Surveys of community garden affiliates and soils in Houston, Texas.

Although urban community food gardens have the capacity to strengthen and support neighborhoods in need, the benefits of such operations must be considered in tandem with the potential risks associated with urban environmental contamination. Therefore, research is needed to characterize existing community gardens in urban areas. In the present study, a survey of Houston, TX, community gardeners (N = 20) was conducted to better understand their risk-based knowledge and perceptions, current gardening practices, and willingness to implement risk mitigation measures. Soil samples collected from the beds (N = 22) and surrounding grounds (N = 24) of existing community garden sites in Houston, TX, were screened for trace and heavy metals using X-ray fluorescence spectrometry. The survey indicated that community gardeners had few concerns with regard to potential soilborne hazards and were generally willing to use diverse strategies to reduce potential hazards related to garden soil contamination. Ground and garden bed soil collected from community gardens were found to have excess concentrations of arsenic compared to federal health screening limits. The information provided here provides insight into possible discordance between community gardening risk perception and contamination risk that could be addressed through outreach, engagement, and remediation approaches.

Hurricane Recovery and Ecological Resilience: Measuring the Impacts of Wetland Alteration Post Hurricane Ike on the Upper TX Coast.

Recovery after hurricane events encourages new development activities and allows reconstruction through the conversion of naturally occurring wetlands to other land uses. This research investigates the degree to which hurricane recovery activities in coastal communities are undermining the ability of these places to attenuate the impacts of future storm events. Specifically, it explores how and to what extent wetlands are being affected by the CWA Section 404 permitting program in the context of post-Hurricane Ike 2008 recovery. Wetland alteration patterns are examined by selecting a control group (Aransas and Brazoria counties with no hurricane impact) vs. study group (Chambers and Galveston counties with hurricane impact) research design with a pretest-posttest measurement analyzing the variables such as permit types, pre-post Ike permits, land cover classes, and within-outside the 100-year floodplain. Results show that permitting activities in study group have increased within the 100-year floodplain and palustrine wetlands continue to be lost compare to the control group. Simultaneously, post-Ike individual and nationwide permits increased in the Hurricane Ike impacted area. A binomial logistic regression model indicated that permits within the study group, undeveloped land cover class, and individual and nationwide permit type have a substantial effect on post-Ike permits, suggesting that post-Ike permits have significant impact on wetland losses. These findings indicate that recovery after the hurricane is compromising ecological resiliency in coastal communities. The study outcome may be applied to policy decisions in managing wetlands during a long-term recovery process to maintain natural function for future flood mitigation.

What is the spatiotemporal pattern of benzene concentration spread over susceptible area surrounding the Hartman Park community, Houston, Texas?

The Hartman Park community in Houston, Texas-USA, is in a highly polluted area which poses significant risks to its predominantly Hispanic and lower-income residents. Surrounded by dense clustering of industrial facilities compounds health and safety hazards, exacerbating environmental and social inequalities. Such conditions emphasize the urgent need for environmental measures that focus on investigating ambient air quality. This study estimated benzene, one of the most reported pollutants in Hartman Park, using machine learning-based approaches. Benzene data was collected in residential areas in the neighborhood and analyzed using a combination of five machine-learning algorithms (i.e., XGBR, GBR, LGBMR, CBR, RFR) through a newly developed ensemble learning model. Evaluations on model robustness, overfitting tests, 10-fold cross-validation, internal and stratified validation were performed. We found that the ensemble model depicted about 98.7% spatial variability of benzene (Adj. R2 =0.987). Through rigorous validations, stability of model performance was confirmed. Several predictors that contribute to benzene were identified, including temperature, developed intensity areas, leaking petroleum storage tank, and traffic-related factors. Analyzing spatial patterns, we found high benzene spread over areas near industrial zones as well as in residential areas. Overall, our study area was exposed to high benzene levels and requires extra attention from relevant authorities.

Twenty years of research on shrinking cities: a focus on keywords and authors.

Most scholarly attention to vanishing cities is fairly recent so, to guide future research, a comprehensive evaluation of prior findings is required. This study is a network analysis of 333 publications authored in English, published over the last two decades. The findings are as follows: (1) shrinking city research has increased significantly since 2016; (2) the key themes are planning, decline, depopulation, policy, regeneration, vacant land, green infrastructure, and case studies such as Detroit; and (3) major academic groups have not yet collaborated effectively on the subject.

Modeling the Relationships Between Historical Redlining, Urban Heat, and Heat-Related Emergency Department Visits: An Examination of 11 Texas Cities.

Place-based structural inequalities can have critical implications for the health of vulnerable populations. Historical urban policies, such as redlining, have contributed to current inequalities in exposure to intra-urban heat. However, it is unknown whether these spatial inequalities are associated with disparities in heat-related health outcomes. The aim of this study is to determine the relationships between historical redlining, intra-urban heat conditions, and heat-related emergency department visits using data from eleven Texas cities. At the zip code level, the proportion of historical redlining was determined, and heat exposure was measured using daytime and nighttime land surface temperature (LST). Heat-related inpatient and outpatient rates were calculated based on emergency department visit data that included ten categories of heat-related diseases between 2016 and 2019. Regression or spatial error/lag models revealed significant associations between higher proportions of redlined areas in the neighborhood and higher LST (Coef. = 0.0122, 95% CI = 0.0039 - 0.0205). After adjusting for indicators of social vulnerability, neighborhoods with higher proportions of redlining showed significantly elevated heat-related outpatient visit rate (Coef. = 0.0036, 95% CI = 0.0007-0.0066) and inpatient admission rate (Coef. = 0.0018, 95% CI = 0.0001-0.0035). These results highlight the role of historical discriminatory policies on the disparities of heat-related illness and suggest a need for equity-based urban heat planning and management strategies.

Repurposing Vacant Land through Landscape Connectivity.

Storm surge protection systems have proven effective in protecting populations in developed areas and can allow for development in otherwise potentially flood-prone areas. Resultant intensification of land conversion can result in large scale habitat fragmentation. Simultaneously, urbanized areas worldwide are increasingly accumulating large amounts of vacant land, creating an unprecedented opportunity to improve green space networks and natural systems. This article describes creation of a regional growth framework that balances the need to repurpose vacant lots with the provision of ecosystem services. The analysis seeks to maximize the structural connectivity of the landscape by using high ecological potential of vacant lands as a device for linking existing habitat patches, wildlife conservation areas, wetlands, riparian corridors, and small-scale green spaces. The research uses raster-based suitability models generated in ArcGIS to determine development potential and ecological values of vacant land parcels. Vacant lands having low development potential and high ecological value are linked spatially to create ecological corridors among patch areas using a least cost path connectivity model generated with Linkage Mapper software. Results indicate that vacant land can connect existing ecological patch and core areas with relatively minimal negative impact on development potential while simultaneously enhancing provision of ecological services. The approach provides a model for an ecological based solution to repurposing vacant urban land.

Understanding the Notion between Resiliency and Recovery through a Spatial-Temporal Analysis of Section 404 Wetland Alteration Permits before and after Hurricane Ike.

Historically, wetlands in the United States have been lost due to agriculture, anthropogenic activities, and rapid urbanization along the coast. Such losses of wetlands have resulted in high flooding risk for coastal communities over the period of time. In addition, alteration of wetlands via the Section 404 Clean Water Act permits can increase the flooding risk to future hurricane events, as the cumulative impact of this program is poorly understood and under-accounted. Further, recovery after hurricane events is acting as an encouragement for new development and reconstruction activities by converting wetlands under the wetland alteration permitting program. This study investigates the degree to which hurricane recovery activities in coastal communities are undermining the ability of these places to absorb the impacts of future storm events. Specifically, this work explores how and to what extent wetlands are being affected by the federal permitting program post-Hurricane Ike in 2008. Wetland alteration patterns are examined across three counties (Harris, Galveston, and Chambers County) along the Texas Gulf Coast over a 10-year time period, from 2004-2013 (five years before and after Hurricane Ike) by conducting descriptive spatial analyses. Results indicate that after Hurricane Ike, the number of permits substantially increased in Harris and Chambers County. The vast majority of individual and nationwide type permits were issued within the 100-year floodplain, storm surge zones, and areas damaged by Ike flooding, suggesting that recovery after the hurricane is compromising the ecological resiliency on which coastal communities depend. The authors expect that the findings of this study can increase awareness to policy makers and hazard mitigation planners regarding how to manage wetlands during a long-term recovery process to maintain their natural functions for future flood mitigation.