水旱災害風險普查技術體系探索
時(shi)間:2023-05-11 09:12:33
導語:水旱(han)災害風險普查技(ji)術體系(xi)探索一文來源于網友上傳,不(bu)代(dai)表本站觀點,若(ruo)需要原創文章可咨詢客服老師,歡(huan)迎參考(kao)。
摘要:結合第一次全國自然災害綜合風險普查要求,基于水旱災害風險管理理論,從水旱災害致災調查與評估、洪水隱患調查與評估、風險評估與區劃、數據庫建設等方面探索構建了水旱災害風險普查技術體系該體(ti)系在普查(cha)實(shi)踐(jian)中得(de)到驗證和(he)完善(shan),支撐各(ge)地圓滿完成(cheng)水旱(han)災害風險普查(cha)任務,形(xing)成(cheng)系列(lie)普查(cha)成(cheng)果(guo),實(shi)現預期(qi)普查(cha)目(mu)標(biao),為(wei)水利高質量發(fa)展提供(gong)了技(ji)術支撐。
關鍵(jian)詞:水旱災害(hai);風險(xian)普查;區劃;技術體系
我(wo)國(guo)(guo)(guo)是世(shi)界上自(zi)(zi)然(ran)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)最嚴(yan)重(zhong)(zhong)的(de)國(guo)(guo)(guo)家之(zhi)一(yi),災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)種類(lei)多,分(fen)(fen)(fen)布(bu)地域廣,發生(sheng)頻率高,造成損(sun)失(shi)重(zhong)(zhong)。第一(yi)次(ci)(ci)(ci)全(quan)國(guo)(guo)(guo)自(zi)(zi)然(ran)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)綜合風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)普(pu)(pu)查(cha)(cha)(cha)(cha)是我(wo)國(guo)(guo)(guo)也是世(shi)界上首次(ci)(ci)(ci)開展的(de)一(yi)項(xiang)重(zhong)(zhong)大國(guo)(guo)(guo)情國(guo)(guo)(guo)力(li)(li)調(diao)查(cha)(cha)(cha)(cha),是提升自(zi)(zi)然(ran)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)防治能力(li)(li)的(de)基(ji)(ji)礎性(xing)工(gong)作。水(shui)旱(han)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)普(pu)(pu)查(cha)(cha)(cha)(cha)是自(zi)(zi)然(ran)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)(包括地震災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)、地質(zhi)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)、氣象災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)、水(shui)旱(han)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)、海(hai)洋災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)、林草(cao)火(huo)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)等(deng)(deng))風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)普(pu)(pu)查(cha)(cha)(cha)(cha)的(de)重(zhong)(zhong)要組成部分(fen)(fen)(fen)。為(wei)滿(man)足全(quan)國(guo)(guo)(guo)自(zi)(zi)然(ran)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)綜合風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)普(pu)(pu)查(cha)(cha)(cha)(cha)需求(qiu),指(zhi)導各地順利開展水(shui)旱(han)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)普(pu)(pu)查(cha)(cha)(cha)(cha),水(shui)利部按照《第一(yi)次(ci)(ci)(ci)全(quan)國(guo)(guo)(guo)自(zi)(zi)然(ran)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)綜合風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)普(pu)(pu)查(cha)(cha)(cha)(cha)總體方案》,基(ji)(ji)于洪水(shui)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)管理理論,首次(ci)(ci)(ci)建立了(le)(le)一(yi)套完整的(de)水(shui)旱(han)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)普(pu)(pu)查(cha)(cha)(cha)(cha)技(ji)術體系(xi)。體系(xi)涵蓋水(shui)旱(han)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)致災(zai)(zai)(zai)(zai)(zai)(zai)(zai)調(diao)查(cha)(cha)(cha)(cha)和危(wei)險(xian)(xian)(xian)(xian)性(xing)評估(gu)、承災(zai)(zai)(zai)(zai)(zai)(zai)(zai)體調(diao)查(cha)(cha)(cha)(cha)、風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)評估(gu)與(yu)區劃(hua)、防治區劃(hua)等(deng)(deng)內(nei)容,確定了(le)(le)普(pu)(pu)查(cha)(cha)(cha)(cha)指(zhi)標、技(ji)術路線、分(fen)(fen)(fen)析評估(gu)與(yu)區劃(hua)方法,可用于系(xi)統(tong)識別和分(fen)(fen)(fen)析評估(gu)水(shui)旱(han)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)來(lai)源、區域分(fen)(fen)(fen)布(bu)和風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)水(shui)平,為(wei)實現全(quan)國(guo)(guo)(guo)水(shui)旱(han)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)普(pu)(pu)查(cha)(cha)(cha)(cha)目標,基(ji)(ji)本摸清水(shui)旱(han)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)隱患底數(shu),查(cha)(cha)(cha)(cha)明水(shui)旱(han)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)防御能力(li)(li),客(ke)觀(guan)認(ren)識我(wo)國(guo)(guo)(guo)不同(tong)地區水(shui)旱(han)災(zai)(zai)(zai)(zai)(zai)(zai)(zai)害(hai)(hai)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)水(shui)平提供了(le)(le)有力(li)(li)支撐(cheng)。
一、水旱災害風險普查需求分析與技術特點
按照水旱災害風險管理理論,水旱災害風險是各類風險要素共同作用的結果。水旱災害風險由水旱事件的隨機性、人類社會及自然環境承災的脆弱性相互作用產生,包括水旱災害危險性、承災體暴露度和脆弱性三方面(也稱風險三要素)。采用調查、評估和區劃三種方法識別風險三要素,同時分析水旱災害風險普查的需求如下。①水旱災害危險性。需要調查各河流、區域的洪水干旱風險來源,分析暴雨洪水產匯流規律和干旱致災規律,量化不同頻率暴雨洪水規模和干旱嚴重程度;需要摸清主要防洪工程防災能力,基于流域地形、水系和防洪工程分布,構建水文水動力學模型,分析不同頻率洪水干旱的影響范圍和影響程度,計算洪水干旱的綜合風險度指數R值,查明水旱災害危險性。②承災體暴露度。承災體是可能遭受水旱災害作用的對象,包括房屋建筑、基礎設施、人口、經濟、農作物等。需要通過調查和數據共享,掌握水旱承災體的數量、空間位置和屬性特征,為風險評估提供基礎數據。③承災體脆弱性。不同承災體對水旱災害表現出的易于受到傷害和損失的性質不同。需要總結分析已有調查和試驗成果,歸納各類承災體強度-破壞曲線和損失特征,支撐水旱災害風險評估。基于上述需求分析和風險管理理論,水利部探索建立了(le)水(shui)(shui)(shui)旱(han)(han)災(zai)(zai)(zai)害風險(xian)(xian)(xian)普(pu)(pu)查內(nei)容體系和(he)技(ji)術標準規范(fan)體系,通過調查分(fen)析獲取水(shui)(shui)(shui)旱(han)(han)災(zai)(zai)(zai)害風險(xian)(xian)(xian)各要素(su)數據,開展(zhan)危(wei)(wei)險(xian)(xian)(xian)性、暴露(lu)度(du)和(he)脆弱性評估,確定(ding)不同(tong)評估單元或區域(yu)的(de)(de)洪(hong)(hong)水(shui)(shui)(shui)干旱(han)(han)風險(xian)(xian)(xian)水(shui)(shui)(shui)平(ping)和(he)等(deng)級,完成了(le)不同(tong)空(kong)間尺度(du)水(shui)(shui)(shui)旱(han)(han)災(zai)(zai)(zai)害風險(xian)(xian)(xian)評估與區劃。在(zai)水(shui)(shui)(shui)旱(han)(han)災(zai)(zai)(zai)害風險(xian)(xian)(xian)普(pu)(pu)查中,與其他災(zai)(zai)(zai)種(zhong)風險(xian)(xian)(xian)普(pu)(pu)查相比(bi),洪(hong)(hong)水(shui)(shui)(shui)災(zai)(zai)(zai)害風險(xian)(xian)(xian)普(pu)(pu)查采用具有(you)物理含義的(de)(de)洪(hong)(hong)水(shui)(shui)(shui)淹沒(mei)水(shui)(shui)(shui)深(shen)、流(liu)速和(he)淹沒(mei)歷時等(deng)淹沒(mei)特征數據量(liang)化洪(hong)(hong)水(shui)(shui)(shui)危(wei)(wei)險(xian)(xian)(xian)性。通過構建河道和(he)防(fang)洪(hong)(hong)區的(de)(de)水(shui)(shui)(shui)力學(xue)模(mo)型,聯合(he)(he)(he)(he)求解連續方程(cheng)和(he)動量(liang)方程(cheng),精準量(liang)化洪(hong)(hong)水(shui)(shui)(shui)波的(de)(de)演進過程(cheng),計算洪(hong)(hong)水(shui)(shui)(shui)綜合(he)(he)(he)(he)風險(xian)(xian)(xian)度(du)指(zhi)數R值(zhi)(zhi)。利(li)(li)用綜合(he)(he)(he)(he)風險(xian)(xian)(xian)度(du)指(zhi)數在(zai)全國范(fan)圍內(nei)表征洪(hong)(hong)水(shui)(shui)(shui)危(wei)(wei)險(xian)(xian)(xian)性,使得(de)不同(tong)區域(yu)的(de)(de)洪(hong)(hong)水(shui)(shui)(shui)風險(xian)(xian)(xian)具有(you)可(ke)比(bi)性,有(you)助于在(zai)統一標準下制定(ding)風險(xian)(xian)(xian)等(deng)級閾(yu)值(zhi)(zhi)。干旱(han)(han)災(zai)(zai)(zai)害風險(xian)(xian)(xian)普(pu)(pu)查則綜合(he)(he)(he)(he)考慮了(le)干旱(han)(han)頻率、水(shui)(shui)(shui)資源量(liang)稟賦(fu)條件與負(fu)異常狀態,反(fan)映水(shui)(shui)(shui)利(li)(li)工(gong)程(cheng)防(fang)旱(han)(han)抗旱(han)(han)減災(zai)(zai)(zai)能力,更加客觀揭示干旱(han)(han)災(zai)(zai)(zai)害風險(xian)(xian)(xian)水(shui)(shui)(shui)平(ping)。
二、技術體系構建
水(shui)旱(han)(han)(han)災(zai)(zai)(zai)(zai)害(hai)(hai)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)普(pu)查技(ji)術體(ti)系涵蓋(gai)水(shui)旱(han)(han)(han)災(zai)(zai)(zai)(zai)害(hai)(hai)致災(zai)(zai)(zai)(zai)因子(zi)、洪(hong)水(shui)災(zai)(zai)(zai)(zai)害(hai)(hai)隱患、水(shui)旱(han)(han)(han)災(zai)(zai)(zai)(zai)害(hai)(hai)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)評(ping)估(gu)(gu)與(yu)(yu)區(qu)(qu)(qu)劃(hua)(hua)(hua)、普(pu)查數(shu)(shu)據(ju)庫(ku)等(deng)方面內容(rong)。應用(yong)水(shui)文水(shui)動(dong)力學、空間聚類分(fen)(fen)析、災(zai)(zai)(zai)(zai)害(hai)(hai)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)分(fen)(fen)析等(deng)理論方法,進(jin)行水(shui)旱(han)(han)(han)災(zai)(zai)(zai)(zai)害(hai)(hai)危險(xian)(xian)(xian)(xian)性、洪(hong)水(shui)干(gan)旱(han)(han)(han)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)評(ping)估(gu)(gu)與(yu)(yu)區(qu)(qu)(qu)劃(hua)(hua)(hua)等(deng)方面的(de)調(diao)查和(he)分(fen)(fen)析評(ping)估(gu)(gu);引入承災(zai)(zai)(zai)(zai)體(ti)脆弱性曲線,進(jin)行洪(hong)水(shui)災(zai)(zai)(zai)(zai)害(hai)(hai)影響人(ren)口、經濟(GDP)的(de)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)評(ping)估(gu)(gu);針對干(gan)旱(han)(han)(han)災(zai)(zai)(zai)(zai)害(hai)(hai)相(xiang)關(guan)的(de)水(shui)資源量(liang)空間配(pei)置特點,以縣級行政區(qu)(qu)(qu)為單(dan)元(yuan)進(jin)行農業干(gan)旱(han)(han)(han)災(zai)(zai)(zai)(zai)害(hai)(hai)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)度、人(ren)飲困難風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)度、城市(shi)干(gan)旱(han)(han)(han)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)度分(fen)(fen)析和(he)干(gan)旱(han)(han)(han)災(zai)(zai)(zai)(zai)害(hai)(hai)綜合風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)評(ping)估(gu)(gu)與(yu)(yu)區(qu)(qu)(qu)劃(hua)(hua)(hua)。此外(wai),基于數(shu)(shu)值區(qu)(qu)(qu)間合理性、邏輯判斷(duan)、空間拓撲關(guan)系分(fen)(fen)析等(deng)方法,提出(chu)普(pu)查數(shu)(shu)據(ju)質(zhi)檢(jian)審核(he)規則和(he)質(zhi)量(liang)控制(zhi)方法,規定風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)評(ping)估(gu)(gu)與(yu)(yu)區(qu)(qu)(qu)劃(hua)(hua)(hua)制(zhi)圖(tu)標準。此次水(shui)旱(han)(han)(han)災(zai)(zai)(zai)(zai)害(hai)(hai)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)普(pu)查在原(yuan)有基礎(chu)上組織新編7項(xiang)普(pu)查技(ji)術要求或規范性技(ji)術文件,系統(tong)構建(jian)了(le)水(shui)旱(han)(han)(han)災(zai)(zai)(zai)(zai)害(hai)(hai)風(feng)(feng)(feng)險(xian)(xian)(xian)(xian)評(ping)估(gu)(gu)與(yu)(yu)區(qu)(qu)(qu)劃(hua)(hua)(hua)技(ji)術體(ti)系,如圖(tu)1所示。
三、關鍵技術
1.基于統計學與分布(bu)式(shi)水文(wen)模型融合的洪水災害致災分析方法
應用精確性、不偏性及穩健性更優的線性矩法編制暴雨頻率圖,提高稀遇頻率估計值的擬合精度,降低了常規矩法低估的安全隱患。假定降雨年最大值系列X服從某一分布函數,X1:n≤X2:n≤...≤Xn:n是一組隨機樣本的次序統計量,定義r階線性矩變量的通式為:式中,EXr-k:r為樣本容量n中排在第r-k位的次序統計量的期望值,λr為r階線性矩變量。綜合應用多種水文模型編制中小流域洪水頻率圖。結合暴雨頻率分析成果,在綜合單站洪水頻率分析法、區域洪水頻率分析法的基礎上,以分布式水文模型法為主,推求山丘區主要小流域出口節點設計洪水,豐富了洪水頻率分析成果,為開展災害風險評估提供堅實基礎資料。單站洪水頻率分析法適用于有流量資料的站點,且站點上游控制流域內不存在大中型水庫,可結合歷史實測和調查洪水資料進行洪水頻率分析;對有水位資料的站點,可轉換為流量數據進行洪水頻率分析。區域洪水頻率分析法綜合多個小流域單站洪水頻率分析成果,構建不同水文分區的洪水區域回歸方程或增長曲線,根據小流域所在區域,快速推算小流域設計洪水。具體見公式(2)和(3)。式中,QT是T年一遇的洪峰流量,Ai是第i個流域特征變量,αi是模型參數,n是特征變量的個數,是乘積誤差項。3?:55^??z{?EHm??è)$·?^°6?’??m???‰?+‰–·4?j?H?êá?èíptu?á$á!#$?á"#$?;;;?á$#$dp?ˉ?ì·m?ó?EY$–???”??òYmW?Vú5(1)?L$