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311.
沿长乐-南澳断裂带分布有非蛇绿岩型的镁铁、超镁铁质岩块;具中、新生代裂谷型岩浆组合;断裂两侧具有相似的变质岩基底及对应显著的地幔隆升地带。说明该断裂带为一条正在发育的中、新生代裂谷带。 相似文献
312.
巷道围岩温度分布及调热圈半径的影响因素分析 总被引:3,自引:3,他引:3
分析了巷道壁面水分蒸发情况下通风时间、岩石的热物理性质、巷道几何尺寸、巷道风流与围岩壁面的对流换热系数、壁面湿度系数与风流相对湿度的变化对围岩温度分布及调热圈半径的影响。随着通风时间的延长 ,围岩冷却范围逐渐向围岩内部推移 ,推移速度逐渐降低 ;巷道壁面水分蒸发和风流相对湿度对靠近壁面处围岩温度分布影响很大 ,但对深部围岩温度分布的影响逐渐变小 ,所以对调热圈半径的影响很小 ;岩石导温系数对调热圈半径及其内部的温度分布影响较大。巷道壁面风流与围岩的换热系数和巷道的几何尺寸对巷道围岩的冷却范围影响非常小。 相似文献
313.
This paper describes a remote sensing approach used to monitor temporal land use/cover (LULC) changes in Cukurova, an extensive coastal plain in the southeast Mediterranean coast of Turkey. The area has varied terrain ranging from low-lying alluvial deposits to rocky hills and mountains characterized by limestone outcrops. The ecological and economic importance of the area can be attributed to the existence of important coastal ecosystems (e.g., wetlands and sand dunes) and a wide range of industries located along the eastern coast. Temporal changes in the coastal landscape between 1984 and 2000 were evaluated using digital interpretation of remotely sensed satellite data. Pairwise comparison methods were used to quantify changes from 1984 to 1993 and 1993 to 2000 using multitemporal Landsat TM and ETM+ images, acquired in 1984, 1993, and 2000, respectively. Total change area was 2448 ha from 1984 to 1993 and increased more than twofold, to 6072 ha from 1993 to 2000. Change trends were determined using the information provided from individual change detection outputs of different periods. The most prominent changes were estimated to have occurred in agriculture, urban, and natural vegetation cover. Agriculture has increasingly grown over marginal areas, whereas urban development occurred at the expense of prime croplands across both time steps. 相似文献
314.
海湾处于陆地和海洋交汇部位,由于开发环境优越,在人类社会发展中占有非常突出的地位.浙江乐清湾海岸带地区在经济迅速发展的同时,也面临着诸如淡水资源缺乏、海洋经济发展层次和城镇化水平偏低等问题.针对这些问题,提出了相应的调控对策和建议. 相似文献
315.
316.
总结了洪泽湖湿地的11种生态服务功能,采用生态服务功能相容性分析方法,将洪泽湖湿地生态系统划分为6个功能区:重要物种栖息区、湖体水产养殖区、水产品精养区、水源供应区、社会文化功能区和污染物降解区,并提出了相应的保护措施。 相似文献
317.
A Method for Improving the Management of Controversial Wetland 总被引:3,自引:0,他引:3
Merot P Hubert-Moy L Gascuel-Odoux C Clement B Durand P Baudry J Thenail C 《Environmental management》2006,37(2):258-270
Valley bottom wetlands in agricultural landscapes often are neglected in national and regional wetland inventories. Although
these areas are small, located in the bottomlands of the headwater catchments, and scattered in the rural landscape, they
strongly influence hydrology, water quality, and biodiversity over the whole catchment area. Valley bottom wetlands often
are considered as controversial wetlands. Awareness of the functional role of wetlands is increasing, in parallel with their
progressive disappearance in intensive farming landscapes. The need to improve tools for controlling wetland management is
a primary consideration for decision makers and land users. This article proposes a method for the inventory of valley bottom
wetlands. The method is based on the functional analysis of potential, existing, and efficient valley bottom wetlands (the
PEEW approach). Several indicators are proposed for checking the validity of such an approach. Potential wetlands are delineated
by means of a topographic index using topographic and pedoclimatic criteria computed from a Digital Elevation Model and easily
accessible databases. Existing wetlands are identified from observed surface moisture, the presence of specific wetland vegetation,
or soil feature criteria. Efficient wetlands are defined through a given function, such as flow or pollutant regulation or
biodiversity control. An analysis of areas at the limits between potential, existing, and efficient wetlands highlights land
cultivated or drained in the past, which currently represents negotiating areas in which rehabilitation and other intended
management actions can be implemented. 相似文献
318.
道路全封闭声屏障的实践 总被引:2,自引:1,他引:1
简要介绍了在城市汽车道路桥上安装的一定长度的全封闭声屏障 ,简要分析了全封闭声屏障特有的隔声效果 ,介绍了全封闭声屏障的结构型式及实施过程中主要的技术问题 相似文献
319.
320.