Analyzing Urban Expansion and Spatial Growth Patterns in Barahathawa Municipality of Central Tarai Region, Nepal

The rapid transformation of rural settlements into municipalities in Ne­pal has brought significant changes in land use,and urban expansion and growth patterns mostly through the conversion of agricultural land into the built-up area.The issue is studied taking a case of the rapidly growing town,Barahathawa Municipality of Tarai Region of Sarlahi District.After the declaration of the municipality,several new roads have been opened and upgraded;and the municipality is well-connected to the national transportation network.After promulgated the Constitution of Nepal 2015 and functioning the elected local body,the municipality budget has been increased significantly as a result of increasing municipal investment in so­cio-economic and physical infrastructure development and environmental protection which has attracted people,goods,and services creating the zone of influence on the municipality.One of the changes found in the munici­pality is the increasing built-up area and expansion of urban growth through the decreasing agricultural land.Urban growth has been observed taking place around the Barahathawa Bazaar and main roadsides.The built-up area in Barahathawa municipality has remarkably increased by 183percent with the decrease of shrub and agricultural land within 10 years.Implica­tions of such spatial and temporal dynamics have been a core issue of urban planning in most of the newly declared municipalities in Nepal.

Multi-scenario land use prediction and layout optimization in Nanjing Metropolitan Area based on the PLUS model

The metropolitan area is a crucial spatial element in promoting new urbanization in China.It possesses theoretical and empirical value in the determination of the evolutionary patterns and development trends necessary for regional integration and high-quality development.This study focused on Nanjing Metropolitan Area,the first national metropolitan area in China,and established three development scenarios by combining ecological–economic spatial conflict(EESC)zones and national key ecological functional areas.These scenarios simulate the spatial distribution of future land use and land cover change(LUCC)using the development zone planning function of the patch generation land use simulation(PLUS)model.The results show that:(1)Between 2000 and 2020,the most prominent characteristics of land use change were largely the massive expansion of built-up land and the significant decline of farmland,while changes in the area of ecological land were less evident.(2)EESC areas experienced significant changes over the past 20 years,but the overall level of conflict was low.Ecological land was the main land use type in the lowest-conflict area,while built-up land was the main land use type in the highest-conflict area.(3)From 2030 to 2050,further expansion of built-up areas is expected,with continued decrease of farmland.The regulation of these land use changes can be achieved through different development zone plans.The economic development scenario had the largest built-up land area,while the ecological protection scenario had the largest farmland area.This study simulates the spatial pattern changes in the metropolitan area based on spatial conflict patterns and national main functional area planning process,providing a scientific reference for future spatial planning and management.

Spatial expansion and potential of construction land use in the Yangtze River Delta

Based on remote sensing data of the Yangtze River Delta(YRD) in the years of 1991, 2001 and 2008, the paper built an index system of land use potential restraint factors in YRD, according to geological condition, terrain condition, water area, natural reserve area and basic farmland, and evaluated construction land potential based on the platform of GIS spatial analysis model. The results showed that:(1) the construction land increased rapidly since 1991 and reached 24,951.21 km2 in 2008, or 21.27% of the total area. Among all the cities in the YRD, Shanghai took the greatest percentage, followed by Jiangsu and Zhejiang. Spatially, areas where government departments are located became the growth center of construction land. Prefecture-level cities were the fastest growth region and the changing trend showed circle layered characteristics and significant increase with Shanghai and Suzhou as the core.(2) The higher the quality of construction land potentials(CLP), the smaller the number of CLP units. High sensitive area accounted for the largest percentage(40.14%) among all types of constraint regions and this was followed by medium sensitive region(31.53%) of the whole region.(3) The comprehensive CLP in the YRD was 24,989.65 km2, or 21.76% of the total YRD. The land use potential showed spatial distribution imbalance. CLP of Zhejiang was obviously larger than that of Jiangsu. CLP was insufficient in regional central city. Moreover, CLP in the YRD formed a circle layered spatial pattern that increasingly expanded centered in prefecture-level cities. Low potential area expanded from north to south. High potential area was mainly located in south YRD. Areas with zero potential in the YRD formed a northwest-southeast "Y-shaped" spatial pattern in north Hangzhou Bay.(4) CLP per capita in YRD was 0.045 ha/person and also unevenly distributed. Some 25.57% of the study units at county level nearly had no construction land and 8.24% of the units had CLP per capita below the national average level. CLP per capita in less than 25% of the county-level units was larger than the YRD average level, which were mainly located in Zhejiang. Therefore, research on the construction potential area in YRD was favorable for analysis of the development status and potential space of this region under the background of rapid urbanization and industrialization.

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.

基于GeoCA模型的城市土地利用空间扩展预测——以贵州省开阳县为例

针对当前城市土地利用空间扩展预测方法忽略了影响因子的动态转换参数的设置,容易影响空间变化预测的精度,本文提出基于地理元胞自动机模型的城市土地利用空间扩展预测方法;选择Voronoi形式,对城市土地利用空间进行划分,得到预测数据基础;根据地理元胞自动机模型的“自上而下”预测要求,确定城市土地利用空间扩展分析因子,设置动态转化参数;构建城市土地利用空间扩展预测模型,选择Kappa指数验证预测结果精度。至此,基于地理元胞自动机模型的城市土地利用空间扩展预测方法设计完成。构建实例分析环节,分析此方法的使用效果。实验结果表明:此方法所得到的预测面积与实际面积较为接近,预测精度均可达到95%以上,最高可达到99.97%,整体预测准确率可达到98%以上,具有较高的预测精度。文章对2022—2026年的土地利用情况进行了预测,并根据预测结果提出相对应的建议。

Exploring complex urban growth and land use efficiency in China's developed regions:implications for territorial spatial planning

Developed regions in China have experienced rapid urban expansion and have consequently induced a series of challenging environmental issues since its economic reform and opening-up.Taking Zhejiang as a case study area,the present paper explores the complex types of urban growth over the last four decades as well as land use efficiency.Moreover,it discusses the implications of the aforementioned on China national territorial spatial planning(TSP).The acquired results have shown that:1)urban expansion has slowed down,exhibiting a three-stage trend of"slight increase(1980-1990)—dramatic growth(1990-2010)—slow growth(after 2010)";2)the complex types of urban growth reveal that the urban diffusion has been gradually controlled and the urban form tends to be more condensed;and 3)the mean values for pure technical efficiency(PTE)and scale efficiency(SE)of urban land use are 0.83 and 0.95 respectively,indicating PTE as the main factor restricting the improvement of urban land use.Based on these results,some beneficial policy implications and suggestions for TSP are provided.First,it is suggested that"Inventory Planning"will be the main direction of TSP other than"Incremental Planning".Secondly,we should pay more attention to the protection of cultivated land and ecological resources.Lastly,TSP should guide the economic growth away from simply relying on resource inputs and steer it toward technology and capital investment.

Urban expansion in China and its spatial-temporal differences over the past four decades

The urban expansion process in China from the 1970s to 2013 was retrieved based on remote sensing and GIS technology. With the latest zoning method used as reference, annual expansion area per city, urban expansion type, and fractal dimension index were employed to analyze the Chinese urban expansion characteristics and its spatial difference from the aspects of urban expansion process, influence of urban expansion on land use, and urban spatial morphological evolutions. Results indicate that 1） under the powerful guidance of policies, urban expansion in China went through six different stages, and cities in the eastern region entered the rapid expansion period the earliest, followed by cities in the central, northeastern and western regions; 2） cultivated lands and rural settlements and industrial traffic lands were the important land sources for urban expansion in China; the influence of urban expansion on land use in the eastern region was the strongest, followed by the central, northeastern and western regions; 3） urban spatial morphology tended to be complex and was directly related to the adopted spatial expansion mode. Infilling expansion became the main urban expansion mode in the western region first, then in the central and northeastern regions, and finally in the eastern region. This study establishes the foundation for an in-depth recognition of urban expansion in China and optimization of future urban planning.

Monitoring periodically national land use changes and analyzing their spatiotemporal patterns in China during 2015–2020

High-resolution mapping and monitoring of national land use/cover changes contribute significantly to the knowledge of the interaction between human activities and environmental changes.China’s Land Use/cover Dataset(CLUD)for 2020 and its dynamic changes in 2015-2020 were developed to extend the CLUD to over 30 years(i.e.,the 1980s to 2020 at 5-year intervals)by integrating remote sensing big data and knowledge-based human-computer interaction interpretation methods.This integrating method for CLUD 2020 improved the efficiency of national land use/cover mapping and the accuracy of land use pattern change detection compared to earlier CLUD products,with an overall accuracy of 95%.The intensity of land use change decreased across China in 2015-2020 compared to 2010-2015,although both characteristics of its spatial changes were similar.The cropland area continued to shrink at national scale in 2015-2020,with two regional hotspots including the widespread conversions from dry land into paddy land in Northeast China and the coexistence of widespread land cultivation and cropland abandonment in Xinjiang of Northwest China.Built-up land area continued to expand in China,showing consistency between 2015-2020 and 2010-2015,in which hotspots transited from the surroundings of coastal megacities to the city surroundings of the central and western zones.For natural land,although the woodland and grassland decreased in 2015-2020,its magnitude expanded compared to 2010-2015.In comparison,the water body area in Qinghai-Tibet Plateau increased significantly under the continuous impact of climate change.These characteristics of land use change were closely related to the development strategy of the top-level design of the 13th Five-Year Plan(2016-2020)(e.g.,ecological civilization construction and high-quality development).

重庆市主城区建设用地扩张特征分析及其预测

考虑到地块本身空间特征对城镇规划和扩张的影响,有必要耦合空间格局因子来研究建设用地的扩张过程。以重庆市主城区为研究区域,在甄别土地利用扩展特征的基础上,综合采用平均增长率法和基于地块空间属性的优势度评价法,预测了2020年的建设用地需求量和新增建设用地的空间分布。研究结果显示:12010—2016年,重庆市主城区建设用地从749.14 km^2增加至905.06 km^2,年平均增长率为3.35%;22010—2016年,研究区内新增建设用地主要来源于耕地(53.25%)或林地(37.89%)的转化,同时更倾向分布于坡度低于12°、海拔低于400 m的区域,尤其是0~3°坡度区间(24.44%)和200~300 m高程区间(47.60%);3至2020年,研究区内建设用地面积将增长115.31 km^2,其中56.24%来源于耕地的转化,47.45%位于200~300 m海拔区间,58.39%位于0~12°坡度区间,主要分布于沙坪坝区、九龙坡区和渝北区。