Pattern and mechanism of urban spatial growth in Nanjing City, 1979-2007

Urban spatial growth has become a hot topic of geographic science and urban research. Exploring the patterns and mechanisms of urban growth is the prerequisite to understand the urbanization process of China. The paper provides a spatial analysis method of using Remote Sensing （RS） and Geographic Information System （GIS）. and presents major patterns and mechanisms of urban spatial growth during the period from 1979 to 2007 in Nanjing City. Firstly, the paper introohwes the data, study area and methodology of the research. Then. the patterns of urban spatial growth are identified Subsequently, the main mechanisms of urban spatial growth are analyzed Finally some conclusions are drawn definitely. The features of urban spatial growth in Nanjing are as follows： during 1979-1988, urban spatial growth of each district was stow. and the inner growth was in excess of suburban growth; during the period of 1988-2000. urban growth of suburban was in excess of inner city. the most insensitive growth appeared in the southeast, and the growth of each aspect was relatively insensitive expect ecst and west; during the period of 2000-2007, urban growth of suburban was violent, the most insensitive growth appeared in the southeast. and the urban growth of each direction was insensitive except the west. The mechanisms of urban spatial growth are complex, the main ones of which are social and economic development. Besides. the guiding of urban planning and influence of urban spatial structure are quite obvious.

Future Land-Use Land-Cover Scenarios for the Flint River Watershed in Northern Alabama Using the Prescott Spatial Growth Model

A changing mosaic of natural vegetation and human land uses has evolved within and around the Flint River Watershed (FRW) in Alabama and Tennessee over the past several decades. To determine the cause of change and linkage between human activities and environmental change can prove problematic. Subsequently, there is a need to produce projections of future environments based on planning instruments and socio-economic parameters. Scenarios of potential future land use land cover (LULC) change are required in order to better manage potential impacts on many environmental issues. This study creates future scenarios for the year 2030 from baseline land use of 2001, relative to three projected land use scenarios which include differences related to conservation, planning, and development. The future growth scenarios were created using the ArcGIS tool, Prescott Spatial Growth Model (PSGM). The model allows users to build different future growth scenarios based on socio-economic projections such as population, employment and other controlling factors. The simulation results indicate that LULC changes associated with future urbanization can increase by ~23% - 43% within the FRW, which will lead to significant environmental issues if not managed properly. The overall analysis and model results demonstrate the ability of future growth scenarios to explore and evaluate options for a future environment. Spatial modeling and analysis tools, such as PSGM, provide a powerful approach to evaluate potential impacts of LULC change in the future and should be used to manage urbanization in areas with more intense development.

Temporal and Spatial Characteristics of Rainstorm during the Crops Growth Period in North China Region

By using the daily precipitation data from 1961 to 2005 in North China region,the temporal and spatial distribution characteristics of rainstorm process occurrence and the rainstorm intensity during the crops growth period were studied.The results showed that the rainstorm intensity and the rainstorm process during the crops growth period in North China region both had the obvious annual fluctuations and era variation characteristics.Although the rainstorm and heavy rainstorm occurred in North China region every year,the annual variations were great,and the variation coefficients respectively reached 36.9% and 53.1%.The torrential rain occurred once in every 4-5 years,and the rainstorm process occurred once in every 11 years.Although the torrential rain and rainstorm process occurred in fewer years,their annual fluctuations were more obvious.The peak value zones of rainstorm intensity which was greater and the rainstorm process which occurred frequently were in the 1960s.After 1999,the rainstorm intensity and the rainstorm process were in low value zone of historical stage from 1961 to 2005.Moreover,the 1970s-1990s was between high value and low value,and the rainstorms in different intensities which weren't synchronous happened in the period.In addition,the spatial distribution of annual average rainstorm days presented the tendency which increased obviously from northwest to southeast in Northern China,and the variation coefficient of rainstorm days presented the tendency which increased gradually from southeast to northwest.Generally,the more the annual average rainstorm days are,the smaller the variation coefficient is,and vice versa.The statistics results also showed that precipitation in North China had obvious positive correlation relationship with the rainstorm days.

Remarks on Urban Spatial Growth Management Research

"Urban spatial growth management(USGM)" is developed from "urban growth management(UGM)",and is more specific on urban space than UGM.An urban spatial plan can achieve its goals in virtue of USGM.This paper reviews the research on urban growth management both in China and abroad,and then puts forwards the development issue of USGM in China which requires further study in two main aspects:systemic research on the basic theories of USGM with Chinese characteristics,and the utilization of modern techniques to examine the effectiveness of USGM.In turn,the methods to develop the modeling and analysis techniques of USGM are discussed.

Spatial patterns of urban land use growth in Beijing

By using digitized land use maps of Beijing in 1982, 1992 and 1997 and employing GIS spatial analysis techniques, this paper conducts an empirical study on the spatial differentiation and spatial patterns of urban land use growth in Beijing in the period of 1982–1997. It is observed that urban land use growth in Beijing went beyond the control of urban planning, in terms of the extraordinary high growth rate and undesired spatial pattern. The rate of urban expansion after 1982, which was predominated by growth of industrial land, was extraordinary high compared to its historical period. While its growth centers have been actively shifting toward the northern part, rather than toward the southern and eastern parts as designated by the latest General Plan (1991–2010) of Beijing, its spatial pattern of urban land use growth in general was in distinct concentric sprawl, which seriously violated the General Plan of Beijing.

Research on Spatial Influence Mechanism of Chongqing Urban Growth Management

After illustrating the concept of Urban Growth Theory and Urban Growth Management,by taking relevant theoretical research literatures for reference,based on the specific conditions of Chongqing City,the paper had analyzed the spatial growth and evolution of Chongqing City,and the spatial influence mechanism for urban growth management.The spatial influence mechanism of Chongqing urban growth had been divided into four aspects including natural environment,economic development,urban traffic organization and regional policy planning,which were considered as the primary mechanism,driving mechanism,essential condition and driving force of urban spatial growth and development,respectively.From the perspective of analyzing problems,the comprehensive analysis had been conducted on the urban growth management in economy and planning,and corresponding urban growth space management strategies had been formulated.From the perspective of combining theory with practice,it had studied and revealed the spatial influence mechanism for urban growth management,which was of practical guiding significance to the development of Chongqing urban space pattern,and also vital significance to the construction of theoretical system of Chinese urban management and guidance of further development and renovation of specific urban planning.

A Spatially Heterogeneous Expert Based (SHEB) Urban Growth Model using Model Regionalization

Urbanization changes have been widely examined and numerous urban growth models have been proposed. We introduce an alternative urban growth model specifically designed to incorporate spatial heterogeneity in urban growth models. Instead of applying a single method to the entire study area, we segment the study area into different regions and apply targeted algorithms in each subregion. The working hypothesis is that the integration of appropriately selected region-specific models will outperform a globally applied model as it will incorporate further spatial heterogeneity. We examine urban land use changes in Denver, Colorado. Two land use maps from different time snapshots (1977 and 1997) are used to detect the urban land use changes, and 23 explanatory factors are produced to model urbanization. The proposed Spatially Heterogeneous Expert Based (SHEB) model tested decision trees as the underlying modeling algorithm, applying them in different subregions. In this paper the segmentation tested is the division of the entire area into interior and exterior urban areas. Interior urban areas are those situated within dense urbanized structures, while exterior urban areas are outside of these structures. Obtained results on this model regionalization technique indicate that targeted local models produce improved results in terms of Kappa, accuracy percentage and multi-scale performance. The model superiority is also confirmed by model pairwise comparisons using t-tests. The segmentation criterion of interior/exterior selection may not only capture specific characteristics on spatial and morphological properties, but also socioeconomic factors which may implicitly be present in these spatial representations. The usage of interior and exterior subregions in the present study acts as a proof of concept. Other spatial heterogeneity indicators, for example landscape, socioeconomic and political boundaries could act as the basis for improved local segmentations.

Effect of calcitonin gene-related peptide and nerve growth factor on spatial learning and memory abilities of rats following focal cerebral ischemia/reperfusion

BACKGROUND: Calcitonin gene-related peptide (CGRP) and nerve growth actor (NGF) cam improve spatial learning and memory abilities of rats with cerebral ischemia/reperfusion; however, the effect of combination of them on relieving learning and memory injury following cerebral ischemia/reperfusion should be further studied. OBJECTIVE: To study the effects of exogenous CGRP and NGF on learning and memory abilities of rats with focal cerebral ischemia/reperfusion. DESIGN: Randomized controlled animal study. SETTING: Department of Neurosurgery, the Second Hospital of Xiamen; Department of Neurosurgery, the Second Affiliated Hospital of China Medical University; Department of Neurobiology, Basic Medical College of China Medical University. MATERIALS: A total of 30 healthy male SD rats, aged 8 weeks, of clean grade, weighing 250-300 g, were provided by Experimental Animal Department of China Medical University. All rats were randomly divided into sham-operation group, ischemia/reperfusion group and treatment group with 10 in each group. The main reagents were detailed as the follows: 100 g/L chloral hydrate, 0.5 mL CGRP (2 mg/L, Sigma Company, USA), and NGF (1× 106 U/L, 0.5 mL, Siweite Company, Dalian). METHODS: The experiment was carried out in the Department of Neurobiology, Basic Medical College of China Medical University from February to July 2005. Rat models of middle cerebral artery occlusion were established by method of occlusion, 2 hours after that rats were anesthetized and the thread was slightly drawn out for 10 mm under direct staring to perform reperfusion. Rats in the ischemia/reperfusion group received intraperitoneal injection of 1 mL saline via the abdomen at two hours later, while rats in the treatment group at 2 hours later received intraperitoneal injection of 2 mg/L CGRP (0.5 mL) and 1×106 U/L NGF (0.5 mL) once a day for 10 successive days. First administration was accomplished within 15 minutes after ischemia/reperfusion. Rats in the sham-operation group were separated of the vessels without occlusion or administration. The neural function was evaluated with Zea Longa 5-grade scale. Animals with the score of one, two and three points received Morris water-maze test to measure searching time on platform (omitting platform-escaping latency). Meanwhile, leaning and memory abilities of animals were reflected through testing times of passing through platform per minute. MAIN OUTCOME MEASURES: Experimental results of omitting platform-escaping latency and spatial probe. RESULTS: Three and two rats in the ischemia/reperfusion group and treatment group respectively were not in accordance with the criteria in the process, and the rest were involved in the final analysis. ① Comparisons of platform-escaping latency during Morris water-maze test in all the three groups: Ten days after modeling, the platform-escaping latency in the ischemia/reperfusion group was obviously longer than that in sham-operation group (P < 0.01), and was significantly shorter than that in the treatment group (P < 0.01). ② Comparisons of times of passing through platform in all the three groups: Times of passing through platform were remarkably less in the ischemia/reperfusion group than those in the sham-operation group [(1.79±0.39), (4.30±0.73) times/minute, P < 0.01], and those were markedly more in the treatment group than the ischemia/reperfusion group [(3.16±1.03), (1.79±0.39) times/minute, P < 0.01]. CONCLUSION: CGRP and NGF are capable of ameliorating the abilities of spatial learning and memory in MCAO rats, which indicates that CGRP and NGF can protect ischemic neurons.

Spatial Effect Research on Educational Output and Economic Growth in China

This thesis is to study spatial effect of education output on economic growth through the use of spatial measurement technique. According to the study: there’s the presence of spatial spillover effects in human capital, economic growth, and others;in previous years, human capital depended on mainly the employers with junior school education or below;in recent years, with the reduction of employers with junior school education or below, employers with regular higher education can best promote the economic growth. However, it’s very difficult for human capital with vocational education to promote economic growth, especially in recent years. Therefore, from the perspective of long-term economic growth, China should focus on culturing professional talents and put more resources into the development of vocational education while developing the higher education.

The Spatial Spillover Effect of Input and Output of Scientific Progress on Regional Economic Growth: The Case of Guangdong Province

This paper makes an empirical analysis of the spatial spillover effect of regional economic growth by using Moran’s I and Spatial Durbin Model to study the input and output of technological progress, with the panel data of 21 prefecture-level cities in Guangdong Province from 2008 to 2017. The empirical results show that the spatial autocorrelation exists in the economic development of Guangdong Province, and both the input and output of scientific research innovation have a significant positive effect on the regional economic growth. Under the spatial contiguity weights matrix, the output of scientific research and innovation has a more obvious spillover effect on the economic growth of neighboring cities than the input of scientific research and innovation.

AGE STRUCTURE AND SPATIAL PATTERN OF OLD-GROWTH KOREAN PINE FOREST IN XIAOXING'ANLING MOUNTAIN

Spatial pattern of trees, basal stem increment and height were examined in a 5.0 ha mixed deciduous/ Pinus koraiensis forest from October in 1984 to May in 1987. Conclusions arc as following: 1. Analysis of the age-structure of the korcan pine forest shows that it is different from general steady-state forest type. The lack of saplings and individuals in small-diameter class clearly indicates that regeneration is not continuous. Continuous regeneration depends on thinning of the canopy to form a gap. Similar-aged korcan pine seedings grow in these gaps. 2. The horizontal structure of the korcan pine is a mosaic of more or less even-aged groups of trees. The mosaic is a result of korcan pine by regeneration strategy. The aggregations of korcan pine of different ages overlaps to form a continuous population generation. As a results, the population is maintained in steady state.

数字经济发展与区域经济收敛——基于动态空间面板模型的实证研究

数字经济发展对于扎实推进共同富裕具有重要意义。基于经济增长条件收敛模型,采用动态空间杜宾模型实证考察数字经济发展对区域经济增长收敛的影响。研究发现:考察期内全国经济增长具有显著的条件收敛特征,数字经济发展显著促进了区域经济收敛;东中西部地区和南北地区均存在明显的俱乐部收敛现象,仅东部地区和南方地区数字经济发展能够显著缩小地区经济差距;东部地区数字经济发展对本地区及邻近地区的经济增长均具有显著的正向累积效应,西部地区数字经济发展的空间溢出效应为负。为此,提出以下政策建议:一是充分把握数字经济发展机遇,二是巩固数字经济的区域经济收敛效应,三是推行差异化的数字经济政策,四是推动数字经济均衡发展。

闽楠-杉木人工混交林混交比对闽楠生长形质和空间利用能力的影响

为了分析混交比例对闽楠-杉木人工混交林中闽楠生长形质性状、空间利用能力的影响,明确珍贵用材树种闽楠的经营方向,以江西省分宜县上村实验林场6年生闽楠-杉木人工混交林和闽楠纯林为研究对象,分析不同混交比例处理对闽楠生长、干形形质、空间利用能力的影响,并通过主成分分析方法综合评价不同混交比例的闽楠生长表现,筛选出最佳混交模式。结果表明:(1)混交处理促进了闽楠生长,改善了闽楠干形形质。2楠1杉混交处理中,闽楠的胸径、树高、单株材积、枝下高、枝下高比例均为最大,分别比闽楠纯林增加了21.44%、31.78%、79.41%、48.00%、30.23%(P<0.05);但尖削度和胸高形数均小于闽楠纯林,尖削度和胸高形数分别降低了24.43%、7.20%。(2)混交处理提升了闽楠的空间利用能力。混交林的平均冠幅、冠高、树冠体积、树冠表面积、生长空间指数均显著高于闽楠纯林,各指标分别提高了6.49%~10.27%、11.28%~27.89%、45.36%~86.09%、27.56%~44.39%、13.24%~36.76%;但混交林的树冠圆满度均低于闽楠纯林。(3)混交处理能够改善闽楠的生长特征和空间利用能力,综合评价得分由高到低依次为2楠1杉(2.282)、1楠1杉(1.479)、3楠1杉(0.973)、纯林(-1.365),2楠1杉混交处理为最优混交比例。因此,营建闽楠-杉木人工混交林可提升闽楠的生长形质和空间利用能力。

迈向中国式现代化的高质量国土空间体系:内容构成、动力机制与构建思路

构建优势互补、高质量发展的国土空间体系是事关国家发展全局的重要举措,对于推动实现中国式现代化具有重要意义。在迈向中国式现代化的新征程上,应把握好高质量国土空间体系的构成内容,将新型城镇化、区域创新和区域可持续开发作为构建高质量国土空间体系的强大动力。其构建思路如下:以数字化赋能区域经济布局优化,通过区域规划和政策引导促进要素资源合理分配,培育空间增长极驱动高质量发展,落实主体功能区战略保障各类型地区协调发展,推进以新质生产力为核心的新型工业化,优化重大生产力布局。

基于SEBAL模型的陆浑灌区生育期内实际蒸散发研究

【目的】探索基于遥感技术和能量平衡模型建立准确快捷评估灌区高空间分辨率蒸散发值的方法。【方法】基于SEBAL模型,利用Landsat-8遥感影像和气象数据估算了作物生育期内陆浑灌区的实际蒸散发值,验证了能量平衡模型在陆浑灌区的适用性,进而分析了陆浑灌区实际蒸散发的时空演变特征。【结果】SEBAL模型模拟值与蒸散发产品(v 1.5)的相关系数在0.8以上,SEBAL模型模拟值与站点实测值的相关系数在0.96以上。生育期内,2—5月实际蒸散发值逐月增加,作物种植区实际蒸散发值大于林区,实际蒸散发高-高聚类点主要分布在作物种植区;6—7月实际蒸散发出现年内最高值106.52 mm,林区实际蒸散发值大于作物种植区,实际蒸散发高-高聚类点主要分布在林区;8—9月实际蒸散发值整体开始降低,实际蒸散发高-高聚类点数量减少,并向东北地区收缩。【结论】SEBAL模型利用遥感卫星影像等数据可以得到准确的高空间分辨率地表实际蒸散发估算结果,在灌区尺度具有强适用性。

撤县设区、空间一致性与县域经济发展

县域经济是我国实现城镇化发展的主战场。本文利用夜间灯光数据代理县域经济发展水平,突破统计数据受制于行政区划的空间限制,获得空间一致且跨时间可比的县域经济衡量指标。这不仅可避免因使用统计数据可能导致的可塑性面积单元问题,还可以同时分析“撤县设区”对县(市)和市辖区的影响,为“撤县设区”的研究提供更细致完整的图景。研究发现:“撤县设区”改革无论对被撤并县(市),还是对原市辖区的经济发展均未产生显著影响。原因在于,尽管“撤县设区”能够促进县域企业吸收更多人力资本,但却显著降低了企业的固定资产净投资和全要素生产率,这在一定程度上解释了为何“撤县设区”改革不能显著推动县域经济发展的原因。

海岛地区碳排放脱钩效应及驱动因素研究——基于Tapio脱钩指标和LMDI分解模型

海岛作为陆海复合生态系统的典型地带,通过科学测度海岛的碳排放强度及其脱钩效应,可以为海岛低碳绿色发展模式确定和实施路径选择提供依据。基于IPCC碳排放核算方法及线性插值法,构建海岛地区碳排放测度模型,以中国12个县级海岛为案例区,测算其2000—2020年的碳排放规模,采用Tapio脱钩模型及莫兰指数空间自相关法揭示其脱钩状态和空间格局演化特征,并运用LMDI分解方法探讨碳排放的影响因素。结果表明:(1)海岛县域碳排放总量与经济发展均呈增长趋势,经济发展与碳排放增长的速率相当;(2)海岛县域碳排放量多种脱钩类型共存的特征突出,弱脱钩成为主导性脱钩状态,低碳经济仍有很大的发展空间;(3)海岛县域脱钩效应存在显著的全局空间正相关性,空间集聚特征显著,崇明区成为典型脱钩优势区,嵊泗县、长岛县脱钩状态欠佳,呈现脱钩不稳定与区域不均衡的状态;(4)碳排放强度、产业结构、人口规模对碳排放具有正效应,而财政政策、经济发展具有负效应,且经济发展效应保持平稳状态。基于海岛县的脱钩态势,提出了通过优化产业结构、加大财政支持等差异化政策措施,助推“双碳”目标。

数字金融对农民增收的影响:基于门槛效应和空间收敛性分析

数字金融发展是否有利于提升农民收入并对农民收入差距产生影响值得深入研究。论文基于2011—2020年全国31个省(自治区、直辖市,不包含港澳台地区)的面板数据,从农民增收和收入差距的双重视角,考查数字金融的非线性门槛增收效应及对农民收入差距的空间收敛影响。研究发现,数字金融对农民收入的影响存在“边际效应递增”,即随着数字金融发展水平跨越相应门槛值,农民增收效应递增;各地区数字金融发展水平呈现“高-高”和“低-低”的空间集聚特征;进一步分析发现,农民收入水平具有显著的空间β条件收敛特征,且数字金融加剧了各省(自治区、直辖市,不包含港澳台地区)农民收入差距。论文为数字金融与农民增收关系的研究提供了一个新的视角,为优化数字金融助力农民增收、缓解农民收入差距的相关政策提供了参考。

黑木相思家系适地适树品种综合评价

[目的]为选出适宜南方山地的黑木相思家系,揭示黑木相思长势土壤养分的空间分异规律与地形变化的关系。[方法]本文以杉木采伐迹地上营造的15年生7个黑木相思家系(M1~M7)为研究对象,采用经典统计学、描述性统计、地统计学方法和GIS技术,研究了7个黑木相思家系分别在不同坡位的土壤理化性质的变化规律和土壤养分的空间分布,并通过因子分析法和模糊评价法对7个黑木相思家系进行综合评价选优。[结果]7个黑木相思家系的理化性质在不同坡位的含量大多表现为下坡位>中坡位>上坡位,下坡位显著高于其他坡位;家系间土壤结构和养分含量均表现出M7、M6和M5较好;研究区各养分含量总体呈块状或条带状分布,呈现从东北和西北方向往南方向递增的趋势。[结论]综合评价值在上下坡位黑木相思家系M7值最高,其生长对土壤理化性质的改良效果最佳,在中坡位黑木相思家系M6最佳。研究结果对南方山地适地适品种和可持续发展研究具有参考价值,可用于黑木相思人工林经营管理实践中。

生态旅游对经济增长影响的空间溢出效应研究——基于中国60个重点旅游城市数据

以2010—2019年我国60个重点旅游城市作为研究样本,先构建城市生态旅游发展指标评价体系,再采用熵权法测度各个城市的生态旅游发展水平,最后建立空间计量模型分析生态旅游发展对经济增长的影响。研究得出以下结论:根据空间自相关性检验结果,我国60个重点旅游城市的生态旅游发展和经济增长存在正的空间相关性,并不是随机分布的;同时发现生态旅游发展水平的提升,不仅会对当地经济发展产生正向促进作用,还会对周边城市经济发展产生一定的正向促进作用。