综合自然地理学在山区国土整治中的应用     

徐樵利 《地理学报》1987,(2)

本文论述了如何运用综合自然地理学的理论,揭示山区的自然结构,为国土整治服务。论文以湖北省山区国土整治的实践为例,在研究自然结构的基础上,分别论述了山区的农业经济、工业经济、小流域生态和旅游地等四方面的规划设计。  相似文献   

沙氏指数计算方案探讨   总被引：1，自引：0，他引：1  

张年成  朱俊峰  陈红萍  郭英莲  葛坤芳 《气象科技》2007,35(2):171-174

从沙氏指数的物理定义出发,给出了计算沙氏指数的4种方案并进行了误差分析。A方案没有考虑水汽凝结潜热,计算结果误差大;B方案虽然考虑水汽凝结潜热,但计算方法没有考虑湿绝热线的曲率等问题,计算结果虽优于A方案,但误差仍较大;C方案不仅考虑水汽凝结潜热,并从计算方法上作了改进,不仅考虑了湿绝热线的曲率等问题,同时避免了由气压直接求取气温造成误差较大的问题,计算结果优于A、B方案,比较理想,可在实际工作中使用;D方案由假绝热方程经过转化求得上升气块的温度,然后算出沙氏指数,虽然精确,但计算复杂,实际应用较困难。  相似文献   

Effect of marine litter on the benthic megafauna of coastal soft bottoms: a manipulative field experiment     

Katsanevakis S  Verriopoulos G  Nicolaidou A  Thessalou-Legaki M 《Marine pollution bulletin》2007,54(6):771-778

The effect of litter on the abundance and community structure of soft-bottom epibenthic megafauna was investigated in three coves of the Saronikos Gulf (Aegean Sea). At each site, two surfaces were defined on the sea-bottom. One of the surfaces was uniformly littered with debris (16 items per 100 m(2)), while the other remained 'clean' and acted as control. Benthic megafauna was censused with SCUBA diving, once before the littering episode and then monthly for one year. Both total abundance and the number of species showed an increasing trend in the impacted surfaces, either because the litter provided refuge or reproduction sites for mobile species or because hard-substratum sessile species had the opportunity to settle on provided surfaces. A marked gradual deviation in the community structure of the impacted surface from the control and a clear successional pattern of change in the community composition of the impacted surfaces were demonstrated.  相似文献   

Influence of seasonal variability in benthic invertebrate community structure on the use of biotic indices to assess the ecological status of a Portuguese estuary   总被引：2，自引：0，他引：2  

Chainho P  Costa JL  Chaves ML  Dauer DM  Costa MJ 《Marine pollution bulletin》2007,54(10):1586-1597

The present study focused on the use of benthic invertebrate communities to assess the ecological quality of a Portuguese estuary characterized by strong seasonal changes and with eutrophication problems. Seasonal benthic samples were collected during a flood year and the methodology proposed by the WFD Portuguese group was used to classify benthic assemblages into five different quality classes. Factor analysis was applied to classify stations based on their physical-chemical status. Different classifications were obtained with different indices and among seasons and there was low agreement between indices and index-season interactions. Diversity indices were better correlated to eutrophication related variables than AMBI and ABC method. Predictable responses of benthic indices to anthropogenic stress symptoms were stronger during the dry period.  相似文献   

汕头海岸湿地示范区的环境综合管理     

兰竹虹  廖岩  彭逸生  陈桂珠 《湿地科学与管理》2007,3(4):34-37

汕头海岸湿地由于丰富的生物多样性以及突出的人地矛盾,被联合国环境署和全球环境基金资助的"扭转南海和泰国湾的环境退化趋势"项目确定为湿地示范区。本文在对汕头海岸湿地示范区的海岸环境现状、威胁、现有管理框架进行深入分析的基础上,采用因果链分析的方法,构建了跨部门的社区参与的综合管理模式,拟通过实施综合管理,实现汕头海岸湿地的可持续发展。  相似文献   

The regionalization of urban natural disasters in China   总被引：1，自引：1，他引：0  

Jing-ai Wang  Pei-jun Shi  Xiang-sheng Yi  Hui-cong Jia  Lai-yin Zhu 《Natural Hazards》2008,44(2):169-179

An integrated urbanization level (CL) index and an integrated natural disaster intensity (QC) index were developed on the basis of Disaster System Theory and China Natural Disaster Database for integrated urban disaster risk assessment. Integrated quantitative assessments of the urban socio-economic system and the intensity of hazards in China were carried out by the Model-Tupu (map series) and inter-feedback process using digital map technology. On the basis of this assessment, China can be regionalized into three regions, namely, coastal urban disaster region, eastern urban disaster region and western urban disaster region, 15 sub-regions and 22 units. These results can provide a scientific basis for determining a city’s disaster risk management and natural disaster relief regionalization in China.

Pei-jun ShiEmail:

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Amelioration of marine farming impact on the benthic environment using artificial reefs as biofilters     

Gao QF  Shin PK  Xu WZ  Cheung SG 《Marine pollution bulletin》2008,57(6-12):652-661

An in situ monitoring of the sediment characteristics and macrobenthic communities was undertaken at a marine fish culture site in subtropical waters of Hong Kong before and after the deployment of biofilters which were made of cement concrete artificial reef (AR) structures. According to the distance to the boundary of the fish cages, 6 points were selected as sampling stations: 2 at the fish cages, 2 near the boundary of the fish culture area, and 2 reference sites further away from the culture area. Bimonthly sediment samples were collected for analysis of silt-clay fraction (SCF), moisture content (MC), total organic carbon (TOC), total Kjeldahl nitrogen (TKN) and total phosphorus (TP). The macrobenthos (>0.5mm) present in the sediment were sorted, identified and enumerated. TOC, TKN and TP levels at the fish cage stations were consistently higher than those at the reference stations over the 1-year pre-AR and 2-year post-AR deployment monitoring period. The diversity of macrofauna was significantly reduced at the fish cage stations relative to the reference sites. The intermediary stations near the fish culture area showed a transitional state of disturbance. Over the 2-year post-AR deployment period, TOC, TKN and TP showed a decreasing trend at the fish cage and intermediary stations. More diverse macrofaunal communities were recorded at the fish cage stations, with species diversity H'increasing from 0-1 at the beginning of the AR deployment to H'>2 at the end of the study. The present results demonstrated that artificial reefs can improve the benthic abiotic environment and biotic conditions beneath fish rafts which are deteriorated due to farming activities.  相似文献   

Assessing coral reef health across onshore to offshore stress gradients in the US Virgin Islands     

Smith TB  Nemeth RS  Blondeau J  Calnan JM  Kadison E  Herzlieb S 《Marine pollution bulletin》2008,56(12):1983-1991

Managing the effects of anthropogenic disturbance on coral reefs is highly dependant on effective strategies to assess degradation and recovery. We used five years of field data in the US Virgin Islands to investigate coral reef response to a potential gradient of stress. We found that the prevalence of old partial mortality, bleaching, and all forms of coral health impairment (a novel category) increased with nearshore anthropogenic processes, such as a five-fold higher rate of clay and silt sedimentation. Other patterns of coral health, such as recent partial mortality, other diseases, and benthic cover, did not respond to this potential gradient of stress or their response could not be resolved at the frequency or scale of monitoring. We suggest that persistent signs of disturbance are more useful to short-term, non-intensive (annual) coral reef assessments, but more intensive (semi-annual) assessments are necessary to resolve patterns of transient signs of coral health impairment.  相似文献   

Benthic input rates predict seagrass (Posidonia oceanica) fish farm-induced decline     

Díaz-Almela E  Marbà N  Alvarez E  Santiago R  Holmer M  Grau A  Mirto S  Danovaro R  Petrou A  Argyrou M  Karakassis I  Duarte CM 《Marine pollution bulletin》2008,56(7):1332-1342

Fish farms represent a growing source of anthropogenic disturbance to benthic communities, and efficient predictors of such impacts are urgently needed. We explored the effects of fish farm benthic organic and nutrient inputs on the population dynamics of a key seagrass species (Posidonia oceanica) in four Mediterranean deep meadows adjacent to sea bream and sea bass farms. We performed two annual plant censuses on permanent plots at increasing distance from farms and measured benthic sedimentation rates around plots. High shoot mortality rates were recorded near the cages, up to 20 times greater than at control sites. Recruitment rates increased in variability but could not compensate mortality, leading to rapid seagrass decline within the first 100 m from cages. Seagrass mortality increased with total sedimentation rates (K=0.55, p<0.0002), and with organic matter (K=0.50, p=0.001), total nitrogen (K=0.46, p=0.002) and total phosphorus (K=0.56, p<3.10(-5)) inputs. P. oceanica decline accelerated above a phosphorus loading threshold of 50mg m(-2)day(-1). Phosphorus benthic sedimentation rate seems a powerful predictor of seagrass mortality from fish farming. Coupling direct measurements of benthic sedimentation rates with dynamics of key benthic species is proposed as an efficient strategy to predict fish farm impacts to benthic communities.  相似文献   

Influence of oyster culture practices and environmental conditions on the ecological status of intertidal mudflats in the Pertuis Charentais (SW France): a multi-index approach     

Bouchet VM  Sauriau PG 《Marine pollution bulletin》2008,56(11):1898-1912

The ecological quality status (EcoQ) of intertidal mudflats constrained by Pacific oyster farming was assessed by single (H’, AMBI, BENTIX and BOPA) and multimetric (M-AMBI and average score) index approaches in the Pertuis Charentais (SW France). Fifteen sampling stations were monitored seasonally for sedimentological features and macrozoobenthos in 2004. Sediments affected by oyster biodeposits showed organic matter enrichment, and sediments from off-bottom culture sites had higher organic matter contents and lower redox potentials than sediments from on-bottom culture sites. Biotic indices consistently registered responses of macrozoobenthos to organic enrichment but there was only partial agreement between single index-derived EcoQs. The average score was better than M-AMBI and single indices for determining EcoQs. Accordingly, oyster farming alters intertidal macrozoobenthic assemblages moderately, and off-bottom cultures cause more disturbance than on-bottom cultures. Hydrodynamics and seasons may interact with culture practices in smothering/strengthening biodeposition-mediated effects through dispersal/accumulation of biodeposits.  相似文献