基于PSR模型的围填海对海洋资源影响评价方法研究

利用PSR模型中压力、状态、响应相互作用的关系阐述围填海开发活动对海洋资源的影响,基于压力、状态、响应子系统确定并标准化处理了影响评价指标,根据判断矩阵分析结果赋值了指标权重,构建了围填海开发活动对海洋资源影响的评价体系,应用该评价体系进行了福建省福清湾及海坛峡海域围填海开发活动对其海洋资源的影响分析,评价结果表明福清湾及海坛峡海域围填海开发活动对其海洋资源的影响较小。     

莱芜市煤矿区土地复垦的现状及策略研究

在人地矛盾日益紧张的大环境下,土地后备资源的开发显得愈来愈重要.作为煤炭主产区的莱芜市,煤矿区的土地复垦还处在起步阶段.该文从分析莱芜市煤矿区土地复垦的现状人手,对今后莱芜市煤矿区的土地复垦提出了建议.     

临泽边缘绿洲区盐化草甸开垦后土壤质量演变

 以黑河中游临泽边缘绿洲区为分析样区,研究了绿洲盐化草甸开垦后,不同开垦年限土壤的物理化学性状特征。结果表明,盐化草甸土壤中的黏粒从开垦前的9.18％增加到开垦30 a后的12.93％;除速效钾从开垦前的1315.50 mg·kg-1降至开垦30 a后的240.84 mg·kg-1外,土壤养分含量均有不同程度的增加;由于采取了工程、生物及农业措施来治理盐渍化,土壤全盐量明显降低,从开垦前的70.28 g·kg-1减至开垦30 a后的2.00 g·kg-1,减小了97.15％。土壤理化性状随开垦年限的增加而逐步改善。     

Dynamics of Coastal Land Use Patterns of Inner Lingdingyang Bay in the Zhujiang River Estuary

To satisfy the growing of land demand from economic development,a large scale of land reclamation from sea has been carried out in Inner Lingdingyang Bay in the Zhujiang(Pearl)River estuary in recent years.As a result,the tidal flat and the water channels became narrow,the frequency of floods increased,and the environment was un-dermined.Guangzhou Marine Geological Survey(GMGS)conducted an integrated project for marine geo-environ-ment and geo-hazards survey in 2003.With the integration of multi-temporal remote sensing images of 1977,1978,1988,1996,and 2003,GIS spatial analyzing approach and GPS technique,as well as field data and other background data of the region,this research investigated the comprehensive characteristics and the drivers of coastal land use dy-namics and shoreline changes in Inner Lingdingyang Bay.The results reveal that the reclaimed coastal land was mainly for agriculture and aquaculture in early years,but now they are used for construction sites of harbors and in-dustries,especially high-tech industry.     

Comparison of stormflow responses of surface‐mined and forested watersheds in the Appalachian Mountains,USA

The results of a hydrological analysis that was conducted as part of a larger, multifaceted, collaborative effort to quantify ecosystem functions in watersheds subjected to land‐use and land‐cover change are presented. The primary goal of the study was to determine whether a small watershed in the Appalachian region (USA) that was recently subjected to surface mining and reclamation practices produces stormflow responses to rain events that are different from those produced by a nearby reference watershed covered by young, second‐growth forest. Water balances indicated that runoff yields did not vary significantly between the two watersheds on an annual basis. Statistically significant differences (p?0·05) in runoff responses were observed on an event basis, however, with the mined/reclaimed watershed producing, on average (a) higher storm runoff coefficients (2·5×), (b) greater total storm runoff (3×), and (c) higher peak hourly runoff rates (2×) when compared with the reference watershed. Results of a unit hydrograph analysis also showed, unexpectedly, that the modelled unit responses of the two watersheds to effective rainfall pulses were similar, despite the noted differences in land cover. Differences in stormflow responses were thus largely explained by dramatic reductions in cumulative rates of rainfall abstraction (measured using infiltrometers) attributable to soil compaction during land reclamation. Additional field hydrological measurements on other mined watersheds will be needed to generalize our results, as well as to understand and predict the cumulative hydrological impacts of widespread surface mining in larger watersheds and river basins. Copyright © 2006 John Wiley & Sons, Ltd.     

北部湾软土吹填场地不同地下水位动力响应研究

为了探究不同地下水位的场地条件下对吹砂填海场地动力响应的影响,以广西北部湾吹砂填海场地为研究对象,基于FLAC3D软件结合前期室内试验结果建立了场地模型,进行了数值模拟分析。在此研究中着重分析地下水位的变化对场地加速度放大系数、加速度反应谱和地震液化效应的影响,为减轻吹砂填海建设场地的震害程度提供参考依据。结果表明:随着地下水位埋深的增加,地表加速度放大系数呈现出逐渐减小的趋势,地震放大作用主要集中在短周期,卓越周期也在短周期处取得;随着地下水位埋深的减小,地震波高频成分被过滤,低频成分被放大,场地特征周期与卓越周期均有增大趋势;地下水位变化对吹填沙土层液化的产生和发展具有显著的影响,随着地下水位的上升,砂土表现出更强的液化效应,并且液化现象随着地震峰值加速度的增大逐渐沿土层深部发展。     

Tide-induced airflow in a two-layered coastal land with atmospheric pressure fluctuations

Tide-induced airflow is commonly seen in coastal lands and affects ground stability especially with a less permeable pavement on the ground surface. A tide-induced airflow model in a two-layered unsaturated zone consisting of a highly permeable layer underneath a less permeable layer was established by Li and Jiao [Li HL, JJ Jiao. One-dimensional airflow in unsaturated zone induced by periodic water table fluctuation. Water Resour Res 2005;41:W04007. doi:10.1029/2004WR003916] to describe the one-dimensional airflow with constant atmospheric pressure at the ground surface. In this study, we expand the Li and Jiao model by considering the realistic atmospheric pressure fluctuations and the initial condition. A new transient solution to the airflow model is developed for an initial boundary value problem (IBVP). The transient solution can be used not only to calculate the subsurface air pressure at a future time with a known initial condition, but also to evaluate the asymptotic air pressure variations when time becomes long. The amplitude ratio and phase lag of the subsurface air pressure relative to the tide-induced hydraulic head variations inside the unconfined aquifer below the unsaturated zone are investigated. The results reveal that effect on the subsurface pressure due to changes of atmospheric pressure amplitude depends on the configurations of air resistance in the less permeable layer and the air-filled porosity difference in the two layers. The introduction of atmospheric pressure fluctuations into the airflow model leads to insignificant influence on water table level. A field application of the new solution at Hong Kong International Airport in Hong Kong, China is demonstrated. It indicates that the new transient solution can be conveniently used to evaluate the subsurface air pressure with discrete atmospheric pressure data at the ground surface.     

填海造陆区水环境演变与对策研究进展

填海造陆区普遍存在次生盐渍化、地下结构物腐蚀等生态环境问题,尤其在中国北方沿海地区年蒸发量远大于降雨量的水循环条件下,此类问题更为突出。在简要回顾了填海现状和发展趋势的基础上,总结了填海后地下水系统和土体环境的演变趋势,并分析了造成上述影响的主要原因。通过对比湿润地区与半干旱地区的气候差异,认为利用集雨措施来引导自然淡化过程从而构建长效淋盐机制是半干旱填海区盐渍化防治的关键。同时指出,因地制宜地规划土体结构、提升排盐能力和种植绿化植物,是搭建和维持填海造陆区健康稳定生态系统的必要之举。     

济宁市引黄充填复垦项目对黄河防洪影响评价

根据防洪影响评价的有关规范,分析了济宁市采煤塌陷地引黄充填复垦项目对黄河河势的影响,以及黄河对项目运用的影响,就影响作出防洪综合评价,并提出有关防治措施。     

连云港围填海工程对海洋生态环境的影响及防治对策研究

本文根据连云港近年来围填海造地过程及未来发展趋势,系统阐述了围填海造地对连云港海洋水环境质量、湿地功能、生物多样性、渔业资源以及海岸景观等方面的影响,进而提出了控制围填海造地对海洋生态环境不良影响的对策建议,以期为决策层提供参考依据。