快速城市化进程中土地集约利用的对策探讨

土地是中国可持续发展的最基础资源。在我国城市化的快速发展中,原本稀缺的土地资源供求矛盾日益突出,土地的集约利用成为时代必需。在分析我国城市化进程中用地矛盾的基础上,探讨了土地集约利用的可行性,并有针对性地提出了土地集约利用的对策措施。     

北京市湿地面积动态变化及其驱动因子分析

在研究了北京市湿地面积赋存量与降雨量、上游水资源量、地下水资源量、城建区面积和GDP等因素的基础上,试图找出影响湿地赋存面积的主要因素,以期为湿地的合理规划和管理提供科学依据。结果显示,北京市湿地动态变化存在显著的自然和人为方面的驱动力因素,自然因素如降雨量,上游来水量和地下水资源量为湿地的退化提供了内在动因,而人类的城市化活动如建成区面积和经济开发则加速了湿地的退化和转化;主成份分析结果显示,第一、第二主成份的累积贡献率92.73%,第一主成份与入境水量、地下水量和降雨量有较大的正相关,贡献度高达93.2%以上;第二主成份与建成区面有较大的正相关,贡献度高达96.6%。     

Channel Evolution Model of Semiarid Stream Response to Urban‐Induced Hydromodification1

Hawley, Robert J., Brian P. Bledsoe, Eric D. Stein, and Brian E. Haines, 2012. Channel Evolution Model of Semiarid Stream Response to Urban‐Induced Hydromodification. Journal of the American Water Resources Association (JAWRA) 48(4): 722‐744. DOI: 10.1111/j.1752‐1688.2012.00645.x Abstract: We present a novel channel evolution model (CEM) that qualitatively describes morphologic responses of semiarid channels to altered hydrologic and sediment regimes associated with urbanization (hydromodification). The CEM is based on southern California data from 83 detailed channel surveys, hundreds of synoptic surveys, and historical analyses of aerial photographs along 14 reaches. Channel evolution sometimes follows the well‐known sequence described by Schumm et al. (Incised Channels: Morphology, Dynamics, and Control, Water Resources Publications, Littleton, Colorado, 1984) for incising, single‐thread channels; however, departures from this sequence are common and include transitions of single thread to braided evolutionary endpoints, as opposed to a return to quasi‐equilibrium single‐thread planform. Thresholds and risk factors associated with observed channel response are also presented. In particular, distance to grade control and network position emerged as key controls on channel response trajectory. The CEM and quantitative extensions provide managers with a framework for understanding channel responses and rehabilitation alternatives, and may be transferable to other semiarid settings. It also offers insights regarding channel susceptibility to hydromodification, highlights key boundary conditions for high‐risk channels, and underscores critical knowledge gaps in predicting the complex, discontinuous response trajectories that are highly prevalent in urbanized watersheds.     

新疆和田地区城市化与土地利用变化的定量分析

选取自然环境和人文环境比较典型的西部欠发达贫困地区-新疆和田地区作为研究区域,借助国内外城市化与土地利用变化关系方面的理论和研究成果,分析城市化进程中土地利用变化的特征;采用回归分析方法,研究城市化与土地利用变化的相关关系及城市化进程对土地利用变化的影响程度.分析结果显示,城市化与耕地、居民点及工矿用地、交通用地和未利用地间有显著的相关性,表明城市化的快速发展是造成农业用地减少和建设用地增加的主要原因.同时,耕地与未利用地等两种土地类型和城市化间的负相关关系说明,两种地类的减少与城市化的快速发展有着密切的关系.这体现了和田地区城市建设和经济的快速增长是影晌生态环境等一系列有关可持续发展问题的重要原因.     

Stormwater Runoff Quality and Quantity From Traditional and Low Impact Development Watersheds1

Abstract: The quality and quantity of residential stormwater runoff from a control, traditional, and low impact development (LID) watershed were compared in a paired watershed study. A traditional neighborhood was built using typical subdivision standards while a LID design was constructed with best management practices including grass swales, cluster housing, shared driveways, rain gardens, and a narrower pervious concrete‐paver road. Weekly, flow‐weighted, composite samples of stormwater were analyzed for nitrate + nitrite‐nitrogen (NO₃ + NO₂‐N), ammonia‐nitrogen (NH₃‐N), total Kjeldahl nitrogen (TKN), total phosphorus (TP), and total suspended solids (TSS). Monthly composite samples were analyzed for total copper (Cu), lead (Pb), and zinc (Zn). Mean weekly storm flow increased (600x) from the traditional watershed in the postconstruction period. Increased exports of TKN, NO₃ + NO₂‐N, NH₃‐N, TP, Cu, Zn, and TSS in runoff were associated with the increased storm flow. Postconstruction storm flow in the LID watershed was reduced by 42% while peak discharge did not change from preconstruction conditions. Exports were reduced from the LID watershed for NH₃‐N, TKN, Pb, and Zn, while TSS and TP exports increased.     

城市化背景下我国环境侵权救济制度的完善

21世纪是世界城市化高度发展的世纪，更是中国加速城市化进程的世纪。城市是发展现代化不可或缺的重要指标，由城市化高速发展而引发的城市特有的环境侵权正日益突显并极可能在不久的将来集中爆发，法律作为最为有效的制度手段，应该也必须为解决这一问题作出积极的回应。通过分析城市化所引发的环境侵权以及考察城市环境侵权救济的现状，对这一现状的形成原因进行探讨，并对城市化背景下如何完善我国环境侵权救济制度提出可行性建议。     

Study on Economic growth,Urbanization and Sustainable Utilization of Cultivated Land in China

By means of the dynamic regression model, this paper analyzes the relationships among economic growth, urbanization and changes of cultivated land in China, finds that the ratio of cultivated land occupied by economic growth is decreasing with social and economic growth. And, based on that, some policy suggestions on how to promote the sustainable use of cultivated land in China are put forward.     

Reduction of Urban Runoff Through Economic Incentives: Boulder,Colorado1

ABSTRACT: The problems of increased surface runoff which follow in step with urbanization can be conceptualized in terms of environmental economics. The private transformation of land from a permeable to an impermeable surface imposes the externality of increased surface runoff upon society as a whole and especially on those downstream. The city of Boulder, Colorado, has enacted an ordinance which attempts to internalize some of these external costs and at the same time decrease surface runoff from the urban environment.     

ANALYZING URBANIZATION IMPACTS ON PENNSYLVANIA FLOOD PEAKS1

ABSTRACT: The impact of man made change on the hydrology of developing watersheds is frequently measured in terms of the ratio: flood peak after development to flood peak before development over a range of return periods. However, the analysis of urbanization effects on flood frequency presents a vexing problem because of a general lack of flood data in urban areas and also because of nonstationarity in the development process. Clearly, the flood peak ratio depends on the impervious fraction and percent of basin sewered and these factors have been taken into account in recent urban flood peak models. In genral, these models are developed either by: (1) split sample analysis of available annual flood data, or (2) by computer simulation using mathematical watershed models capable of representing man made changes. The present paper discusses the results of work in progress to characterize the impact of urbanization on small developing watersheds in Pennsylvania.     

长江流域经济发达地区城市发展思路

长江流域具有优越的区位条件和良好的经济基础,改革开放后城市化水平大幅提高,目前该流域的城市格局正处于由传统的封闭型工业生产城市向经济型、开放型和以第三产业为主转变,单体城市也开始向相互依托、相互发展的城市群体转变。本文分析和总结了长江流域城市发展的现状和存在的问题,如城市化滞后于工业化、城市规划同城市发展不相适应、城市建设资金就足和城市生态环境问题等。在此基础上重点对长江中下游地区城市２１世纪发展