丹尼爾·布蘭德 雨果·尼科爾森

施騰鑫 [譯]

1 城市設(shè)計(jì)與抗逆力的定義

“城市設(shè)計(jì)”一詞出現(xiàn)于20世紀(jì)中葉，1956年，由哈佛大學(xué)設(shè)計(jì)研究生院主辦的現(xiàn)代會(huì)議中提出[1]。美國(guó)城市規(guī)劃者和理論家Edmond Bacon通過將城市作為“意志行為”和“重大事故”[2]加以區(qū)分而對(duì)城市設(shè)計(jì)的理念進(jìn)行定義。時(shí)至今日，此定義依然以中立的態(tài)度對(duì)該學(xué)科的內(nèi)涵作出優(yōu)雅的概括。城市設(shè)計(jì)實(shí)踐的改變?cè)?0世紀(jì)后半葉和21世紀(jì)初得到廣泛傳播。隨著時(shí)間的變化，城市設(shè)計(jì)與不同的因素相互結(jié)合，如工業(yè)化和后工業(yè)化的城區(qū)和城郊情況，經(jīng)濟(jì)、文化、全球化對(duì)空間設(shè)計(jì)的影響，城市化帶來的區(qū)域分布和競(jìng)爭(zhēng)不均衡，可持續(xù)發(fā)展、氣候變化以及自然災(zāi)難對(duì)當(dāng)代城市社區(qū)的影響。最終，城市設(shè)計(jì)成功地與許多專業(yè)相結(jié)合，包括設(shè)計(jì)、建筑、科學(xué)、經(jīng)濟(jì)和社會(huì)服務(wù)。跨學(xué)科結(jié)合的目標(biāo)在于建立新的社區(qū)，與可持續(xù)性的地面景觀產(chǎn)生經(jīng)濟(jì)和社會(huì)聯(lián)系。

“抗逆力”是城市設(shè)計(jì)中的一個(gè)環(huán)節(jié)?？鼓媪υ诓煌瑢W(xué)科中的含義都不相同，但所有定義都大致關(guān)于系統(tǒng)、整體、社區(qū)或個(gè)人的能力能夠承受強(qiáng)烈沖擊并維持其基本的功能[3]?？鼓媪σ仓笧?zāi)后快速有效恢復(fù)的能力以及承受更大壓力的能力[4-5]。

圖1 / Figure 1基督城中央?yún)^(qū)域震前和震后對(duì)比圖Figure grounds of central Christchurch pre- and postearthquake來源 / Source: William Thornton

21世紀(jì)災(zāi)難文獻(xiàn)首先關(guān)注的是氣候變化帶來的負(fù)面影響。人們將近年來發(fā)生的災(zāi)難文獻(xiàn)進(jìn)行分類，如颶風(fēng)（卡特里娜和桑迪）、海嘯（印度洋和日本海）、地震（智利和海地），并對(duì)后續(xù)的社區(qū)規(guī)劃方案進(jìn)行討論。這些方案對(duì)如何降低災(zāi)難影響并提高適應(yīng)力提出調(diào)查信息。文獻(xiàn)內(nèi)容囊括了城市環(huán)境的不同規(guī)模，并采用空間規(guī)劃理論學(xué)家[6]提出的城市填充、城市拓展和新社區(qū)對(duì)比性方案作為備選性適應(yīng)策略，以及采用了城市規(guī)劃和設(shè)計(jì)者Vale[7]對(duì)近年重建城市的社會(huì)經(jīng)濟(jì)成果和基礎(chǔ)設(shè)施成果提出的疑問。曼哈頓的Bergdoll[8]和新奧爾良佛吉尼亞建筑學(xué)校的Roettger[9]針對(duì)潮汐淹浸提出了設(shè)計(jì)方案、適應(yīng)性建筑方法和社區(qū)構(gòu)建策略。Aquilino[10]對(duì)洪水、地震、海嘯和火災(zāi)等災(zāi)難發(fā)生后的重建提出質(zhì)詢，其關(guān)注點(diǎn)集中在建筑設(shè)計(jì)、建筑過程和材料選擇。

Godschalk[11]對(duì)城市理論和抗逆力理論的交集點(diǎn)進(jìn)行了研究，他也對(duì)自然災(zāi)害相關(guān)的城市抗逆力提出探討。Jianguo Wu和Tong Wu[12]在抗逆力范疇內(nèi)提出了經(jīng)典城市設(shè)計(jì)理論，并圍繞動(dòng)靜辯證法針對(duì)未來可持續(xù)性設(shè)計(jì)實(shí)踐中的熱點(diǎn)領(lǐng)域提出設(shè)想。

一些學(xué)者對(duì)特定問題進(jìn)行了研究。這些研究與坎特伯雷市地震后的城市、地面景觀和建筑設(shè)計(jì)有關(guān)。Bennett等人[13]對(duì)基督城地震后的重建過程進(jìn)行了論述和探討。Swaffield[14]對(duì)基督城重建中涉及的場(chǎng)地類型和文化進(jìn)行了探討，從而找出負(fù)責(zé)指導(dǎo)的中央政府管理過程和社區(qū)自營(yíng)項(xiàng)目之間的關(guān)系。Wesener[15]則更加具體地描述了基督城過渡性社區(qū)開創(chuàng)的開放式空間。Jacques等人[16]評(píng)估了基督城醫(yī)院系統(tǒng)的運(yùn)行成效，并提出一種方法，從地震準(zhǔn)備策略的角度對(duì)未來的醫(yī)院運(yùn)行情況進(jìn)行預(yù)測(cè)。然而，對(duì)于城市設(shè)計(jì)能夠制定出城市抗逆力規(guī)劃方案的潛在益處，文中并未提及。本文旨在對(duì)新西蘭基督城的案例研究進(jìn)行討論來解決此問題。

本文將討論城市設(shè)計(jì)、抗逆原則和過程如何對(duì)基督城在2010年和2011年的地震災(zāi)難后產(chǎn)生的重塑作用（圖1），并重點(diǎn)探討3個(gè)議題：城市設(shè)計(jì)讓災(zāi)后重建城市成為低樓層綠色城市、城市設(shè)計(jì)讓公共社區(qū)更具抗逆力、城市設(shè)計(jì)給各個(gè)城區(qū)帶來更好的項(xiàng)目投資，最后探討城市設(shè)計(jì)尚未解決的問題。每個(gè)議題將針對(duì)基督城近7年來的重建實(shí)際案例進(jìn)行討論。

2 城市設(shè)計(jì)讓災(zāi)后重建城市成為低樓層綠色城市

通過公眾咨詢流程產(chǎn)生愿景：共享理念

作為開發(fā)市政府制定的《中央城市規(guī)劃草案》（DCCP）[17]的一部分，政府從震后的二月份開始，面向基督城市民舉行為期3個(gè)月的公眾意見征集活動(dòng)（共享理念），用于起草中央城區(qū)的重建方案?！肮蚕砝砟睢被顒?dòng)的網(wǎng)站共獲得58,000個(gè)點(diǎn)擊量并在4個(gè)關(guān)鍵領(lǐng)域征集公眾意見：移動(dòng)（運(yùn)輸）、市場(chǎng)（商業(yè)）、空間（公共空間和娛樂）和生活（綜合用途）?；顒?dòng)采用傳統(tǒng)方式和社交媒體網(wǎng)絡(luò)方式同時(shí)進(jìn)行。活動(dòng)中舉行了一項(xiàng)超過1萬名來訪者的互動(dòng)展出、1個(gè)國(guó)際專題講座、10個(gè)社區(qū)研討會(huì)、超過100個(gè)利益相關(guān)者會(huì)議，并在5個(gè)不同的場(chǎng)地舉辦一項(xiàng)48小時(shí)的設(shè)計(jì)挑戰(zhàn)賽。超過6周的公眾參與共產(chǎn)生了106,000個(gè)創(chuàng)意，促成了《中央城市規(guī)劃草案》的誕生[18]?！肮蚕砝砟睢被顒?dòng)為塑造城市共同的景觀奠定了基礎(chǔ)，并為城市重建項(xiàng)目帶來了廣泛的公眾認(rèn)同。這種類型的公眾咨詢和社區(qū)參與方式成為創(chuàng)建方案的極佳流程，公眾可以通過不斷參與來進(jìn)行持續(xù)討論。公眾咨詢產(chǎn)生的兩大主要結(jié)果達(dá)成了構(gòu)建低樓層以及綠色城市的共識(shí)。

低樓層城市

由于高樓引起的視覺障礙以及當(dāng)前存在的城市研究和補(bǔ)救措施，令公眾對(duì)震后再次構(gòu)建高樓層城市極為反感?！吨醒氤鞘幸?guī)劃草案》大膽提出首創(chuàng)理念，將樓層高度限制在28m或7層以內(nèi)（與華盛頓紀(jì)念碑的高度相同），路墻限高21m（圖2）。這種組合方式使橫截面之比為1:1，令街道的視覺感受很好。同時(shí)，這也能讓冬日的陽光照射在道路的一側(cè)。

經(jīng)濟(jì)影響研究結(jié)果表明，以基督城中央城區(qū)的巖土工程條件，若建造超過6～8層的建筑將需要構(gòu)建昂貴的結(jié)構(gòu)系統(tǒng)，因此建筑的層數(shù)最好保持在6～8層?！吨醒氤鞘幸?guī)劃草案》采納了28m限高的提議并獲得市議會(huì)一致通過。辦公需求研究表明，基督城中央城區(qū)的擬建辦公樓層空間，在中央商務(wù)區(qū)或辦公樓區(qū)內(nèi)應(yīng)均勻分布并符合28m限高的規(guī)定。《基督城中央城市重建方案》確定了28m限高的規(guī)定，這令重建的中央商務(wù)區(qū)更為寬闊，締造出一個(gè)充滿活力、繁榮的綜合性中央城市。

圖2 / Figure 2中央城市藍(lán)圖中低樓層城市模擬圖A redeveloped Otakaro Avon River from the Draft Central City Plan來源 / Source: 基督城市議會(huì) / Christchurch City Council

綠色城市

新的重建方案中存在許多方法，可以讓基督城成為更顯綠色的城市?！吨醒氤鞘幸?guī)劃草案》和《基督城中央城市重建方案》[19]都規(guī)定，必須環(huán)繞ōtākaro Avon河和教堂廣場(chǎng)拓展綠色開放式空間的布局網(wǎng)。根據(jù)城市既定的停車場(chǎng)空間規(guī)劃，城市的布局煥然一新。對(duì)ōtākaro Avon河的重新塑造，使之成為主要的室內(nèi)公共生活空間（圖3）。在和首位土著Ngai Tahu的親密合作下，重新開發(fā)方案中包含河流步道、一些重要的藝術(shù)景致和大量的本地沿岸居民。

傳統(tǒng)的教堂廣場(chǎng)是含有道路的空間，原先就包含多條馬路，是有軌電車和巴士的主要出發(fā)點(diǎn)。在20世紀(jì)90年代后期，這里經(jīng)過大規(guī)模的整修，在環(huán)繞廣場(chǎng)的周邊區(qū)域修建了一些慢速機(jī)動(dòng)車通道后，這里便不再受到公眾青睞?！肮蚕砝砟睢被顒?dòng)中收到的反饋信息強(qiáng)烈要求在中央城區(qū)建設(shè)更加亮麗的綠色空間。ōtākaro Avon河的重新開發(fā)工程已大部分完工，但教堂廣場(chǎng)的綠色改造工程仍在規(guī)劃階段（圖4）。

關(guān)于“無障礙城市”的內(nèi)容作為新增章節(jié)，后來添加到CCRP內(nèi)，并提出了許多措施，用于提高中央城市街道的品質(zhì)，其中包括將市內(nèi)車速降至30km/h并改善行人和騎行設(shè)備等。作為工程的一部分，人們重點(diǎn)關(guān)注的是，將街道上超過500個(gè)停車位用更加寬闊的人行道、道旁樹和雨水花園代替?；匠侵醒虢值篮涂臻g設(shè)計(jì)指南中寫明，完工的街道環(huán)境將擁有更為綠色且更加可持續(xù)的中央城市空間（圖5）[19]。

緊湊型城市

對(duì)于拓寬城市設(shè)計(jì)的目標(biāo)，DCCP和《基督城中央城市重建方案》（CCRP）[20]要求重新建造一個(gè)更加緊湊的低樓層商務(wù)核心區(qū)，增加室內(nèi)居民的人數(shù)和密度，并在核心區(qū)域周邊推動(dòng)綜合性開發(fā)(圖6)。核心工程周邊區(qū)域的重新開發(fā)由政府牽頭，旨在吸引投資并重新建設(shè)中央商務(wù)區(qū)。這些工程包含一個(gè)地鐵樞紐、一個(gè)會(huì)議中心、一個(gè)中央圖書館和一個(gè)新的巴士站。

DCCP采納了融合方案來進(jìn)行重建，其中包含大量的工程項(xiàng)目和實(shí)施工具，其目的在于保持激勵(lì)機(jī)制和規(guī)章制度之間的平衡，完成主要的刺激項(xiàng)目和公共空間項(xiàng)目，同時(shí)兼顧可持續(xù)性、住宅、藝術(shù)和運(yùn)輸項(xiàng)目。CCRP更關(guān)注的是，在大量刺激項(xiàng)目中包含規(guī)劃愿景，并且當(dāng)項(xiàng)目涉及對(duì)關(guān)鍵公共設(shè)施和經(jīng)濟(jì)基礎(chǔ)設(shè)施的重建（如醫(yī)院和會(huì)議中心）時(shí)，應(yīng)更謹(jǐn)慎地執(zhí)行政府優(yōu)先事項(xiàng)。

東部框架

DCCP提出采用建筑形式規(guī)劃法規(guī)來進(jìn)一步推進(jìn)緊湊型商務(wù)核心區(qū)建設(shè)，而CCRP則主張用干預(yù)手段來建立“綠色框架”，重現(xiàn)19世紀(jì)環(huán)繞城市中心的公園區(qū)（最早于1850年在Jollie計(jì)劃中提出）[21]，并在環(huán)繞核心區(qū)域強(qiáng)制性地征用大面積土地。東部框架用于進(jìn)行中等密度的綜合住宅區(qū)開發(fā)，同時(shí)南北線形公園大約分布在中心區(qū)域約30m寬的范圍內(nèi)。由于土地成本的持續(xù)上漲，南部框架的土地不會(huì)執(zhí)行強(qiáng)征；但根據(jù)建筑形式規(guī)劃法規(guī)，公共通道框架和中央城市學(xué)校已獲準(zhǔn)建立，用以限制開發(fā)潛力。設(shè)定東部框架的目的是在這里建造可以容納超過900個(gè)公寓的綜合住宅區(qū)。此項(xiàng)工程的談判將與一個(gè)獨(dú)立開發(fā)商單獨(dú)進(jìn)行，確保開發(fā)工程的統(tǒng)一性，從而獲得激勵(lì)機(jī)制對(duì)城市建設(shè)的長(zhǎng)期獲益?！霸O(shè)計(jì)框架”與一系列的城市設(shè)計(jì)控制手段，同屬于協(xié)議內(nèi)容的組成部分。這代表建設(shè)將采用合作方式進(jìn)行，在Fletchers、中央政府和當(dāng)?shù)刈h會(huì)之間重建城市。建筑的布局由開發(fā)商提供，街道環(huán)境和公共空間由王室和基督城市議會(huì)共同確定。

都市游樂場(chǎng)

在東部框架的北部邊緣地帶，王室和市議會(huì)對(duì)重要公共空間的開發(fā)提供資助。本地居民稱此地為都市游樂城或Margaret Mahy家庭游樂場(chǎng)，以此命名來紀(jì)念新西蘭著名兒童作家（圖7）。此地已經(jīng)成為重建項(xiàng)目的重點(diǎn)區(qū)域，無論晝夜均吸引數(shù)千名兒童及其家庭前來游玩。這里也是青少年安全的玩樂場(chǎng)所。

東部郊區(qū)重建

由于政府決定在此處對(duì)原先脆弱的住宅區(qū)進(jìn)行重建，這令A(yù)von River沿岸（圖8）低地和港口山區(qū)的陡峭空地上騰出大片土地以供建設(shè)。土地上只有草叢和林木，表明這里屬上市公司Regenerate Christchurch的管理范圍。對(duì)這片土地的規(guī)劃和公眾參與活動(dòng)尚在進(jìn)行。土地由王室和市議會(huì)共同所有，目前仍存在一些問題尚待解決，其中包括“紅色地帶”的所有權(quán)歸屬、土地用途和管理方式。

由于遭受地震襲擊，重建后的基督城將變成一座更為綠色的城市。CCRP規(guī)定，圍繞中央商務(wù)區(qū)的公園帶和Avon 河的必要重建工程，將在沿岸建造一道環(huán)保的洪水緩沖區(qū)。在東部郊區(qū)已被劃為紅色地帶的土地上，有許多潛在的交通要道可供食品生產(chǎn)或娛樂。在臨近市中心的區(qū)域以及中央商務(wù)區(qū)和海岸線之間的郊區(qū)，公眾擁有的綠色空間數(shù)量正在顯著增加。這些可能性通過大量的社區(qū)咨詢和嚴(yán)格的規(guī)劃策略獲得，從而讓基督城的地面景觀和住宅區(qū)獲得重建，并能夠?qū)⒒匠窃谖磥碜兂梢蛔o湊、可持續(xù)和宜居的城市。

圖3 / Figure 3中央城市藍(lán)圖中重新開發(fā)的 ōtākaro Avon 河A redeveloped ōtākaro Avon River from the Draft Central City Plan來源 / Source: 基督城市議會(huì) / Christchurch City Council

3 城市設(shè)計(jì)讓公共社區(qū)更具抗逆力

街道網(wǎng)絡(luò)、交通要道和開放空間

自2010年和2011年地震后，基督城的規(guī)劃網(wǎng)絡(luò)和恢宏的市內(nèi)開放空間為民眾提供了有效并具有抗逆性的建筑格局。這一點(diǎn)從其他城市的角度得到了證實(shí)[22-23]。交錯(cuò)的歷史街區(qū)具有的靈活性和備選方案，無論從應(yīng)急角度或是在建筑拆除和重建期間，都能讓街道的封閉性降至最低。市內(nèi)公園可以為震后地區(qū)的民眾提供即時(shí)的庇護(hù)，并可以作為研究基地用于國(guó)際研究和營(yíng)救行動(dòng)[24]。

地震發(fā)生前，基督城市內(nèi)最有活力并最具吸引力的中央城區(qū)的市區(qū)建筑之一是交通要道。這些交通要道原先用作服務(wù)通道，特別是用于市中心南部的工業(yè)建筑。隨著工業(yè)的衰敗，許多倉庫轉(zhuǎn)而用作零售商店、酒店和住宅，使所屬區(qū)域變得繁榮。這些區(qū)域的建筑中，許多已在地震中損毀或無法獲得保險(xiǎn)理賠（如 Lich field 大道和 Sol 廣場(chǎng)）。DCCP 和CCRP 均已要求對(duì)這些網(wǎng)絡(luò)形態(tài)交錯(cuò)連接的市內(nèi)建筑進(jìn)行二次修復(fù)。在零售區(qū)，在獲得資源許可證書之前，必須保證針對(duì)至少一半街區(qū)（或7,500m3）的開發(fā)計(jì)劃大綱(ODP)起草完畢。ODP的其中一項(xiàng)要求是修建南北大道。隨著ODP的內(nèi)容大部分已擬定完畢，已經(jīng)有不少大道和庭院（圖9）在零售區(qū)建造完畢 — 這并不是用作服務(wù)通道，而是用于鼓勵(lì)公眾經(jīng)過這些通道進(jìn)入零售和酒店所在區(qū)域。類似地，南部框架和一些大型的重要項(xiàng)目，包括司法和緊急服務(wù)區(qū)、創(chuàng)新區(qū)和會(huì)議中心在內(nèi)，都已納入公共大道和庭院的設(shè)計(jì)之中。這座城市見證了人工設(shè)計(jì)的休閑風(fēng)格給傳統(tǒng)市區(qū)帶來的轉(zhuǎn)變，讓震前基督城內(nèi)建筑變成重建后的城市名片。

圖4 / Figure 4中央城市藍(lán)圖中設(shè)想的綠化程度更高的教堂廣場(chǎng)Greener Cathedral Square from the Draft Central City Plan來源 / Source: 基督城市議會(huì) / Christchurch City Council

重塑傳統(tǒng)城市可以給當(dāng)代商務(wù)類建筑的設(shè)計(jì)（帶有大型開放式樓面）帶來一定優(yōu)勢(shì)，這一點(diǎn)與其本身定位并不矛盾。后者給城市塑造帶來了新的創(chuàng)意，可以將傳統(tǒng)意義上的公共空間變?yōu)樗饺丝臻g，這是因?yàn)槭袃?nèi)一些區(qū)域的新通道和庭院是私人使用的（如這些通道并非按公共街道進(jìn)行設(shè)計(jì)）。這就是對(duì)遭受自然災(zāi)害而獲得重建的現(xiàn)代城市房地產(chǎn)開發(fā)的真實(shí)情況，其公共投資的空間很小?；匠侵亟ǖ暮诵膯栴}在于，商務(wù)建筑和住宅的分類不斷地快速更新，其使用情況和規(guī)模發(fā)生了根本性的變化。而政府則以私人建筑所在區(qū)域?qū)ξ磥沓鞘羞M(jìn)行定位。

過渡性公共空間

由社區(qū)和商業(yè)機(jī)構(gòu)引導(dǎo)，震后的公共空間干預(yù)措施受資本化的影響，進(jìn)而產(chǎn)生了過渡性公共空間[13]。當(dāng)?shù)貦?quán)力機(jī)關(guān)、商業(yè)機(jī)構(gòu)和社區(qū)服務(wù)機(jī)構(gòu)通過設(shè)定方案對(duì)過渡性公共空間提供支持，例如通過Vacant Spaces信托（LiVS）重建中央生活區(qū)。公共空間項(xiàng)目提供方包括：

（1）Gap filler (臨時(shí)性激活閑置場(chǎng)地的城市再生方案)。例如，使用跳舞機(jī)。這種機(jī)器包含室外舞臺(tái)，帶有投幣式聲光系統(tǒng)并通過洗衣機(jī)啟動(dòng)；也可使用超級(jí)街道露面，這是一種巨型室外懸掛在露面上的游戲系統(tǒng)，通過大型操縱桿和按鈕進(jìn)行操作（圖10）。

（2）FESTA，過渡建筑節(jié)（免費(fèi)的年度公眾活動(dòng)，旨在通過舉辦大型協(xié)作項(xiàng)目并執(zhí)行城市干預(yù)行動(dòng)來探索城市再生方案）。2012年的活動(dòng)被稱為L(zhǎng)uxcity，包含照明系統(tǒng)安裝活動(dòng)。這些照明裝置由新西蘭周邊的建筑專業(yè)學(xué)生設(shè)計(jì)制造（圖11）。

（3）re-START（包含50個(gè)商業(yè)機(jī)構(gòu)的超級(jí)購物中心，由建筑所屬集團(tuán)建造，并由基督城地震申訴信托基金和ASB銀行的贊助商提供無息貸款）可以為基督城市中心提供臨時(shí)性的零售區(qū)，吸引本地居民和游客返回市中心。

（4）瓦礫綠化行動(dòng) (志愿者們?cè)趽p毀的商用建筑上設(shè)計(jì)、制造并維持公園和花園的風(fēng)貌)?；顒?dòng)產(chǎn)生的效果讓人印象深刻。在2011年至2014年期間，共有150個(gè)創(chuàng)意項(xiàng)目在100多個(gè)空置場(chǎng)地上實(shí)現(xiàn)了城市活力重生。每個(gè)納稅人的稅款投資，以1:3的回報(bào)率獲得了巨大成功[26]。

最終，社區(qū)居民通過裝置裝配和過渡性空間的構(gòu)建實(shí)現(xiàn)了城市的重新塑造，為城市開發(fā)提供了全新的探索機(jī)遇。

圖5 / Figure 5基督城中央街區(qū)和2015年空間設(shè)計(jì)指南中的中央街區(qū)綠化設(shè)想Greening of central city streets from Christchurch Central Streets and Spaces Design Guide 2015來源 / Source: 基督城市議會(huì) / Christchurch City Council

圖6 / Figure 6包含東部框架和Margaret Mahy家庭游樂場(chǎng)、零售商品協(xié)同定位以及司法管轄區(qū)的基督城中央商務(wù)區(qū)損毀（2013年）和重新開發(fā)（2018年）衛(wèi)星圖Christchurch Central Business District demolition (2013)and redevelopment (2018) including the East Frame and Margaret Mahy playground, retail co-location,and Justice Precinct來源 / Source: 谷歌地圖/ Google Earth

4 城市設(shè)計(jì)讓各個(gè)城區(qū)獲得更好的項(xiàng)目投資

城市設(shè)計(jì)者鼓勵(lì)不同類型的投資人群通過不同的集群投資方式對(duì)城市進(jìn)行開發(fā)。例如，協(xié)同定位零售商店、創(chuàng)新和健康活動(dòng)以強(qiáng)化投資活動(dòng)的回報(bào)率。除政府和當(dāng)?shù)厣虡I(yè)機(jī)構(gòu)的投資以外，一些信托機(jī)構(gòu)也推動(dòng)著不少重大的重建項(xiàng)目，其中就包括re-START購物中心。該購物中心在基督城市中心推出彈出式購物區(qū)，吸引超過40家零售商加盟[27]。另外，還包括Isaac皇家歌劇院和藝術(shù)中心的翻新項(xiàng)目和Cardboard教堂與Epic高科技公司創(chuàng)新樞紐的震后重建項(xiàng)目。最近，新的零售區(qū)已在Columbo大街成立，讓購物者們?cè)跁r(shí)隔6年后重返故地。此處是城郊購物中心的重要零售區(qū)，在地震后大部分完好無損。

根據(jù)《基督城融合式政府辦公大樓計(jì)劃》的規(guī)定，15家政府機(jī)構(gòu)和1,700名雇員已重新分配到4個(gè)中央商務(wù)區(qū)的建筑內(nèi)辦公。政府辦公地點(diǎn)位于臨近零售區(qū)、巴士站和其他中央城市設(shè)施的區(qū)域。訂立的政府租約支出以杠桿的形式分布到私人開發(fā)建筑的重建計(jì)劃之內(nèi)。

司法和緊急服務(wù)區(qū)

從震后的經(jīng)驗(yàn)學(xué)習(xí)中衍生的集群投資的例子之一，是對(duì)司法、警察、變更機(jī)構(gòu)、消防機(jī)構(gòu)、St John 急救機(jī)構(gòu)、國(guó)家和地區(qū)公民防護(hù)機(jī)構(gòu)的協(xié)同定位。其結(jié)果是，以固定配置的方式，通過降低資產(chǎn)和行政支出大幅提高了公共服務(wù)效率。這就要求在遭遇重大災(zāi)難期間，鼓勵(lì)各方協(xié)同合作和創(chuàng)新來提供緊急服務(wù)。共享式通訊和緊急情況運(yùn)作中心可以讓各機(jī)構(gòu)對(duì)緊急情況的協(xié)同響應(yīng)變得更為簡(jiǎn)單。建筑符合IL4地震標(biāo)準(zhǔn)（重要等級(jí)4，遭遇自然災(zāi)難時(shí)保持運(yùn)行狀態(tài)）和新辦公樓的綠色評(píng)級(jí)要求。建筑底層與城區(qū)公共場(chǎng)所一樣對(duì)公眾開放(圖12)。

圖7 / Figure 7 Margaret Mahy 家庭游樂場(chǎng)Margaret Mahy Family playground來源 / Source: Hugh Nicholson

圖8 / Figure 8基督城東部郊區(qū)（2009年）和重建后（2018年）的對(duì)比圖Christchurch eastern suburbs 2009 and retreat 2018來源 / Source: 谷歌地圖/ Google Earth

圖9 / Figure 9 Hereford 和 Cashel 大街之間 BNZ 中心的中央庭院Central courtyard in the BNZ Centre between Hereford and Cashel Streets 來源 / Source: Hugh Nicholson

圖10 / Figure 10 Tuam大街上的超級(jí)街道樓面[25]Super Street Arcade in Tuam Street來源 / Source: Hugh Nicholson

醫(yī)院區(qū)

坎特伯雷地震對(duì)城市的建筑和設(shè)備造成了巨大破壞，共有6,600～6,800名民眾受輕傷（2011年10月ECAN 時(shí)評(píng)）?；匠堑尼t(yī)院接待了220名因地震而遭受嚴(yán)重外傷的傷員。急救行動(dòng)持續(xù)時(shí)間超過一周，之后轉(zhuǎn)為傷員康復(fù)行動(dòng)。由于醫(yī)院某些區(qū)域也遭受了一定的破壞，醫(yī)院相關(guān)人員也在同一時(shí)間予以疏散。但大部分時(shí)間內(nèi)，醫(yī)院還是保持開放狀態(tài)以接納傷員。

在健康領(lǐng)域，關(guān)鍵的抗逆和恢復(fù)問題是，使傷員免于建筑倒塌的風(fēng)險(xiǎn)；增加傷員的健康需求；對(duì)危險(xiǎn)建筑內(nèi)的人員進(jìn)行疏散?；匠堑貐^(qū)衛(wèi)生局采用了一項(xiàng)有效的策略，使災(zāi)后的醫(yī)療資源得到合理分配，令患者可以盡可能地留在家里或社區(qū)內(nèi)。這對(duì)醫(yī)院系統(tǒng)進(jìn)行了重新考量— 在整個(gè)城市內(nèi)采用了更好的醫(yī)療設(shè)備。醫(yī)院針對(duì)中央城區(qū)的在建建筑推出了新的緊急服務(wù)，為Burwood的醫(yī)院派出新的專家服務(wù)團(tuán)隊(duì)，還在醫(yī)院主樓的前門增設(shè)了一個(gè)門診大樓。此項(xiàng)集群投資由新的地區(qū)醫(yī)院網(wǎng)絡(luò)進(jìn)行記錄備份。這些設(shè)施均采用IL4標(biāo)準(zhǔn)結(jié)構(gòu)，確保在自然災(zāi)害期間保持持續(xù)運(yùn)轉(zhuǎn)。因此，新的醫(yī)療設(shè)施的投資針對(duì)終端用戶，有效地使衛(wèi)生系統(tǒng)保持運(yùn)轉(zhuǎn)。

校園重建

地震給163間中小學(xué)造成不同程度的影響，其中大部分閉園3周。90間學(xué)校在經(jīng)過建筑結(jié)構(gòu)核證完畢后重新開學(xué)。共有24份建筑的記錄證明建筑須進(jìn)行進(jìn)一步評(píng)估，其中11座建筑損壞嚴(yán)重。整個(gè)城市建立了學(xué)習(xí)中心網(wǎng)絡(luò)，為需要在家里進(jìn)行遠(yuǎn)程學(xué)習(xí)的學(xué)生提供有效的資源和設(shè)備支持。截至2011年3月5日，共有4,879名基督城的學(xué)生在新西蘭其他地區(qū)的學(xué)校登記入學(xué)。

目前，基督城的校園重建計(jì)劃預(yù)期持續(xù)10年，其中包括：對(duì)13間學(xué)校作重新選址修建；10所學(xué)校原址重建；34所學(xué)校全部翻修；58所學(xué)校作中等翻修；一些小規(guī)模的校園作關(guān)閉或合并處理。新的建筑系統(tǒng)規(guī)定旨在接納震后的轉(zhuǎn)學(xué)學(xué)生，讓校園在運(yùn)營(yíng)和管理方面更有效率，并執(zhí)行“彈性學(xué)習(xí)空間”。此計(jì)劃由于缺乏社區(qū)參與和社區(qū)內(nèi)的學(xué)校認(rèn)可而廣受詬病。

圖11 / Figure 11公共空間活動(dòng)：2012年的LuxCity活動(dòng)Public space activation: LuxCity Event 2012來源 / Source: 國(guó)家創(chuàng)意藝術(shù)和產(chǎn)業(yè)學(xué)院 /National Institute of Creative Arts and Industries

圖12 / Figure 12司法和緊急服務(wù)區(qū)中心庭院Courtyard in centre of Justice and Emergency Services Precinct來源 / Source: Hugh Nicholson

5 城市設(shè)計(jì)無法解決的問題

可持續(xù)性建筑設(shè)計(jì)和基礎(chǔ)設(shè)施

DCCP 提出建造更多的可持續(xù)性運(yùn)輸，包括修建一條從大學(xué)到中央商務(wù)區(qū)的輕軌，從而最終實(shí)現(xiàn)地區(qū)軌道網(wǎng)絡(luò)和自行車道網(wǎng)絡(luò)的連通。《中央城市規(guī)劃草案》和《基督城中央城市重建方案》終稿均包含刪除相關(guān)內(nèi)容，其中包括要求改善環(huán)境指標(biāo)和建筑包容性設(shè)計(jì)的規(guī)定，議會(huì)提出的重建項(xiàng)目財(cái)政激勵(lì)措施，留待后續(xù)調(diào)查的關(guān)于交通和住宅的大部分規(guī)定（新自行車道除外）。

分散式排污系統(tǒng)

在西方城市對(duì)基礎(chǔ)設(shè)施老化和延期維護(hù)的問題緊抓不放之時(shí)，基督城將編織出一張現(xiàn)代化的基礎(chǔ)設(shè)施網(wǎng)絡(luò)，這將使得基礎(chǔ)設(shè)施整體能夠滿足重建計(jì)劃的質(zhì)量標(biāo)準(zhǔn)。更多的基礎(chǔ)問題仍停留在選擇何種系統(tǒng)將具有更高的抗逆力?；匠莾?nèi)分布著分散式供水系統(tǒng)，覆蓋了整個(gè)城市內(nèi)超過170口水井。相對(duì)而言，集中式廢水處理系統(tǒng)可以在一家污水處理廠內(nèi)統(tǒng)一處理幾乎整個(gè)城市的污水。地震后人們發(fā)現(xiàn)，供水系統(tǒng)比污水處理系統(tǒng)更具抗逆力。供水系統(tǒng)能夠迅速地重新啟動(dòng)運(yùn)行，這是因?yàn)檎麄€(gè)系統(tǒng)仍然能夠保持其功能，受損部分可以通過修補(bǔ)得以繼續(xù)使用。相反，集中式污水處理系統(tǒng)如果主要管道和處理池遭遇損毀，就將影響到整體功能，系統(tǒng)就必須關(guān)閉很長(zhǎng)一段時(shí)間。這種基礎(chǔ)設(shè)施的設(shè)計(jì)方式可以讓系統(tǒng)在災(zāi)難期間依然可以持續(xù)運(yùn)轉(zhuǎn)。這是系統(tǒng)保持抗逆性的重要一環(huán)。

6 結(jié) 語

抗逆性在城市設(shè)計(jì)中的重要性正不斷增加[28]，這體現(xiàn)在城市恢復(fù)和災(zāi)難準(zhǔn)備兩方面?？鼓嫘詫?shí)踐必須得到執(zhí)行，從而改變城市設(shè)計(jì)的實(shí)踐方法。本文對(duì)抗逆性規(guī)劃和傳統(tǒng)城市設(shè)計(jì)實(shí)踐之間的矛盾之處，通過一系列的案例研究進(jìn)行了分析討論。首先，采用集群投資可以更好地獲得災(zāi)后的投資效益。這種趨勢(shì)削弱了采用自由混合處理的傳統(tǒng)城市設(shè)計(jì)原則的重要性。盡管自由混合處理通常是基督城重新開發(fā)策略的一個(gè)特征，但這種處理方式在城市設(shè)計(jì)者的應(yīng)用選項(xiàng)中所占比重已經(jīng)下降。它通過集群式醫(yī)院、司法和緊急服務(wù)中心限制了既有的公共服務(wù)設(shè)施功能，并進(jìn)一步約束了城市內(nèi)零售商店分布的數(shù)量。具有針對(duì)性的抗逆力理論[29]建議，東部郊區(qū)紅色地帶可以永久性廢棄，這是因?yàn)槠渌麉^(qū)域會(huì)不斷遭受潮汐和洪水的侵襲。這就要求使用環(huán)保的手段實(shí)現(xiàn)抗逆性的未來城市拓展，而非采用現(xiàn)今的工程手段[30]。

城市設(shè)計(jì)在基督城重建的物理配置和環(huán)境品質(zhì)的確定方面起主要作用。在震后重建工作的時(shí)間范圍內(nèi)，我們很容易看到這門科學(xué)的影響力。因此，這座城市本身就是一個(gè)很好的案例，可以用來進(jìn)行目前城市設(shè)計(jì)方法和抗逆性思考在城市恢復(fù)中的案例研究。其他的城市設(shè)計(jì)過程更為緩慢，設(shè)計(jì)過程中所進(jìn)行的調(diào)整繁雜不堪。盡管針對(duì)性的抗逆性策略應(yīng)該得到采用，但并非所有的創(chuàng)新舉措都已得到實(shí)施，有些尚未采用的措施也代表著與未來機(jī)遇失之交臂。盡管如此，基督城人民在抗逆性和城市設(shè)計(jì)方面取得了眾多成果。

ORIGINAL TEXTS IN ENGLISH

The Role of Urban Design in Re-building Christchurch

Diane Brand, Hugh Nicholson

1 Urban Design and Resilience De finitions

The phrase “urban design” emerged in the mid-20th century at a conference on modernism hosted by the Harvard Graduate School of Design in 1956[1]. American urban planner and theorist Edmond Bacon defined design in the context of urban design by distinguishing between the city as an “act of will” and the city as a “grand accident”[2]and this definition still encapsulates the essence of the discipline in an elegantly time and agenda neutral manner. Changes in the practice of urban design have been wide ranging in the latter half of the twentieth century and in the new millennium. In chronological sequence urban design has engaged with the industrial and post-industrial urban and suburban condition, the economic, cultural and spatial impacts of globalisation, the inequalities and contested territories that cities generate, and sustainability, climate change and the impact of natural disasters on contemporary urban communities. As a result successful urban design now engages professionals from many sectors including design, construction, science, economic and social services, with the aim of establishing communities,which are deeply connected to economically and socially sustainable landscapes.

The term “resilience” is now part of the urban design equation. Resilience means different things across a variety of disciplines, but all definitions are linked to the ability of a system, entity, community or person to withstand shocks while still maintaining its essential functions stress[3]. Resilience also refers to an ability to recover quickly and effectively from catastrophe, and a capability of enduring greater stress[4,5].

Twenty- first century disaster literature is primarily concerned with the negative impacts of climate change, and divides into the documentation of recent disasters such as Hurricanes (Katrina and Sandy), Tsunamis (Indian Ocean and Sea of Japan),Earthquakes (Chile and Haiti), and the discussion offorward community planning initiatives which investigate mitigation and adaption. The literature encompasses multiple scales of the urban environment, with spatial planning theorists[6]comparing scenarios of urban in fill, urban extension and new settlement as alternative adaption strategies, and urban planners and designers[7]interrogating the urban social and economic and infrastructural outcomes of recent reconstructions. Bergdoll[8]in Manhattan and Roettger and University of Virginia School of Architecture[9]in New Orleans have curated design solutions and adaptive architectures and settlement strategies for tidal inundation, and Aquilino[10]has interrogated the pragmatics of rebuilding after floods, earthquakes, tsunamis and fires, with particular attention to building designs,construction processes and materiality.

The intersection of urban theory and resilience theory has been investigated by Godschalk[11]who discusses resilient cities in relation to natural hazards and terrorism, and Wu and Wu[12]who position classic urban design theory within resilience literature and posit areas of tension in future sustainable design practice around the dialectic of stasis and change.

A number of writers have researched speci fic issues related to urban, landscape and building design in the aftermath of the Canterbury earthquakes.Bennett et al[13]document and debate the recovery process after the Christchurch earthquakes.Swaffield[14]interrogates the kinds of places and cultures that have evolved in a rebuilt Christchurch as a result of the nexus between directive central government processes and spontaneous bottom-up community projects. Wesener[15]has described in more detail the resulting transitional community-initiated open spaces in Christchurch.Jacques et al[16]have evaluated the performance of the Christchurch hospital system and developed a method which can predict the future performance of hospitals in terms of seismic preparedness strategies. However a gap remains in the literature with respect to the potential contribution that urban design can make to urban resilience planning,which this paper aims to address through a discussion of the case study of Christchurch, New Zealand.

This paper will discuss how urban design and resilience principles and processes have informed the Christchurch Re-build since the devastating earthquakes of 2010 and 2011 (Figure 1), and will focus on four propositions: that urban design delivered a post-disaster vision of a low-rise city green city;that urban design delivers a resilient public realm;that urban design delivers better project investment from multiple sectors; and finally what urban design hasn't been able to deliver. Each proposition will be discussed in terms of actual case studies from the reconstruction of the city of Christchurch over the last seven years.

2 Urban Design has Delivered a Postdisaster Vision of a Low-rise City Green City

Public consultation process to create a vision:Share an idea

As part of developing the Council's Draft Central City Plan (DCCP) (Christchurch City Council,2011)[17]an extensive public consultation exercise(Share an Idea) was undertaken with the people of Christchurch within three months of the February earthquake to help shape the recovery plan for the central city. The Share an Idea website generated 58,000 hits and engaged the public in four key areas: move (transportation), market (business),space (public place and recreation) and life (mixed uses), and the campaign used traditional and social media networks. This was followed by an interactive expo with more than 10,000 visitors, an international speaker series, 10 community workshops,more than 100 stakeholder meetings and a 48-hour design challenge for five selected sites. Public participation generated 106,000 ideas over six weeks and these informed the development of the Draft CCP[18]. Share an idea became the basis for developing a shared vision for the city and resulted in a broadly agreed direction to measure projects against. This type of public consultation and community engagement should ideally be to be an iterative process resulting in an ongoing discussion.The two principal outcomes of the consultation process were the vision for a sustainable low-rise city in a green setting.

Low-rise city

A strong public resistance to tall buildings emerged in the aftermath of the earthquakes in response to the highly visible building failures and the ever present urban search and rescue activity. A bold initiative embedded in the urban design proposals in the Draft CCP was a reduction in height limits to 28 metres or seven storeys (the same height as Washington DC), with a 21 metre road wall height (Figure 2). This combination provides a 1:1 cross-sectional proportion giving a good sense of enclosure to the street corridor while allowing the sun to reach the opposite side of the road in midwinter.

Economic impact studies indicated that given the geotechnical conditions in central Christchurch,buildings of more than 6-8 stories required a more expensive structural system, making 6-8 stories was the optimal return on construction investment.The 28 metre height limit was adopted into Draft Central City Recovery Plan with unanimous support from Council. An office demand study indicated that the expected uptake of office floor space in central Christchurch could be accommodated with an even spread of 28 metre buildings across the central business district or in a small number of towers. The Christchurch Central Recovery Plan was approved with the 28 metre height limit which would spread the rebuild across a wider area of the CBD to create a vibrant and prosperous mix-use central city.

Green city

Several opportunities emerged in the new plans to make Christchurch a greener city. Both the DCCP and the Christchurch Central Recovery Plan(CCRP)[19]set out to provide an enhanced network of green open spaces based around the ōtākaro Avon River and Cathedral Square. From a space lined with carparks which the city turned its back on, the ōtākaro Avon River has been recast as the primary public space in the city (Figure 3). In partnership with Ngai Tahu, the indigenous first people, the redevelopment includes a river promenade,a number of significant artworks, and extensive native riparian habitats.

Traditionally Cathedral Square has been a paved space which originally included roads and was the main point of departure for trams and subsequently buses. Largely pedestrianised in the late 1990s with slow vehicle access around some of the edges, the space was unloved by the public. Feedback from Share an Idea was strongly in favour of creating a greener space in the centre of the city. While the Otakaro Avon River redevelopment has been largely completed, greening Cathedral Square is still in the planning stages (Figure 4).

The Accessible City chapter was a late addition to the CCRP and included a range of measures to improve the quality of central city streets including slowing traffic to 30 kilometres per hour and improving pedestrian and cycling facilities. As part of these works there has been a focus on replacing more than 500 on-street carparks with wider footpaths, street trees and rain gardens. Encapsulated in the Christchurch Central Streets and Spaces Design Guide the completed streetscapes have created greener and more sustainable central city spaces(Figure 5)[20].

Compact city

In terms of broad urban design objectives both the DCCP and the Christchurch Central Recovery Plan (CCRP)[19]set out to rebuild a more compact intensive low rise commercial core, to increase the number and density of inner city residents, and to promote mixed use developments in areas surrounding the core (Figure 6). The redevelopment clustered around a set of core projects seeded by government, which were designed to attract investment and rebuilding in the CBD. These included a metrosports hub, a convention centre, a central library and a new bus exchange.

The DCCP adopted an integrated approach to recovery which incorporated a wide range of projects and implementation tools. The vision balanced incentives and regulation to deliver major catalyst and public space projects, alongside sustainability,housing, arts and transport projects. The CCRP is focused more deliberately on National government priorities providing a regulated vision embodied in a range of catalyst projects which involve rebuilding critical public and economic infrastructure such as the hospital and the convention centre.

East Frame

While the DCCP proposed using built form planning regulations to further promote a compact commercial core, the CCRP adopted a far more interventionist approach by establishing a “green frame”, reinstating the 19th century parklands around the city centre (which were originally proposed in the Jollie Plan in 1850)[21]and compulsorily acquiring large areas of land surrounding the core. The east frameis being used for a comprehensive medium density residential development,with a north south linear park approximately 30 metres wide through the centre. The south frame will not be compulsorily acquired due to increasing land costs but a framework of public laneways and a central city school has be established in tandem with built form planning regulations to limit development potential. The East Frame was designated for comprehensive residential development with more than 900 apartments. The delivery of these was negotiated with single developer to ensure an integrated development that incentivises long term bene fits for city rather than short term pro fits.A “Design Framework” forms part of agreement together with a set of urban design controls. This represents a partnership approach to rebuilding the city between Fletchers, central government and the local council, with the buildings being provided by the developer and the streetscape and public realm being delivered by the Crown and the Christchurch Council.

Metropolitan Playground

At the Northern end of the East Frame the Crown and the Council have funded the development of an important public realm initiative called the metropolitan playground or the Margaret Mahy Family Playground named after New Zealand's famous children's writer (Figure 7). It has become anchor for rebuild which attracts thousands of children and their families during the day and in the evenings it has become a safe location where teenagers can hang out.

Eastern suburbs retreat

Decisions to affect a strategic retreat from vulnerable areas of residential housing have vacated swathes of land along the lower reaches of the Avon River (Figure 8) and in steep and exposed parts of the Port Hills leaving them derelict and maintained as mowed grass with the trees still showing the former lot patterns in a form of suburban stasis. These areas are generally surrounded by existing houses and although many of the streetsand services within the red zone have been signi ficantly damaged they still constitute important con-nections within a fractured urban fabric. Currently planning and public engagement on the future of this land is underway, managed by a public company Regenerate Christchurch, half owned by the Crown and half by the Council. Questions which are still to be answered include who will own the“red zone” land, what it will be used for, and how it will be governed.

As a result of the devastation of the earthquakes,Christchurch will become a greener city in the future. The CCRP has reinstated the parklands around the CBD and the necessary retreat from the Avon River will create an ecological and flood corridor along its banks. Much potential exists for food production or recreational use of the Eastern suburbs land that has been red zoned. The quantity of green space in public ownership, both adjacent to the city centre and in the suburban land between the CBD and the coast has increased dramatically.These possibilities have been captured by extensive community consultation and responsive planning strategies which evoke the landscape and settlement history of Christchurch and facilitate a more compact, sustainable and liveable city of the future.

3 Urban Design Delivers a More Resilient Public Realm

The grid, laneways and open spaces

Christchurch's planned grid and generous innercity open spaces provided an effective and resilient urban structure after the earthquakes in 2010 and 2011, con firming the observations from other cities[22,23]. The historic street grid provided flexibility and alternative options to cope with limited street closures, both as part of the emergency response and during subsequent building demolition and construction phases. The inner city parks provided refuge and shelter immediately after the earthquakes and were used as a base for the international search and rescue operations (Nicholson 2013)[24].

Prior to the earthquakes one of the most interesting and vibrant parts of Christchurch's urban structure were the laneways within central city blocks. Originally these were built to provide service access,particularly to industrial buildings to the south of the city centre. With the decline of these industries the warehouses were converted to a mixture of retail, hospitality and residential uses providing vibrant and highly popular precincts. Many of these areas were either destroyed by the earthquakes or are tied up in insurance claims (e.g. Lichfield Lanes and Sol Square). Both the DCCP and the CCRP have sought to recreate these secondary elements of urban structure within the formal grid. In the retail precinct there has been a requirement to develop Outline Development Plans (ODPs) for a minimum of half a block (or 7500 m2) before lodging a resource consent. One of the requirements of the ODPs is to provide north-south laneways. With the majority of ODPs now in place therehave been a series of laneways and courtyards (Figure 9) created throughout the retail precinct - not for service access but to encourage public access and to support retail and hospitality uses. Similarly, the South Frame and a number of the major anchor projects,including the Justice and Emergency Precinct, the Innovation Precinct and the Convention Centre,have incorporated public laneways and courtyards into their design. The city is seeing the conscious recreation of a traditional urban form that characterized Christchurch pre-earthquake as part of recreating the city's identity.

Contradicting that evocation of the traditional city is the predominance of contemporary commercial building typologies (with large open floor plates)which are creating a new super grain to the urban fabric central city fabric, and which privatise what would traditionally have been the public realm,since the land on which the new lanes and courtyards sit have an private existing use status (i.e.they are not designated as public streets). This is the reality of real estate development in a modern city recovering from natural disaster off a low public investment base. The essential issue in the Christchurch rebuild is the fundamental change in both the use and scale of the new and fast repeating typologies of commercial and residential buildings where the government is relying on the private sector to deliver the future city.

Transitional Public Space

This capitalised on the public realm interventions post-earthquake led by communities and business which provided transitional public space[13]. These were supported by local authorities, businesses,and community agencies through initiatives such as Rebuild Central and Life in Vacant Spaces Trust(LiVS).Public space project providers included:

(1) Gap filler (an urban regeneration initiative that temporarily activated vacant sites) for example Dance-o-mat which consisted of outdoor dance venue with a coin operated sound system and lights operated via a washing machine, and Super Street Arcade, a giant outdoor arcade game system operated by a giant joystick and buttons (Figure 10[25]).

(2) FESTA, Festival of Transitional Architecture (a free, annual public event that explores urban regeneration through large scale collaborative projects and urban interventions). The 2012 event called Luxcity comprised of light installations designed and built by architecture students from around New Zealand (Figure 11)

(3) re-START (a 50 business container mall built by a property and building owners group, with an interest free loan from the Christchurch Earthquake Appeal Trust and sponsorship from the ASB Bank)providing a temporary retail precinct for central Christchurch which attracted both locals and tourists back to the city centre.

(4) Greening the Rubble (volunteers who design,construct and maintain parks and gardens on the sites of demolished commercial buildings)

The results have impressive with more than 100 vacant sites activated 450 times with 150 creative projects between 2011 and 2014. This success is re flected in a three to one return on investment for every ratepayer dollar spent[26].

As a result the city has been reshaped by these community driven installations and transitional spaces which have allowed the exploration of new opportunities for urban development.

4 Urban Design Delivers Better Project Investment From Multiple Sectors

Urban Designers have encouraged the development of use clusters implemented by groups of different kinds of investors. For example the co-locating of retail, innovation and health activities designed to enhance the benefit of any single investment.In addition to investment by government council and local business, a number of signi ficant rebuild projects have been run by Trusts. These include the ReStart Mall which has provided a pop-up shop-ping area in central Christchurch involving more than 40 retailers at its peak[27]the refurbishment of the Isaac Theatre Royal and the Arts Centre,the construction of Cardboard Cathedral and Epic innovation hub for hi-tech companies displaced by the earthquakes. A new retail precinct has recently been completed in Columbo Street to bring shoppers back to the centre after six years of the retail dominance of suburban malls which were largely unaffected by the earthquake.

Fifteen government agencies and 1,700 staff have relocated into four CBD buildings as part of the Christchurch Integrated Government Accommodation Programme. The government offices are located close to retail precinct, the bus interchange and other central city facilities. Guaranteed government tenancies have leveraged the rebuilding of these privately developed buildings.

Justice and Emergency Services Precinct

An example of clustered investment which has been directly derived from learnings after the earthquake is the co-location of Justice, Police,Corrections, the Fire Service, St John Ambulance and national and local Civil Defence agencies. The result will be greater public service efficiencies through reduced property and administration costs in a con figuration which encourages collaboration and innovation in the delivery of emergency services during large scale disasters. Shared communications and a shared emergency operations centre will make coordinated responses to emergencies much easier to achieve. The building meets IL4 seismic standards (Importance Level 4 keep operating through natural disasters) and the green star rating required for new offices. At ground level the site is permeable to the public and reads like a city block (Figure 12).

Hospital Precinct

The Canterbury earthquakes inflicted large scale damage to buildings and equipment across the city. Between 6,600 and 6,800 people were treated for minor injuries (ECAN Review October 2011),and Christchurch Hospital alone treated 220 major trauma cases connected to the quake. Rescue efforts continued for over a week, then shifted into recovery mode. Christchurch Hospital was partly evacuated due to damage in some areas, but remained open throughout to treat the injured.

For the health sector, critical resilience and recovery issues are: balancing patient care against risk of building failure; increased health demands from injuries; and the evacuation of dangerous buildings. The Christchurch District Health Board has developed a compelling strategic vision for the post disaster future of healthcare centred dedicating resources to helping patients stay in their homes and communities for as long as possible. This has involved rethinking the hospital system -and new provision of enhanced facilities across the city. A new acute services building under construction in central city, a new specialist services hospital in Burwood, and a new outpatients building at the front door to main hospital building. This cluster is backed up by a network of new regional hospitals.These facilities are all IL4 structures -which can keep operating through natural disasters. The net result is an investment in new healthcare facilities which will herald a stronger more efficient health system focused on the end users.

Schools Rebuild

One hundred and sixty three primary and secondary schools were affected by the earthquake, most of which were closed for three weeks. Ninety schools had full structural clearance and were able to reopen. Twenty four had reports indicating further assessment and 11 were seriously damaged.Learning hubs were established throughout the city to provide resources and support for students needing to work from home. By March 5th 2011, a total of 4879 Christchurch students had enrolled in other schools across New Zealand.

There is now a comprehensive ten year programme for rebuilding Christchurch schools. This includes:Thirteen new schools on new sites; Ten rebuilt schools on existing sites; 34 schools fully redeveloped; 58 schools moderately developed and number of smaller schools have being closed or merged. The new system of building provision has been aimed at accommodating changed student rolls after earthquakes, providing greater efficiency in procurement and operations, and implementing“flexible learning spaces”. The programme has attracted wide criticism for the lack of community engagement and lack of recognition of the role schools play as community foci.

5 What Urban Design wasn't able to Deliver

Sustainable building design and infrastructure

The DCCP proposed more sustainable transportation systems, including a light rail system from the University to the CBD which would eventually connect into a regional rail network, and a network of cycle ways. Major changes between the Draft CCP and final CCRP included the removal of the regulations requiring improved environmental performance and inclusive design standards from buildings, the removal of the financial incentives for rebuilding proposed by the Council, and the removal of the majority of the transport and residential provisions (apart from the new cycleways)pending further investigation.

De-centralised sewage system

While most western cities are grappling with issues of deferred maintenance and ageing infrastructure,Christchurch will have a modernized infrastructure network which will have been repaired to an acceptable standard by the end of the rebuild programme. More fundamental questions remain about what kind of system is more resilient. Christchurch has a decentralized water supply system with more than 170 wells spread across its urban area, in contrast to its centralized wastewater system where almost all of the city's sewage is treated at one treatment plant. In the aftermath of the earthquakes the water system proved to be more resilient than the wastewater. It was able to start operating again more quickly as parts of the system remained functional and could be patched to support damaged areas. In contrast, the centralized wastewater system suffered damage to main sewer lines and to the treatment ponds themselves, effectively closing down the entire system for a longer period. Designing infrastructure so that parts of the system can continue to function independently in a disaster would seem to be an important step towards resilience.

6 Conclusion

Resilience is of increasing relevance to the design of cities[28], both in terms of recovery and in disaster preparedness. Resilience practice is set to modifying urban design practice and the case study above illustrates a couple of emerging contradic-tions between resilience planning and traditional urban design practice. The first is the use clustering for better post-disaster investment. This trend undermines the traditional urban design principle of liberally mixing uses. While mixed use is a feature of the Christchurch redevelopment strategy in general, the range of uses in the urban designers menu has been reduced by circumscribing an already limited palette of public service uses with the clustering hospital,justice and emergency services functions, and further constraining the quantum of distributed retail across the city. Targeted resilience theory[29]suggests that the eastern suburbs red zone will be permanently abandoned for settlement as will other areas subject to repeated liquefaction and flooding, leading to an ecological approach to the resilience future urban expansion rather than an engineering approach which has been used to date[30].

Urban design has played a major part in determining the physical configuration and environmental quality of the Christchurch re-build. It is easy to see the extent of the discipline's impact due to the short post-earthquake construction timeframes, so the city is an ideal case study of the impact of current urban design and resilience thinking on urban recovery. Elsewhere urban design processes occur at a slower pace and adjustments in the design process happen in a more fluid and incremental way. Not all initiatives have been implemented and some gaps represent lost opportunities for the future, while targeted resilience strategies are required moving forward. However much has been achieved in terms of resilience and urban design for the people of Christchurch.