Coastal Roulette: Planning Resilient Communities for Galveston Bay By
SWA Group
, Houston。更多请至:
▲项目所在地在德克萨斯州的自由港The project area extends from Freeport, TX to High Island, TX
世界各地海岸线的居民都需要面对风暴,一个无法逃避需要放眼未来的问题。这个项目所在地是美国德克萨斯州,南向墨西哥湾的加尔维斯顿湾。设计师旨在解决沿海地区的挑战,将景观与风暴保护,经济回增,环境效益还有可持续的沿海社区关联。
艾克飓风在2008年9月13日袭击了德克萨斯州海岸上游,彻底的洗劫当地一番,让数百万人的生活就此改变。历史上的缓解沿海风暴往往采用物理结构,修建工程成为风暴前进的障碍。而这种做法是政绩型的,非安全的,不充分的。那个修建100公里长堤坝防止暴风雨的建议不仅破坏自然与人文景观,更将这里的生命与墨西哥湾彻底切断。我们真的要成为始作俑者吗?
整个设计团队与水文学家,生态学家,地质学家,还有大学建筑/环境/社会/经济学系合作,对区域进行现场分析,得此规划建议和具体的干预措施。根据水文团队最初提供的最新技术风暴模型,根据海拔定义了各种参数频度洪水泛滥区,然后在与人口普查数据叠加并预计未来25年的人口增长情况,目前土地价值,紧急服务设施,疏散路线,疾病传播潜力,天然屏障区,公共开放空间,主要生态系统区。还做了28个公园的生态研究报告,涉及状态,自然,可持续发展,人口,以及游客等方面。
建议一:结构和非结构性防御整合
采用多种方法,而非一种,就像球类比赛有多种战术一样。结构防御主要是修堤坝,墙,障碍以阻止洪水。非结构的办法是在高风险区域做阻碍,然后尽可能的回复其生态系统,让洪水风暴成为经济增长的推力。结构保护可与先由的地形联系,在海峡口地区创建一个简单的格栅结构,以保护这个美国的第二大港。创建一些口袋式防御保护重要的人口和经济中心,历史区域和紧急服务设施。非结构防御根据风暴模型做出对应,着眼未来的发展和是加尔维斯顿海湾成为生态系统丰富地区之一。
建议二:利用公共区域
利用公共区域建立保护地可节约成本,比如在沿海146号高速公路一处地方建立一个大堤坝可以保护大的人口中心并有助于潮汐沼泽的恢复。海拔0—5米区域有大面积的沼泽地,而这里距离全美第四大都市圈仅一小时车程,若将这里恢复,将具有巨大的发展潜力。目前这项计划已经取得实际的支持。
建议三:经济的可持续发展
维持建立一个不用税收建立的具有影响力的NRA协会保证协同管理,社区参与,区域发展。10多年后这里将每年吸引150万游客,创造5260个就业机会,产成1.92亿美元经济效益,未来还将翻倍。
风暴需要面对,而面对应该积极用多样而务实的方案应对。
Coastal populations worldwide are playing a dangerous game. Frequent hazardous storms along coastlines are a given, and yet we continue to place our heads in the sand when considering the future. This submission focuses on an innovative project in Galveston Bay serving as a model for proactively solving coastal planning challenges. The summary below demonstrates how we can reconnect to these valued landscapes while providing storm protection, economic stimulus, environmental benefits, and sustainable coastal communities.
▲暴风后一片狼藉,人造草坪和排水渠形成大片冲刷区,只剩原生植被依旧。Hurricane Ike’s rising waters stripped the Bolivar Peninsula of the majority of its structures. Man made drainage channels and nonnative lawns created vast “scour zones” where little native vegetation remained.
▲目前的建筑法可能会让业主一无所有Current building regulations leave property owners playing a dangerous financial game of Russian roulette with hurricane inundation.
▲百年风暴警戒区划分。35万人居住在25年风暴警戒区内。Risks within the 100 year storm surge are clear and easily measured through both historic surge depth and modeled inundation. 350,000 people live within 25′ of sea level and experience a gradient of storm surge.
▲244500人和8万个工作机会都在25年风暴警戒区内。Galveston Bay’s funneling geometry places the communities of West Bay in harm’s way;244,500 people and 81,500 jobs exist within the 25′ contour.
▲人口密集,具有保护价值的历史社区的结构解决方案。Densely populated and historically important communities are protected with structural solutions. A National Recreation area would create a thick sponge to dissipate and protect inland communities.
▲针对不同的海岸区域类型有不同的保护方案,并重新恢复被破坏的生态环境,在最危险的地区创造新的娱乐经济区。Layered landscapes along the project’s coast aim to protect large populations, bolster industry from storms, and reestablish lost ecologies. A National Recreation Area would create new economic opportunities within the riskiest areas.
▲针对不同的海岸区域类型有不同的保护方案Layered coastal protections continue. At the right, design strategies for Galveston Island’s existing Seawall create new opportunities along the Galveston coastline by selectively thickening its iconic boardwalk.
▲加斯威尔顿岛历史和人口密集区结构性保护方案,内墙与外墙为未来的发展创造机遇。Galveston Island is protected with intensive structural solutions to preserve its unique historical fabric and existing infrastructure. A dredge spoils island to the north is included within the wall to provide opportunities for future development.
▲在洪水易发生的地区创造国家娱乐区。Establishing a National Recreation Area within the most flood prone areas because Texas is under served by federal parks and coastal parks in general.
▲对海岸公园进行评估,项目所在地的海岸是重要的海岸公园候选。研究包括了28个公园的调查,涉及公园的大小,形状,邻里,经济还有区域。Planning team publications have evaluated the ‘vital statistics’ of successful coastal parks. The Galveston Bay area is a prime candidate for a significant coastal park. Investigations include: 28 park case studies, urban access to regional parks, precedent parks sizes and shape, and park proximity and economic impact.
▲先驱性经济预测。第一年将吸引50万人次,创造1200个就业机会和4600美元的本地销售业绩。到了第十年,会上升到150万游客。创造5260个就业机会和本地销售业绩1.92已美元。Economic Gateways. An independent study by the Harbinger Consulting Group projects that the LSCNRA will attract 500,000 visitors in its first year , create 1,200 jobs and $46 million in local sales. By its tenth year, this will rise to 1,500,000 visitors, 5,260 jobs and $192 million in local sales per year.
▲沿岸现场调查与沿海国家游乐区结合,人人都可进入。除了休闲娱乐,这里也将风险转化为沿海地区的经济引擎。Park programming and site research show that the Lone Star Coastal National Recreation Area would have opportunities for everyone. In addition to recreation, the park is an economic engine for at risk coastal areas.
▲另外一场风暴。我们现在有了方法去创造一个具有弹性的,生态的公众海岸线,造福子孙后代。让我们工作吧。Another storm will strike. We have the tools to reduce its effects and create a more resilient, ecologic, and public coastline for future generations. Let’s get to work!
On September 13, 2008 Hurricane Ike struck the Upper Texas Coast, wreaking havocon infrastructure and washing away entire communities. Labeled as a category two storm by wind speed, Ike surpassed all inundation damage predictions and changed the lives of millions of people in the region. While devastating, the storm was a considerably smaller version of the modeled “worst case scenario” in which bay surge tracks up the densely populated west shore of Galveston Bay and into the heavily industrialized Houston Ship Channel.
Historically, the mitigation of coastal storms has focused on the use of intensive structural solutions — single-purpose engineered barriers designed to protect against often inadequately modeled storms. Once these engineering feats realize their massive physical form, the public develops an attitude of complacency and invincibility against storm events. They are “behind the wall”. The submitting team references this phenomenon as the “moral hazard” where a false sense of security results in more coastal development, subpar construction standards, inadequate policy, and greater public risk.
As expected, shortly after Ike a proposal for a much longer, higher, wider, 100 mile long dike surfaced that would span and isolate all of Galveston Bay. Life defining interactions
with the Gulf of Mexico would be severed and the cultural landscape destroyed not by nature, but ourselves.
Galveston Bay Process
The submitting team was engaged with local hydrologists, ecologists, geologists, and a university architecture department to create environmental/social/economic inventories,
regional site analysis, proposed planning recommendations, and site specific design interventions. Team hydrologists initially provided revised storm models derived from advanced
engineering technologies. The 25 ft. elevation was defined as the limit of the 1% storm event and elevations 0 to 5 ft. were found to be susceptible to frequent inundation. These parameters were used to create a layered approach that responded to 2010 census data, a projected doubling of regional population in 25 years, current land values, emergency service facilities, limited evacuation routes, toxic dispersal potential, natural barrier island migration patterns, public open spaces, primary ecosystems identified by regional, national, and international ecologists, and a published team research report analyzing 28 significant state, national, and international parks relative to their economic sustainability, population proximity, and annual visitorship.
Recommendation 1: Structural and Non-structural Integration
Diverse tools are needed rather than the standard application of monolithic levees. Included in the team’s approach are both structural and non-structural solutions. Structural methods utilize constructed levees, walls, barriers and gates to block floodwaters. Non-structural methods regulate and discourage development in high risk areas and rely on existing and restored ecosystems. These natural systems rebound quickly after inundation and have proven to be significant economic resources for long-term sustainability. Proposed structures occur where levees exist and protections can tie into existing topography. For example, the plan utilizes narrowing topography at the mouth of the Houston Ship Channel to create a simple gate structure to secure America’s second largest port. Shelters of last resort are identified and surrounded by robust, cost effective structural measures that create small pockets of defense rather than highly vulnerable linear barriers. These pockets all have existing economic bases, significant population centers, emergency service facilities, or historic relevance. Non-structural elements guide current and future development to mitigate moral hazard concerns. Natural processes that make Galveston Bay one of the nation’s most biologically diverse ecosystems are identified and protected, building codes revised to respond to current storm models, and the existing Coastal Barrier Resource Act (COBRA) is expanded to frequent inundation areas to limit federal protections for high risk development. Public education is also essential and would be best accomplished by creating an online inundation database modeled after FEMA’s 100 year floodplain maps.
Recommendation 2: Utilizing the Public Domain
Existing public lands can be used as a cost effective means for implementation. Rather than purchasing private property, structural solutions are designed to seamlessly occur within public rights of way already in need of infrastructure improvements. For example, the team’s largest structural intervention calls for elevating a portion of coastal Highway 146 to create a West Bay levee protecting large population centers and providing tidal marsh restoration opportunities. South bay elevations from 0 to 5 ft. contain broad marshlands with considerable parcels under public ownership. This area’s unique biodiversity defines the bay’s established national and international ecotourism reputation. As a result, a major component of the
project is the creation of a National Recreation Area (NRA) in this zone. Located within an hour drive of the nation’s fourth largest metropolitan area, an organized framework plan with a sensitive footprint has immense potential. To date, this proposal has been adopted by an organized action committee and has and continues to gain the support with local Galveston Bay communities.
Recommendation 3: Economic Sustainability
Establishing an NRA will have considerable economic impact. Its designation would be an act of congress, require no tax money to create, and all participation would be voluntary. Harbinger Consulting Group estimates that after a decade the NRA would attract 1.5 million annual visitors, create 5,260 jobs, and generate $192 million. Its economic impact would quadruple after 10 yrs. and tourism would triple. The collaborative management structure of the NRA ensures that existing communities will be involved in its development and can profit from its formation.
Implementation
Severe storms are a reality. Recent foreshadowing in Galveston Bay has resulted in a new discourse on its future. This project provides a diversity of pragmatic solutions that are gaining both political and community support in the region. Risk taking? The oddsare not favorable.
VIA:ASLA
{{item.text_origin}}