胶东半岛的减少趋势更为显著。48 a来,极端降水事件的4个指标均存在明显的年代际特征,而且还存在准11 a的震荡周期,并以1984年为中间轴呈左右对称分布。 &nbsp

Comparative studies on remote sensing techniques for red tide monitoring in Bohai Sea

In Bohai Sea, one of the red-tide worst-hit areas of China, the red-tide disasters occurred frequently and aggravated in recent years. Effectively monitoring the processes of the red tide from happening to extinction is of great significance for Bohai Sea. Based on MODIS(moderate resolution imaging spectroradiometer) data, five methods including the chlorophyll concentration anomalies, the red tide index, the Rrs band ratio method, the red band difference,the Karenia brevis bloom index have been comparatively analyzed to examine their availability for red tide extraction in Bohai Sea. The results showed that these five methods could effectively extract the red tide information in the offshore area of Tianjin Binhai tourism area. Not only the range but also the spatial distribution of remote sensing detection agreed with the fact. In contrast, the red tide extraction by these five methods indicated a distinct difference in the offshore area of Qinhuangdao area,which was relatively reasonable for the chlorophyll concentration anomalies and the band ratio method. However,no matter what the method was used, the field survey data or ERGB(enhanced redgreen-blue) composite was necessarily combined to validate the performance of red tide extraction at different times or in different regions

Temporal and Spatial Characteristics of Extreme Temperature Events over Shandong Province During 1961—2008

利用山东省1961—2008年18个气象站点的日平均温度资料,分析了山东省近48年极端温度事件的时空特征。结果表明,山东省极端温度事件年发生频率的空间差异比较突出,频发区域主要集中于胶东半岛,但高、低值区域发生频率的差值相对较小,大部分区域在15～16d/a之间;无论年还是季节,极端高温和低温事件的发生频率分别呈增加和减少趋势,两者的变化趋势分别在春季和冬季最显著;变化幅度也存在空间差异,相对于西部,胶东半岛极端温度事件年发生频率的变化趋势更为显著;极端高温和低温事件的年发生频率在所有站点(极端高温事件除海阳站)均发生了突变现象,变化趋势均在20世纪90年代以来更加显著;极端温度事件呈波动变化,普遍存在准5年周期。