Evaluation of Intensive Urban Land Use Based on an Artificial Neural Network Model:A Case Study of Nanjing City,China

In this paper, the artificial neural network(ANN) model was used to evaluate the degree of intensive urban land use in Nanjing City, China. The construction and application of the ANN model took into account the comprehensive, spatial and complex nature of urban land use. Through a preliminary calculation of the degree of intensive land use of the sample area, representative sample area selection and using the back propagation neural network model to train, the intensive land use level of each evaluation unit is finally determined in the study area. Results show that the method can effectively correct the errors caused by the limitations of the model itself and the determination of the ideal value and weights when the multifactor comprehensive evaluation is used alone. The ANN model can make the evaluation results more objective and practical. The evaluation results show a tendency of decreasing land use intensity from the core urban area to the periphery and the industrial functional area has relatively low land use intensity compared with other functional areas. Based on the evaluation results, some suggestions are put forward, such as transforming the mode of urban spatial expansion, strengthening the integration and potential exploitation of the land in the urban built-up area, and strengthening the control of the construction intensity of protected areas.

Subsidence associated with land use changes in urban aquifers with intensive extraction

Land use change is a major factor in alterations in natural processes and cycles. Remote sensing has become an excellent tool to evaluate technological changes in land cover and land use changes over large areas, such as those occurring in the Valley of San Luis Potosi (VSLP). Here, such changes have impacted a system which is 95% dependent on the aquifer. The methodology for the present study is based on the use of satellite images for the years 1976, 1986, 1995 and 2000. To asses land use change, a supervised classification process was used with a decision tree technique and ENVI 4.3 software. The evolution of groundwater levels for the years 1977, 1986, 1995, 1998 and 2007 was also analyzed, as well as problems of subsidence and fissuring in the urban area of the valley in 2006. With the support of remote sensing, it was possible to analyze the dynamic changes in land use over large areas and highlight their impact on the environment.

A Study of Current Land Use in the Urban Area of Ma'anshan City

With the acceleration of urbanization,urban development poses a growing demand for land.China's national conditions of a large population with relatively little arable land require us to intensively use land,and more and more departments have been aware of the importance of intensive urban land use.The study on the current land use in the urban area of Ma'anshan City,is not only conducive to adjustment of land use layout and structure as well as urban ecological construction,but also of guiding significance to the economical and intensive land use in Ma'anshan City.This paper first describes the natural,social and economic situation of Ma'anshan's urban area,then analyzes the land use structure,layout and problems,and finally puts forth the recommendations for improving current land use situation in the urban area of Ma'anshan City.

Evaluation and Obstacle Diagnosis of Low-carbon Intensive Land Use in Kaifeng City

Low carbon intensive use of urban land is an important trend to achieve regional high quality development.In this study,with Kaifeng municipal district as an example,the catastrophe progression model was used to estimate and analyze the low-carbon intensive use level of urban land in Kaifeng City from 2011 to 2020,and the obstacle factors in the process of low-carbon intensive land use in Kaifeng City were revealed by using the obstacle degree model.The results showed that during the study period,the low-carbon intensive use of land in Kaifeng City showed a slow,fluctuating and declining trend,and the overall situation was in a generally intensive state.The land input level and land output level were on the rise,while the low-carbon level of land and the degree of land use were on the decline.Currently,the main obstacle factors restricting the low-carbon intensive use of land in Kaifeng City were the carbon structure coefficient of land use,energy consumption per square kilometer,carbon emissions per square kilometer,carbon emissions per capita,and non-agricultural land use efficiency.In the future,it is necessary to further improve the land use structure and promote the high-quality development of Kaifeng City.

Analog simulation of urban construction land supply and demand in Chang-Zhu-Tan Urban Agglomeration based on land intensive use

Urban land intensive use is an important indicator in harmonizing the relationship between land supply and demand. The system dynamics(SD) can be used to construct the feedback loop between urban construction land supply and demand and index variable function. Based on this, this study built a supply and demand system dynamic model of urban construction land for Chang-Zhu-Tan urban agglomeration. This model can simulate the change trends of supply and demand of construction land, industrial land, and residential land in 2016–2030 by three scenarios of low, medium, and high intensity modes. The results showed that the scale of construction land of urban agglomeration is expanding, with a rapid increase rate for the urban construction land. The scale and speed of land use based on the three intensity modes existed differences. The large scale and supply of construction land in the low intensity mode caused easily the waste of land resources. In high intensity mode, the scale and supply of construction land were reduced against the healthy development of new-type urbanization. In the medium intensity mode, the scale and supply of land use adapted to the socio-economic development and at the same time reflected the concept of modern urban development. In addition, the results of this study found that the proportion of industrial land in construction land ranged from 15% to 21%, which increased year by year in the low intensity mode, and decreased slowly and stabilized in medium and high intensity modes. The proportion of residential land in construction land ranged from 27% to 35%, which decreased in the low and the medium intensity modes, and maintained a high level in the higher intensity mode. This study contributes to provide scientific reference for decision-making optimization of land supply and demand, urban planning, and land supply-side reform.

Development of evaluation model for intensive land use in urban centers

Starting with exptoration from the perspective of urban spaces, this research was conducted by anatyzing the functionat areas--urban centers with the most hightighted contradictions in terms of intensive land use in order to devetop an evatuation model for intensive land use in urban centers. Based on quantitative research methods, and taking into account three aspects of intensive use, i.e., buitdings, lands and traffic as wetl as muttiple evaluation factors, this paper conducted the research horizontatty by means of quantitative and comparative studies on each individual factor, devetoped the evatuation model for intensive rand use in urban centers, and anatyzed the driving forces of intensive land use from the aspects of buitdings, land use, roads, etc.

Spatiotemporal influences of land use/cover changes on the heat island effect in rapid urbanization area

Rapid urban sprawl and growth led to substantial urban thermal environment changes and influenced the local climate, environment, and quality of life of residents. Taking the Chang-Zhu-Tan urban agglomeration in China as a case, this study firstly identified the spatiotemporal patterns of surface urban heat island intensity (SUHII) and the land use/cover changes (LUCC) based on multi-temporal Landsat TM satellite data over 21 years, and then investigated the relationship between LUCC and SUHII by methods of logistic regression model and centroid shift analysis. The results showed that green spaces (e.g., cropland, forestland) of 899.13 km2 had been converted to built-up land during the 1994—2015 period, which caused significant urban expansion. The SUHII was the highest for built-up land, high for unused land, low for cropland and grassland, and the lowest for forestland and open water. Many areas experienced extensive rapid urbanization because of the emergence of the urban agglomeration, which resulted in the loss of green spaces and increased SUHI effects over the 21-year study period. In addition, the results of centroid shift analysis found that the growth of SUHII and the expansion of high SUHII areas are closely related to the expansion of an existing urban area in Xiangtan, while the increases of building density and height in Changsha resulted in the decrease of SUHII and spatiotemporal change of high SUHII areas. The analysis of the effects of land use/cover types on the SUHII in this study will contribute to future urban land use allocation for the mitigation of SUHI formation.

Spatiotemporal evolution of national development zones and their impact on urban land growth in China

Development zones are important growth poles for promoting regional economic development. However, the spatiotemporal relationship between development zone construction and urban land growth is still unclear. This paper analyzes the spatiotemporal changes of national-level development zones(NDZs), approximately 219 national economic development zones, and 156 high-tech development zones during 1990–2018 in China. The impact of development zone establishment on the growth of surrounding urban land was quantitatively explored using circle buffering analysis and time series comparative analysis. The results show that China's NDZs spread from the southeast coast to the inland area from 1990 to 2018, and the establishment of the development zones has an obvious promoting effect on the surrounding urban land growth. The scope and intensity of influences of the development zone established in different periods present distinct nonstationarity in space and time. Overall, the impact on urban land(IU) of China's NDZs established in different years was mostly highest at the 100 m buffer zone radius, while the slope of the IU was mostly negative, which meant that the 100 m buffer zone radius of the development zone center was the most efficient scale to promote urban land growth. In the meantime, the curve of IU of NDZs established before 1990, during 1996–2000 and 2001–2005 has a clear inflection point, which indicates that the most efficient scales of NDZs established before 1990, during 1996–2000, and 2001–2005 are 1300 m, 900–1000 m, and 800 m, respectively. NDZs established in other periods do not have the most obvious efficient scale. The development zone played the greatest role in promoting urban land growth from 2000 to 2010. Three association modes, including post-growth, pre-growth and steady-growth, were identified based on the differences in geographical location, establishment time, and type of development zones. We quantitatively identify the impact of the growth pole of NDZs on urban land growth from the perspective of spatiotemporal evolution. The findings would provide decision-making support for optimizing the spatial relationship between development zone construction and urban land growth.

Comprehensive assessment on the ecological stress of rapid land urbanization per proportion, intensity, and location

Aiming at assessing the ecological stress of land urbanization comprehensively,three perspectives are considered and combined,i.e.the amount effect with the proportion of construction lands as the indicator,the intensity effect per the density of environmental pollutant emissions,and the location effect based on their spatial distribution in the heterogeneous landscape.The quantitative results of Southern Jiangsu case in Eastern China show the single-perspective ecological stress are spatially different;the proportion effect is higher in city propers which are more densely populated and industrialized.However,the intensity effect is more significant for units along the Yangtze river where heavy industries are gathered,while the location effect is higher in“ecologically suitable”regions.As the integration of proportion,intensity,and location effects,the comprehensive stress differs across Southern Jiangsu and are also different with the single-perspective results.Dominant stressors of each unit are spatially distinct,which benefits policymakers in targeting their objectives as per primary influencing factors.It is concluded that the comprehensive assessment could efficiently reveal the spatial differentiation of the ecological effects of land urbanization and also the differentiated role of different factors for each unit.

我国城市土地集约与合理利用的制度经济学分析

我国正处于城市化快速发展时期,土地资源需求巨大,城市存量土地粗放利用,而耕地资源又严重不足。因此,城市土地集约与合理利用成为我国城市化与城市可持续发展的必然选择。从城市土地集约与合理利用的概念出发,通过介绍我国城市土地利用制度的改革历程,对制度变迁中的路径依赖和制度变迁的成本——效益进行分析。

东北地区产业结构优化与城市土地集约利用协调性

精准识别产业结构优化与城市土地集约利用的协调状况,对于推动东北地区产业结构转型升级、协调国土空间规划及产业布局具有重要现实意义。运用耦合协调度模型及探索性空间数据分析法,深入探究了2009—2018年东北地区产业结构优化与城市土地集约利用的耦合协调水平及其空间相关性。结果表明:(1)东北地区城市产业结构合理化水平逐年降低,且区域差异程度较大;产业结构高级化水平小幅上升,但不存在明显的空间分异特征。(2)城市土地集约利用水平呈现出先上升后下降的倒"U"型演变特征,并沿着哈大交通经济带的中心城市向两侧梯度递减。(3)产业结构合理化、产业结构高级化与城市土地集约利用协调度分别呈现先上升后下降及稳步上升的演变态势。两协调度均以大连、哈尔滨等城市为中心向外辐射,呈现"多中心多圈层"的空间分布特征。(4)城市两系统协调度存在显著的空间正相关,但显著性逐年减弱,其中高—高聚集类型主要集中在辽中南城市群,低—低聚集类型集中在黑龙江东部城市群。