新型城镇化背景下的中国农村土地制度变革研究

中国农村土地制度变革在即.文章首先讨论了在新型城镇化的历史背景下需要关注“三农”问题和农村土地制度变革,进而阐述中国农村土地制度的历史变迁、本质特征,分析其历史贡献和当前面临的制度困境,在此基础上研究主张私有化的激进土地制度变革及坚持集体化的保守土地制度变革两种不同的方式,及其与不同的城镇化策略结合后将会对中国城镇化进程产生深刻的影响.文章最后指出,在农村土地制度改革方向的选择上,笔者反对集体土地的私有化,而倾向于在土地集体所有制内部进行具体制度设计的优化和调整.     

An examination of land use change due to irrigated agriculture in north‐eastern Jordan using geoinformatics

The Jordanian government has encouraged irrigated agriculture since the early 1990s by providing low cost loans to drill private wells. The impacts of this practice on land use change were examined within a small (362 km²) area of the Jordanian Badia using Geoinformatics. Aerial photographs, SPOT and Landsat TM imageries were used, in a GIS environment, to map and examine changes in the farming patterns since 1990. Field surveys and questionnaires were used to ground truth the remotely sensed data. The results indicate that the cultivated area has increased from just 28.5 ha in 1990 to over 1000 ha in 2000 and that the number of farms has increased from 2 to 32 over the same time period. Furthermore, farm locations are moved annually restricted by the position of the well and land availability; this also causes land use change.     

The basalt stone quarries of eastern India

Quarrying of basalt stone in the Early Cretaceous Rajmahal Trap region of eastern India is increasing at an alarming pace. The quarries have created an extensive ugly landscape of pits and overburden dumps. The stone workshops continuously emit dust. These quarries generate year‐round employment in an impoverished terrain. The workforce mostly comprises the socio‐economically deprived indigenous tribal population. They are an important source of income to the State Governments of Jharkhand and West Bengal. While the need for building stone cannot be denied in a region that is rapidly industrialising and urbanising, issues of land degradation and health cannot be ignored. The paper offers measures to contain environmental degradation and generate alternative sources of income with bio‐fuel crops such as Jatropha curcas.     

A review of recent trends in house construction and land prices in Great Britain

Over the last few decades, house prices in the UK have risen at a higher rate than general prices, as measured by, for example, the retail price index. Construction prices, on the other hand, tend to have risen broadly in line with general prices. Assuming the same things are being measured in each case, this implies that, over the period, the price of land, the most significant non-construction element of house prices, has risen at a faster rate than house prices and a much higher rate than construction prices. This paper reviews past price trends and concludes that not only have house prices risen faster than construction prices but also that, as a result, construction prices represent a smaller proportion of house prices. The paper also considers briefly what might be the implications if that trend continued- or if it did not.     

From Flood Land to New Urban Area: Water Adaptation History and Visions for Daodi Flood Land in the West of Beijing

Daodi Flood Land, located in Mentougou District of Beijing, is a relatively separate flood land in the lower reaches and on the east of Yonding River. This largest landscape character area in the west of Beijing along the river illustrates the history of human–water interaction and discloses the trends and problems of rural urbanization. Focusing on Daodi Flood Land, this paper expands the research on adaptation by introducing basic concepts and research framework, and reviews the research trends from spatial, temporal, and participant aspects. Considering the typical characters of the study area, this research employed participatory approaches, such as mapping and problem and solution trees, due to the lack of continuous and accurate data. Basing on literature review and field investigation on issues of floods, agricultural irrigation, and water resource utilization, water adaptive development visions for the study area were proposed from perspectives of landscape and culture. Finally, the paper further analyzes the structural relations between adaptation problems, natural and social systems, passive and active adaptations, and planned and unplanned adaptations, with the aim to provide reference for relevant studies and applications of adaptation approaches in other cases.     

The necessity of sustainability

The objective of this study was to obtain empirical data on how well various contextual urban design principles work and thus assist in formulating evidence‐based planning. This paper reports findings from three studies, covering 51 environments and 164 participants, on how strongly these factors were related to visual appeal of a whole block of houses: (a) individual style of an infill house; (b) number of matches between an infill house and the houses in their contexts; (c) the diversity of the existing context; (d) proximity of an infill house to other houses; and (e) compatibility of the infill house with respect to the houses in their contexts. The strongest effect was found for the individual style of a new building, followed by the equivalence of judgments of compatibility and visual appeal, by the number of other houses the infill house matched, by existing visual diversity, and by distance. Policy guidance is provided for effects sufficiently strong to support evidence‐based decision making and withheld for effects for which the scientific support is currently insufficient.     

Planning for Areas Adjacent to National Parks in Victoria

Threats to national parks from development outside their boundaries are increasing especially on the urban fringe. This article examines the threats in Victoria and the USA. It looks at what has been done so far by town planners in Victoria to combat these threats. Various measures such as the use of siting and design guidelines, conservation covenants and agreements, zoning controls and the role of state and local government legislation are discussed. The article goes on to suggest what could be done. It discusses the importance of having buffer zones around parks in which the Department of Conservation and Natural Resources would become a statutory referral authority. The problems of defining the buffer zone and administering it are also discussed. The author calls for more co-operation between state and local government authorities to reduce these threats. How America handles these threats is also mentioned.     

Population growth away from the coastal zone: Thirty years of land use change and nutrient export in the Altamaha River, GA

We used more than thirty years of water quality monitoring data collected by the United States Geological Survey at several stations in the Altamaha River and its tributaries to examine the relationship between population density, agricultural land use, and nutrient export from the watershed. Population densities in the Altamaha River watershed increased during the study period, most notably in the upper watershed near metropolitan Atlanta, while agricultural land use declined throughout the watershed. NO_x, TN and P in rivers were related to human population densities, while OC and NH₄⁺ concentrations in rivers were apparently related to agricultural land use. A general pattern of increasing NO_x and TN and decreasing NH₄⁺, P and OC over time throughout the watershed reflected changing population and land use. The overall average load from the Altamaha River to the coastal zone during the study period was 1.1, 5.6, 16.9, 0.9 and 262 kmol km^− 2 yr^− 1, delivering 40, 197, 596, 30, and 9213 · 10⁶ mol yr^− 1 of NH₄⁺, NO_x, TN, P and OC, respectively, to the coastal zone. The nutrient export patterns suggest that N and P loading to rivers in the Altamaha River watershed was greatest in the upper watershed where high population densities were found, and in-stream processing, dilution, and only moderate inputs during transit through the lower watershed resulted in relatively low export from the watershed to coastal waters.     

三元复合超早强掺合料的配制及应用

利用硫酸盐、亚硝酸盐和活性掺料粉末等原料配制出了能够明显改善混凝土的早期强度、且不会对混凝土耐久性产生不利影响的三元复合超早强掺合料。使用快硬硫铝酸盐水泥、氨基苯磺酸系高效减水剂及研制的掺合料配制的路面修补混凝土,和易性好、5h抗折强度达到3.7 MPa,并具有良好的界面粘结性能和抗冻性能,在实际工程修补应用中取得了很好的效果。     

土地集约利用的规划探索与实践--以佛山市一环沿线地区控制性详细规划为例

集约利用土地要求建设用地总量限定要保证土地结构合理、功能布局结构应力求高效、在土地使用性质确定上注重价值的取向,应根据不同地块的规划用地性质、地块规模、环境容量、交通条件、景观要求及现状情况等评价因素综合确定相关控制指标的幅度范围,采用双向控制的指标体系.