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1.
This article offers some reflections on beach management, on the basis of the results of a survey on the recreational use of beaches and beach users' perception, which was carried out in the Metropolitan Region of Barcelona in 1992. The first part outlines the situation of the beaches, recent metropolitan beach policy and the organization of administrative bodies responsible for beach management. Survey objectives and methods are also explained briefly. In the second part, the principal results of the survey are presented and different beaches are compared in an attempt to analyse the types of users, the uses they make and the perception they have of the beaches. The conclusions identify new emerging social needs which demonstrate that new trends in beach management are also needed. Practical recommendations, related to this emerging perception of beaches as natural systems, are suggested.  相似文献   

2.
The reflection of wave energy from natural beaches is a quantity that is rarely measured. This paper addresses the question as to whether the reflected wave energy from a beach is an important component of energy flux from an engineering point of view. Wave run-up and wave set-up are important nearshore processes in which wave reflection appears to play a major role and, consequently, the prediction of reflected wave energy from the offshore forcing irregular wave train energy at natural beaches is a first step in a better understanding of these processes. The present paper reports on wave reflection measurements at two natural beaches with different characteristics. The issue of wave reflection is addressed via separation of input and output signals using coincident pressure and velocity measurements. In the present limited analysis, reflected wave energy was not found to be significant.  相似文献   

3.
山东省滨海沙滩现状调查   总被引:1,自引:0,他引:1  
为了揭示山东滨海沙滩现状,为合理开发、利用和保护沙滩资源提供科学依据,项目组与2019年6月—8月,通过现场观测沙滩现状,收集沙滩的生态环境和其开发状态的资料,利用RTK-GPS高程仪获取沙丘-海滩剖面数据,并结合卫星遥感资料调查分析可知:滨海沙滩总个数为148个,沙滩岸线总长度约335 km,主要分布在烟台、威海、青岛和日照。74%的沙滩受人工干预,干预的方式主要以旅游型开发和渔业性开发为主,其中旅游型开发占比61.5%,渔业性开发占比35.6%。26%的沙滩保持自然状态,主要分布在乡村。在现场调查中发现,沙滩侵蚀较严重的大多为自然形态的沙滩渔业性开发的沙滩。多数沙滩的沙丘以及植被带上已经被建起养殖厂房、度假场所、娱乐设施及抛石护岸等,建筑垃圾、生活垃圾、养殖垃圾、微塑料垃圾等在滩面上屡见不鲜。结合数据及现场调查结果来看,山东省多数滨海沙滩已经处于开发状态,但是由于缺乏科学合理的规划,滨海沙滩的平衡系统已经受到严重威胁,沙滩面临消失的危险,严重影响了滨海沙滩的持续利用与发展。  相似文献   

4.
Sandy beaches constitute nearly 46 per cent of the coastline between the Cape of Good Hope and the Orange River along the west coast of South Africa. In addition, shores of mixed sand and rock make up a further 24 per cent although these are not considered here. Sandy beaches are therefore the dominant shore type along the coastline, and most are subject to high wave energy. There are two main ecological beach types along the study coastline: those that receive a high input of organic matter in the form of stranded kelp and those that do not. Neither type appears to support large stocks of surf-zone phytoplankton, but despite this, even beaches receiving no stranded kelp bear high standing stocks of infauna. This fact may be related to the location of the beaches alongside a highly productive upwelling region. Existing ecological information on sandy beaches along the Benguela coastline is reviewed and integrated to form a composite picture of present understanding of these beaches. The definition of a sandy beach includes not only the sandy intertidal zone but also the surf zone and sand dunes associated with it. Sandy beaches are characterized by the absence of attached primary producers, although in some parts of the world primary production by surf-zone phytoplankton has been found to be important. Secondary production by the infauna usually depends on matter imported into the system, except on beaches supporting important stocks of surf-zone phytoplankton. Imported organic matter is retained by beach sediments which act as a physical sieve, filtering large quantities of water with each wave and tide.  相似文献   

5.
The purpose of this paper is to compare the differences between oceanside and bayside beaches. Field data on twelve beach process and response variables were gathered from February 1972 to April 1973 on four sample beaches at Sandy Hook Spit, New Jersey. Linear correlation is used to identify the most influential process variables and determine how the interrelationships among variables differ on each beach. The analysis confirms the importance of breaker height, wave steepness and wind direction on beach response. The correlation of beach processes with their associated responses are higher on the oceanside than on the bayside beaches, indicating that local, non-storm waves may be relatively insignificant in effecting substantial beach modification.Despite the greater magnitude of processes and beach change on the oceanside sites, erosion was more persistent on the bayside during the period of study. The frequent occurrence of short, steep erosional waves on the bayside prevented onshore movement of sediment between storms, resulting in a permanent loss of material from the beach face and dune. On the oceanside, long, low, depositional waves occurring between storms replenished most of the material carried away during the storm. This fresh beach material acted as a buffer against the erosion of the dunes during the following storm.The dominant bay waves are locally generated and may therefore be simulated using meteorological variables. However, the low wave energies on the bayside sites result in an increase in the relative importance of tidal currents, wind-induced currents, and refracted ocean swell. These factors complicate the application of simplified wave process—beach response models to the study of beaches exposed to these effects.  相似文献   

6.
华南砂质海滩的动力地貌分析   总被引:12,自引:3,他引:12  
为探讨华南砂质海滩的动力地貌学特征,对不同地理岸段不同地貌形态的8 个沙滩剖面于冬、夏季进行现场重复调查和室内分析工作.据此,通过对华南海岸带地质构造、地貌和现代海岸动力环境地域变化的分析,将华南沿海砂质海岸划分为岬湾岸、沙坝-潟湖岸和夷直岸三种基本海岸地貌类型,并且从滩面倾向、海岸动力环境影响、季节冲淤变化趋势和滩面沉积物粒径、坡度的动力响应等方面探讨砂质海滩的动力地貌,得出其受制于多种环境因素的影响,其中地质构造背景和海平面变化为大尺度的砂质海岸地貌的发育奠定了基础,而全新世海侵海平面相对稳定后,海岸动力条件的塑造起着决定性的影响,浪潮作用指数是其中重要的影响指标.  相似文献   

7.
It is known that the fauna of the exposed sandy beaches are primarily controlled by physical variables; but how these variables operate along and across the beach still remains fairly under discussion. In our study, we sampled a range of exposed sandy beaches along the Northwest coast of Spain to determine the relationship between the principal physical variables of the beaches (including beach morphodynamic state), and the macrofaunal community. The fauna of these beaches comprise truly marine species along the intertidal zone as well as semi-terrestrial species in the upper and supratidal environments. These two groups respond in a different manner to the physical environment. The first group is directly controlled by the morphodynamic state of the beach, and variations in the physical environment; the second group is not clearly affected by these physical conditions. In this case, other variables such as food availability and the human uses of the upper limits of the beach seem to be more relevant in explaining the patterns observed in the macrofaunal community.  相似文献   

8.
This paper describes the environmental status and the social perception of Casa Caiada (bay 1) and Rio Doce (bay 2 and bay 3) as a consequence of the several impacts that these beaches have been suffering. The methodology adopted in this work was based on interviews with beach users and direct observations of the physical, biological and human aspects. The obtained result denotes that in Casa Caiada the better beach quality is a consequence of the better water quality, infrastructure and services permitting a higher investment in housing development, recreation, commercialization, fishing, tourism, amongst others. In contrast, northward of Rio Doce (bay 3), the beach has been considered of bad quality for the beach users. In Casa Caiada the users were the most demanding when describing the status of the beach and the necessary changes to mitigate the actual situation. On the other hand, in the most degradated area (bay 3) the users were less demanding when proposing possible changes to improve the beach/water and life quality.  相似文献   

9.
Sea-level rise is likely to cause significant changes in the morphodynamic state of beaches in the higher latitudes, resulting in steeper beaches with larger particle sizes. These physical changes have implications for beach invertebrate communities, which are determined largely by sediment particle size, and hence for ecosystem function. Previous studies have explored the relationships between invertebrate communities and environmental variables such as particle size, beach slope and exposure to wave action, and often these physical variables can be integrated in various indices of morphodynamic state. Most of these studies incorporated a full range of beach types that included wave-dominated surf beaches, where the wave action is harsh enough to enable reliable estimates of breaker height, a parameter included in several of the indices, and concluded that more dissipative beaches with gentler slopes and finer particle sizes often support a higher number of species and greater abundance than more reflective beaches. Whether these predictions remain valid for less wave-dominated beaches, where breaker height is more difficult to determine, is uncertain. In the present study, the abundance of meio- and macrofauna was quantified across a range of beaches in the UK, which are generally towards the lower energy end of the morphodynamic gradient, and their relationships with beach physical properties explored. No significant relationships were found between abundance and the standard morphodynamic indices, but significant relationships were found for both macro- and meiofaunal abundance when these indices were combined with an exposure index (derived from velocity, direction, duration and the effective fetch). All the relationships identified between abundance and combined morphodynamic indices indicated a higher abundance of both macro- and meiofauna on the more dissipative beaches. The reverse was however found for species richness. If predictions that accelerated sea-level rise will move beaches towards a more reflective morphodynamic state are correct, this could lead to declines in the abundance of meio- and macrofauna, with potential adverse consequences for ecosystem functioning.  相似文献   

10.
The applicability of recommendations of the Eurosion project to define a policy to manage coastal erosion has been tested at the “beach” scale in the Mediterranean coast. Thus, a favourable sediment status has been defined for these beaches taking into account their main functions: recreation and protection. Because they act at two different seasons, this status needs to be seasonally defined. For the protection function, the favourable sediment status depends on the level of safety fixed by the manager taking into account the importance of existing infrastructures and, for recreation it depends on the use density of the beach. The concept has been formalized for beach management within a framework where benchmarking plays a crucial role to determine the need of intervention. This has been illustrated for open cell beaches where one of its boundaries can permit variations in the sediment budget and for pocket beaches that act as closed sediment cells.  相似文献   

11.
Between 1972 and 1974 plastic marine litter on ten 1-km beaches at Amchitka Island increased from 2,221 to 5,367 items—a 2·4 x increase in a two-year period. Most litter originated from Japanese and Soviet fishing vessels, but some items were from the Asian coast, at least 1,150 km distant. In 1974 there were 345 kg of common items of plastic litter per kilometre of beach. In 1972, an estimated 1,664 metric tons of plastic litter was lost or dumped from fishing vessels in the Bering Sea and North Pacific Ocean. Stranded plastic litter persists indefinitely but rapidly becomes buried in beach material or is blown inland and covered with vegetation. The most serious environmental impact is probably entanglement of marine mammals and birds in some types of litter. The accelerating accumulation of litter could be reduced through unilateral action by countries that regulate coastal fishing privileges if these countries make litter control a condition for permission to fish.  相似文献   

12.
13.
浙江海岛沙滩质量评价体系及其应用研究   总被引:1,自引:0,他引:1  
在参考国内外主要沙滩质量评价体系的基础上,结合浙江省海岛沙滩的具体状况,构建了适用于浙江省海岛沙滩的质量评价体系,包括3大类7个亚类共29个因子。运用该体系对浙江海岛63个沙滩进行了评价,结果显示浙江海岛沙滩质量总体处于中等水平,其中五星级沙滩有7个,四星级沙滩有19个,三星级沙滩有29个,二星级沙滩有8个,表明该评价体系具有较好的适用性。  相似文献   

14.
The equation most commonly used to describe the bay planform was proposed by Hsu and Evans (1989) and it was obtained through empirical analysis of sand beach planforms.In the last decade interest in gravel sediments increased owing to their greater stability on beaches, compared with sand sediments. Due to the differences between the morphodynamics of sand and gravel beaches, which is strictly influenced by their different hydraulic characteristics, it was necessary to create a predictive instrument for this beach type as well.Therefore, in this study the standard Hsu and Evans equation (1989) was modified in order to make it applicable not only to sand beaches but also to gravel beaches. The shoreline was computed according to a parabolic model in polar coordinates whose coefficients are considered linearly dependent on the wave direction and related to the beach type. The estimation of the free parameters of the model was performed according to a statistical analysis of a shorelines data set of Mediterranean sand and gravel embayed beaches.  相似文献   

15.
Meiofauna as descriptor of tourism-induced changes at sandy beaches   总被引:9,自引:0,他引:9  
Tourism has long been considered as a 'clean industry' with almost no negative effects on the environment. This study demonstrated, in two different coastal systems (Mediterranean and Baltic), that tourism related activities are particularly affecting the sandy beach meio- and nematofauna in the upper beach zone, the specific ecotone in which many meiofauna species from both the marine and the terrestrial environment congregate. Tourist upper beaches are characterized by a lower % total organic matter (%TOM), lower densities, lower diversities (absence of Insecta, Harpacticoida, Oligochaeta, terrestrial nematodes and marine Ironidae nematodes) and higher community stress compared to nearby non-tourist locations. The %TOM was found to be the single most important factor for the observed differences in meiofauna assemblage structure at tourist versus non-tourist beaches in both the Mediterranean and the Baltic region. The free-living nematode assemblages from tourist upper zones depart significantly from expectations based on random selections from the regional nematode species pool. Furthermore upper zone assemblages are characterised by a low species diversity consisting of taxonomically closely related nematode species with r-strategist features. Generally, faunal differences between tourist and non-tourist beaches are decreasing towards the lower beach zones.  相似文献   

16.
This study describes the distribution patterns of interstitial polychaetes along morphodynamic gradients on six exposed sandy beaches in Santa Catarina and Paraná (South Brazil). Three random transects were sampled at two points on each beach, one at the swash and another at the surf zone, in winter and summer conditions. Six sediment replicates were collected at each sampling point using a corer of 4.6 cm internal diameter that removed 10 cm into the sediment. Abundance and composition of interstitial polychaete were correlated to wave height, slope, grain size, CaCO3, chlorophyll a , omega indexes, temperature and relative tide range using a canonical correspondence analysis (CCA). A factorial ANOVA showed that taxa richness, mean density and Shannon's diversity were significantly higher at the reflective beaches, but average values differ significantly between transects and these differences change according to the beach zones on both sampling dates. PERMANOVA showed that polychaete associations differ among transects according to the beach zones. The composition of interstitial polychaete associations was significantly correlated to beach morphodynamics and features (P < 0.01). Polychaete associations of reflective beaches were more diverse than in other morphodynamic states. Intermediate beaches may also sustain diverse associations due to temporal variability of the morphodynamic patterns. Beaches presenting extreme dissipative morphodynamics and compacted sediments appear to be unfavourable for the occurrence of interstitial polychaetes.  相似文献   

17.
据调查,福建沿海分布有143处主要滨海沙滩,其中已开发利用28处,可合理利用81处,需加强生态保护修复的有21处,被严重破坏已不适宜做海滩资源的有13处。本文在介绍福建滨海沙滩分布及其资源特点基础上,阐述了沿海各地海滩资源的保护与利用现状,分析了主要的资源环境问题及成因,提出了制度建设、资源管控、优化岸滩工程、污染治理、公众宣传、资金保障等有针对性的对策措施。  相似文献   

18.
国内外海滩质量评价体系研究   总被引:4,自引:0,他引:4  
海滩作为宝贵的旅游资源越来越受到关注,国外学者在海滩质量评价方面的研究工作起步较早,多个国家都已经建立了不同的海滩评价体系。其中"蓝旗"评价标准在世界范围内得到了广泛的应用。我国海滩资源较为丰富,但是质量评价体系仍处于起步阶段,尚没有形成完善的体系,仅有少部分海滩进行了质量评价,使用的标准也不统一,多由评价者自己建立标准进行评价。总结了欧洲、北美洲、大洋洲使用的主要海滩评价标准,将国外各海滩质量评价体系的启示和国内海滩质量评价的特点相结合,探讨我国海滩质量评价应选用的评价因子。认为目前建立适应我国国情、充分考虑海滩用途及沉积特征、区分旅游地和乡村的海滩质量评价体系进行海滩评价较为适宜。根据已有研究和实地考察情况,分别对旅游地和乡村海滩从自然因素、环境因素、其他因素3个方面选取了20个、15个评价因子。  相似文献   

19.
The aim of this paper is to study the macrofaunal community dynamics and the biological–environmental interactions in the mid- and sublittoral ecosystems of the microtidal Mediterranean sandy shores. Four sandy beaches, three on the island of Crete and one on the northwest coast of Italy were selected to investigate the spatial and temporal changes in the community structure and the associated environmental variables. The littoral zone, which has not been adequately studied in the Eastern Mediterranean, presents special interest not only from the scientific point of view but also for practical reasons of ecological management. The multivariate techniques revealed that the community pattern of the sandy beach macrofauna is mainly spatial rather than temporal. There are pronounced differences in species composition and abundance of the macrofaunal assemblages of the mid- and sublittoral zone. The multicausal environmental severity hypothesis appears to be valid for the sandy beach macrofaunal communities of the Mediterranean. The abundance and composition of the macrofaunal assemblages are highly variable and are affected by the synergistic effects of many environmental variables. The polychaete taxonomic assemblage structure closely follows the macrofaunal community pattern. Differences between the two patterns may arise from the different responses that polychaetes may show to the environmental stress.  相似文献   

20.
Spatial patterns of nematode community structure from two geographically spaced intermediate, micro-tidal beaches (i.e. Mediterranean and Baltic) were investigated. Differences in the nematode assemblages were found to be significantly different and related to the morphodynamic characteristics of the studied zones (upper beach, swash/breakers and subtidal). Highest nematode densities and species diversities were recorded on the coarse-grained, more physically controlled, Italian beach in contrast to the more chemically controlled Polish beach. This is in contrast to the worldwide patterns of macrofaunal communities. As demonstrated by higher taxonomic distinctness measurements, upper beaches were found to harbour species from both the marine and terrestrial ecosystem and are considered to be important ecotones between these adjacent systems. The swash/breaker zones are characterised by the loss of distinctive species caused by the high water percolation in these zones. The concept of parallel ecological communities ‘isocommunities’ is only supported for the upper beach zones.  相似文献   

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