Regimes of human and climate impacts on coastal changes in Vietnam

Vietnam is a tropical to subtropical country located on the eastern Asian coast where the Red (Song Hong) and Mekong rivers discharge into the sea. The catchments of these two transboundary rivers cover parts of six countries, and their water and sediment discharges greatly influence the coastal seas of Vietnam. The impact of human activities include changes in the supply and distribution of water, sediments, and nutrients; changes in the relationships and balance among dynamically interacting factors and processes; and changes in the quality of the coastal and marine environments due to the increased use and accumulation of pollutants and the loss of habitats. These impacts have resulted in increasing unpredictability and severity of coastal problems such as floods, erosion, sedimentation, and saltwater intrusion; environmental pollution; and the degradation of ecosystems, with accompanying decrease in biodiversity and fishery productivity.     

Recent socio-economic changes in relation to environmental quality of the Pearl River delta

Due to the favorable weather, abundant water resources and fertile soil, the area has been known as the homeland for crops and fish. However, being one of the most developed regions in China, the environmental quality of the Pearl River delta has deteriorated due to recent socio-economic changes during the past two decades. The drivers are industrialization and economic growth, population growth and agricultural development; and the pressures are water pollution which include nutrients and suspended solids, pesticides, other persistent toxic substances (PAHs and PCBs) and oil. These have imposed various impacts such as eutrophication, formation of red tides and biomagnification of organic contaminants through food chains. In response to these, regulatory measures have been established by the Environmental Protection Bureau of Guangdong Province, joining forces with environmental protection authorities in all urban cities and most counties, in addition to the Hong Kong Environmental Protection Department, to control pollution in order to prevent further environmental deterioration and economic loss. The present paper is an attempt by following the DPSIR approach promoted by the OECD in the early 1990s and further developed by IGBP LOICZ to review the environmental quality of Pearl River with emphasis on water quality and the impact of rapid socio-economic changes.     

江苏太湖地区农业耕作制度变化及其对地表水土环境的影响

农业耕作制度变化及其环境效应是国内外广泛关注的学术前沿问题。近60 a来，江苏太湖地区农业耕作制度发生较大变化，主要表现在种植制度从偏重粮食生产转向粮经作物协调发展，用地作物增多而养地作物减少，作物品种经历了改进与优化过程，作物熟制经历了从“双三制”恢复到两熟制。施肥种类从有机肥为主转变为完全施用化肥，氮磷钾肥投入比例从长期严重失调发展到逐渐趋于协调。在总结近60 a来江苏太湖地区农业耕作制度变化特征的基础上，〖JP2〗分析了农业耕作制度变化对地表水土环境的影响，并提出了今后需要进一步关注的研究方向     

南水北调西线一期工程对金沙江上游梯级开发的发电影响

南水北调西线一期调水工程规划从大渡河调水25亿m3，从雅砻江调水15亿m3，调水对金沙江上游大渡河及岷江、雅砻江、金沙江（简称“三江”）的水电开发带来一定影响，调水减少了电站入库水量，使“三江”的可开发水力资源减少；改变了径流的年内分配过程，使年内丰平枯期发电量结构发生变化，装机规模减少；而且，上中游河段受影响大于下游。跨流域调水工程可缓解缺水地区水资源供需矛盾，也将给调水地区带来生态环境及水电开发影响，必须全面规划，统筹兼顾，趋利避害，促进全流域，全地区经济、社会、资源与环境相互协调与可持续发展。     

Changes in rice disasters across China in recent decades and the meteorological and agronomic causes

Both climate extremes and agricultural disasters have been reported to increase in recent decades; however, so far, we have little idea on the characteristics of agricultural disasters changes, as well as their meteorological and agronomic causes. Here, using the observed records on rice disasters at agro-meteorological stations across China and the meteorological indexes, we investigated the temporal and spatial changes of major rice disasters occurrence frequency and their relationships to climate change, climate extremes and agronomic practices from 1991 to 2009. We presented the temporal and spatial changes in occurrence frequency of major rice disasters, including droughts, floods, heat stress, chilling damage, insects and diseases, during the warmer period of 2000–2009, in comparison with the period of 1991–2000, based on both the observed records and the meteorological indexes. The results showed that changes in rice disasters could be largely ascribed to changes in climate extremes in recent decades. Floods, insects and diseases occurred more frequently at earlier growth stages; in contrast, chilling damage occurred more frequently at later growth stages in southwestern China during the period of 2000–2009, in comparison with the period of 1991–2000. Our findings highlighted the options should be taken timely and scientifically to reduce the disasters and to cope with ongoing climate change, based on the characteristics of agricultural disasters changes in recent decades.     

Changes in the flood regime of S?o Francisco River (Brazil) from 1940 to 2006

Flow regulation causes various environmental impacts in the downstream reaches of impounded rivers. The S?o Francisco River (SF) basin is Brazil’s third most important watershed. Several dams have been built in its course in the last four decades, mostly for flow regulation and hydropower generation. This paper presents an evaluation of historical changes in the flood regime. Three regions of the SF River basin, which are under the influence of different levels of regulation, were studied: the lower, middle, and upper SF River. The components of magnitude, frequency, and duration of floods were quantified for each region from 1940 to 1960 (prior to the construction of the first dam) and from 1986 to 2006 (after the last dam). The results have shown the inexistence of big floods in the downstream areas, decreasing durations of small floods as well as significant changes in the annual seasonality of floods. Reductions in the flood frequency were verified in all stretches, even in non-regulated systems, such as the lower Velhas River. The climate variation, which occurred in both period, was not able to explain the changes in the flood regime of S?o Francisco River; therefore, dams and other anthropogenic activity are the main factors promoting the temporal variability of streamflows in the S?o Francisco basin.     

Island-based catchment—The Taiwan example

Rapid economic and industrial development in Taiwan over the past five decades has elevated the islands standing and earned it a place in the group known as the Four Small Dragons of Asia. Such growth, however, has been at the expense of the environment. There are currently nearly 23 million people juggling for space on the small island of 35,873 km². Aggravating the matter further, the central mountain ranges and hills take up 73.6% of the land area with some 156 peaks surpassing 3,000 m. As a result, most people live in coastal plains which amount to only 9,490 km². Pressure to move people inland has led to road construction and deforestation, both of which have contributed to an already high denudation rate of topsoil. As a consequence of this, thirteen rivers in Taiwan are now ranked among the top 20 worldwide in terms of sediment yield. Aside from this, the frequency of both floods and droughts increased prior to 1990, perhaps because of deforestation and global warming. Fortunately, the new conservation-orientated forest management policy of 1991 has alleviated the problem, somewhat, and the occurrence of floods and droughts has since decreased. The problem of water shortage, however, has worsened because of the warming trend in atmospheric temperature. Damming may ameliorate the water shortage problem but may affect the shoreline stability, as well as the ecology and water quality in the estuaries. Furthermore, these detrimental effects may go far beyond the estuaries, and even fisheries on the continental shelves may be affected.     

江苏湖泊富营养化特征、成因及解决途径

应用湖泊营养类型评价标准对江苏省主要湖泊富营养化进行了评价,以区域环境特征对苏南和苏北湖群及城郊湖泊富营养化现状、发生原因及对策进行了探讨,分析表明：城郊湖泊全部为富营养和重富营养水平,苏北湖群营养程度已接近苏南湖群,呈中富营养中期,太湖东部营养程度较之太湖西部高出一个营养级别以上。苏北湖群多为过水性湖泊,易受高浓度工农业污水脉冲式入湖影响;苏南湖群污染成因则相对较复杂,主要受城镇生活和工农业生产高污染负荷的氮磷排放影响。严格控制流域内各类污染源的源头污染物排放量、充分利用河网湿地净化功能、适度进行湖内污染底泥疏浚和生态重建工程,对控制江苏湖泊富营养化将是较有效的途径。     

河流水污染损失补偿模型研究

我国水污染问题的突出表现之一是省际间、地区间水污染纠纷接连不断, 严重影响经济发展和社会稳定。在流域不同主体之间建立水污染补偿机制,可以把水污染造成的环境外部损失内部化,从而促使污染者在治污成本和经济补偿之间进行权衡,促进水污染治理措施的有效执行和水污染纠纷的解决。在水污染经济损失评估的基础上,以河流为研究对象,采用水环境数学模型的方法描述了污染物排放的空间影响关系,进而把超量排放的环境影响与经济影响联系起来,对模型的基本特征、处理方法和应用范围进行了讨论,并且以太湖流域范围内的京杭运河为例进行实证研究,得到了河流水污染损失补偿的数学模型。     

基于环境同位素的鄱阳湖与长江关系变化解析

在气候变化和三峡工程调节的双重影响下,长江中下游通江湖泊江湖关系发生显著改变,而最大的通江湖泊—鄱阳湖—水情的变化及其引发的一系列生态和环境问题受到了高度重视和关注。为了揭示不同时期鄱阳湖与长江间的江湖关系,并初步分析三峡运行对鄱阳湖水情的影响,通过对鄱阳湖北部通江水道湖水、降水和九江段长江干流水同位素特征进行调查并探讨长江水与湖水同位素联系。结果表明:湖水、降水和长江水中δ~(18)O和δ~2H值存在明显的季节和空间变化,可用于揭示湖泊与长江间的关系。在三峡调洪削峰期(7月)湖水δ~(18)O和δ~2H值明显要高于长江水,且湖水主要以外排形式补给长江为主,其比例达75%;在三峡蓄水期(10月)长江水位高于湖口水位,从鄱阳湖出口到老爷庙湖水与长江水同位素值具有较高的相似性,表明了此水域受长江水倒灌影响;而在三峡蓄水期(11和12月)湖水同位素值偏大说明了其受到一定较强的蒸发富集影响。三峡水库运行明显改变了长江水位和流量,进而影响了鄱阳湖与长江的补排关系,调洪削峰调度阶段,较高的长江水位对鄱阳湖存在一定的顶托作用,导致湖水难以排泄。因此,三峡水库的调度需要考虑到鄱阳湖流域水情,以免加重该流域丰水期的洪涝灾害和枯水期的水资源短缺。     

气候变化下水资源适应性系统脆弱性评价——以鄱阳湖流域为例

从系统科学的视角出发,分析气候变化下水资源适应性系统脆弱性的内涵,基于脆弱性PSR分析框架,从胁迫性、敏感性、适应性3个维度构建了脆弱性评价指标体系,并采用熵值法和集对分析相结合的方法对脆弱性进行评价。结合2001～2010年鄱阳湖流域数据进行了实证研究,结果表明：10 a间鄱阳湖流域水资源适应性系统脆弱性的变化受胁迫性、敏感性和适应性的综合影响,脆弱性先明显增加后缓慢下降,但基本处于中等偏差水平。鄱阳湖流域水资源适应性系统脆弱性主要由降水量变化、自然灾害和经济发展产生的能源消耗、污染问题引发,提高系统适应性对缓解脆弱性有明显作用。根据评价分析,建议鄱阳湖流域未来从提高管理能力、经济及社会响应能力和加强环境生态治理等方面采取适应性对策;通过改善鄱阳湖流域发展方式和生态环境,减少脆弱性和提高可持续发展能力,更好地发挥鄱阳湖流域对国家生态安全的保障作用     

Expansion of cropland area and formation of the eastern farming-pastoral ecotone in northern China during the twentieth century

Land cover changes induced by historical cultivation in ecologically fragile areas involving important issues such as environmental change, ecology, and human sustainability are particularly worthy of attention. This paper reconstructs the spatial distribution of cultivated areas at the county level in the eastern farming-pastoral ecotone of northern China for four time periods during the twentieth century. The paper also analyzes how the location of cultivation ratio contours of 15 and 30 %, representing the boundaries of agricultural areas, have moved and the formation process of farming-pastoral ecotone patterns during this period. The study concludes that the area and ratio of cultivated land fluctuations increased during the twentieth century. The boundaries of the cultivation ratio contours of 15 and 30 % continually moved west and north. Moving north took priority over the other directions during the period of 1916–1940, when its center moved the farthest during the twentieth century, and the boundaries primarily moved westward during 1940–1980 and northwestward during 1980–2000. The distance, direction, and extent of the movement of the cultivation boundaries are all related to agricultural area expansion processes during this period, finally resulting in the creation of the modern farming-pastoral ecotone pattern.     

中国农业发展与环境变迁

我国农业历史悠久,农业人口众多,人类活动尤其是农业发展对地理环境的影响极大。我国地理环境在时间与空间上都有很大差异。我国的环境变迁是自然条件与人类活动相互作用的结果。有些环境变化是“积极的”,如土地开发与绿洲建设、水利与灌溉、作物与家畜驯化、平原森林的营造等等,但更多环境变化是“消极的”,如旱灾、洪涝灾害、流沙、盐渍化、森林破坏、动物灭绝、土壤侵蚀、山地灾害等等。当地理环境利用得当时,积极的环境变化将占主导;但若利用不当或利用过度,消极的环境变化将最终占优势。     

南四湖水质空间分布监测分析与水环境问题解析

南四湖作为南水北调东线工程重要的输水通道和调蓄湖泊,其水质状况一直受到人们的广泛关注。根据南四湖水质空间分布监测数据,按平均综合污染指数Pj>2的标准共筛选出29个重污染测点,其中有19个处于重污染河口外混合区,说明南四湖污染物主要来自于重污染河流;南四湖2006年秋和2007年春监测的总体平均综合污染指数分别为2.12和1.98,表明南四湖污染依然相当严重,而且秋季比春季水质更差,按湖区南阳湖、微山湖岛北、小北湖的水质最差,特别是南阳湖水质四项主要指标平均超标2倍以上。南四湖两次监测CODcr、TP、TN的单项污染分摊率平均值依次为30.6%、36.0%、33.4%,表明南四湖的主要污染物是TP、TN、CODcr。因此,在调整区域内重污染企业工业结构的同时,应实行管辖区内工业和城市生活等污水的深度处理和截蓄导用,严格执行水污染物排放标准和总量控制指标。     

水资源开发与生态环境协调发展的实例研究

结合水资源工程的必要性和以三峡工程为代表的水资源工程的环境保护措施，指出水资源开发与生态环境协调发展在理论和实践上的可行性。从防洪、能源安全、可持续发展以及水能资源蕴藏量等方面分析，我国总体水资源有限，而主要江河的中下游地区仍受到洪水威胁，在总体水资源利用程度上与世界平均水平相比还较低。水资源工程可以充分调节和利用水资源，以保障人类社会的可持续发展，但同时也会对河流形态、水文水动力学条件、水生态环境形成多方面的不利影响。为减缓或减免这些不利影响，必须从设计、施工、管理等各方面重视水资源开发与生态环境保护的协调发展。三峡工程是长江干流防洪和水资源利用的骨干工程，该工程从论证、施工及初期运行各个阶段，严格履行环境保护责任和义务，建立相关环境制度和标准，建立环境监测体系，设立科研项目和落实环境保护措施，保证了工程在发挥防洪、航运和发电功能的同时，努力成为环境友好型工程。     

南水北调工程及其生态安全：优先研究领域

南水北调工程的实施将大幅度增加黄河上游径流量，并同时减少长江尤其是其上游及汉江下游的径流量，从而导致两条主要河流及其支流的水环境改变。中线工程从汉江上游丹江口水库调水，库区上游90 000余km2内的非点源污染和1 300万人口的生活污水处理设施的缺乏对水质将产生重大影响;调水引起水文节律的改变从而对东线沿途的湖泊生态系统产生重大影响;黄淮海平原受水区可利用水量的增加也可能导致该地区的盐渍化。介绍了南水北调工程并讨论了其必要性，提出了工程对生物迁移的影响、水环境及水生态安全、水资源保护的流域生态系统管理和西部退化生态系统的恢复和重建等优先研究领域，并提出结合“中国生态系统研究网络”、“生态环境国家野外科学观测研究站”的建设和长期监测来保障工程生态安全的策略。     

南京市经济增长与工业“三废”污染水平计量模型研究

根据环境库兹涅茨曲线原理，选取南京市1985～2004年的经济与环境数据，运用SPSS和EXCEL软件，分析了经济因子与环境因子的相关关系，并建立了模拟经济因子与环境因子之间动态回归模型。研究结果表明，南京市工业废水排放量和人均GDP具有一般相关性，并不呈现库兹涅茨曲线倒“U”模型，而是呈三次曲线的“N”型，两个拐点分别在9 000元和29 000元，这可能与产业结构转变较快有关。工业废气排放量和固体废物产量与人均GDP存在显著相关性， 符合环境库兹涅茨曲线的倒“U”模型，拐点分别在30 000元和38 000元,均提前实现拐点。此外环境政策与科技对工业废水排放量影响也较大。经济结构是影响工业废气排放量和固体废物产量的主要因素，同时，南京市有利的环保科技政策使这两个环境指标提前实现拐点。     

农业面源污染现状与防治进展

通过对国内外农业面源污染研究资料的分析,认为农业面源污染的形式主要有:化肥污染、农药污染、农膜污染、秸秆燃烧污染、养殖业污染及水土流失等。农业面源污染导致了土地退化,在全世界不同程度退化的12亿hm2耕地中,约12%由农业面源污染引起;是河流和湖泊的重要污染源,导致美国40%的河流和湖泊水质不合格;是引起地表水氮、磷富营养化的主要因素,欧洲国家由农业面源污染排放的磷为地表水污染总负荷的24%-71%;中国的农业面源污染造成的水体氮、磷富营养化也显著超过来自城市的生活点源污染和工业点源污染。提出目前比较好的防治措施有:最佳农田管理措施、植被过滤带和人工湿地。建议我国控制农业面源污染必须从政策和法律上对农业生产活动进行规范,采用先进的理论和技术实行源头控制,并辅助以过程控制和末端控制。     

Urban water-related environmental transitions in Southeast Asia

This article reviews water-related urban environmental conditions in Southeast Asia. It argues that the development of urban environmental challenges in the region follows a unique pattern compared with those experienced in the now developed world. The new pattern is defined by the so called time–space telescoping of the development process. The process of time–space telescoping reduces the levels of income at which environmental challenges emerge and forces their appearance in a simultaneous fashion, as sets of problems. During previous eras, cities experienced sequential environmental transitions. Urban water-related environmental burdens emerged on local scales and expanded geographically and temporally in impact, with growing levels of affluence. Moreover, certain environmental challenges appeared later in economic growth because the technologies and practices that induced these problems emerged at higher levels of income. The article has two main findings. First, except for wealthy urban centers, for example Singapore, cities in the region are experiencing multi-scaled water burdens simultaneously. Second, low-income and middle-income cities are experiencing burdens at lower levels of income than did their contemporaries in the north.

Study on the Evolution of River Networks during Urbanization since the Development and Opening of Pudong New Area, Shanghai

1 INTORDUCTIONRivers are the artery of the earth surface system; and it isone of the major components of natural environment incities, whose quantity and quality result from the long-time interaction between environment and human activities(Chen Dechao, et al. 2002; Wang Ying, Sheng Jingfen.2002). As a symbol of reform and opening in China,Pudong New Area plays an important role in the economicdevelopment around Yangtze Delta and even all over thecountry. The 14th congress of the Com…