Using MCMC Probit Model to Value Coastal Beach Quality Improvement

Dichotomous choice elicitation technique of contingent valuation method is broadly used in the research fields of environmental resource and recreational activity management. The binary choice type of questions are generally analyzed by using Logit or Probit probability distribution models in which a common analysis procedure is to apply MLE for estimating variable parameters before calculating the respondents’ willingness to pay. In this paper, a MCMC Gibbs sampling Probit model is adopted to maintain the three advantages it has in dealing with heteroscedasticity, high dimension numerical integral and sample size restriction problems. The results revealed that the MCMC model and MLE Probit model are strikingly consistent, which suggests that the former is much simple and reliable estimation method. At the same time, the empirically based existence value estimation of coastal beach quality improvement in Dalian, China is RMB?168 per person.

A Numerical Model of Coastal Processes of Sand Beaches Based on Long-Term Wave Series

A numerical model of shoreline change of sand beaches based on long-term field wave data is proposed, the explicit and implicit finite difference forms of the model are described, and an application of the model is presented. Results of the application indicate that the model is sensitive to the order of the input wave data, and that the effects of long-term wave series and the effects of the mean annual wave conditions on the model are different. Instead of a single wave condition, the wave series will make the calibration and the verification of the model more practical and the results of the model more reasonable.

不同行间距和秸秆覆盖量对沿海滩涂土壤特性变化和小麦产量的影响

2021年11月—2022年6月,在江苏南通沿海滩涂地区开展不同行间距和不同秸秆覆盖量的滩涂小麦种植试验,设置2个行间距模式即均匀行距25 cm+25 cm(A1)、宽窄行30 cm+20 cm(A2)和3个秸秆覆盖量处理即0 t/hm^(2)覆盖量(S0)、1.5 t/hm^(2)覆盖量(S1)、3.0 t/hm^(2)覆盖量(S2),旨在研究不同行间距和秸秆覆盖量处理下滩涂小麦生育期土壤盐分、pH、水分和温度的动态变化规律,明确行间距和秸秆覆盖组合对沿海滩涂小麦产量及其构成因素的影响。结果表明:沿海滩涂小麦种植过程中各处理0~20和20~40 cm土层盐分均具有相似的季节性变化特征,表现为12月—翌年2月盐分变化比较平稳,3月出现明显降盐,之后随着温度升高出现土壤返盐状态;同时,整体上S1和S2处理下0~20和20~40 cm的土壤盐分显著低于S0处理,但A1和A2模式下土壤盐分没有显著差异(P>0.05)。整体上A1和A2模式下滩涂小麦产量均没有显著的差异性(P>0.05),S1和S2处理相比S0处理下滩涂小麦分别提高了8.68%和11.58%(P<0.05);从产量构成因素分析,S1和S2处理相比S0处理下公顷穗数分别提高了8.90%和7.91%,每穗粒数分别提高了6.23%和6.23%。因此,研究得出秸秆覆盖对耕层土壤具有较好的控盐降盐作用,且小麦拔节分蘖期盐分降低促进了小麦穗数形成和小麦孕穗期减缓土壤返盐促进了穗粒数的增加,最终实现滩涂小麦增产的目的。

Arbuscular mycorrhizal fungi communities associated with wild plants in a coastal ecosystem

Arbuscular mycorrhizal fungi(AMF)form a near-ubiquitous mutualistic association with roots to help plants withstand harsh environments,and play a key role in the establishment of coastal beach plant communities.Yet little is known about the structure and composition of AMF communities on coastal beaches of eastern China.In this study,we investigated the occurrence,community composition and diversity of AMF associated with common wild plants on a coastal beach of North Jiangsu,China.Almost all of the local wild species were colonized by AMF except for Chenopodium album L.Thirty-seven AMF species were isolated from the rhizosphere belonging to 12 genera in seven families.Glomus was the dominant genus and Funneliformis mosseae the dominant species.The colonization,spore composition and diversity of AMF were strongly related to edaphic factors.Sodium(Na^(+))ions in the soil significantly and negatively affected the colonization rate by AMF and both soil Na^(+)levels and pH had a significant negative effect on AMF spore density and evenness.However,there was a significant positive correlation between species richness and total organic carbon.The results provide insights into soil factors affecting native AMF communities in coastal beach habitats which could benefit vegetation recovery and soil reclamation efforts.

冀东沿海沙滩微塑料污染特征及影响因素研究

沿海海滩是微塑料聚集和暴露的重要区域,并广泛存在于沙质海滩。以河北省秦皇岛浅水湾滨海浴场、昌黎黄金海岸滨海浴场、唐山祥云湾滨海浴场为例,探究了沙滩微塑料的污染特征及影响因素。通过采集12个沙滩样品进行分析,显示浅水湾、黄金海岸、祥云湾沙滩微塑料丰度处于较低水平,黑色为3个沙滩微塑料常见颜色,纤维状为主要微塑料形状,粒径主要分布在500~2 000μm之间,聚合物成分均以人造丝为主要类型,浅水湾沙滩中也存在一定量的氯化聚乙烯。从统计结果看出,微塑料的丰度主要受游客数量、渔业活动和潮汐动力等人为和自然的多种因素影响。研究成果有助于了解沙滩沉积物中微塑料的污染特征及来源,为微塑料管控、减排及防治决策提供科学依据。

岬湾海滩岬角沙丘过路输沙研究现状

文章从岬湾海滩、岬角沙丘以及岬角沙丘过路输沙的概念出发,引出岬角沙丘过路输沙的概念模式,总结岬角沙丘过路输沙的常用研究方法和研究现状,指出岬角-海滩-沙丘系统在海岸带输沙中的重要作用;针对我国海岸风沙地貌研究的现状,提出应加快海岸风沙资源现状调查、加强海岸风沙地貌过程研究以及协调海岸风沙地貌资源开发利用与修复保护,为我国海岸沙丘相关研究明确方向。

Quantitative Estimation of Coastal Changes Along Selected Locations of Karnataka, India: A GIS and Remote Sensing Approach

Qualitative and quantitative studies on changes of coastal geomorphology and shoreline of Karnataka, India have been carried out using toposheets of Survey of India and satellite imageries (IRS-P6 and IRS-1D). Changes during 30 years period are studied at each station. Significant morphological changes in landforms like spit, channel Island, coastal plain, tidal flat, lateritic plain, alluvial plain and sand bar within and adjcent to estuarine river mouths of Kali, Sharavathi, Kollur-Chakkara - Haladi and Udyavara Rivers are observed. The study indicates that gradual erosion is observed at i) Karwar spit along the northern side of the Kali river mouth, ii) the spit at the southern side of the Sharavathi river mouth and iii) at some regions of Kundapur.

Application of the Static Headland-Bay Beach Concept to a Sandy Beach: A New Elliptical Model

The headland-bay beach is one of the most common coastal types in the world.Its morphology reflects the changes that occurred during long-term evolution of the sandy coast.Several headland-bay beach models have been proposed to simulate the coastline’s configuration in equilibrium.In this paper,a new elliptical model is proposed,described,and applied.On the east coast of Laizhou Bay in Shandong Province from Longkou Port to Diaolongzui,four typical headland-bay beaches have developed,and four headland-bay beach models are used in this paper to simulate the morphology of these beaches to assess the applicability of each model.The simulation results of the elliptical model verify that it is applicable to the study area.In addition,the elliptical model is easy to use.Through simulation and field investigations,we concluded that most of the coastal segments in this area will remain in an erosion state,and the human activity has a significant impact on the shoreline’s evolution.

Georgia Black Sea Coast Protection with Free Beaches

In the paper, it is discussed reinforced coastal zones with resort-recreational functions, destructed in terms of anthropogenic pressure of the Black Sea, Georgia. Results of many years’ observations and researches prove low effectiveness of active methods of coastal protection, mostly causing and provoking intensive degradation of the beaches. Article highlights developing and constructing of free and unbounded beaches as an optimal coastal protection approach. Successful example of this approach was developing of coastal zone in 90s, in Gagra (West Georgia), Black Sea. Positive impact of this kind of artificial beach still survives. In the thesis, it is presented an attempt to scientifically prove extrapolation-traduction on the other similar coasts of the recovery of Gagra Zone beach. Based on morphodynamic analysis and comparison, according to the priorities of major features of reinforced coasts, it turned out that coast of three similar objects (Gagra, Ochamchire and Sokhumi) show homogenous aspects. Scientific expediency of providing extrapolation on other similar objects of etalon objects i.e. Gagra Beach recovered by successful coastal protection experiment. Thereby, for the purposes of creating free-artificial beach, choosing of wrecking zone of Ochamchire is based on coastal protection effectiveness and economical principals, including technical-economical effectiveness.

Floral Diversity Status in Urban Coastal Wetland &Associated Coastal Ecosystems of Crow Island Mattakkuliya, Sri Lanka

Colombo is the capital of Sri Lanka and the only wetland city in South Asia under the Ramsar Convention. Crow Island Beach Park and associated coastal area belong to the Colombo urban coastal wetland ecosystems. Crow Island wetland contributes diverse habitats for numerous flora and fauna species. The present study was conducted to assess the status of floral diversity in the Crow Island Beach Park and associated coastal ecosystem during the months of August to October 2021. Study area is divided in to three sites (A, B, C). Line transects method and field observations were used in the study. This coastal wetland consists of mosaic of five major vegetation types: Herbaceous, tree, shrub, creeper, grass and other than that marine algae namely Chaetomorpha antennina, Rhizoclonium africanum, Ulva compressa belonging to chlorophyta (green algae) and Grateloupia lithophila belonging to rhodophyta (red algae) were found in the study area. A total number of 102 flora species belonging to 50 families were recorded from the study area. There were two true mangrove species and 16 mangrove associated species in the study sites. Out of the 102 plant species 46 were recognized and documented as plants with medicinal values. Shannon-Wiener diversity indexes for mangrove and mangrove associated species were recorded as 2.378, 2.304 and 1.676 in site A, B and C respectively. Simpson’s diversity index for mangrove and mangrove associated species was recorded as 0.889, 0.874 and 0.735 respectively in site A, B and C and Jaccard index of similarity between three study sites showed high values ranging from 41% to 69% for mangrove and mangrove associated species.

近岸人工沙坝的剖面演变规律和泥沙输运机制研究综述

近岸人工沙坝养滩是一种重要的海滩养护手段,开展人工沙坝地形演变研究是海岸带保护修复工程的重要需求。本文围绕不同动力条件下的人工沙坝横向迁移规律、形态演变模式、地貌耦合规律和水沙运动机制等理论层面,以及人工沙坝平衡剖面描述和演变过程数值模拟等方法层面,总结了近年来关于人工沙坝剖面演变规律和泥沙输运机制的国内外研究进展,并提出了关键过程机理深化、模拟预测方法改进和实际养滩工程应用等方面的今后研究重点。

盐城沿海滩涂湿地不同植物群落对土壤理化性质的影响

[目的]研究沿海滩涂湿地不同植被的生长与分布对土壤理化性质影响。[方法]以江苏盐城地区滩涂湿地芦苇-互花米草群落交错带、互花米草-盐地碱蓬群落交错带、盐地碱蓬群落内部带、盐地碱蓬群落边缘带为研究对象,对各梯度带植物生长状况及土壤理化性质进行分析。[结果]整个研究区内芦苇-互花米草交错带中植株盖度、株高较高;土壤整体偏碱性,pH高于7.78;盐地碱蓬内部群落带表层土壤盐分含量较高;土壤含水量高,均大于30%,蓄水能力较强;在互花米草-盐地碱蓬高覆盖区的土壤中有机质、氨氮、总氮含量整体较高且之间呈正相关。[结论]该研究为海滨湿地保护与合理利用提供科学指导。

丁坝附近交叉波浪场引起的裂流系统实验研究

裂流是狭窄而集中的离岸方向水流,对海岸水底变形、物质输移和游泳者安全有重要影响。波浪在垂直海岸建筑物(如丁坝、航道挡沙堤等)上产生的反射会导致沿岸驻波,在驻波节点区域由于波高很小会产生裂流,这是海岸出现裂流原因之一。本研究通过物理模型实验给出了沙坝海岸上建筑物附近裂流系统不同于开敞水域交叉波裂流系统的特征,讨论了波高沿岸变化对裂流系统的各裂流单元流量平衡的影响。结果表明:建筑物的存在引起了沙坝和海岸之间背离建筑物方向的沿岸流动,这导致了裂流系统中各裂流单元之间存在着流量的交换,对各单元裂流流量大小和分布产生了直接影响;各单元侧向流流量对裂流的贡献依赖于单元距建筑物的距离。

2020—2022年临海市近岸海域海洋垃圾分布特征研究

对浙江省临海市2020—2022年近岸海域及海滩垃圾的数量和组成进行调查,并对海洋垃圾来源进行分析。结果表明:临海市近岸海域海面漂浮大块及特大块垃圾平均密度为36个/km^(2);海面漂浮小块及中块垃圾平均数量密度为3 710个/km^(2),质量密度为6.24 kg/km^(2)。海滩垃圾数量密度和质量密度分别为2.2万个/km^(2)和2 795.4 kg/km^(2)。海面漂浮垃圾和海滩垃圾主要类型均为塑料类和聚苯乙烯泡沫塑料类。海洋垃圾主要来源于人类海岸活动和其他弃置物,约93%的海洋垃圾来自陆地人类生产活动。建议增强海洋垃圾监测能力建设,完善海洋垃圾分类方法,开展多元化海洋垃圾评价体系。

波浪—海滩—沙丘相互作用研究进展

基于Web of Science数据库搜索关键词“波浪—海滩—沙丘相互作用”,筛分出与主题紧密相关的文献近百篇并对其梳理与分析,将研究阶段与理论模式进行划分,厘清当前研究存在的问题与机遇。结果发现,波浪—海滩—沙丘相互作用研究自1980s以来经历了理论提出、区域拓展、深入研究3个发展阶段。理论模式从单一的概念模式发展为不同尺度概念下的相互作用理论模式,研究方法从单一的野外测绘和海图测深资料发展到野外实地观测、室内风洞试验、3S技术与数值模拟相结合的综合研究方法;研究区域,从澳大利亚东南部海岸扩展到欧洲、北美洲、南美洲和亚洲等地海岸。同时,波浪—海滩—沙丘相互作用研究中也存在一些尚未解决的问题:针对不同区域的海岸沙丘动力地貌系统难以总结出一个具有普适应的理论模式;微观尺度内,已有的理论内容难以完全的揭示波浪、潮汐水动力与碎波带/海滩和风动力与海滩—沙丘地貌之间的复杂相互作用机理;中观尺度内,整个碎波带、海滩与沙丘系统对风暴的响应与反馈机理还需要进一步观测与深入研究,且建立事件尺度内的动力与地貌响应过程和中期地貌形态变化之间的联系还需要更长时期的实地观测与模型改进;宏观尺度内,海平面抬升引起海岸变化的预测模型需要多时空的实地观测数据支持与验证。未来可结合历史资料、实地观测数据、高分辨率遥感影像数据,综合分析各环境要素与碎波带、海滩、沙丘地形地貌之间的动力过程与形态响应关系,采用数值模拟技术揭示不同时空尺度的波浪—海滩—沙丘相互作用关系机理,进一步完善波浪—海滩—沙丘相互作用理论内容。

深圳龙岐湾海滩资源调查与开发建议

文章基于2022年春、秋季开展的龙岐湾沙滩资源调查数据,分析较场尾沙滩、大塘角沙滩、黄泥湾沙滩和桔钓沙沙滩的剖面特征、沉积物粒径和裂流发生情况。研究结果表明:4处沙滩剖面的坡度秋缓春陡,剖面受风浪和潮汐直接作用时坡度变化大,受遮蔽时坡度变化小,整体呈冬春淤积、夏秋侵蚀;沙滩沉积物以中砂、粗砂和砾石为主,粒径变化不大;沙滩均无明显裂流发生,为低风险等级。建议开发沙滩旅游应考虑季节性的补沙方案,开展围垦养殖和海岸工程应注意削弱ESE向和SE向的波浪作用。

沿海地区高校体育课程引入海滩体育运动特色项目的实践研究

沿海地区高校的体育课程资源在其环境价值和课程创新倾向上有一定的优势,一方面源自于沿海地区特殊的地理位置和自然环境支持,另外一方面源自于沿海地区较为开放的课程发展思想和意识。对于高校而言,结合独特的地理位置和优越的自然环境构建多元化和特色化的体育课程是当前高校在体育学科建设方面进行跨越式发展的必经之路。本文围绕沿海地区高校体育课程引入海滩运动的特色项目建设展开研究,旨在为今后进行类似的体育课程建设提供参考。

藜麦的耐盐性评价及在滨海盐土的试种表现

为了评价不同藜麦种质资源的耐盐性差异,以123份藜麦种质资源为材料,设置4个盐浓度(100、150、250和350m M)进行苗期盐胁迫处理试验,并鉴定其盐胁迫表型。结果表明,分别有3、20和94份种质能够耐受350、250和150 m M浓度的盐胁迫,所有藜麦种质对100 m M盐处理均不敏感。之后选取可耐受350m M盐浓度的3份种质PI 614921、Ames 13726、Ames 13761和另外3个可耐受250 m M盐浓度的现代藜麦品种Pasto、Atlas和Riobamba进行全生育周期盐胁迫处理试验,盐浓度为100、150和250m M,检测盐处理后4周和收获期藜麦的株高、叶绿素含量、根系干重、地上部干重以及最终籽粒产量。结果表明,藜麦植株的各生理指标和盐处理浓度均呈显著负相关;藜麦根系干重受盐胁迫影响最大,籽粒产量所受影响最小。最后选取Pasto、Atlas和Riobamba在电导率为7.0 m S·cm-1的盐土耕地上进行株行距密度分别为5 cm×12.5 cm和5 cm×50 cm的小区试验,收获后检测各小区的产量。3个品种的折算产量最高分别可达2.18、2.48和2.26 t·hm-2,其中Atlas和Pasto适于高密度种植、Riobamba适于低密度种植。综上所述,藜麦是一种普遍耐盐的物种,但是不同种质的耐盐性之间存在较大差异;盐胁迫对于藜麦产量的影响较小,因此盐土环境下种植不会使其经济价值大幅度下降。藜麦良好的耐盐性和较高的经济价值对进一步科学合理地利用盐土资源具有重要意义。

海南岛三亚湾现代沉积环境

海南岛三亚湾海滩沉积物主要以中细砂为主,中值粒径在2.0-2.5Φ之间,为细砂质,少量样品在1.0-2.0Φ之间,属中砂质,适合于海滩旅游。近岸海底沉积物总体分布较细,为砂-粉砂-黏土的组合,仅仅在海湾西侧靠近岬角处,以中粗砂为主。近岸海底沉积物是低海平面时古河道的堆积物,能够为现代海滩提供很好的砂源,为确保海滩的稳定性提供了物质前提条件。但是,由于近20年的海岸开发,海滩东部受到人类开发活动的深刻影响,人为排放的有机物污染使海滩部分出现泥化和变黑,而且,由于人为的违规建筑物紧逼高潮线和大潮高潮线,破坏海滩的整体形态,改变海岸的动力条件,进而破坏了海滩旅游资源。

沿海滩涂地区不同栽培措施对禾本科牧草产量及品质的影响

为探讨沿海滩涂地区牧草高产栽培技术,以4种禾本科牧草为材料,研究了3种不同的栽培措施对不同饲草品种的饲草产量和品质的影响。结果表明:覆秸秆与添加保水剂处理饲草的产量和叶/茎比显著高于对照(P<0.05)。同一品种,覆秸秆处理饲草的可溶性碳水化合物(WSC)、粗蛋白(CP)、干物质体外消化率(IVDMD)和体外可消化干物质产量最高,粗灰分(Ash)、酸性洗涤纤维(ADF)和中性洗涤纤维(NDF)含量最低,品质最好,其次是添加保水剂处理,对照最差。不同品种之间的饲草产量和品质差异显著(P<0.05),其中青贮玉米(Zea mays L.)和高丹草(Sorghum bicolor×Sorghum sudanese)表现较好。在沿海滩涂地区,覆秸秆和添加保水剂处理可以显著提高饲草产量,改善饲草品质,但不同品种之间产量和品质差异较大。