Time function of surface subsidence based on Harris model in mined-out area

The surface subsidence is a common environmental hazard in mined-out area. Based on careful analysis of the regularity of surface subsidence in mined-out area, we proposed a new time function based on Harris curve model in consideration of the shortage of current surface subsidence time functions. By analyzing the characteristics of the new time function, we found that it could meet the dynamic process, the velocity change process and the acceleration change process during surface subsidence. Then its rationality had been verified through project cases. The results show that the proposed time function model can give a good reflection of the regularity of surface subsidence in mined-out area and can accurately predict surface subsidence. And the prediction data of the model are a little greater than measured data on condition of proper measured data quantity, which is safety in the engineering. This model provides a new method for the analysis of surface subsidence in mined-out area and reference for future prediction, and it is valuable to engineering application.

The “Valley Economy” Model of Regional Development: A Case Study of Mountain Areas in Beijing, Northern China

A case study is presented of a regional development model for valley economies in the mountain areas of Beijing, China. The nature and framework of the valley economy model are described and the development of the model, which is specific to the mountain areas of Beijing, is analyzed. Five different valley economy models applied in the Beijing mountain areas are compared. The major purpose of the valley economy model is to develop the regional economy, including the selection of appropriate industries, the allocation of industrial space, the establishment of supply chains and the integration of various industries. Pilot experiments using the valley economy model have been conducted in seven counties(districts) in Beijing: Pinggu, Huairou, Changping, Mentougou, and Fangshan districts, and Yanqing and Miyun counties. Five models for developing the Beijing mountain areas have been explored, including: creative cultural industries, characteristic industry clusters, the promotion of large tourist areas, natural scenic tourism and folk cultural tourism. Each model has its own unique features and potential to help in the regional development of mountain areas.

A comparison of the management models of protected areas between China and the southern Africa region

A comparison of the management models of protected areas between China and the African south region allows reading and evaluating the similarities and differences in the use of management model as a management tool for protected areas and specifi- cally some positive and negative features of the management approaches in these two regions. Previous to this study it verified the designation of protected areas as increasing at a faster rate than ever before, comparatively much faster now in China than southern Africa regions. With the aim of evaluating similarities and differences in the use of management model as a management tool for pro- tected areas in China and southern Africa Region, both qualitative and quantitative data were collected. Qualitative data were mainly from policy documents, scientific articles and magazine reports, whereas quantitative （secondary data） statistical data from Interna- tional Union for Conservation of Nature Resources （IUCN） and World Database on Protected Areas （WDPA）. In view of the data sources above, the study found that in China all the protected areas are state owned whilst in southern Africa regions there are some protected areas that are privately owned; also that the models or typology of governance applied are successful for the fact that they both combine co-management or collaborative management, community-conserved areas and private protected areas that are subject to greater success and can help design planning and management than those who use exclusively government management. To this, the study concluded that the use of management model is influenced by the type of governance a country applies to its reserved areas.

A Nonlinear Grey Bernoulli Model with Conformable Fractional-Order Accumulation and Its Application to the Gross Regional Product in the Cheng-Yu Area

This study considers a nonlinear grey Bernoulli forecasting model with conformable fractionalorder accumulation,abbreviated as CFNGBM(1,1,λ),to study the gross regional product in the ChengYu area.The new model contains three nonlinear parameters,the power exponentγ,the conformable fractional-orderαand the background valueλ,which increase the adjustability and flexibility of the CFNGBM(1,1,λ)model.Nonlinear parameters are determined by the moth flame optimization algorithm,which minimizes the mean absolute prediction percentage error.The CFNGBM(1,1,λ)model is applied to the gross regional product of 16 cities in the Cheng-Yu area,which are Chongqing,Chengdu,Mianyang,Leshan,Zigong,Deyang,Meishan,Luzhou,Suining,Neijiang,Nanchong,Guang’an,Yibin,Ya’an,Dazhou and Ziyang.With data from 2013 to 2021,several grey models are established and results show that the new model has higher accuracy in most cases.

Roles and Functions of Tourism Destinations in Tourism Region of South Anhui:A Tourist Flow Network Perspective

Theoretic and practical significance has been highlighted in the research of the roles and functions of destinations,as destinations are restricted by the spatial structure based on tourist flow network from the perspective of relationship.This article conducted an empirical analysis for Tourism Region of South Anhui(TRSA) and revealed the necessity and feasibility of studying the roles and functions of destinations from tourist flow network's perspective.The automorphic equivalence analysis and centrality analysis were used to classify 16 destinations in TRSA into six role types:tourist flow distribution center,hub of tourist flows,passageway destination,common touring destination,attached touring destination,and nearly isolated destination.Some suggestions were given on suitable infrastructure construction and destinations service designs according to their functions in network.This destination role positioning was based on tourist flow network structure in integral and macroscopic way.It provided an important reference for the balanced and harmonious development of all the destinations of TRSA.In addition,this article verified the applicability of social network analysis on tourist flow research in local scale,and expanded this method to destination role and function positioning.

Economic polarized trends,function and expanded boundaries of the Yangtze Delta Region

In the era of economic globalization,the concept of Economic Polarized Area comes into being as an effective vehicle to agglomerate the economic elements and sustain the economic lifeline of the region. Based on the region's specific development mode and construction form the concept is working in such a way that it will contribute to guide the economic development of the country and will play an important role in competing with other regions or countries in the world. Due to the high speed development of the last 30 years,the Yangtze Delta Region starts to show the features of Economic Polarized Area. But,compared with other world-class Economic Polarized Areas,the economic strength and the ability of the Yangtze Delta Region to drive the country's economic development is still very low and the competitive power is still very limited. Expanding the boundaries of the Economic Polarized Area of the Yangtze Delta may extend the economic hinterland of the core area of the Yangtze Delta Region,will lighten the pressures from the limited resource and promote the rationalization of the industrial structure in the Yangtze Delta Region's core area. With regard to the reasonable boundaries of the Yangtze Delta Region,there are different opinions and controversial arguments in political and academic circles. Starting from the idea of increasing the competitive power and improving the economic strength of the Yangtze Delta Region,the paper firstly is discussing the requirements to become a world-class Economic Polarized Area. In a second step an analysis of functional complementation and economic collaboration between the cities of an "extended" Yangtze Delta Region has been carried out by in particular considering the feasibility of integrating these "newly included" cities. The final result of the study is,that the Region should be expanded from the number of 16 cities to 37 cities,and the appended cities should be divided up into two categories:Wenzhou,Jinhua,Yancheng,Huaian,Maanshan,Wuhu,Tongling,Chaohu,Hefei,Chuzhou,Xuancheng should be taken as Preferred Extending Area,and Suqian,Xuzhou,Lianyungang,Lishui,Quzhou,Chizhou,Anqing,Bengbu,Huangshan,Suzhou (Anhui Province) should be taken as Retained Qualification Area.

Probabilistic modeling of soil moisture dynamics in a revegetated desert area

Soil moisture is the key link between land hydrological and ecological processes which plays an important role in the terrestrial water cycle. As extreme weather events have increased in recent years, the stochastic simulation of soil moisture has gradually become the focus of ecohydrology research. Based on continuous monitoring of soil moisture data from 2008 to 2011, and histor- ical precipitation data from 199l to 2011, combined with the Rodriguez-Iturbe soil moisture dynamic stochastic model, soil mois- ture dynamics and its probability density fimction in a revegetated desert area was simulated. Results show that annual soil mois- ture dynamic changes of the revegetated desert area during the growing season complied with rainfall distribution; soil moisture probability presents a single-peak distribution in the plant rhizosphere layer （0-60 cm）. The peak width in the 20 cm topsoil was wider than in other soils, and the distribution presented the strong fluctuations and multiple aggregates. The peak widths of 40 cm and 60 cm soil moisture probability distribution were small, which are in accordance with simulated results of the Rodri- guez-lturbe model. This confrms that the Rodriguez-Imrbe model has good applicability and can well simulate the statistical characteristics of soil moisture in an arid revegetated desert area.

A Study on the Counter Measures for Eco-friendly Land Use Model in Mountainous Area——a Case of Qianjiang District of Chongqing Municipality

Accompanying the development of social economy,the land use model of mountainous area,typically eco-weak area,is changing gradually. Here the establishment of eco-friendly land use model in mountainous area,will pioneer the model of sustainable development in that area. Concerning Qianjiang District of Chongqing Municipality,huge change of land use model,mainly embodied in the unceasing increase of construction land and gradual decrease of agricultural use land,has taken place in recent years. To explore the eco-friendly land use model in mountainous area,Qianjiang District was chosen as the study object in the present study. Via analyzing the changes in land use model,we found that related eco-environment restrictive factors mainly regional climatic change,soil texture,hydrological environment as well as soil erosion and land degradation,etc. And based on these results,we further analyzed the effect of land use change on eco-environment and the factors restricting the maintenance of eco-environment and regional development,finally put forward the counter measures for balancing land use and co-environment in mountainous area. The results will be important for the development of social economy and eco-system construction in Qianjiang District.

Regional green innovation system mode and its implication:Acase study in eastern China coastal areas

Developing circular economy is the inevitable choice to realize regional sustainable development.And innovation is the fundamental driving force for regional sustainable development.Therefore,the combination of circular economy and regional innovation systems is of great value in the study of regional circular innovation systems.Based on the concepts and basic characteristics of the regional circular innovation system,the author takes Beijing,Shanghai,and Jiangsu as examples,which are the circular economy pilot provinces in developed region of eastern coastal China.With outstanding circular economy and innovation achievements,Beijing Economic-Technological Development Area,Shanghai Caohejing Hi-Tech Park,and Suzhou Industrial Park(the National Eco-Industrial Demonstration Park),served to summarize the characteristics,formation mechanism and inspiration of the circular innovation system model in capital economic-technological development zones(characterized by innovation in the recycling of water and land resources and energy,and innovation in circular service industries supplemented with"Internet+Wisdom Park"),coastal new&hi-tech industrial development zones,(featured by innovation in the recycling of water and land resources and energy,in addition,the companies’management and export processing cooperate with government)and hi-tech industrial parks(marked by open innovation and Sino-foreign governments cooperate in construction and management).This paper mainly focuses on the concepts and characteristics,formation mechanisms,evaluations,structure laws,the optimizing strategies and the cases in China to study the progress of regional green innovation system.

A data-adaptive network design for the regional gravity field modelling using spherical radial basis functions

A high-precision regional gravity field model is significant in various geodesy applications.In the field of modelling regional gravity fields,the spherical radial basis functions(SRBFs)approach has recently gained widespread attention,while the modelling precision is primarily influenced by the base function network.In this study,we propose a method for constructing a data-adaptive network of SRBFs using a modified Hierarchical Density-Based Spatial Clustering of Applications with Noise(HDBSCAN)algorithm,and the performance of the algorithm is verified by the observed gravity data in the Auvergne area.Furthermore,the turning point method is used to optimize the bandwidth of the basis function spectrum,which satisfies the demand for both high-precision gravity field and quasi-geoid modelling simultaneously.Numerical experimental results indicate that our algorithm has an accuracy of about 1.58 mGal in constructing the gravity field model and about 0.03 m in the regional quasi-geoid model.Compared to the existing methods,the number of SRBFs used for modelling has been reduced by 15.8%,and the time cost to determine the centre positions of SRBFs has been saved by 12.5%.Hence,the modified HDBSCAN algorithm presented here is a suitable design method for constructing the SRBF data adaptive network.

粮食功能区视角下农业高质量发展水平及区域差异研究

基于2016—2020年省级农业发展数据,综合运用改进后的熵值法、Dagum基尼系数等方法,测算了全国及粮食功能区农业高质量发展水平及差异程度,并进一步从一级指标入手,分析了引起区域差异产生和波动的原因。结果表明:(1)三大粮食功能区的农业高质量发展水平均保持上升趋势,按水平由大到小依次为“主销区、主产区、平衡区”。(2)三大粮食功能区存在区域差异,区域间的差异是总体差异的主要来源,区域内差异也出现不同程度的变动。(3)主销区内部差异波动与产业升级指标相关,主产区内部差异波动主要受产出高效和产业升级指标影响,平衡区内部差异波动源于产业升级指标中的追赶效应。(4)区域间差异主要源自产业升级指标,成果共享指标也起到部分影响作用,三大区域各具发展短板。因此,为提升我国农业高质量发展均衡性,应坚持“因地制宜”原则,以水平最低的平衡区为发力点,以产业升级指标为抓手,以各区域发展短板为突破,采取更具针对性的发展措施。

基于改进LSTM的蘑菇生长状态时空预测算法

密集蘑菇簇会严重影响蘑菇质量和自动采摘成功率。为避免形成超密集蘑菇簇,提出一种蘑菇生长状态时空预测算法,对蘑菇生长状态进行预测以指导提前疏蕾。该算法采用编码器-预测器框架,将历史序列图像转换为3D张量序列作为模型的输入;编码器网络中将卷积和长短时记忆(Long short term memory, LSTM)网络融合实现对蘑菇生长的时空相关性特征的提取;在预测网络中加入扩散模型以解决预测图像的模糊问题;此外,在损失函数中增加了蘑菇面积差异损失函数来进一步减小预测蘑菇与实际蘑菇的形状和位置偏差。实验结果表明,本文算法峰值信噪比可达35.611 dB、多层级结构相似性为0.927、蘑菇预测准确性高达0.93,有效提高了蘑菇生长状态图像预测质量和精度,为食用菌生长预测提供了一种新思路。

2000~2020年锡林郭勒草原植被覆盖时空动态变化及影响因素分析

锡林郭勒盟生态地位十分重要,因此定量分析其植被覆盖度时空分布变化特征及驱动因素具有重要意义。本研究首先针对草原植被结构特征,基于优化的多角度像元二分模型构建了锡林郭勒草原2000~2020年植被覆盖度数据集,然后分析了覆盖度的时空变化特征,最后利用地理探测器研究了植被覆盖度变化的影响因素。结果表明:(1)2000~2020年锡林郭勒草原植被覆盖度呈“东高西低”的分布格局,不同生态功能区覆盖度差异较大,覆盖度主要集中在0.2~0.6;不同生态亚区植被覆盖度变化趋势基本一致,呈现波动增长趋势。(2)锡林郭勒草原不同生态功能区植被覆盖度变化差异明显,整体呈上升趋势,显著上升区为11.99%,主要分布在大兴安岭南部落森林草原生态亚区南部,锡林郭勒典型草原生态亚区北部和西部,阴山山地落叶灌丛-草原生态亚区的东部和内蒙古高原荒漠草原生态亚区中部和东南部;14.21%的像元覆盖度显著下降,集中分布在大兴安岭南部落森林草原生态亚区北部、锡林郭勒典型草原生态亚区中部条带状区域和南部以及坝上高原草原与农业生态亚区,需要重点关注。(3)湿润程度是锡林郭勒草原植被覆盖度变化的主要驱动因素,降水的影响力次之,两者与覆盖度均为正相关关系,且湿润指数对中等覆盖度区域影响力较大;气温对覆盖度的驱动力最小,两者为负相关关系。该研究期望为锡林郭勒草原生态保护与合理利用提供科学支撑。

粤港澳大湾区四大合作平台区域治理模式的比较研究

推进重大合作平台建设是粤港澳大湾区落实“一点两地”新定位,进一步全面深化改革、稳步扩大制度型开放的重要依托,有利于“以点带面”引领带动粤港澳全面深化合作。从实践来看,四个重大合作平台在建设发展过程中逐步形成了图景各异的区域治理模式:横琴的“合作政府”治理模式、前海的“法定机构”治理模式、南沙的“属地管理”治理模式以及河套的“园区合作”治理模式。比较四大合作平台区域治理模式的样态可以发现,纵向、横向、斜向和网络状的府际关系对于形塑多样化的区域治理权力结构产生了不同的作用。“自上而下”是四大合作平台构建区域治理权力结构的共同路径;府际权力配置是四大合作平台构建区域治理权力结构的差异化条件。区位属性、服务对象、战略定位、利益配置催生了不同的区域治理模式。

我国本土气温指数期货产品的研发设计——源于京津冀“首都经济圈”核心功能区的气温数据

我国幅员辽阔,对天气变化非常敏感,迫切需要对天气风险进行有效管理,以消除或减少天气风险对各行业的不利影响。从产品研发设计视角出发,以京津冀“首都经济圈”核心功能区为例,参考国外成熟产品,对我国本土气温指数期货产品进行合约设计和模拟定价,根据行业需求阐述产品的应用价值,提出产品在天气风险管理中的显著作用。研究贡献有,搭建起我国本土气温指数期货产品的研发体系;基于国外成熟市场规则构建出符合我国国情的气温指数期货产品标准化合约框架;运用ARMA模型构建出精确度高的气温预测模型;采用蒙特卡罗模拟法制定出气温指数期货两款产品价格;明确产品的应用推广需求和风险管理作用。

面向多区域防洪的珠江流域水库群协同调度模型研究

珠江流域洪水组成与遭遇复杂多变,防洪保护对象多而分散,且兼顾供水、生态、发电、航运、库区安全等多种任务,水库群防洪调度面临多区域、多目标协同调度技术难题。以位于西江、北江、东江上的水库为研究对象,基于流域防洪格局和防洪任务阐明了水库群多区域协同防洪的调度节点和角色定位,提出了嵌套式多维属性的模型功能结构,构建了珠江流域水库群多区域协同防洪调度模型。以流域防洪极为不利的2005年6月中下游型大洪水为例进行流域水库群防洪调度模型研究,结果表明,通过龙滩水库加大拦蓄,岩滩水库、百色水库、西津水库、飞来峡水库等西江、北江水库群协同调度,可将西江梧州站洪峰流量削减至安全泄量50 400 m^(3)/s以下,较原设计调度方案多削减3 200 m^(3)/s,将三角洲思贤滘(马口+三水)断面洪峰削减至62 700 m^(3)/s,较原设计调度方案多削减4 500 m^(3)/s,有效保障了粤港澳大湾区城市的防洪安全。

粤港澳大湾区规划能否提高企业全要素生产率?--来自中国制造业上市公司的证据

近年来,通过城市群规划重构区域发展格局,释放企业发展新动能,已成为国内外驱动经济增长的重要引擎。文章基于2015—2021年中国制造业上市公司数据,以粤港澳大湾区规划作为准自然实验,使用双重差分法考察大湾区城市群规划对企业全要素生产率(TFP)的影响。研究发现:(1)大湾区规划显著提高了区域内企业全要素生产率,在进行了一系列稳健性检验后,结论依然成立。(2)相比之下,大湾区规划更大程度提升了外资及其他企业、中心城市企业和传统制造企业的全要素生产率。(3)从机制分析来看,大湾区规划主要通过缓解融资约束和提高人力资本集聚来促进企业提高全要素生产率。文章丰富了区域政策效应的研究,为制定区域发展战略和促进企业全要素生产率提供参考。

长江经济带城乡地域功能融合发展的时空格局与响应过程

城乡地域功能融合发展是纾解国土空间冲突的关键路径。该研究运用熵权TOPSIS、核密度估计和融合发展度模型分析长江经济带130个城市的城镇、乡村地域功能水平,以及城乡地域功能融合发展的时空格局,采用双变量空间自相关模型识别其响应过程。结果表明:①长江经济带各市城镇、乡村地域功能呈上升趋势,城镇地域功能形成“点-团-面”的分布格局,区域差异逐渐收窄;乡村地域功能呈“簇团”状分布格局,上中下游的地理梯度分异现象突出。②长江经济带各市城乡地域功能由融合过渡型向融合提升型突变发展,融合发展水平呈现下游>中游>上游的特征,由以中心城市为节点向以核心城市群为组团的分布格局演进,东西部极化加剧、省域内部差异扩大。③长江经济带城镇与乡村地域功能相互促进发展作用显著增强,先后历经需求融合、引导融合和自发融合等阶段,融合发展过程呈现由融合过渡到融合提升再到融合优化的螺旋式上升规律。根据研究结论提出以下建议:①上游地区以政策引导发展为契机,吸引下游地区资金、技术、劳动密集型产业向上游地区转移,集中资源全面推进乡村振兴,促进城镇、乡村地域功能双提升。②中游地区着力推进城乡一体化发展,强化武汉、长沙和南昌等区域性中心城市城镇地域功能的辐射带动效应,拉动乡村地域功能发育。③下游地区需促进城镇的生产、生活活动逐步向乡村转移,促进农村土地流转和农业生产经营规模化,助推城乡地域功能优质融合。

砒砂岩覆土区典型小流域土壤可蚀性K值空间变异特征

[目的]研究砒砂岩覆土区典型小流域土壤可蚀性的空间变异特征,为砒砂岩覆土区土壤侵蚀机理深入探究和土壤侵蚀有效防治提供科学依据。[方法]以内蒙古准格尔旗砒砂岩覆土区二老虎沟小流域为研究对象,采集0—10 cm和10—20 cm土层共144份土壤样品,基于EPIC模型估算土壤可蚀性K值,并利用GIS和地统计学方法分析土壤可蚀性K值空间变异特征。[结果](1)二老虎沟小流域土壤砂粒、粉粒、黏粒和有机碳均呈中等变异程度,除黏粒和有机碳为中等空间自相关性外,其他土壤属性均呈弱空间自相关性。(2)小流域土壤可蚀性K值介于0.018 7~0.047 6 t·hm^(2)·h/(hm^(2)·MJ·mm),0—10 cm和10—20 cm土层K值变异系数分别为15.5%和20.3%,属中等变异强度;0—10 cm土层K值主要受随机性因素影响,呈弱空间自相关性,而10—20 cm土层受随机性因素和结构性因素共同影响,为中等空间自相关性。(3) 3种克里格插值方法结果表明:小流域土壤可蚀性K值空间变异受海拔和坡度影响明显,其总体分布趋势为西部和东南部较高、中部及偏东部较低;普通克里格插值方法较适宜应用于砒砂岩覆土区小流域,其估算结果可较好地显示土壤可蚀性的整体和局部两方面的空间变异特征。(4)在垂直空间变异上,0—10 cm和10—20 cm土层土壤可蚀性K值总体分布规律相似,但10—20 cm土层土壤可蚀性K值较0—10 cm土层空间变异更为明显。[结论]海拔和坡度对砒砂岩覆土区典型小流域土壤可蚀性K值空间变异影响明显,未来应优先对坡面和坡顶区域进行土壤侵蚀防治。