遥感技术在三亚海岸带地质环境调查中的应用

为了研究三亚海岸带地质环境状况,本文通过遥感技术,采用1987年的TM、2000年的TM、2010年的Rapideye和2015年的QB2四个时相的卫星遥感数据,对比研究过去28年来三亚海岸带地质环境变化情况,利用平衡岬湾模型软件Mepbay对工程用海海岸进行静态平衡岸线模拟,在研究中发现三亚海岸带地质环境有较大变化,地质灾害点较多,岸线侵蚀、淤积问题突出,岸线变迁幅度较大,造成三亚海岸带地质环境变化的主要原因是人们过度开发海岸带资源,用海工程规划设计不合理,缺乏环境保护意识,其次是自然因素。     

新区土地集约利用评价——以5个国家级新区为例

针对城市新区土地集约利用低,不能统分发挥其经济效益、社会效益和环境效益等问题,本文对新区进行了熵权模糊综合评价。本文以5个国家级新区为研究对象,研究选取了重要程度较高,能客观反映开发区状况的12项指标,并利用熵权法对指标赋予权重;根据模糊变换原理以及最大隶属度原则,构建了模糊综合评价模型;使用Python构建模糊计算流程脚本,输入权重及各指标值,计算5个国家级新区的结果向量,并利用最大隶属度原则确定了其对应的土地集约利用程度,从而得出结论:5个国家级新区中,1个新区处于集约利用,3个新区处于适度利用,1个新区处于轻度利用。本文采用的土地集约利用评价方法具有较高的适用性,可为土地集约利用程度的提升提供现实依据。     

Long-duration PMP and PMF estimation with SWAT model for the sparsely gauged Upper Nujiang River Basin

For large sparsely gauged basins, it is difficult to estimate long-duration probable maximum precipitation (PMP) and probable maximum flood (PMF) due to insufficient observed data and precipitation spatial distribution uncertainty. In this paper, a framework coupling the China Grid Daily Precipitation Datasets (CGDPDs) with Soil and Water Assessment Tool (SWAT) was proposed to estimate the 15-day PMP and PMF for the sparsely gauged Upper Nujiang River Basin (with a drainage area of 73,484 km²). CGDPD was tested against the observations and further corrected considering the error distribution characteristics. Results showed that 1-, 3-, 7- and 15-day maximum areal precipitations based on the corrected CGDPD were 17, 7, 4 and 18% larger than those calculated only by six observed stations’ precipitation. Then CGDPD was used as the precipitation data to estimate PMP. For the spatial distribution of PMP, the 15-day PMP process on the sub-basin scale (PMP_sub-basin) could be obtained with the following procedure. First, the basin’s 15-day areal PMP was estimated. Among this estimation, the maximum 3-day PMP was estimated by moisture maximization, while the remaining 12-day PMP was estimated with the combined storm obtained by the similar process substitution method. Second, the model storm amplification approach based on water balance principle was used to distribute the areal PMP to each sub-basin to obtain the PMP_sub-basin at all 27 sub-basins. The designed PMF could be finally estimated through inputting PMP_sub-basin into SWAT. In comparison with PMF derived from PMP without spatial distribution, different duration PMFs could increase by 3–15% when considering PMP spatial distribution uncertainty. This study could provide a reasonable procedure to estimate long-duration PMP and PMF for similar basins.     

深圳大鹏湾一次球形棕囊藻藻华的发生过程及成因分析

2021年1月下旬深圳大鹏湾沿岸海域发生球形棕囊藻(Phaeocystis globosa)藻华。为了探究球形棕囊藻藻华发生动态特征及其影响因素, 于1月20日至2月1日系统调查分析了藻华发生过程中浮游植物优势种演替、球形棕囊藻囊体数量、营养盐水平以及其他环境因素的变化。结果表明: 1月20日, 中肋骨条藻(Skeletonema costatum)为绝对优势种, 1月21日球形棕囊藻囊体开始出现, 1月25日囊体数量达到最高, 达69colonies·L^-1; 1月27日红色赤潮藻(Akashiwo sanguinea)藻华出现, 随后球形棕囊藻藻华逐渐消退。灰关联分析显示, 铵盐和硝酸盐是影响球形棕囊藻囊体丰度的最主要因素。水体扰动和球形棕囊藻在磷限制条件下的竞争优势也可能有利于球形棕囊藻藻华的发生。红色赤潮藻藻华可能是球形棕囊藻藻华消退的主要原因。球形棕囊藻藻华的发生和消亡是各种理化因素和生物因素共同作用的结果。     

海底地质取样的技术标准

依据海洋地质调查的需求和海底地质取样技术规范的编制原则,研究了海底地质取样标准编制内容及作业规范技术要点,对海底地质取样标准体系构成及作业技术规程进行了探讨。     

Effects of supplemental coated or crystalline methionine in low-fishmeal diet on the growth performance and body composition of juvenile cobia Rachycentron canadum （Linnaeus）

We evaluated the effects of supplemental coated and crystalline methionine （Met） on the growth performance and feed utilization of juvenile cobia （Rachycentron canadum Linnaeus） in a 60-d feeding trial. Fish groups were fed one of six isonitrogenous and isolipidic diets： 1） fishmeal control; 2） un- supplemented experimental （low-fish-meal diet deficient in Met）; or 3） one of four Met diets supplemented with crystalline L-Met, cellulose-acetate-phthalate coated L-Met, acrylic-resin coated L-Met, or tripalmitin- polyvinyl alcohol coated L-Met. The test diets were fed to triplicate groups of cobia （initial body weight 5.40-4-0.07 g） twice a day. The weight gain and specific growth rate of the fish fed the RES diet were highest among the Met-supplemented groups and were 23.64% and 7.99%, respectively, higher than those of the fish fed with the un-supplemented experimental diet （P〈0.05）. The protein efficiency ratio of the fish fed the MET diet was significantly higher than that of the fish fed the un-supplemented experimental diet and the fish in the other methionine supplementation groups （P〈0.05）. Our results suggest that supplementation of crystalline Met in low-fish-meal diets promotes the growth performance of juvenile cobia.     

X波段相控阵天气雷达对流过程观测 外场试验及初步结果分析

中国气象科学研究院灾害天气国家重点实验室与安徽四创电子股份有限公司联合研发了专门用于快速观测对流过程、具有多波束观测能力的X波段相控阵天气雷达(XPAR),并利用该雷达与C波段双线偏振雷达(CPOL)于2013年4~6月在广东省江门市鹤山站进行了对比观测试验,以检验该雷达观测模式及其对快速变化的对流云演变过程的观测能力,为进一步改进雷达观测模式提供依据。本文首先介绍了XPAR的主要技术指标和观测模式,利用实测数据对比分析了三种观测模式观测的回波结构、灵敏度,并与C波段双线偏振雷达数据进行了对比,详细分析了2013年5月30日一次中尺度线状对流系统后部的单体的发展和消亡过程,讨论了XPAR分钟级数据在分析对流过程演变中的作用。结果表明:(1)XPAR三种观测模式获取的降水回波结构合理,实现了在1 min内完成一个高空间分辨率的体扫的探测功能,数据的时空分辨率远远高于现有的机械扫描雷达;(2)XPAR的精细观测模式数据揭示了单体触发、发展和演变过程,清晰给出了两次径向辐合发展过程及其与回波发展的关系,给出了新一代天气雷达和C波段双线偏振雷达不能提供的新的事实;(3)XPAR分钟级数据对进一步认识对流单体内部γ中尺度及其更小尺度系统的发展和演变有非常大的帮助。     

黑碳在渤海泥质区的百年沉积记录

在渤海泥质沉积区采集柱状沉积物样品,分析其黑碳含量和沉积通量,结合210Pb年龄测定,探讨百年尺度黑碳沉积通量的时间序列变化对区域人类活动的响应。结果表明:(1)研究区黑碳含量和沉积通量分别为0.24~0.49mg/g[平均为(0.32±0.07)mg/g]和0.026~0.053mg/(cm2·a)[平均为(0.040±0.008)mg/(cm2·a)],黑碳含量与我国东海内陆架等海区相当,但远低于美国港湾和瑞典大陆架等污染较严重地区;(2)黑碳通量在20世纪50年代-70年代中期和90年代初-90年代末出现两个明显的峰值,分别对应于两个阶段的生物质燃烧量和煤炭、石油等化石燃料燃烧量的急剧增加;而20世纪70年代末-80年代末较低的黑碳通量以及21世纪初黑碳通量下降的趋势则分别与黄河改道事件、我国能源利用技术提高及污染控制减排措施逐步实施等有关;(3)通过比较本文结果以及国内外其它海域和湖泊的研究资料,证明黑碳沉积记录可以作为一个良好的地球化学指标,用于评估人类活动对生态环境的影响历史。     

基于背景场的一种新的赤潮监测算法

Remote sensing has been proven to be an effective means of monitoring red tides. The spectral information is an important basis for establishing a model to monitor red tides. The spectral curves of red tide events are analyzed and compared with multiyear monthly averaged spectral curves based on MODIS data from July 2002 to June 2012, as well as spectral differences at the same location during red tide presence and absence. A red tide monitoring algorithm is developed based on the background field to extract the red tide information of the East China Sea （ECS）. With the application of the algorithm in the ECS, the results reveal that the developed model can effectively determine the location of red tides, with good correspondence to the results from an official bulletin. This demonstrates that the algorithm can effectively extract the red tide information.