Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
U.S. Geological Survey, Sioux Falls, SD, USA.
Environ Res. 2020 Jun;185:109384. doi: 10.1016/j.envres.2020.109384. Epub 2020 Mar 12.
Hurricane Katrina made landfall in New Orleans, Louisiana as a Category 3 storm in August 2005. Storm surges, levee failures, and the low-lying nature of New Orleans led to widespread flooding, damage to over 70% of occupied housing, and evacuation of 80-90% of city residents. Only 57% of the city's black population has returned. Many residents complain of gentrification following rebuilding efforts. Climate gentrification is a recently described phenomenon whereby the effects of climate change, most notably rising sea levels and more frequent flooding and storm surges, alter housing values in a way that leads to gentrification.
To examine the climate gentrification following hurricane Katrina by (1) estimating the associations between flooding severity, ground elevation, and gentrification and (2) whether these relationships are modified by neighborhood level pre- and post-storm sociodemographic factors.
Lidar data collected in 2002 were used to determine elevation. Water gauge height of Lake Ponchartrain was used to estimate flood depth. Using census tracts as a proxy for neighborhoods, demographic, housing, and economic data from the 2000 decennial census and the 2010 and 2015 American Community Survey 5-year estimates US Census records were used to determine census tracts considered eligible for gentrification (median income < 2000 Orleans Parish median income). A gentrification index was created using tract changes in education level, population above the poverty limit, and median household income. Proportional odds ordinal logistic regression was used with product terms to test for effect measure modification by sociodemographic factors.
Census tracts eligible for gentrification in 2000 were 80.2% black. Median census tract flood depth was significantly lower in areas eligible to undergo gentrification (0.70 m vs. 1.03 m). Residents of gentrification-eligible tracts in 2000 were significantly more likely to be black, less educated, lower income, unemployed, and rent their home rather than own. In 2015 in these same eligible tracts, areas that underwent gentrification became significantly whiter, more educated, higher income, less unemployed, and more likely to live in a multi-unit dwelling. Gentrification was inversely associated with flood depth and directly associated with ground elevation in eligible tracts. Marginal effect modification was detected by the effect of pre-storm black race on the relationships of flood depth and elevation with gentrification.
Gentrification was strongly associated with higher ground elevation in New Orleans. These results provide evidence to support the idea of climate gentrification described in other low-elevation major metropolitan areas like Miami, FL. High elevation, low-income, demographically transitional areas in particular - that is areas that more closely resemble high-income area demographics, may be vulnerable to future climate gentrification.
卡特里娜飓风于 2005 年 8 月以 3 级风暴强度在路易斯安那州新奥尔良登陆。风暴潮、堤坝决口以及新奥尔良地势低洼，导致广泛洪灾、超过 70%的居住房屋受损，以及城市居民 80-90%的撤离。只有 57%的城市黑人居民返回。许多居民抱怨重建工作之后出现了高档化。气候高档化是最近描述的一种现象，即气候变化的影响，尤其是海平面上升以及更频繁的洪水和风暴潮，改变了住房价值，从而导致高档化。
通过（1）估计洪水严重程度、地面高程与高档化之间的关联，以及（2）这些关系是否受社区层面风暴前后社会人口因素的影响，来检验卡特里娜飓风之后的气候高档化。
利用 2002 年收集的激光雷达数据确定高程。利用庞恰特雷恩湖水位计测量的高度来估算洪水深度。以普查区作为社区的代表，使用 2000 年十年普查和 2010 年和 2015 年美国社区调查五年估计的人口普查记录中的人口统计、住房和经济数据，确定被认为符合高档化条件的普查区（中位家庭收入低于 2000 年奥尔良县中位家庭收入）。使用教育水平、贫困人口比例和家庭中位数的变化创建高档化指数。使用比例优势有序逻辑回归和乘积项来检验社会人口因素对效应测量的修饰作用。
2000 年符合高档化条件的普查区 80.2%是黑人。在符合高档化条件的地区，普查区的中位数洪水深度明显较低（0.70 米与 1.03 米）。2000 年符合高档化条件的普查区的居民更有可能是黑人、受教育程度较低、收入较低、失业和租房而不是拥有住房。2015 年，在这些同样符合高档化条件的普查区，经历了高档化的地区变得明显更加白人化、受教育程度更高、收入更高、失业人数更少，并且更有可能居住在多户住宅中。高档化与洪水深度呈负相关，与符合条件的普查区的地面高程呈正相关。在风暴前黑人种族对洪水深度和高程与高档化之间的关系的影响检测到边际效应修饰。
高档化与新奥尔良的高地面高程密切相关。这些结果提供了支持在迈阿密等其他低海拔主要大都市地区描述的气候高档化的证据。特别是高海拔、低收入、人口结构过渡地区，即更接近高收入地区人口统计数据的地区，可能容易受到未来气候高档化的影响。
