Publications

The objectives of this paper were to examine the risk of depression and depressive symptoms among Han and minority children and adolescents in rural China, the links between academic performance and depressive symptoms, and the prevalence of these links among specific subgroups. A total of 8392 4th, 5th, and 6th grade students at 105 sample rural schools in eight low-income counties and districts in a prefectural-level city in Southwestern China were randomly selected using a three-step sampling strategy. A total of 51% of the sample were female (SD = 0.50), and the age range was 7 to 19 years (mean = 11.35 years; SD = 1.05). Using the Patient Health Questionnaire 8-item depression scale, the prevalence of depressive symptoms in the sample was assessed, while data on students’ academic performance (standardized math test) and demographic characteristics were also collected. Our results show that the rates of major depression were 19% for Han students, 18% for Tibetan students, and 22% for Yi students; the rates of severe depression were 2% for Han and Tibetan students, and 3% for Yi students. Yi students were at significantly higher risks for major and severe depression than Han students. We conducted multivariate regression and heterogeneous analyses. Academic performance was negatively and significantly correlated to depressive symptoms. Across the whole sample, students with lower math scores, minority students, boys, younger students, and students with migrant parents were most vulnerable to depressive symptoms. The heterogeneous analysis suggests that among poor-performing students, subgroups at higher risk for depression include boys, non-boarding students, and students whose mothers had graduated from high school or above. These findings indicate a need to improve mental health outcomes of rural Han and minority primary school students, targeting academic performance for possible intervention.

This study conducts an exploratory analysis of the impacts of a center-based early childhood development intervention on the mental health of caregivers, using data from a cluster-randomized controlled trial of 1664 caregivers (Mage = 36.87 years old) of 6- to 24-month-old children in 100 villages in rural China. Caregivers and children in 50 villages received individual parenting training, group activities and open play space in village parenting centers. The results show no significant overall change in caregiver-reported mental health symptoms after 1 year of intervention. Subgroup analyses reveal heterogeneous effects by caregiver socioeconomic status and identity (mother vs. grandmother). Findings suggest that early childhood development interventions without targeted mental health components may not provide sufficient support to improve caregiver mental health.

Although children living in low- and middle-income countries (LMICs) account for 90% of the global population of children, depression, and anxiety among children in LMICs have been understudied. This study examines the prevalence of depression and anxiety and their associations with biological and psychosocial factors among children across China, with a focus on rural areas. We conducted a large-scale epidemiological study of depression and anxiety among 53,421 elementary and junior high school-aged children across China. The results show that 20% are at risk for depression, 6% are at risk for generalized anxiety, and 68% are at risk for at least one type of anxiety. Girls and junior high school students show a higher risk for both depression and anxiety symptoms, while socioeconomic status has varying associations to depression and anxiety symptoms. Our results also show consistent correlations between depression and anxiety symptoms and standard math test scores. These findings underscore the importance of identification, prevention, and treatment of youth depression and anxiety in underdeveloped areas. As China constitutes 15% of the global population of children under age 18, this study offers valuable information to the field of global mental health.

Using a three-wave longitudinal survey conducted in 815 households in rural Western China, this study aims to examine the association between parental self-perception and early childhood development and the mediation effect of parental investment on the association between parental self-perception and child development when the sample children are at different ages in the early childhood (18–30, 22–36, and 49–65 months). The results demonstrate that parental self-perception are positively and significantly associated with child social-emotional development in all three ages of childhood (from 18 to 65 months). Positive and significant association between parental self-perception and child cognitive development is found in the ages from 22 to 65 months. In addition, findings of this study show that parental investment plays a mediating role in the association between parental self-perception and child cognitive development. The study calls on policymakers to help to strengthen parental self-perception and parental investment related to early childhood development, which should result in better child development in rural China.

Extant research continues to establish the importance of teacher job satisfaction to student performance, yet teacher job satisfaction remains under-investigated in rural China. In this paper, we examine the prevalence and correlates of teacher job satisfaction. Using data from 634 teachers across 120 schools in rural China, we find an alarmingly high prevalence of teacher job dissatisfaction: roughly 21% of rural teachers were less than satisfied with their jobs. In addition, we find that several individual- and school-level characteristics, including being a male teacher, being a homeroom teacher, not having a management role in school, being a middle-aged teacher, and a school’s boarding status, are correlated with teacher job dissatisfaction. In sum, the results demonstrate a need for further research and policy interventions to improve teacher job satisfaction in rural schools.

This study documents the COVID-19 disease-control measures enacted in rural China and examines the economic and social impacts of these measures. We conducted two rounds of surveys with 726 randomly selected village informants across seven provinces. Strict disease-control measures have been universally enforced and appear to have been successful in limiting disease transmission in rural communities. The infection rate in our sample was 0.001 per cent, a rate that is near the national average outside of Hubei province. None of the villages reported any COVID-19-related deaths. For a full month during the quarantine, the rate of employment of rural workers was essentially zero. Even after the quarantine measures were lifted, nearly 70 per cent of the villagers still were unable to work owing to workplace closures. Although action has been taken to mitigate the potential negative effects, these disease-control measures might have accelerated the inequality between rural and urban households in China.

The cost-effectiveness of policies providing subsidized health goods is often compromised by limited use of the goods provided. Through a randomized trial involving 251 primary schools in western China, we tested two approaches to improve the cost-effectiveness of a program distributing free eyeglasses to myopic children. Relative to delivery of free eyeglasses to schools, we find that providing vouchers redeemable in local optical shops modestly improved the targeting of eyeglasses to those who would use them without reducing effective coverage. Information provided through a health education campaign increased eyeglass use when eyeglasses were delivered to schools, but had no effect when requiring voucher redemption or when families were only given a prescription for eyeglasses to be purchased on the market. Though most expensive, free delivery to schools with a health education campaign was the most socially cost-effective approach tested and increased effective coverage of eyeglasses by 18.5 percentage points after seven months.

Background

Despite rising incomes and rapid economic growth, there remains a significant gender gap in health outcomes among rural children in China. This study examines whether the gender gap in child health is related to the behavior of caregivers when seeking healthcare, and whether healthcare subsidies help to bridge the gender gap in rural health outcomes.

Methods

Focusing on vision care specifically, we draw on data from a randomized controlled trial of 13,100 children in Gansu and Shaanxi provinces in China that provided subsidized eyeglasses to myopic children in one set of schools (henceforth, referred to as the treatment schools) and provided prescription information but not subsidized eyeglasses to myopic children in another set of schools (control schools).

Results

The baseline results reveal that while female students generally have worse vision than male students, they are significantly less likely than male students to be taken by their caregivers to a vision exam. The experimental results indicate, however, that caregivers respond positively to both health information and subsidized healthcare, regardless of the gender of their children. When prescription information is paired with a subsidy voucher for healthcare (a free pair of eyeglasses), the uptake rate rises dramatically.

Conclusions

The gender gap in healthcare can be minimized by implementing subsidized healthcare policies.

Poor knowledge, scarce resources, and lack of or misaligned incentives have been widely documented as drivers of the irrational use of medicine (IUM), which significantly challenges the efficiency of health systems across the globe. However, there is limited understanding of the influence of each factor on IUM. We used detailed data on provider treatment of presumptive asthma cases in rural China to assess the contributions of provider knowledge, resource constraints, and provider behavior on IUM. This study enrolled 370 village providers from southwest China. All providers responded to a clinical vignette to test their knowledge of how to treat presumptive asthma. Resource constraints (“capacity”) were defined as the availability of the prescribed medicines in vignette. To measure provider behavior (“performance”), a subset of providers (104 of 370) were randomly selected to receive unannounced visits by standardized patients (SPs) who performed of presumptive asthma symptoms described in the vignette. We found that, 54% (201/370) of providers provided the vignette-based patients with prescriptions. Moreover, 67% (70/104) provided prescriptions for the SPs. For the vignette, only 10% of the providers prescribed the correct medicines; 38% prescribed only unnecessary medicines (and did not provide correct medicine); 65% prescribed antibiotics (although antibiotics were not required); and 55% prescribed polypharmacy prescriptions (that is, they prescribed five or more different types of drugs). For the SP visits, the numbers were 12%, 51%, 63%, and 0%, respectively. The lower number of medicines in the SP visits was due, in part, to the injections’ not being allowed based on ethical considerations (in response to the vignette, however, 65% of providers prescribed injections). The difference between provider knowledge and capacity is insignificant, while a significant large gap exists between provider performance and knowledge/capacity (for 11 of 17 indicators). Our analysis indicated that capacity constraints play a minor role in driving IUM compared to provider performance in the treatment of asthma cases in rural China. If similar findings hold for other disease cases, this suggests that policies to reduce the IUM in rural China have largely been unsuccessful, and alternatives for improving aligning provider incentives with appropriate drug use should be explored.

Rural China has seen an increase in its migrant workers returning home. As a result, many of these workers’ children, who had previously boarded at school, needed to return home as well. While the existing research indicates that boarding affects the development of disadvantaged children, the effect of the switch to nonboarding on the growth of vulnerable boarding children remains unknown. Using two-stage data from 20,594 fourth- and fifth-grade students in rural Shaanxi and Gansu provinces as well as the difference-in-differences method, this study estimates the impact of switching to nonboarding on the academic performance and mental health of vulnerable boarding students. The results suggest that the shift toward nonboarding significantly reduces boarding students’ academic performance, and further testing shows that these results are robust. Additionally, the switch to nonboarding insignificantly increased the standardized mental health scores of rural primary school students but significantly increased their standardized impulsive tendency scores. Heterogeneity analysis found that boarding students whose mothers had lower educational achievement or whose families belonged to lower economic levels had poorer academic performance after switching, while boarding students whose parents had higher education achievement or myopia possessed better mental health after switching. This study offers novel, policy-relevant insights into potential strategies that would improve the academic performance and mental health of students who transition to nonboarding, especially those with low-educated parents and those belonging to poor families.

Purpose

To study the factors determining spectacle-wear compliance and reasons for non-wear among students in rural China.

Methods

This study was based on a spectacle intervention trial among 162 schools in rural China. Students with refractive errors were randomly assigned to either a free or voucher group to receive spectacles at baseline. Spectacle-wear compliance was assessed through an unannounced follow-up 7 months after spectacles were distributed. Students not wearing spectacles were also asked their reasons for non-wear. The collected data underwent descriptive, bivariate, and logistic regression analyses.

Results

A total of 1904 students received spectacles at baseline, 1826 (95.9%) of whom were present at the 7-month follow-up. Among those students, 41.7% wore their spectacles. There was no significant difference in compliance rates between the free and voucher groups. Predictors of wearing spectacles at follow-up included older age (Odds ratio = 1.56, 95% CI: 1.12–2.19), the severity of refractive error (3.68, 2.23–6.07), wearing spectacles before baseline (3.91, 2.53–6.04) and having friends who wore spectacles (1.87, 1.32–2.63). When students could see the blackboard from their seats (0.68, 0.51–0.89) and thought that wearing spectacles was bad looking (0.76, 0.57–1.00), they were reluctant to wear spectacles. The two main reasons for non-wear were the widespread perception that wearing spectacles would weaken eyesight (32.8%) and the inconvenience of wearing spectacles during activities (23.6%).

Conclusions

The main reason that accounts for the low compliance of spectacle wear was misconceptions around spectacle. School-based spectacle programs should consider enhancing the compliance rates to maximize the benefits of spectacle wear.

Background: Social-emotional development during the first three years of life is associated with later social-emotional development and cognitive development. In rural China, research has found large shares of children under age three are developmentally delayed, yet little is known about the paths of social-emotional development before age 3 or how developmental paths predict later social-emotional skills and cognitive skills. 

Aims: To investigate the paths of child social-emotional development during ages 0–3 and examine how different paths predict social-emotional development and cognitive development at preschool age. 

Methods: Three waves of longitudinal panel data from 1245 children in rural Western China was collected. Child social-emotional development was measured by the Ages and Stages Questionnaire: Social-Emotional. Child cognitive development was measured by the Bayley Scales of Infant Development and by the Wechsler Preschool and Primary Scale of Intelligence-Fourth Edition. Four paths of child social-emotional development were classified: “never” social-emotionally delayed; “persistently” social-emotionally delayed; “improving,” or “deteriorating.” 

Results: 331 (27%) were never social-emotionally delayed; 373 children (30%) were persistently social-emotionally delayed; 149 children (12%) experienced improving social-emotional development; and 392 children (31%) experienced deteriorating social-emotional development. Children who were never social-emotionally delayed or who were on an “improving” path had higher social-emotional development at preschool age (p < .01). Children who were persistently social-emotionally delayed (p < .5) and on a deteriorating path (p < .01) had lower social-emotional development at preschool age. Children on the persistently delay path also were shown to have lower levels of cognitive development at preschool age (p < .01). 

Conclusions: Different paths of child social-emotional development before age 3 are associated with different social-emotional and cognitive development at preschool age.

School bullying is a widely recognized problem in developed countries, but remains under-investigated in developing countries, especially in remote rural areas. In this paper, we examine the prevalence, correlates, and consequences of bullying victimization and its relation to educational performance and creative attitudes. Using data from 10,528 students across 120 primary schools in rural China, we find an alarmingly high prevalence of bullying victimization and that several individual, family, and school characteristics are correlated with bullying victimization. Analyses indicate students who are bullied frequently score lower in Chinese, reading, and math tests and creative attitudes. Taken together, the results demonstrate a need for further research and policy interventions to reduce bullying in schools.

Research continues to highlight the central relationship between caregivers’ mental health and their children’s development. This study examined the relation between primary caregivers’ mental health and school-aged children’s outcomes, including student mental health, resilience, and academic performance, in rural China. Using cross-sectional data from economically poor areas in the Gansu province, 2989 students (mean age = 11.51, 53.33% male, 46.67% female) and their primary caregivers (74.2% female) completed the 21-item, self-report Depression Anxiety Stress Scale. Students also completed the 25-item Connor-Davidson Resilience Scale and a standardized math test. The results indicated a high prevalence of caregiver depression (31%), stress (39%), and anxiety (24%). Characteristics that were significantly correlated with caregiver mental health issues included being a grandparent, having a low socioeconomic status and low education level, and living in a household with at least one migrant worker. Apart from caregiver stress and student resilience, caregiver mental health issues were negatively correlated with all student outcomes, including student mental health, resilience, and academic performance. Although additional empirical research is needed to investigate the associations between caregiver mental health and student outcomes, our results suggest that rural communities could benefit greatly from programs focused on improving the mental health of caregivers and this, in turn, may have a positive impact on student outcomes.

Background: Maternal mental health problems play an important role in infant well-being. Although western countries have extensively studied the associations between maternal mental disorders, hygiene practices and infant health, little is known in developing settings. This study investigates the correlations between postnatal mental health problems, hand washing practices and infant illness in rural western China. Methods: A total of 720 mothers of infants aged 0–6 months from four poor counties in rural western China were included in the survey. Mental health symptoms were assessed using the Depression, Anxiety, and Stress Scale-21 (DASS-21). Questions about infant illness and hand washing practices followed evaluative surveys from prior studies. Adjusted ordinary least squares regressions were used to examine correlations between postnatal mental health (depression, anxiety, and stress) symptoms, hand washing practices, and infant illness outcomes. Results: Maternal depression, anxiety and stress symptoms were significantly associated with reduced hand washing overall and less frequent hand washing after cleaning the infant's bottom. Mental health symptoms were also associated with a higher probability of infants showing two or more illness symptoms and visiting a doctor for illness symptoms. Individual hand washing practices were not significantly associated with infant illness; however, a composite measure of hand washing practices was significantly associated with reduced probability of infant illness. Conclusion: Postnatal mental health problems are prevalent in rural China and significantly associated with infant illness. Policy makers and practitioners should investigate possible interventions to improve maternal and infant well-being.

We present evidence from a randomized experiment testing the impacts of a six-month early childhood home-visiting program on child outcomes at school entry. Two and a half years after completion of the program, we find persistent effects on child working memory - a key skill of executive functioning that plays a central role in children's development of cognitive and socio-emotional skills. We also find that the program had persistent effects on parental time investments and preschool enrollment decisions. Children were enrolled earlier and in higher quality preschools, the latter reflecting a shift in preferences over preschool attributes toward quality. Our findings imply an important role for the availability of high-quality subsequent schooling in sustaining the impacts of early intervention programs.

Research in developed countries has found that paternal involvement has positive and significant effects on early childhood development (ECD). Less is known, however, about the state of paternal involvement and its influence on ECD in rural China. Using data collected in Southern China that included 1,460 children aged 6–42 months and their fathers (as well as their primary caregivers), this study examines the association between paternal involvement and ECD. Although the results demonstrate that the average level of paternal involvement is low in rural China, paternal involvement is related to a significant increase in three domains of ECD (cognition, language, and social-emotional skills). Older children benefit significantly more than do younger children from paternal involvement in all domains of ECD. The results also show that, if the mother is the primary caregiver, the mother’s higher educational level and the family’s higher socioeconomic status are positively associated with paternal involvement.

We present the results of a cluster-randomized controlled trial that evaluates the effects of a free, center-based parenting intervention on early cognitive development and parenting practices in 100 rural villages in China. We then compare these effects to a previous trial of a home-based intervention conducted in the same region, using the same parenting curriculum and public service system, accounting for potential differences between the studies. We find that the center-based intervention did not have a significant impact on child development outcomes, but did lead to increases in the material investments, time investments, and parenting skills of caregivers. The average impact of the center-based intervention on child skills and investments in children was significantly smaller than the home-visiting intervention. Analysis of the possible mechanisms suggests that the difference in effects was driven primarily by different patterns of selection into program participation.

Purpose: To determine the prevalence of visual impairment and glasses ownership among Han Chinese and Hui minority junior high school children in Ningxia Hui Autonomous Region, China. 

Design: Population-based cross-sectional study. 

Methods: Vision screening was conducted on 20,376 children (age 12–15 years) in all 124 rural junior high schools in Ningxia. Personal and family characteristics, glasses ownership, and academic performance were assessed through a survey questionnaire and standardized mathematics test, respectively. 

Results: The prevalence of visual acuity (VA) ≤6/12 in either eye was significantly higher among Han (54.5%) than Hui (45.2%) children (P<0.001), and was significantly positively associated with age, female sex, Han ethnicity, parental outmigration for work, shorter time spent outside during recess, shorter time spent watching television and higher time spent studying. Among children with VA≤6/12 in both eyes, only 56.8% of Han and 41.5% of Hui children had glasses (P<0.001). Glasses ownership was significantly associated with worse vision, greater family wealth, female sex, higher test scores, age, parental outmigration for work, understanding of myopia and glasses, higher time spent studying and Han ethnicity. 

Conclusion: One of the first of its kind, this report on Han and Hui ethnic schoolchildren confirms a high prevalence of visual impairment among both populations, but slightly higher among the Han. Both groups, especially the Hui, have low rates of glasses ownership. Future interventions and policies designed to improve glasses usage should focus on populations with lower incomes and seek to correct erroneous beliefs about the safety of glasses and efficacy of traditional eye exercises.

Introduction: Inadequate care during early childhood can lead to long-term deficits in skills. Parenting programmes that encourage investment in young children are a promising tool for improving early development outcomes and long-term opportunities in low-income and middle-income regions, such as rural China.

Methods: We conducted a systematic review and a meta-analysis to investigate the prevalence of early developmental delays and stimulating parenting practices as well as the effect of parental training programmes on child development outcomes in rural China. We obtained data in English from EconPapers, PubMed, PsycARTICLES, Cochrane Library, Web of Science and Scopus (Elsevier) and in Chinese from China National Knowledge Infrastructure, Wanfang Data and VIP Information. We conducted frequentist meta-analyses of aggregate data and estimated random-effects meta-regressions. Certainty of evidence was rated according to the Grading of Recommendations Assessment, Development and Evaluation approach.

Results: We identified 19 observational studies on the prevalence of developmental delays and stimulating parenting practices for children under 5 years of age (n=19 762) and ten studies on the impact of parental training programmes on early child development (n=13 766). Children’s risk of cognitive, language and social-emotional delays in the rural study sites (covering 14 provinces mostly in Central and Western China) was 45%, 46%, and 36%, respectively. Parental training programmes had a positive impact on child cognition, language and social-emotional development.

Conclusion: There is evidence to suggest that early developmental delay and the absence of stimulating parenting practices (ie, reading, storytelling and singing with children) may be prevalent across rural, low-income and middle-income regions in Central and Western China. Results support the effectiveness of parental training programmes to improve early development by encouraging parental engagement.

Objective: Consultation length, the time spent between patient and health care provider during a visit, is an essential element in measuring quality of health care patients receive from a primary care facility. However, the linkage between consultation length and process quality and diagnosis quality of primary care is still uncertain. This study aims to examine the role consultation length plays in delivering process quality and diagnosis quality, two central components of overall primary care quality, in rural China.

Methods: We recruited unannounced standardized patients (SPs) to present classic symptoms of angina and tuberculosis in selected healthcare facilities in three provinces of China. The consultation length and primary care quality of SPs were measured and compared with both international and national standards of care. Ordinary Least Squares (OLS) regressions for process quality (continuous dependent variable) and Logistic regressions for diagnosis quality (binary dependent variable) were performed to investigate the relationship between consultation length and primary care quality.

Results: The average consultation lengths among patients with classic symptoms of angina and those with symptoms of tuberculosis were approximately 4.33 min and 6.28 min, respectively. Providers who spent more time with patients were significantly more likely to complete higher percentage of recommended checklist items of both questions and examinations for angina (β = 1.39, 95%CI 1.01–1.78) and tuberculosis (β = 0.89, 95%CI 0.69–1.08). Further, providers who spent more time with patients were more likely to make correct diagnosis for angina (marginal effect = 0.014, 95%CI 0.002–0.026) and for tuberculosis (marginal effect = 0.013, 95%CI 0.005–0.021).

Conclusions: The average consultation length is extremely short among primary care providers in rural China. The longer consultation leads to both better process and diagnosis quality of primary care.

Practice Implications: We recommend primary care providers to increase the length of their communication with patients. To do so, government should implement healthcare reforms to clarify the requirements of affordable and reliable consultation length in medical care services. Moreover, such an experience can also be extended to other developing countries.

Many countries have undertaken large and high-profile payment-for-ecosystem-services (PES) programs to sustain the use of their natural resources. Nevertheless, few studies have comprehensively examined the impacts of existing PES programs. Grassland Ecological Compensation Policy (GECP) is one of the few pastorally focused PES programs with large investments and long duration, which aim to improve grassland quality and increase herder income. Here we present empirical evidence of the effects of GECP on grassland quality and herder income. Through a thorough and in-depth econometric analysis of remote sensing and household survey data, we find that, although GECP improves grassland quality (albeit to only a small extent) and has a large positive effect on income, it exacerbates existing income inequality among herders within their local communities. The analysis demonstrates that the program has induced herders to change their livestock production behavior. Heterogeneity analysis emphasizes the importance of making sure the programs are flexible and are adapted to local resource circumstances.

In addition to habitat loss and fragmentation, demographic processes—the vagaries of births, deaths and sex ratio fluctuations—pose substantial threats to wild giant panda populations. Additionally, climate change and plans for the Giant Panda National Park may influence (in opposing directions) the extinction risk for wild giant pandas. The Fourth National Giant Panda Census showed pandas living in 33 isolated populations. An estimated 259 animals live in 25 of these groups, ~14% of the total population. We used individual-based models to simulate time series of these small populations for 100 years. We analysed the spatial pattern of their risk of extinction under current conditions and multiple climate change models. Furthermore, we consider the impact of the proposed Giant Panda National Park. Results showed that 15 populations face a risk >90%, and for 3 other populations the risk is >50%. Of the 15 most at-risk populations, national parks can protect only 3. Under the Representative Concentration Pathway 8.5 climate change scenario, the 33 populations will probably further divide into 56 populations. Some 41 of them will face a risk >50% and 35 face a risk >90%. Although national parks will probably connect some fragmented habitats, 26 populations will be outside national park planning. Our study gives practical advice for conservation policies and management and has implications for the conservation of other species in the world that live in isolated, fragmented habitats.

Natural infrastructure such as parks, forests, street trees, green roofs, and coastal vegetation is central to sustainable urban management. Despite recent progress, it remains challenging for urban decision-makers to incorporate the benefits of natural infrastructure into urban design and planning. Here, we present an approach to support the greening of cities by quantifying and mapping the diverse benefits of natural infrastructure for now and in the future. The approach relies on open-source tools, within the InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) software, that compute biophysical and socio-economic metrics relevant to a variety of decisions in data-rich or data-scarce contexts. Through three case studies in China, France, and the United States, we show how spatially explicit information about the benefits of nature enhances urban management by improving economic valuation, prioritizing land use change, and promoting inclusive planning and stakeholder dialogue. We discuss limitations of the tools, including modeling uncertainties and a limited suite of output metrics, and propose research directions to mainstream natural infrastructure information in integrated urban management.