The divergence between acceptability of municipal services and urbanization in developing countries: insights from Accra and Sekondi-Takoradi,Ghana

Abstract

In most developing countries, the provision of municipal services and infrastructure invariably fails to match the pace and demands of urbanization. The outcome is often increased informality due to improper planning, official bureaucratic barriers and perhaps insufficient and shrinking public resources, which then makes leveraging private capital for public service provision imperative. Drawing on in-depth qualitative fieldwork in two Ghanaian cities, this paper aims to extend literature on the divergence between service provision and urbanization in developing countries. More specifically, it attempts to qualify recent macro-level data indicating that access to water, sanitation and electricity services in Accra and Sekondi-Takoradi is improving substantively. Contrary to dominant policy narratives circulating in Ghana, we illustrate how the acceptability of key municipal services within urban settings is often inadequate, and how acceptability is tied to spatial and temporal factors. We then identify and examine the reasons underpinning these variations. Through exploring residents’ perceptions of key services, and examining critically the possibility and feasibility of meeting urban service needs through leveraging private resources, this paper contributes to broader academic debates over urban service provision, while also feeding into contemporary policy discussions concerning how to achieve several of the Sustainable Development Goals by 2030.     

中国医疗卫生资源供给水平的空间均衡状态及其时间演变

为正确认识医疗卫生资源空间分布的现状,以医疗卫生资源空间均衡状态及其时间演变趋势为研究内容,采用中国338个地级市为研究样本,运用核密度估计、基尼系数及其分解和LISA时间路径分析等方法,构建国家-区域-市域3个层次的空间均衡分析框架,定量刻画医疗卫生资源空间均衡状态及其时间演变特征。研究结果表明,医疗卫生资源的空间分布正在走向均衡;医疗卫生资源供给水平在三大区域之间的交错程度较高且呈现逐渐增高的趋势;在东部沿海到中部地区的过渡地带存在集中分布的低低集聚区,即医疗卫生资源供给水平同样存在“京汕低谷带”。     

A Review on the Supply-Demand Relationship and Spatial Flows of Ecosystem Services

Research on spatial flow as it relates to the relationship between the supply and demand of ecosystem services supports a significant connection between the supply of ecosystem services and human well-being. Understanding the entire process of the production and flow, as well as the use of ecosystem services, accurately assessing the balance of supply and demand of ecosystem services, and establishing a two-way feedback relationship between supply and demand are vital for the scientific management of the ecosystem and ensuring the sustainable development of regional resources. Based on a large number of relevant publications, this paper comprehensively summarizes the concepts and assessment methods of ecosystem service supply and demand from the perspective of ecosystem service supply and demand, and discusses the impacts of land use and climate change on the temporal and spatial changes of ecosystem services under the background of global change. Then, an analysis of the research progress in the ecosystem services spatial flow indicated that there are still deficiencies in the quantification of cultural services, the dynamics of ecosystem service flow and the driving mechanism of ecosystem services. We also propose that clarifying the driving mechanism and transfer process of ecosystem services, and realizing the mutual conversion between different spatial-temporal scales of ecosystem services, is an important approach for improving the application of ecosystem services research in practice in the future.     

管制之外的"管制":城中村非正规部门的空间集聚与生存状态——以广州市下渡村为例

国内外现有的研究认为,无管制或缺少管制是非正规经济或非正规部门的核心特征。我国城市中的城中村是非正规部门最为集中的区域。选取广州市海珠区的下渡村这一典型案例,对非正规部门的"管制"状况进行了深入调查研究。发现在我国经济转型与快速城市化的背景下,城中村有宽松的管制环境、廉价的住房市场和良好的区位等条件,吸引了大量的非正规部门。但这些城中村的非正规部门并非完全处于管制之外,而是生存于一种管制之外的特殊"管制"之中。这种"管制"表现为一个以政府力量为主导,地方自治组织、地痞组织、本地村民和周围居民等多方力量共同作用的复杂结构,深刻而切实地影响着非正规部门的生存状态。     

The Use of Comaps to Explore the Spatial and Temporal Dynamics of Fire Incidents: A Case Study in South Wales,United Kingdom*

This article reports on the results from a spatiotemporal analysis of disaggregate fire incident data. The innovative analysis presented here focuses on the exploration of spatial and temporal patterns for four principal fire incident categories: property, vehicle, secondary fires, and malicious false alarms. This research extends previous work on spatial exploration of spatiotemporal patterns by demonstrating the benefits of comaps and kernel density estimation in examining temporal and spatiotemporal dynamics in calls for services. Results indicate that fire incidents are not static in either time or space and that spatiotemporal variation is related to incident type. The application of these techniques has the potential to inform policy decisions both from a reactive, resource‐allocation perspective and from a more proactive perspective, such as through spatial targeting of preventive measures.     

An OLS regression model for context-aware tile prefetching in a web map cache

The increasing popularity of web map services has motivated the development of more scalable services in the spatial data infrastructures. Tiled map services have emerged as a scalable alternative to traditional map services. Instead of rendering map images on the fly, a collection of pre-generated image tiles can be served very fast from a server-side cache. However, during the start-up of the service, the cache is initially empty and users experience a poor quality of service. Tile prefetching attempts to improve hit rates by proactively fetching map images without waiting for client requests.

While most popular prefetching policies in traditional web caching consider only the previous access history to make predictions, significant improvements could be achieved in web mapping by taking into account the background geographic information.

This work proposes a regressive model to predict which areas are likely to be requested in the future based on spatial cross-correlation between an unconstrained catalog of geographic features and a record of past cache requests. Tiles that are anticipated to be most frequently requested can be pre-generated and cached for faster retrieval. Trace-driven simulations with several million cache requests from two different nation-wide public web map services in Spain demonstrate that accurate predictions and performance gains can be obtained with the proposed model.     

Spatiotemporal correlation in WebGIS group-user intensive access patterns

Group-user intensive access to WebGIS exhibits spatiotemporal behaviour patterns with aggregation features and regularity distributions when geospatial data are accessed repeatedly over time and aggregated in certain spatial areas. We argue that these observable group-user access patterns provide a foundation for improved optimization of WebGIS so that it can respond to volume intensive requests with a higher quality of service and improve performance. Subsequently, a measure of access popularity distribution must precisely reflect the access aggregation and regularity features found in group-user intensive access. In our research, we considered both the temporal distribution characteristics and spatial correlation in the access popularity of tiled geospatial data (tiles). Based on the observation that group-user access follows a Zipf-like law, we built a tile-access popularity distribution based on time-sequence, to express the access aggregation of group-users with heavy-tailed characteristics. Considering the spatial locality of user-browsed tiles, we built a quantitative expression for the correlation between tile-access popularities and the distances to hotspot tiles, reflecting the attenuation of tile-access popularity to distance. Moreover, given the geographical spatial dependency and scale attribute of tiles, and the time-sequence of tile-access popularity, we built a Poisson regression model to express the degree of correlation among the accesses to adjacent tiles at different scales, reflecting the spatiotemporal correlation in tile access patterns. Experiments verify the accuracy of our Poisson regression model, which we then applied to a cluster-based cache-prefetching scenario. The results show that our model successfully reflects the spatiotemporal aggregation features of group-user intensive access and group-user behaviour patterns in WebGIS. The refined mathematical method in our model represents a time-sequence distribution of intensive access to tiles and the spatial aggregation and correlation in access to tiles at different scales, quantitatively expressing group-user spatiotemporal behaviour patterns with aggregation features and a regular distribution. Our proposed model provides a precise and empirical basis for performance-optimization strategies in WebGIS services, such as planning computing resource allocation and utilization, distributed storage of geospatial data, and providing distributed services so as to respond rapidly to geospatial data requests, thus addressing the challenges of volume-intensive user access.     

Exploring spatiotemporal clusters based on extended kernel estimation methods

We examined three different ways to integrate spatial and temporal data in kernel density estimation methods (KDE) to identify space–time clusters of geographic events. Spatial data and time data are typically measured in different units along respective dimensions. Therefore, spatial KDE methods require special extensions when incorporating temporal data to detect spatiotemporal clusters of geographical event. In addition to a real-world data set, we applied the proposed methods to simulated data that were generated through random and normal processes to compare results of different kernel functions. The comparison is based on hit rates and values of a compactness index with considerations of both spatial and temporal attributes of the data. The results show that the spatiotemporal KDE (STKDE) can reach higher hit rates while keeping identified hotspots compact. The implementation of these STKDE methods is tested using the 2012 crime event data in Akron, Ohio, as an example. The results show that STKDE methods reveal new perspectives from the data that go beyond what can be extracted by using the conventional spatial KDE.     

基于网络关注度的安徽省居民省内旅游需求时空特征分析

基于百度指数平台,收集2019年安徽省居民对省内64家典型景区的网络关注度数据,利用季节性强度指数、旅游需求偏好指数和基尼系数分析安徽省居民的旅游需求特征,并对影响因素进行探讨。结果显示:全省居民省内旅游需求呈多岭型,形成4月、7―8月和10月3个需求高峰;单岭型景区各月的旅游需求有较明显差别,双岭型和多岭型的景区无明显旅游需求季节性差别;全省居民旅游需求时间主要受经济发展水平、旅游资源的季节性和独特性、景区开发程度、气候舒适度、节假日的影响;安徽省居民形成3个旅游需求偏好区,分别是皖中皖东南休闲娱乐偏好区、皖南自然观光偏好区和皖西南山岳景观偏好区;全省居民旅游需求空间分布主要受景区密集程度、级别、资源开发程度和空间距离的影响。     

Estimating the effect of turn penalties and traffic congestion on measuring spatial accessibility to primary health care

Geographic variations in spatial accessibility to public resources, such as health care services, raise important questions about the efficiencies and inequities of the processes that determine where these services are located. Spatial accessibility can be measured many different ways, but many of methods in use today involve some measure of travel cost (in time or distance). In this study we explore a simple methodological question: how much are models of spatial accessibility influenced by the precise metric of travel cost? We address this question by comparing spatial accessibility to primary care physicians for two different methods of calculating travel cost (in time) on a street network: free-flow travel time and congested with turn penalties travel time—which augments free-flow travel times with the burden of traffic congestion and traffic intersection controls. We consider the effect of these two metrics of travel cost on a gravity-based measure of spatial accessibility to primary health care services in Edmonton, Alberta, Canada. Our results suggest that while travel times between locations of demand and locations of primary care providers greatly differ based on how travel cost is calculated, the gravity-based measure of spatial accessibility provides similar information for both travel cost metrics. Using congested with turn penalties travel time can be an onerous addition to the analysis of spatial accessibility, and is more useful for measuring absolute travel time rather than modeling relative spatial accessibility.     

Spatial and Temporal Patterns of Supply and Demand Balance of Water Supply Services in the Dongjiang Lake Basin and Its Beneficiary Areas

Water-related ecosystem services is a hot topic in ecological research. Water supply services are crucial to regional water cycles and water quantity balance. The Dongjiang Lake basin is a national priority river basin in China where ecological compensation pilot programs concerning water resources and water supply services are top priorities for ecosystem service protection. We analyzed spatial and temporal patterns associated with generation and use of water supply services in the Dongjiang Lake basin using the InVEST model, socio-economic data and water resource data. We found that between 1995 and 2010, water yield in the Dongjiang Lake basin and its beneficiary areas increased before declining, varying 9350-12 400 m³ ha^-1 y^-1; average water yield peaked in 2000. The spatial distribution patterns of water yield during these years are similar, progressively decreasing from upstream to downstream with a remarkable reduction in surrounding areas of city clusters. Average water consumption of the basin and its beneficiary areas ranged from 2900-4450 m³ ha^-1 y^-1 between 1995 and 2010; the spatial distribution patterns of water consumption during these years are similar, dropping gradually from urban construction land to its surroundings with a stronger gradient between urban and rural areas. More water was consumed on both banks and surroundings of the lake. From 1995 to 2010, water supply fell short of demand for urban construction land and its proximity as well as areas along the lake. Water supply services were able to satisfy needs in other regions. The Changsha-Zhuzhou-Xiangtan city cluster suffers from the most strained water supply.     

西宁市老年人口分布与养老资源错位研究

健康中国战略下,积极应对老龄化、建立健全养老和医疗等相关设施,成为许多城市关注的问题。目前相关研究很少关注西北城市的老龄人口的空间分布及养老资源错位的现象。本研究以西宁市主城区为研究区域,基于2010—2018年西宁市公安局各街镇人口数据和兴趣点（POI）数据,选用老年人口系数、赡养率、增长率和地理集中率四个指标,利用综合老龄化指数（CAI）模型、核密度函数模型和空间错位指数模型对西宁市主城区人口老龄化空间分布及养老资源（医疗资源、老年设施）空间错位现象进行探索分析,结果表明：（1）9年间西宁市主城区人口老龄化程度不断加深,已步入老年型社会。（2）通过老龄化综合指数可知：主城区外围街镇人口老龄化增长速度大于城区中心的街道,其中小桥街道、朝阳街道、马坊街道与乐家湾镇人口老龄化最为严重,2018年综合老龄化指数增长速度超过中心城区街道,西宁市主城区人口老龄化严重程度已从中心街道向外围街镇扩散。（3）通过空间错位指数计算可得知：城中区的养老资源数量充足但过于集中,城北区的养老资源分布合理但是数量较少,行政区之间的养老资源与老年人口分布存在较大空间错位问题。     

海南自贸港金融服务实体经济效率的时空异质性及其驱动机理

提升金融服务实体经济效率是海南自贸港建设亟待研究和突破的“靶点”。论文通过测算2011—2020年海南自贸港18市县金融服务实体经济效率,利用Dagum基尼系数与Kernel密度估计方法刻画效率的时空异质性,并借助随机森林模型揭示其驱动机理,创新性地从时空视角挖掘海南自贸港金融服务实体经济效率分异机制。研究发现：(1)海南自贸港金融服务实体经济效率时空非平衡性明显,时序上阶段性显著,空间上呈西高东低、高值聚集、中部“洼地”的分布特征,西北部市县与中部市县各自逐步形成高值、低值聚集区;(2)总体及沿海市县梯度分化特征逐步加强,而非沿海市县内部差距则逐步缩小,沿海区域金融服务实体经济效率的空间分异是总体分异的主要来源;(3)政府干预是效率分化的主导因素,含金融集聚度在内的影响因素对效率均呈非线性影响且作用趋势与阈值各异,各因素的边际产出能力及各市县对要素的吸收与应用能力的动态差异是时空异质性的主要来源。研究结论可为优化海南自贸港金融资源的空间配置、提升金融服务实体经济效率提供科学依据。     

黄土丘陵区生态系统服务供需匹配研究——以兰州市为例

生态系统服务的持续供给是社会和自然可持续发展的基础,人类通过对生态系统服务的消费来满足需求和提高自身福祉。研究生态系统服务的供给和人类对生态系统服务的需求与消费,分析生态系统服务的供需特征与空间权衡关系,对区域生态系统的管理和资源的有效配置具有重要意义。以兰州市为例,利用全市2017年土地覆被、气象观测和统计年鉴等多源数据,应用InVEST模型、ArcGIS和GeoDA等空间分析工具,计算了研究区产水、食物供给、碳固持和土壤保持等4项服务的供给量及需求量,并对区域内生态系统服务的供需匹配状况进行了分析与评价。结果表明：① 兰州市各项生态系统服务的供给与需求空间异质性显著,各项服务总供给量均大于总需求量,且在不同区域与不同生态系统服务之间存在明显差异;② 兰州市综合生态系统服务供需比为0.039,不同生态系统服务供需匹配状况存在差异,产水服务（0.098）>碳固持服务（0.066）>食物供给服务（0.030）>土壤保持服务（0.001）,且城乡供需匹配差异显著;③ 兰州市生态系统服务供需空间匹配有“高高型空间匹配”、“低低型空间匹配”、“高低型空间错位”和“低高型空间错位”4种类型,且各项服务的主导空间匹配类型有所不同;④ 兰州市各项生态系统服务的供需平衡状况存在明显的协同作用,分别是“高高协同”与“低低协同”。     

高质量发展目标下黄河流域城市居民生活质量的时空格局及障碍因子

提高居民生活质量是实现黄河流域高质量发展的重要目标和具体体现。从居民生活、基础设施、公共服务、生态环境4个方面构建城市居民生活质量评价指标体系,测度2004―2018年黄河流域城市居民生活质量水平,利用核密度估计、ESDA、Dagum基尼系数等方法进行居民生活质量时空格局分析及空间差异测度,并运用障碍因子诊断模型分析影响居民生活质量水平的障碍因子,得出如下结论：① 2004―2018年黄河流域城市居民生活质量高水平区域从下游城市逐渐转移到中上游城市;② 黄河流域城市居民生活质量高?高集聚区主要是内蒙古自治区及相邻区域的城市,低?低集聚区主要是河南省、山东省以及山西省的部分城市;③ 黄河流域城市居民生活质量水平的空间差异从上中下游尺度看主要是区域间净值差异贡献,从左右岸尺度看主要是区域内部差异贡献;④ 黄河流域城市居民生活质量水平的障碍因子主要是人均水资源量、移动电话年末用户数、每万人公园绿地面积、教育支出占财政支出比重、每万人拥有的道路面积与人均可支配收入等,因此在未来的高质量发展中要注重生态环境保护,特别是合理利用水资源,完善城市基础设施与提升公共服务水平。     

收缩城市住房空置时空分异及影响机制——基于居民用电量视角

以中国典型的资源型收缩城市——伊春市的伊春区为研究对象,从居民用电量视角对住房空置情况进行判定,同时综合运用核密度估计、网络分析以及问卷访谈等方法,基于区域、居住区、格网3种尺度,对2013—2018年住房空置时空分异格局及影响机制进行深入探究。结果表明：① 伊春区空置住房总量和空置率总体表现为波动上升态势,在国际通行标准下处于“供需基本平衡”状态;② 伊春区住房空置格局在区域尺度、居住区尺度、格网尺度等不同尺度下表现出一定差异性,但各尺度均总体呈现“核心?边缘”的空间分布特点;③ 人口流失、经济支撑、城市功能地位以及居民感知等因素影响伊春区住房空置时序演变,而城市空间开发扩展、住区建设演变、教育医疗设施布局、公共交通可达性等因素共同作用于住房空置的空间分异。     

郑州市旅游资源空间格局特征及便利度评价

以国家中心城市郑州的旅游类兴趣点数据为基础,运用核密度分析、标准差椭圆分析、空间相关性分析等GIS空间分析方法,对郑州市旅游资源空间格局特征及便利度进行分析,为郑州市旅游空间布局规划决策提供科学依据。研究结果表明:(1)郑州市旅游资源空间分布不均衡,整体上表现为“北多南少、北密南疏”的格局,呈现出面状集聚和点状分布并存的局面,市辖区的旅游资源远多于其他区县;(2)郑州市旅游资源相对较分散,各类旅游资源主要沿“东南-西北”“东北-西南”的方向分布,且存在一定的向心性;(3)餐饮、酒店、交通等服务设施与不同城市旅游资源类型的空间匹配度不同,其中交通设施与旅游资源的空间匹配度最高,旅游资源倾向于分布在交通发达、食宿方便的区域;(4)郑州市旅游资源便利度在空间上表现为“中间高,四周低,城区连片,郊区分散”的整体格局。     

珠三角城市群生态游憩空间分异特征及关联性因素

生态游憩空间是居民放松身心、亲近自然的主要活动场所,是提升居民生活质量和幸福感的重要开放空间。随着城市群的一体化发展,以及城市群居民对居住环境和休闲品质要求的提高,生态空间游憩利用的区域组织成为了新的理论课题。本文在界定生态游憩空间并对其进行空间解译的基础上,运用GIS空间分析方法,对珠三角城市群生态游憩空间分布的集聚和分异特征进行了刻画,并分析了其与人文、自然生态要素的空间关系,揭示生态游憩空间分布存在的问题与成因。结果显示：① 各城市生态空间游憩利用率的空间分异明显,反映了生态空间游憩利用缺少有效的区域统筹。② 生态游憩空间数量、规模、等级以及生态空间游憩利用率分布具有空间集聚特征,但四者的集聚导向存在差异。③ 生态游憩空间分布与地形、交通具有空间依存关系,但与水系、旅游要素以及文化资源分布的关联性不明显。④ 生态游憩空间面积分布与人口密度分布相反,说明珠三角城市群生态空间游憩服务存在供需空间错位矛盾。     

生态系统服务供给和需求研究进展

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