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.

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.

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.

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。

不同水热温度条件下典型滩涂植物水热炭及炭化液溶解性有机质(DOM)光谱特征

利用芦苇(Phragmites australis)、獐茅(Aeluropus littoralis)和互花米草(Spartina alterniflora)3种沿海滩涂植物在180、220、260℃条件下制备水热炭,通过光谱技术比较了不同水热温度条件下水热炭溶解性有机质(HDOM)及炭化液溶解性有机质(ADOM)含量和组分性质特征。结果表明:滩涂植物水热炭溶解性有机碳(DOC)含量为18.04~50.13 mg·g^(-1),炭化液DOC浓度为2.67~5.46 g·L^(-1),两者DOC含量均随水热温度上升而降低。HDOM和ADOM均含有2种类腐殖质物质(C1和C2)和2种类蛋白物质(C3和C4),HDOM和ADOM总类蛋白组分含量均随水热温度上升而增加,而总类腐殖质组分随水热温度上升而下降。除互花米草HDOM和ADOM外,其他滩涂植物HDOM和ADOM类蛋白物质占比更高。HDOM和ADOM自生源组分特征明显,生物可利用性高,腐殖化程度低。HDOM芳香性、疏水性和相对分子质量高于ADOM。此外,HDOM和ADOM相对分子质量均随着水热温度的上升而下降。3种植物ADOM的芳香性和疏水性均随水热温度上升而下降,但不同植物HDOM的芳香性和疏水性随水热温度上升出现不同变化特征。HDOM和ADOM主要官能团为羧基化合物C O、芳香族C C、—OH、多糖类C—O或醚类C—O—C,其受水热温度和植物原料的影响明显。本研究结论可为水热炭和炭化液农用时施用量确定、受纳水体水质管理和农田污染物迁移转化评估提供重要的理论支撑。

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。

厦门海滩生态保护修复工程实践回顾与展望

为解决海岸蚀退、滩面下蚀、岸线固化、亲水空间有限等问题,厦门实施了我国内地首个大型海滩修复工程——观音山海滩修复工程,开启了我国生态文明建设“厦门实践”中海滩生态保护修复之先河。通过对厦门海滩生态保护修复工程实践的系统梳理和全面分析,研究了厦门海滩生态修复实践的主要技术应用及其推广,探讨了厦门海滩生态保护修复效益和发展趋势。厦门自2007年始陆续开展了系统而全面的海滩生态保护修复工程,累积修复海滩长度超过16 km,取得了明显的防灾减灾、社会经济和生态环境效益。厦门海滩生态保护修复工程实践积累了大量成功经验和修复技术,在我国沿海地区获得了广泛应用,为我国海滩养护技术体系构建与标准化以及科学化管理水平提升奠定了良好基础,为我国海滩生态保护修复工作树立了典范,是我国生态文明建设“厦门实践”的重要组成部分。

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。

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。

部分暖季型草坪草品种(系)在沿海滩涂的生长适应性及其对土壤盐度的影响

采用8个指标（密度、质地、均一性、盖度、耐旱性、萎蔫率、烧伤率及生长量）对12个暖季型草坪草品种（系）在江苏省沿海滩涂上的生长适应性进行了评价,并以电导率为指标分析了12个品种（系）对种植地土壤盐度的影响。结果表明,12个品种（系）8个评价指标的变异系数为32.51%~40.76%,差异不大;12个品种（系）在8个评价指标方面的排序不一致,但总体上各指标中得分最高的前3位均包含了海雀稗‘P006’（Paspalum vaginatum‘P006’）和沟叶结缕草‘Z014’（Zoysia matrella‘Z014’）,而得分最低的均为狗牙根〔Cynodon dactylon（L.）Pers.〕的品种（系）。12个品种（系）中,海雀稗‘P006’综合排名第1,生长适应性最好;沟叶结缕草‘Z014’、结缕草‘Z080’（Z.japonica‘Z080’）和中华结缕草‘Z008’（Z.sinica‘Z008’）的综合排名分别为第2、第3和第4位,生长适应性也较好;而8个狗牙根品种（系）的得分排在第5至第12位,生长适应性较差。从2006年7月至2007年11月,12个品种（系）种植地的土壤平均电导率均随时间的延长出现一定的波动,但总体上呈现逐渐下降的趋势并达到相对一致的水平,且均明显小于空白地的土壤平均电导率。不同品种（系）对种植地土壤的脱盐作用有一定的差异,其中,狗牙根‘C807’的脱盐效应最佳,在所有供试品种（系）中排序第1;而海雀稗‘P006’和沟叶结缕草‘Z014’也具有一定的脱盐效应,在所有供试品种（系）中分别排在第6和第7位。综合分析结果显示,海雀稗‘P006’和沟叶结缕草‘Z014’对盐碱地的适应性较强并具有一定的脱盐效应,可作为滩涂绿化和盐碱地土壤改良的优良草种;而狗牙根‘C807’可以作为滩涂绿化和土壤改良的先锋草种。

河北省沙质海岸侵蚀灾害和防治对策

河北省沙质海岸是渤海海岸侵蚀灾害最严重的区段之一,海岸侵蚀主要表现于海滩沙粗化,滩肩迅速变窄,滩坡变陡,基岩裸露的比率增多。岸线蚀退率达1.5～3.5m/a,严重制约了海滩旅游事业。整治海难,刻不容缓。采取岸外潜坝和丁坝群等人工建筑物和大量补沙相结合的海滩养护方法应是当前最迫切、最科学和最实际的方法,只有南段沙丘和沙坝-泻湖岸段可采用植树种草的生物学方法护岸。

盐地碱蓬覆被对滨海滩涂土壤理化性质的影响

以滨海滩涂盐地碱蓬〔Suaeda salsa(Linn.)Pall.〕的覆被度(VC)为标准划定低覆被区(30%<VC≤50%)、中覆被区(50%<VC≤80%)和高覆被区(80%<VC≤100%),并以光滩区(0%≤VC≤30%)为对照,对各样地的盐地碱蓬生长指标和土壤理化指标进行测定,并分析了盐地碱蓬生长状况与土壤因子的相关性。结果表明:不同覆被区盐地碱蓬的总生物量、植株密度和株高均有显著(P<0.05)差异,但茎直径则无显著差异;随覆被度增大,盐地碱蓬的各项生长指标依次升高。各覆被区的土壤容重总体上显著低于光滩区,土壤的最大持水量、总孔隙度、毛管孔隙度和通气孔隙度总体上显著高于光滩区,其中,高覆被区的土壤物理性质变幅最大。随土层加深,各覆被区的土壤pH值总体呈升高趋势,但土壤的含水量和水溶性盐含量总体呈降低趋势;而各样地的各土壤养分含量总体呈不同的变化趋势。随覆被度增大,土壤pH值呈降低趋势,而土壤的含水量、水溶性盐和有机质含量总体呈升高趋势。与光滩区相比,各覆被区0~20 cm土层的土壤pH值和土壤全氮含量升高、土壤水溶性盐含量降低,各覆被区各土层的土壤有机质含量不同程度升高、土壤速效磷含量不同程度降低;此外,高覆被区各土层的土壤含水量及中覆被区各土层的土壤全氮含量均高于光滩区,各覆被区40~60 cm土层的土壤速效钾含量均高于光滩区。冗余分析结果表明:盐地碱蓬生长指标与土壤的容重和pH值呈极显著(P<0.01)负相关,与土壤的总孔隙度、含水量、有机质含量和全氮含量分别呈极显著或显著正相关。综合分析结果表明:相较于光滩区,盐地碱蓬覆被区的土壤结构明显改善,土壤的持水能力以及有机质和全氮的含量均不同程度升高;提示盐地碱蓬适度覆被有利于改善滨海滩涂土壤理化性质,提高土壤肥力,特别是对浅层土壤的理化性质有较大影响。

耐盐碱水稻研究现状、问题与建议

我国有234万hm^2沿海滩涂和1亿hm^2内陆盐碱地,是我国不可多得的土地后备资源,综合利用潜力巨大。水稻作为沿海滩涂和盐碱地改良的首选粮食作物,国内外学者对耐盐碱水稻开展了广泛研究。耐盐碱水稻是指能在盐(碱)浓度0.3%以上的盐碱地生长、单产在300 kg/667 m^2以上的水稻品种。本文对耐盐水稻种质资源筛选、耐盐基因/QTL的定位与克隆、耐盐水稻鉴定与评价方法、耐盐水稻新品种选育及其配套栽培技术的研究进行综述,指出耐盐碱水稻研究中存在的问题,提出进一步加强耐盐碱水稻研究的建议。

不同农艺措施对浦东滨海滩涂垦区土壤熟化的影响

上海市浦东新区滩涂垦区土壤经高灌低排水位工程淡水洗盐后进行田间试验,在水旱轮作模式中研究秸秆还田、畜禽粪便和不同茬口模式对滨海滩涂垦区土壤熟化的影响。经过2年田间试验,结果表明:不同改良措施中畜禽粪便对垦区土壤改良的效果最佳,可显著增加土壤转化酶、脲酶活性、微生物量、有机质和CEC。改良示范区产量虽然大幅度低于面上产量,但与常规对照相比,施用鸡粪和猪粪显著提高水稻及小麦产量。