辽东湾东部砂岸严重蚀退及其原因分析

辽东湾东部砂岸属冰后期淤长岸。近些年来遭到强烈侵蚀。不仅岬角、平直砂岸在蚀退．连一向稳定的湾内淤长岸也在转侵后退。目前，调查区１００ｋｍ海岸约有２／３的岸段出现严重蚀退现象，不少岸段年蚀退率已超过６ｍ．有的沿海公路多次内迁，引起沙滩粗化、泻湖水量加大、海水倒灌、土地咸化等一系列严重灾害。     

Locational Errors in Maps from Environmental Surveys and Their Implications for Information Extraction

1.Information on all maps, including those which depict characters of the natural environment, is subject to locational error. 2.Locational errors on field-sketched maps are attributable to inaccuracies both in the base map itself and in the method of locating and recording features onto the base map. 3.Two main sources of error associated with field sketch mapping were quantified using the River Corridor Survey maps as an example. First, channel widths are routinely exaggerated on these maps to allow recording of in-channel features. Distortions of river bank length of the order of 25% were shown to arise from a four-fold exaggeration of the width of a sinuous channel. Second, discrepancies in feature location of the order of 20% were found along a 500 m river stretch, although errors could be reduced to approximately 2% if undistorted, large-scale base maps were used. 4.An abundance scale appropriate to the inherent locational inaccuracy was devised to extract semi-quantitative information from River Corridor Surveys recorded on distorted base maps. Application of this scale to 29 River Corridor Survey maps of a 14·5 km river corridor produced a useful representation of environmental gradients within the corridor. 5.With the increasing potential to integrate and analyse environmental information within large computer databases including Geographic Information Systems, it is essential that the level of accuracy is recognised and quantified so that the errors can be allowed for in the development of methods of extracting information from the maps.     

Applying the principle of sustainability to coastal sand mining: The case of Pakiri-Mangawhai Beach,New Zealand

The purpose of New Zealand's Resource Management Act (1991) is to promote the sustainable management of natural and physical resources. Coastal sand mining may be consistent with this purpose where: (1) extractions occur from sediment systems open to inputs of sediment, and the volumes extracted do not limit the natural development, physical characteristics, and ecological diversity of the coastal environments affected; or (2) extractions from palimpsest or relict sedimentary deposits occur at a rate where the rate of extraction is insignificant compared with the volume of the resource. The response of coastal sand mining companies and consent-granting authorities to the requirements of the Resource Management Act (1991) are examined with respect to recent applications to mine sand from a coastal sand body in the Hauraki Gulf, New Zealand. The assessments of environmental effects (AEE) submitted in support of these applications do not establish the sustainability of the sand mining operations. Specifically they do not define the dimensions of the active sediment system, quantify the volume of the related resource, or state the period within which sustainability is achievable. Further, the AEE do not consider the cumulative effects of the extractions, either in terms of the total volume of sand mined or the cumulative effects of different anthropogenic activities. The test of sustainability demands a quality of information and understanding of coastal systems that is well beyond that obtained in the past or accepted at present. There is a clear need for New Zealand's resource management legislation to be supplemented by technical guidelines that help ensure the test of sustainability is rigorously applied.     

INTEGRATION OF A BASIN-SCALE WATER QUALITY MODEL WITH GIS1

ABSTRACT: Geographic Information Systems (GIS) have been successfully integrated with distributed parameter, single-event, water quality models such as AGNPS (AGricultural NonPoint Source) and ANSWERS (Areal Nonpoint Source Watershed Environmental Response Simulation). These linkages proved to be an effective way to collect, manipulate, visualize, and analyze the input and output date of water quality models. However, for continuous-time, basin large-scale water quality models, collecting and manipulating the input data are more time-consuming and cumbersome due to the method of disaggregation (subdivisions are based on topographic boundaries). SWAT (Soil and Water Assessment Tool), a basin-scale water quality model, was integrated with a GIS to extract input data for modeling a basin. This paper discusses the detailed development of the integration of the SWAT water quality model with GRASS (Geographic Resources Analysis Support System) GIS, along with an application and advantages. The integrated system was applied to simulated a 114 sq. km upper portion of the Seco Creek Basin by subdividing it into 37 subbasins. The average monthly predicted streamflw is in agreement with measured monthly streamflw values.     

Governance across the land-sea interface: A systematic review

Governance across the land-sea interface is an emerging challenge. The propensity for, and intensity of social-ecological interactions across this interface (e.g., eutrophication, sedimentation) are being exacerbated by cross-system threats (e.g., climate change). We draw on a systematic review of 151 peer-reviewed papers on governance and land-sea connections to (1) outline the current state of the literature, (2) examine the predominance of different approaches to address land-sea interactions, (3) characterize how governance is conceptualized within these approaches, (4) investigate governance challenges, and (5) provide insights into effective governance. The review finds that the number of relevant papers published per year has generally been increasing, and most of these papers are found in interdisciplinary journals. Ecosystem-based management is the most predominant approach found in the literature as a means to address land-sea interactions. Papers referring to ecosystem-based management are more likely than those referring to alternative management approaches (e.g., integrated management) to highlight science-policy integration and the need to account for interactions between ecosystem components as elements of effective governance. The main governance challenges include determining boundaries, addressing cross-scale effects, and accessing knowledge. However, few empirical studies of governance across the land-sea interface have been completed. A richer conceptual framework of governance is required to improve our ability to navigate the rapid social and environmental change occurring across the land-sea interface.     

Influence of a Large Herbivore Reintroduction on Plant Invasions and Community Composition in a California Grassland

Abstract:  Despite many successful reintroductions of large mammalian herbivores throughout the world, remarkably little attention has focused on how these actions affect native and exotic vegetation at reintroduction sites. One such herbivore is tule elk ( Cervus elaphus nannodes ), which was on the brink of extinction in the mid 1800s, but now has numerous stable populations due to intensive reintroduction efforts. Here, we summarize results from a 5-year exclosure experiment that explored the effects of tule elk on a coastal grassland in northern California. Elk significantly altered the species composition of this community; the response of annual species (dominated heavily by exotic taxa) was dramatically different from perennial species. Elk herbivory increased the abundance and aboveground biomass of native and exotic annuals, whereas it either had no effect on or caused significant decreases in perennials. Elk also decreased the cover of native shrubs, suggesting that these herbivores play an important role in maintaining open grasslands. In addition, elk significantly reduced the abundance and biomass of a highly invasive exotic grass , Holcus lanatus, which is a major problem in mesic perennial grasslands. Our results demonstrate that the successful reintroduction of a charismatic and long-extirpated mammal had extremely complex effects on the plant community, giving rise to both desirable and undesirable outcomes from a management perspective. We suspect that these kinds of opposing effects are not unique to tule elk and that land managers will frequently encounter them when dealing with reintroduced mammals.     

杭州湾南岸滨海平原土地利用/覆被空间格局变化分析

杭州湾南岸滨海平原位于沪、杭、甬经济金三角的中心地带,是我国沿海经济最发达的地区之一。研究其土地利用/覆被空间格局变化对合理利用土地资源,促进沿海地区的可持续发展具有重要意义。利用1987年和2000年2个时期的TM影像,分析了杭州湾南岸滨海平原土地利用/覆被数量及空间格局变化特征。结果表明,杭州湾南岸滨海平原建设用地、水体和养殖用地呈现明显的增长趋势,水田、旱地、滩地、林地和盐田呈减少趋势。受自然和人类活动的共同影响,土地利用/覆被类型斑块平均面积由0.245 km2降至0.173 km2,斑块密度则由4.081个/km2提高到5.781个/km2,斑块数量增加了42%。由于斑块的破碎化,大部分土地利用/覆被类型的边界密度、形态指数、分维数和斑块密度都有不同程度的增加。城市化和非农化的发展使得建设用地格局指数变化表现出一定的特殊性。     

福建近岸海域悬浮泥沙浓度遥感定量监测研究

论文在分析MODIS数据对海洋水体反射光谱特征的基础上,选用合适的探测波段构成悬浮泥沙遥感参数,并根据2003~2004年福建近岸海域海洋监控区内9个站点的海洋水色数据建立悬浮泥沙浓度遥感定量反演模式。利用已建立的模式对2001~2005年福建近岸海域悬浮泥沙浓度进行遥感反演,根据反演结果分析该海域悬浮泥沙浓度的分布及其变化特征,着重分析闽江口海域的悬浮泥沙运动特点。结果表明:福建近岸海域悬浮泥沙浓度与基于MODIS蓝光(0.438~0.448μm)和绿光(0.545~0.565μm)探测波段数据构成的遥感参数呈指数函数关系,定量反演效果比较理想,反演结果能客观地揭示福建近岸海域悬浮泥沙的浓度分布及其变化特征,为今后对该海域悬浮泥沙运动规律的深化研究奠定了基础。     

海岸带滨海盐土资源发展能源植物资源的研究

文章根据我国生物质能源发展的现状,提出了充分利用我国沿海海涂非耕地资源发展能源植物的构想。收集了一些适于海涂粗放栽培的能源植物资源,系统地筛选了耐海水、高产出的糖基类能源植物菊芋与油脂类植物油葵的一些品种与品系,并分别在江苏大丰、山东莱州海涂进行了大田试验,菊芋糖年产量在16 160~12 102 kg/hm²之间,油葵油脂年产量在2 934 kg/hm²左右。同时对菊芋、油葵的综合利用也进行了有益的探索。     

基于可再生能源配额制的东部沿海地区能源结构优化问题探讨

通过借鉴国外发展可再生能源的经验,分析了我国能源供需分布格局及其区际能源平衡的特点,论证了实施可再生能源配额制在东部沿海地区能源结构优化过程中的意义及其途径。研究表明:①2010年,全国狭义可再生能源配额目标为5.1%,广义可再生能源配额目标为18.4%;②在东部沿海各省份均实现了广义配额目标的前提下,东部沿海地区可再生能源发电占其电力需求总量和能源消费总量的比重分别上升到18.4%和3.05%,能源结构得到优化;③为此,西部水电开发可达到全国总量的63.8%,小水电发电量可占全国总量的90.6%,实现西部优势再生能源的优先开发。