Asian Megacities Research Articles

Keeping the business going: SMEs and urban floods in Asian megacities

Flooding presents one of the main risks to contemporary and future cities, especially those in coastal zones. Given the social–political nature and construction of urban flood risks, it is of cruci...

Neo-Tokyo: Distopia Urbana e Cidades Genéricas

Em Akira (1988) temos uma representação da cidade de Tóquio (neste caso Neo Tokyo) que serve de valioso documento histórico no que diz respeito ao imaginário relativo às transformações pelas quais a cultura, tecnologia e as cidades japonesas passaram durante a segunda metade do século XX. Por lidar com reflexões relativas ao caldeirão do pensamento sócio-econômico-cultural das megacidades asiáticas, a película dialoga com as reflexões de Rem Koolhaas acerca da formação e características das “Cidades Genéricas”, expostas em S,M,L,XL, de 1995. A perda da identidade das grandes cidades asiáticas é discutida neste artigo traçando-se um paralelo entre os textos de Koolhaas e a visão de Katsuhiro Otomo, roteirista e diretor do longa. A primeira parte deste artigo trata da importância de Akira na formulação de um imaginário contemporâneo relativo à cidade de Tóquio, bem como da capacidade que esta obra tem ao capturar e representar questões relativas ao Japão urbano do período. Na segunda parte há um breve comentário sobre a cultura e sociedade japonesas deste período. A cidade de Neo Tokyo, em si, é o objeto da terceira parte, sendo esta distopia comparada em diversos aspectos à utopia apresentada por Kenzo Tange em 1961, em seu plano para a ocupação da Baía de Tóquio. Também nesta terceira parte são observados mais detalhadamente os aspectos que aproximam a representação distópica da mega metrópole asiática àqueles explorados por Koolhaas. Na quarta e última parte, há um comentário final sobre as razões pelas quais o cyberpunk japonês tem tanto apelo ao público ocidental e sua capacidade de síntese e expressão dos problemas enfrentados pelas grandes cidades asiáticas.

Spatial and Temporal Dynamics of Urban Wetlands in an Indian Megacity over the Past 50 Years

Asian megacities have attracted much scientific attention in the context of global urbanization, but few quantitative studies analyze wetland transformation in the rural–urban interface. With its rampant growth and transformation from a tree-lined “Garden City” to a busy megalopolis with often-blocked highways and large built-up areas, Bengaluru (Karnataka, S-India) is a good example for assessing how urbanization has led to the acute degradation of wetlands. We therefore investigated long-term land cover and wetland changes from 1965 to 2018 based on an object-based classification of multi-temporal Corona and Landsat images. To quantify and compare the dynamics of open water surfaces and vegetation, we defined the potential wetland areas (PWA) along the rural–urban gradient and linked our analyses to an index describing the degree of urbanization (survey stratification index (SSI)). During the five decades studied, built-up areas in the Bengaluru Urban district increased ten-fold, with the highest growth rate from 2014 to 2018 (+ 8% annual change). Patches of lake wetlands were highly dynamic in space and time, partly reflecting highly variable annual rainfall patterns ranging from 501 mm in 1965 to 1374 mm in 2005 and monsoon-driven alterations in the hydrologic regime. While water bodies and flooded areas shrunk from 64 km2 in 1965 to 55 km2 in 2018, in 1965, the total rural wetland area with an SSI > 0.5 was twice as high as in 2018. The rural–urban land cover pattern within potential wetland areas changed drastically during this period. This is reflected, for example, by a four-fold increase in the wetland area with an SSI of 0.3, as compared to a decline by 43% in wetland area with an SSI of 0.8. While, in urban areas, wetlands were mostly lost to construction, in areas with a rural character, open water bodies were mainly transformed into green space. The detected changes in urban wetlands were likely accompanied by ecological regime changes, triggering deteriorations in ecosystem services (ESS) which merit further research.

ASSESSING POPULATION SENSITIVITY TO URBAN AIR POLLUTION USING GOOGLE TRENDS AND REMOTE SENSING DATASETS

Abstract. This study demonstrates relationship between remote sensing satellite retrieved fien aerosol concentration and web-based search volumes of air quality related keywords. People’s perception of urban air pollution can verify policy effectiveness and gauge acceptability of policies. As a serious health issue in Asian cities, population may express concern or uncertainty for air pollution risk by performing search on the web to seek answers. A ‘social sensing’ approach that monitors such search queries, may assess people’ perception about air pollution as a risk. We hypothesize that trend and volume of searches show impact of air pollution on general population. The objectives of this research are to identify those atmospheric conditions under which relative search volume (RSV) obtained from Google Trends shows correlation with measured fine aerosol concentration, and to compare search volume sensitivity to rise in aerosol concentration in seven Asian megacities. We considered weekly relative search volumes from Google Trends (GT) for a four year period from January, 2015 to December, 2018 representing diverse PM2.5 concentrations. Search volumes for keywords corresponding to perception of air quality (‘air pollution’) and health effects (‘cough’ and ‘asthma’) were considered. To represent PM2.5 we used fine aerosol indicator developed in an earlier research. The results suggest that tendency to search for ‘air pollution’ and ‘cough’ occurs when AirRGB R is in excess and temperature is below the baseline values. Consistent with this, in cities with high baseline concentrations, sensitivity to rise in AirRGB R is also comparatively lower. The result of this study can used as an indirect measure of awareness in the form of perception and sensitivity of population to air quality. Such an analysis could be useful for forecasting health risks specially in cities lacking dedicated services.

Composition and source apportionment of saccharides in aerosol particles from an agro-industrial zone in the Indo-Gangetic Plain.

The characterization of saccharidic compounds in atmospheric aerosols is important in order to retrieve information about organic carbon sources and their transport pathways through the atmosphere. In this study, composition and sources of saccharides in PM10 were determined in a South Asian megacity (Faisalabad) during the year2015-2016. PM10 sampled on quartz filters was analyzed by anion exchange chromatography for the selected saccharidic compounds. The average PM10 concentration was found to be 744 ± 392μgm-3, exceeding the daily limits proposed by Pak-EPA (150μgm-3), US-EPA (150μgm-3), and WHO (50μgm-3). The average total saccharidic concentration was found to be 2820 ± 2247ngm-3. Among the different saccharidic categories, anhydrosugars were the most abundant in concentration followed by primary sugars and sugar alcohols. The correlation and principal component analysis indicated emissions from biomass combustion, soil suspensions from areas such as farmlands having high microorganism activity, and biogenic emissions such as airborne fungal spores and vegetation detritus as major sources of saccharides in the aerosol samples.

Hard or soft flood adaptation? Advantages of a hybrid strategy for Shanghai

Flood risk is expected to increase in coastal cities, particularly in Asian megacities such as Shanghai. This paper presents an integrated modeling framework to simulate changes in the flood risk in Shanghai and provide a cost-benefit analysis of multiple adaptation strategies used to reduce risk. The results show that the potential flood risk will increase dramatically as a result of sea level rise, land subsidence, and socioeconomic development. By 2100, the expected annual damage could reach 0.8% (uncertainty range: 0.4%–1.4%) of local GDP under an optimistic emission scenario (RCP4.5), compared to the current value of 0.03%. All of the adaptation strategies can effectively reduce the flood risk under the current conditions and those in 2050. In contrast to the ‘hard’ flood protection strategies (i.e., storm-surge barriers and floodwalls), the ‘soft’ strategies (i.e., building codes and nature-based measures) cannot substantially reduce the flood risk in 2100. However, the soft strategies can play a critical role in reducing the residual risk resulting from the hard strategies. A ‘hybrid’ strategy combining a storm-surge barrier, wet-proofing, and coastal wetland development outperforms both hard and soft strategies in terms of low residual risk and high benefit/cost ratio. Additionally, the hybrid strategy can also enable a larger reduction in casualties. These findings imply that managing flood risk is more than the use of single adaptation measures. The methodology developed in this paper can enlighten Shanghai and other coastal cities on an economically and socially feasible adaptation strategy in an uncertain future.

Asian megacity heat stress under future climate scenarios: impact of air-conditioning feedback

Future heat stress under six future global warming (ΔTGW) scenarios (IPCC RCP8.5) in an Asian megacity (Osaka) is estimated using a regional climate model with an urban canopy and air-conditioning (AC). An urban heat ‘stress’ island is projected in all six scenarios (ΔTGW = +0.5 to +3.0 °C in 0.5 °C steps). Under ΔTGW = +3.0 °C conditions, people outdoors experience ‘extreme’ heat stress, which could result in dangerously high increases in human body core temperature. AC-induced feedback increases heat stress roughly linearly as ΔTGW increases, reaching 0.6 °C (or 12% of the heat stress increase). As this increase is similar to current possible heat island mitigation techniques, this feedback needs to be considered in urban climate projections, especially where AC use is large.

Vertical Variation of Carbonaceous Aerosols with in the PM2.5 Fraction in Bangkok, Thailand

ABSTRACT Asian megacities are undergoing rapid population and infrastructure growth, which is resulting in significant air quality problems linked to atmospheric fine particles (PM2.5). This study focuses on characterizing carbonaceous aerosols in an urban area of Bangkok, Thailand. The Microclimate and Air Pollutants Monitoring tower is located on the edge of Kasetsart University campus and was used to perform vertical measurements. Mass concentration data were collected using area dust monitors (ADR1500) at different levels above the ground (30 m, 75 m, and 110 m) during two time periods, daytime (08:00–19:00) and nighttime (20:00–07:00), throughout the monsoon season in 2015. All relevant micrometeorological parameters were simultaneously monitored. Backward air mass trajectories were calculated using HYSPLIT to assess the possible external pollution contributions. The thermal optical transmittance (TOT) method following the NIOSH 870 protocol was used to determine amounts of elemental carbon (EC) and organic carbon (OC) in samples. A data analysis showed average PM2.5 values at observation heights of 30 m, 75 m, and 110 m of 6.21 ± 2.45, 8.12 ± 3.65, and 9.03 ± 3.93 µg m–3, respectively; corresponding OC concentrations of 4.13 ± 2.65, 4.01 ± 4.07, and 4.11 ± 3.58 µg m–3, respectively, and EC concentrations of 1.02 ± 0.84, 1.07 ± 0.95, and 0.50 ± 0.70 µg m–3, respectively. The results show distinct gradients of increasing concentrations of PM2.5 with increasing elevation in contract with the OC and EC concentrations which decrease with height.

Impact and Correlation of Air Quality and Climate Variables with Covid-19 Morbidity and Mortality in Dhaka, Bangladesh

The COVID-19 pandemic unexpectedly stopped the steady life and enhanced environmental quality. To apprehend the transmission of COVID-19 and the improvement of air quality, we have studied air quality indicators (PM2.5, PM10, AQI, and NO2 ), CO2 emission, and climate variables (temperature, relative humidity, rainfall, and wind velocity) in the extremely polluted and densely populated Southeast Asian megacity Dhaka, Bangladesh from March to June 2020. The Kendall and Spearman correlations were chosen to test the connotation of air quality and climate variables with COVID-19 morbidity and mortality. The average concentrations of PM2.5, PM10, and CO2 were 65.0 ± 37.9 and 87.1 ± 52.8 µm m-3, and 427 ± 11.8 ppm, respectively. The average PM2.5 and PM10 drastically reduced up to 62% during COVID-19 lockdown in Dhaka comparing with March 2020 (before lockdown). Comparing with the same period in 2019, PM2.5 reduced up to 33.5%. The average NO2 concentration was 35.0 µmol m-2 during the lockdown period in April, whereas 175.0 µmol m-2 during March (before lockdown). A significant correlation was observed between COVID-19 cases and air quality indicators. A strong correlation was obtained between climate variables and the total number of COVID-19 morbidity and mortality representing a favorable condition for spreading the virus. Our study will be very expedient for policymakers to establish a mechanism for air pollution mitigation based on scientific substantiation, and also will be an essential reference for the advance research to improve urban air quality and the transmission of the SARS-CoV-2 virus in the tropical nations.

Potentially Heterogeneous Cross-Sectional Associations of Seafood Consumption with Diabetes and Glycemia in Urban South Asia.

Aims: In this study, we aimed to estimate cross-sectional associations of fish or shellfish consumption with diabetes and glycemia in three South Asian mega-cities. Methods: We analyzed baseline data from 2010–2011 of a cohort (n = 16,287) representing the population ≥20 years old that was neither pregnant nor on bedrest from Karachi (unweighted n = 4017), Delhi (unweighted n = 5364), and Chennai (unweighted n = 6906). Diabetes was defined as self-reported physician-diagnosed diabetes, fasting plasma glucose ≥126 mg/dL (7.0 mmol/L), or glycated hemoglobin A1c (HbA1c) ≥6.5% (48 mmol/mol). We estimated adjusted and unadjusted odds ratios for diabetes using survey estimation logistic regression for each city, and differences in glucose and HbA1c using survey estimation linear regression for each city. Adjusted models controlled for age, gender, body mass index, waist–height ratio, sedentary lifestyle, educational attainment, tobacco use, an unhealthy diet index score, income, self-reported physician diagnosis of high blood pressure, and self-reported physician diagnosis of high cholesterol. Results: The prevalence of diabetes was 26.7% (95% confidence interval: 24.8, 28.6) in Chennai, 36.7% (32.9, 40.5) in Delhi, and 24.3% (22.0, 26.6) in Karachi. Fish and shellfish were consumed more frequently in Chennai than in the other two cities. In Chennai, the adjusted odds ratio for diabetes, comparing more than weekly vs. less than weekly fish consumption, was 0.81 (0.61, 1.08); in Delhi, it was 1.18 (0.87, 1.58), and, in Karachi, it was 1.30 (0.94, 1.80). In Chennai, the adjusted odds ratio of prevalent diabetes among persons consuming shellfish more than weekly versus less than weekly was 1.08 (95% CI: 0.90, 1.30); in Delhi, it was 1.35 (0.90, 2.01), and, in Karachi, it was 1.68 (0.98, 2.86). Conclusions: Both the direction and the magnitude of association between seafood consumption and glycemia may vary by city. Further investigation into specific locally consumed seafoods and their prospective associations with incident diabetes and related pathophysiology are warranted.

A comparison of the practices and influential factors of pro-environmental behaviors in three Asian megacities: Bangkok, Tokyo, and Seoul

In order to adopt environmentally friendly modes of actions, pro-environmental behaviors (PEBs) have been promoted in many countries to improve people’s consumption patterns and lifestyles in a sustainable manner. The current practices and influential factors of people can differ by country, but related studies in the Asian region are limited. The present study aims to examine the differences in PEBs between developing and developed societies in the Asian context. The practices and reasons of 42 behaviors in Bangkok were analyzed and compared with those of Seoul and Tokyo. The results showed the different tendencies toward PEB practices and reasons in the developing and developed cities. In Bangkok, the most-conducted behaviors were observed in the area of energy saving, while those in Seoul and Tokyo included several domains of PEBs, such as waste separation, energy saving, and transportation. On the other hand, similarities were observed in the less-conducted behaviors across the three cities, where there was less engagement in green-product purchasing. The correspondence analysis mapping of reasons and behaviors indicated that the reasons for or against conducting PEBs differ by city. A more diverse map for the reasons against conducting the behaviors indicated that each PEB is influenced by multiple reasons when it is not conducted, while a sole strong reason exists when a PEB is conducted. Possible reasons for differences PEBs engagement were discussed based on the differences in contextual factors of the three cities, as well as implications and future research.

Analysis and environmental risk assessment of priority and emerging organic pollutants in sediments from the tropical coastal megacity Jakarta, Indonesia

Jakarta, the capital of Indonesia, is one of the rapidly growing coastal megacities in Asia. The implementation of the urban wastewater infrastructure is not keeping up with the rapid expansion of the city, leading to a severe deterioration of water and sediment quality in the metropolitan area. The present study aimed to assess sediment contamination with organic pollutants in Jakarta rivers and the related risks to the coastal ecosystem. To this end, the site-specific and most harmful organic pollutants in the sediments were quantified, and the obtained chemical data were compared to reported sediment toxicity thresholds for an impact assessment on the benthic community.The detected pollutant spectrum included several compounds, such as the detergent residues nonylphenols and the insect repellent DEET (N,N-diethyl-m-toluamide), that were previously reported as contaminants in industrialized countries but have been banned or partly substituted. The risk of sediment contamination for benthic macroinvertebrates was associated with PAHs (polycyclic aromatic hydrocarbons), DDT (bis(chlorophenyl)dichloroethane), nonylphenols and a synthetic fragrance. High concentrations of paper manufacturing educts, a compound class that was recently reported in industrialized areas with a flourishing paper industry, were found in Jakarta sediments. However, sediment quality guidelines or sediment toxicity thresholds for these compounds are not available, which limited the ecotoxicological risk assessment. More studies on sediment toxicities considering emerging industrial pollutants and test species from all climate regions are urgently required, as a prerequisite for an adequate impact assessment of sediment contamination.

Analysis and Evaluation of Contamination Status of Polycyclic Aromatic Hydrocarbons (PAHs) in Settled House and Road Dust Samples from Hanoi

Analysis and Evaluation of Contamination Status of Polycyclic Aromatic Hydrocarbons (PAHs) in Settled House and Road Dust Samples from Hanoi

On the microphysical processing of aged combustion aerosols impacting warm rain microphysics over Asian megacities

This paper delineates the process of activation of soot or black carbon particles into cloud droplets over Chennai, India (an Asian megacity). Archaic wood-fired cooking stove emissions from crowded shantytown settlements dispense copious amounts of carbonaceous particles into the city’s atmosphere during morning and evening cooking periods. Traffic emissions also add considerably to the city’s particulate matter loads. At other times, when these sources are reduced (e.g. during non-cooking periods), a pall of residual pollution hovers above the city. This study assesses this problem definitively through process modelling studies undertaken during a typical pre-monsoonal month (October) when the levels of pollution are very high. The novelty of this paper includes a clear quantification of the percentage of activated nuclei resulting from these sources using a sophisticated cloud chemical parcel model. The results show that 85% of the soot and black carbon particles are activated into very small low-lying cloud droplets within Chennai’s boundary layer. We further show for the first time that the presence of these particles results in a slowing down of the auto-conversion process (cloud water to rain droplets). This study could serve as a pointer for other Asian Cities with a sizeable shantytown population in India and elsewhere.

Urban warming and future air-conditioning use in an Asian megacity: importance of positive feedback

The impact of feedback between urban warming and air-conditioning (AC) use on temperatures in future urban climates is explored in this study. Pseudo-global warming projections are dynamically downscaled to 1 km using a regional climate model (RCM) coupled to urban canopy and building energy models for current and six future global warming (ΔTGW) climates based on IPCC RCP8.5. Anthropogenic heat emissions from AC use is projected to increase almost linearly with ΔTGW, causing additional urban warming. This feedback on urban warming reaches 20% of ΔTGW in residential areas. This further uncertainty in future projections is comparable in size to that associated with: a selection of emission scenarios, RCMs, and urban planning scenarios. Thus this feedback should not be neglected in future urban climate projections, especially in hot cities with large AC use. The impact of the feedback during the July 2018 Japanese heat waves is calculated to be 0.11 °C.

Surface ozone response to satellite-constrained NOx emission adjustments and its implications

Both surface and satellite observations have shown a decrease in NOx emissions in East Asian countries in recent years. In order to reflect the recent NOx emission reduction and to investigate its impact on surface O3 concentrations in Asian megacities, we adjusted two bottom-up regional emission inventories of which base years are 2006 (E2006) and 2010 (E2010), respectively. We applied direct and relative emission adjustments to both E2006 and E2010 to constrain NOx emissions using OMI NO2 vertical column densities. Except for the relative emission adjustment with E2006, modeling results with adjusted emissions exhibit that NOx emissions over East Asian megacities (Beijing, Shanghai, Seoul, and Tokyo) in the bottom-up inventories are generally overestimated. When the direct emission adjustment is applied to E2006, model biases in the Seoul Metropolitan Area (SMA), South Korea are reduced from 24 ppb to 2 ppb for NOx (=NO+NO2) and from −9 ppb to 0 ppb for O3. In addition, NO2 model biases in Beijing and Shanghai in China are reduced from 8 ppb to 18 ppb–0 ppb and 1 ppb, respectively. Daily maximum 8-h average O3 model biases over the same places are decreased by 8 ppb and 14 ppb. Further analyses suggest that the reduction in domestic South Korean NOx emissions plays a significant role in increasing O3 concentrations in SMA. We conclude that the current strong drive to reduce NOx emissions as part of the strategy to lower particulate matter concentrations in South Korea can account for increased O3 concentrations in recent years and suggest that more aggressive NOx emissions will be necessary soon.

The composition and sources of water soluble ions in PM10 at an urban site in the Indo-Gangetic Plain

Analysis of water soluble ions in PM10 in Pakistan is limited and therefore requires in-depth investigation. In this study composition and sources of ionic profile in PM10 were determined from an urban site of an Asian megacity (Faisalabad) in 2015–2016. The PM10 size fraction sampled on quartz filters was analyzed by ion chromatography for selected inorganic and organic ions. The daily mean PM10 mass concentration was found to be 744 ± 392 μgm−3, exceeding the limits proposed by Pak-EPA (150 μgm−3), US-EPA (150 μgm−3) and WHO (50 μgm−3). The ambient PM10 concentration was found to be highest in winter 2015-16 and autumn 2016, while the lowest in the monsoon 2016. The average total ion concentration was found to be 120 ± 51 μgm−3, which made about 16% of the total PM10 mass. CO32− was the most dominant specie followed by NH4+, Ca2+, K+, NO3−, SO42−, C2O42−, CH3COO−, Na+, Cl− and Mg2+. The ratio analysis of selected ions indicated dominant contribution of biomass burning during autumn and winter and higher impact of fossil fuel burning during spring and summer seasons. Positive Matrix Factorization identified traffic induced soil erosion, biomass burning, fugitive dust from construction activities, secondary aerosol formation processes and fossil fuel emissions from traffic and industry as major sources of particulates.

Water quality trend assessment in Jakarta: A rapidly growing Asian megacity.

Megacities are facing serious water pollution problems due to urbanization, rapid population growth and economic development. Water is an essential resource for human activities and socio-economic development and water quality in urban settings has important implications for human and environmental health. Urbanization and lack of sewerage has left the water in Jakarta, Indonesia in a heavily polluted condition. Rigorous assessment of urban water quality is necessary to understand the factors controlling water quality conditions. We use trend analysis to assess the current water quality conditions in Jakarta, focusing on Biochemical Oxygen Demand (BOD), Dissolved Oxygen (DO), and Total Suspended Solids (TSS). In most monitoring stations analyzed, BOD and TSS concentrations have decreased over time, but from large starting concentrations. DO in most monitoring stations has increased. Although Jakarta’s water quality has shown some improvement, it remains heavily impaired. The average value of BOD is low in upper stream stations compared to middle and lower stream stations. BOD and TSS trends of some water quality stations in middle and lower streams show increasing trends. Cluster analysis results suggest three groups for BOD and TSS, and four groups for DO. Understanding water quality conditions and factors that control water quality suggest strategies for improving water quality given current trends in climate, population growth and urban development. Results from this study suggest research directions and management strategies to address water quality challenges.

Habitat between density and urban growth: The urban living in the Asian Megacities

Urban growth and urban population are the most important issues to consider for sustainable planning and urban design for this century. The problem requires a general understanding on the global scale, considering rapid urbanization as a result of the dynamics of immigration from rural to urban areas. Since the 1950s, cities never seized to grow and we are living not in the city or in a metropolitan area, but in mega-urban areas or megacities, where the population is more than tens of millions of people. In the contemporary urban environment, more than half of the entire population live in Urban areas, which can be considered an urban explosion. The research and the studies focus on Asian Cities because of their importance. Their unique context and vast area are interesting assets to understand the network in between and the future balance with the rest of the planet. On the vision of the next urban future, if we are looking at the map of the megacities in 2030, 2050 and 2100, high concentration, large urban areas and high population density will be in that region.

Farm Diversification and Sustainability of Multifunctional Peri-Urban Agriculture: Entrepreneurial Attributes of Advanced Diversification in Japan

Multifunctionality of urban agriculture is essential for the sustainability of both cities and urban farms, especially in Asian mega-cities exhibiting extensive urban sprawl. To maximise the multifunctionality of these farms, entrepreneurial or innovative farm diversification is important. However, there is insufficient research on this issue in developed countries. This study aims to demonstrate the existence of advanced diversified farms characterised by entrepreneurship, skilled farm management and social networks and explore their economic and social sustainability by using data from a survey of 386 farms located close to urban areas in Japan. Gaussian mixture clustering analysis revealed that only about 10% of the sample can be classified as advanced diversified farms and most of the other diversified farms do not exhibit entrepreneurial attributes. Furthermore, regression analysis revealed that advanced diversification has a positive impact not only on the economic viability of farms, but also on their social performance. These findings have significant implications for policies promoting the sustainability of urban agriculture, suggesting that a more balanced promotion of the diversification and entrepreneurial attributes of farms is crucial to building a sustainable relationship between cities and urban agriculture.