Tɔdzisasrãwo ƒe gbagbã kple tsiɖɔɖɔ ƒe ƒutsotsoewo ƒe ʋuʋu si gblẽa nu ŋutɔ¶
Xexlẽme kpatawo toa vovo le dukɔ ɖesiaɖe me. Axa sia zã 911, si nye xexlẽdzesi na United States kple Canada. Dukɔ bubu geɖewo zãa 112, 999, alo xexlẽdzesi bubu. Di xexlẽdzesi si le miaƒe dukɔa me.
Tɔdzisasrã ƒe gbagbã gã aɖe, tɔdzisasrã ƒe gbagbã, alo Glacial Lake Outburst Flood (GLOF) ɖea tsi si woxe si ƒe didime nye kubik meta miliɔn geɖe va ɖo miliɔn alafa geɖe ɖe go le aɖabaƒoƒo ʋɛ aɖewo ko me, si wɔnɛ be tsiɖɔɖɔ ƒe ƒutsotsoe si le abe tsunami ene si le anyigba me si kplɔa tɔsisi ƒe bali blibowo yia kpe ƒuƒluwo dzi. To vovo na tɔsisiwo ƒe tsiɖɔɖɔ dzro siwo dzɔna le ɣeyiɣi aɖewo me siwo dzina ɖe edzi sentimeta ɖeka le gaƒoƒo alo ŋkekewo me la, tɔdzisasrã si wogbã, tomebɔmb ƒe tsiɖɔɖɔ ƒe tsidzɔƒe si do kpo nu, alo tsikpe ƒe moraine si mu la ɖea tsi, anyigbaʋuʋu, kpewo, ati siwo ŋe, kple xɔ siwo gbã **meta 3 va ɖo 30 (afɔ 10 va ɖo 100) ƒe gli si kɔkɔ 20 va ɖo Kilometa 65 le gaƒoƒo ɖeka me (kilometa 12 va ɖo 40 le gaƒoƒo ɖeka me). Esi wònye be ƒutsotsoe sia si me gbeɖuɖɔwo sɔ gbɔ ɖo fũu akpa la ƒe kpekpeme ade tsi gbadzaa ƒe teƒe eve eye wògbãa ati kple anyikpexɔ siwo wozãna ɖaa ne wodze wo dzi ta la, bebeƒe le aƒe aɖe me alo tolili ɖe aƒewo ƒe xɔta le tsiɖɔɖɔ ƒe teƒea me wua ame zi geɖe: agbetsitsi nɔ te ɖe amewo ɖeɖe ɖa enumake le balia ƒe gliwo dzi yi anyigba kɔkɔ si le tsiɖɔɖɔ ƒe teƒe si sɔ gbɔ wu dzi kɔkɔme.
MÈGALI aƒea tame alo ayi dziƒoxɔ dzi le tɔdzisasrã ƒe gbagbã alo GLOF me o
Le tsidzadza ƒe tsiɖɔɖɔ si le dzidzim ɖe edzi blewu me la, xɔnamedɔwɔƒewo ɖoa aɖaŋu na afima nɔla siwo xaxa ɣeaɖewoɣi be woaʋu ayi dzisasrã si le etame dzi (menye dziƒoxɔ si wotu si me xɔtaxɔ aɖeke meto le gbeɖe o). In a catastrophic dam breach, tailings dam collapse, or Glacial Lake Outburst Flood, a residential house roof will NOT save you. The leading edge of a dam-break wave is a high-velocity wall of liquid concrete, whole tree trunks, vehicles, and boulders that shears houses completely off their foundations in seconds. Ne wodo Nuxlɔ̃ame si ku ɖe Tɔdzisasrã ƒe Gbegblẽ ŋu alo nèse tsiɖɔɖɔ ƒe ƒutsotsoe si gbɔna ƒe jet-engine ƒe ɣlidodo la, gblẽ xɔa ɖi enumake eye nàƒu du tẽ ayi togbɛ alo bali ƒe gli si te ɖe ŋuwò wu.
Wɔ esia fifia¶
- **Tsi le eme enumake wòtsi tre ɖe tɔsisia ƒe mɔ ŋu (miyi balia ƒe togbɛ dzi tẽ, mègagblẽ aɖabaƒoƒo 5 atsɔ abla akplowo, ado ʋɔtruwo, alo anɔ agbagba dzem be yeasi le balia gɔme mɔ si kplɔ tɔsisia ɖo la dzi o. Kpɔ anyigba si le balia ƒe akpa eveawo eye lia togbɛ, bluff, alo togbɛ si dzi ke wu si dzi woate ŋu aɖo la tẽ le dzogoe 90 si didi tso tɔsisia ƒe tɔsisi gbɔ vaseɖe esime nàde meta 15 va ɖo 30 ya teti (afɔ 50 va ɖo 100) le balia ƒe anyigba tame (alo nàƒo fli si woŋlɔ ɖe wò nutoa me Dam Inundation Zone la tame).
- Miyi afɔ enumake ne bali me mɔwo xe mɔwo, anyigbaʋuʋu xe wo, alo tɔdzisasrãwo tso wo nɔewo. Tsiɖɔɖɔ ƒe ƒutsotsoe si gblẽa tɔdzisasrãwo me alo GLOF zɔa mɔ sesĩe kilometa 20 va ɖo 65 le gaƒoƒo ɖeka me (kilometa 12 va ɖo 40 le gaƒoƒo ɖeka me) eye wògblẽa tɔdzisasrã siwo le anyigba ƒuƒui dzi gbã. Ne ʋuwo dzudzɔ ʋuʋu alo nèle kilometa 5 (kilometa 3) me tso tɔdzisasrã, tɔdzisasrã, alo tsikpe ƒe bali si me tsikpe le ƒe tɔdzisasrã si le gbagbãm gbɔ la, gblẽ wò ʋu ɖi enumake eye nàzɔ togbɛa dzi tẽ. Ne èlia toa sesĩe aɖabaƒoƒo ewo la, ana nànɔ tsitrenu meta 60 va ɖo 100 (afɔ 200 va ɖo 330) tso tɔsisia ƒe go kemɛ dzi, eye tsiɖɔɖɔ ƒe ƒutsotsoe ɖesiaɖe kloe mate ŋu aɖo o.
- De dzesi dzɔdzɔme nuxlɔ̃amedzesi 4 la ne kaƒomɔ̃ ƒe nuxlɔ̃ame alo siren do kpo dɔwɔwɔ. Tɔdzisasrãwo mu eye GLOF dzɔna enuenu le zã me, le anyigbaʋuʋuwo me, alo le tsidzadza sesẽ siwo ƒoa asitelefon xɔ kɔkɔwo gbã me. Ʋu yi teƒe kɔkɔ enumake ne ède dzesii be: (a) anyigba ƒe ʋuʋu atraɖii, si mebɔ o kple gbeɖiɖi si naa tome tu si ɖina abe agbatsɔketeke si dzona bɔbɔe alo yameʋu siwo me dzo le ƒe hatsotso aɖe si le togbɛa dzi yim ene; (b) tɔsisi me tsi ƒe ɖiɖi kpata, si mele dzɔdzɔme nu o ALOO anyigbaʋuʋu kpata le tɔsisi me tsi ƒe kɔkɔme; © anyigba, sulfur, kple pine/sederti siwo wogbã yeyee ƒe ʋeʋẽ sesẽ aɖe si ya fafɛ aɖe ƒo kpata to balia me; alo (d) anyigbaʋuʋu sesẽ alo kpewo ƒe gbagbã ne èle tɔdzisasrã alo tsikpeta aɖe te.
- Mègaku ʋu alo azɔ to tsiɖɔɖɔ ƒe tsi siwo le ʋuʋum me alo atso tɔdzisasrã si le tɔsisi si le ʋuʋum dzi gbeɖe o. Tsi si le zɔzɔm kabakaba si didi sentimeta 15 (sentimeta 6)** pɛ ko ƒoa ame tsitsi aɖe le woƒe afɔwo dzi, eye tsi si le du dzi si didi sentimeta 30 va ɖo 60 (afɔ 1 va ɖo 2)** la ƒua tsi hekplɔa ʋu kpekpe siwo tsɔa tasiaɖam ene kple SUV dzonae. Tsɔ kpe ɖe eŋu la, mègatso tɔdzisasrã gbeɖe ne tsiɖɔɖɔ ƒe tsiwo le tetem ɖe tɔdzisasrãa ƒe akpata ŋu alo le ʋuʋum sesĩe ƒo xlã tɔdzisasrãawo o: gbeɖuɖɔ siwo sɔ gbɔ ŋutɔ sina eye kpewo ƒoa tɔdzisasrãwo ƒe ƒuƒoƒo doa go tso asphalt la te sɛkɛnd ʋɛ aɖewo hafi mɔa namu.
- Ne èle anyigba ƒe tɔdzisasrã si dze "ke-ƒoƒo" gɔme, si le tsi si me ʋuʋudedi le sisim, alo si le gegem la megbe la, do le eme hafi wòagbã. Hafi anyigba ƒe tɔdzisasrã alo tɔdzisasrã si wotu ɖe tɔdzisasrã dzi nagbã la, tsi si ƒe nyaƒoɖeamenu gã aɖe si toa tome le anyigba te alo toa eme la naa tsi si me ʋuʋudedi le kple ke ƒe vudo siwo le ʋuʋum le anyigba ƒe akpa ƒuƒui** alo **pɔmpiwo **). Togbɔ be tsi si me kɔ si le sisim blewuu bɔ hã la, tsi si me ʋuʋudedi le, si yɔ fũ kple ʋuʋudedi si le dodom tso ke ƒe ƒoƒo alo gbagbã/do si woate ŋu akpɔ le tɔdzisasrãa ƒe fiakuku dzi fia be ememe ƒe ʋuʋu le tɔdzisasrãa vuvum tso eme eye afɔku gã aɖe ƒe gbagbã si goglo bliboe ate ŋu adzɔ le aɖabaƒoƒo ʋɛ aɖewo ko me. Ƒo ka na wò nutoa me xexlẽdzesi kpata (911 le United States kple Canada, 112 le Europa Dukɔwo ƒe Habɔbɔ bliboa me, 999 le United Kingdom, alo kpɔ wo katã xexlẽdzesi siwo wozãna kpata) eye nàdzo enumake.
- Nɔ anyigba kɔkɔ dzi le ƒutsotsoe gbãtɔ ƒe yiyi megbe: ƒutsotsoe evelia, ƒuta ƒe mumu, kple aɖi ƒe mu kplɔnɛ ɖo. Tɔdzisasrãwo ƒe gbagbã kple GLOF dzɔna enuenu le ƒutsotsoe geɖe me esime tsidzadza si yia megbe la kekea gbagbãƒea ɖe enu alo tsikpe evelia ƒe tawo kple anyigbaʋuʋu ƒe tɔdzisasrãwo gbãna le dzigbe gome. Ne tsi ƒe agbɔsɔsɔ ɖiɖi gɔ̃ hã la, nɔ balia ƒe gɔme si woɖe yeyee la me: bali siwo me tsi yɔ fũu ƒe gliwo mu edziedzi le evelia gãwo me anyigba ƒe ʋuʋu, eye tomenukuƒe ƒe tsiɖɔɖɔ alo dɔwɔƒewo ƒe tsiɖɔɖɔ ƒe anyikpe wɔa dɔ zi geɖe abe ke gbagbe si wotsɔ ga kpekpewo, cyanide, tsi gbegblẽwo, kple elektrikŋusẽnamɔ̃ siwo gbagbe siwo ge ɖe anyigba la blae ene.
Dam ƒe kpododonu, levee ƒe gbagbã, kple GLOF ƒe agbetsitsi ŋuti nyametsotsoti¶
Zã nyametsotso kabakaba ƒe nɔnɔmetata sia le ɣeyiɣi si me nèxɔ Dam Watch/Warning, kpɔ levee sand ƒe ƒoƒo, alo se togbɛ aɖe si le dzigbe gome ƒe ɣlidodo.
flowchart TD
Start["Dam ƒe Dodokpɔ ƒe Nuxlɔ̃ame, Levee ƒe Gbegblẽ ƒe Nuxlɔ̃ame,<br/>Glacial Lake Outburst (GLOF) Siren, AL Upstream Canyon Roar"] --> TimeCheck{"Ɣeyiɣi nenie le asiwò hafi<br/>tsiɖɔɖɔ ƒe ƒutsotsoewo nava?"}
TimeCheck -->|"IMMINENT BREACH (Sɛkɛnd va ɖo <15 Mins)<br/>Siren ƒe avifafa, Nuxlɔ̃ame Kpata, alo Gbeɖiɖi se"| RunUpSlope["GBLƆXƆ XƆWO & ƲUWO NE WOXƆ ƲUWO:<br/>Dsi le afɔ dzi le dzidzenu 90 me PERPENDICULAR to the river channel<br/>Lia togbɛ, bluff, alo bali ƒe gli si te ɖe ŋuwò wu la tẽ<br/>Taɖodzinu na >= 15 va ɖo 30 le tsitrenu meta (50 va ɖo 100 afɔ) tso balia ƒe anyigba"]
RunUpSlope --> TrappedCheck{"Ðe tsi ƒo xlã wò keŋkeŋ<br/>le tsiɖɔɖɔ gbadzaa si dzi togbɛ aɖeke mele o dzia?"}
TrappedCheck -->|"Ao: Eɖo anyigba kɔkɔ aɖe dzi"| StayHigh["Nɔ anyigba kɔkɔ dzi hena ƒutsotsoe geɖe<br/>MÈGA ɖiɖi be yeaɖe nunɔamesiwo alo aka asi anyigbaʋuʋu ŋu o"]
TrappedCheck -->|"Ẽ: Anyigba gbadza, ƒutsotsoewo le vavam fifia"| VerticalLastResort["NU MƆKPƆKPƆ MƆKPƆKPƆ VERTICAL EVACUATION:<br/>Lia xɔ kɔkɔtɔ kekeake si wotsɔ gakpo alo kɔkrit si ŋu wodo ŋusẽe ɖo (dziƒoxɔ 3+)<br/>Ƒo asa na xɔ siwo wotsɔ ati tu, aƒe siwo wotsɔna ʋunae, kple tɔdzisasrãwo<br/>Tsɔ mɔ̃ si wotsɔna tsia tsia dzi vɛ; mègatu ɖokuiwò ɖe dziƒoxɔ si wotu me gbeɖe o"]
TimeCheck -->|"NUXLẼME DO ŊGƆ (30 Mins vaseɖe Gaƒoƒo Geɖe)<br/>FEMA / Yame ƒe Nɔnɔme Dɔwɔƒe 'Dam Watch' alo Levee Overtopping Forecast"| VehicleEvac["1. Lé Go-Bag, atikewo, aƒemelãwo, kple ƒomea enumake<br/>2. Ʋu yi DZI eye DO GO le Dam Inundation Zone si wowɔ anyigbatata dzi<br/> to togbɛmɔwo zazã me (MÈGAKU ʋu to tɔsisiwo gɔme alo to tɔdzisasrã siwo bɔbɔ dzi GBEÐE o)<br/>3. Ne ʋuwo xaxa le balia me la, tsɔ ʋua tɔ ɖe mɔa dzi eye nàzɔ togbɛa dzi"]
VehicleEvac --> LeveeInspect{"Ðe nèkpɔ ‘Sand Boil’ alo mu si le sisim<br/>le tɔdzisasrã alo tɔdzisasrã aɖe si te ɖe afima ŋu ƒe gɔmea?"}
LeveeInspect -->|"Ẽ: Tsi si me ʋuʋudedi le si le ʋuʋum"| ReportPiping["PIPING ƑE DODO VEVI SI LE YI YI ŊU:<br/>Mègadze agbagba be ye ŋutɔ yeado doa o.<br/>Tsɔ tsiɖɔɖɔƒea enumake eye nàƒo ka na 911 / 112 / 999<br/>agblɔ afi si tututu GPS si me ke si me ʋuʋudedi le la le"]
LeveeInspect -->|"Ao"| StayOutZone["Kpɔe ɖa kple ƒometɔwo le tsiɖɔɖɔ ƒe teƒea godo<br/>Lé ŋku ɖe NOAA Yame ƒe Nɔnɔme Radio / Dukɔa ƒe Nyadzɔdzɔ Kpatawo Ŋu"]
Ne wotsɔ afɔku ƒomevi 4 siwo gblẽa nu le ame ŋu ƒe kpododonu sɔ kple wo nɔewo¶
Menye tɔdzisasrã kple mɔxenu ƒe gbagbãwo katãe wɔa nu ɖekae o. Kɔkrit-tɔdzisasrã siwo wotsɔa aɖaka wɔe la doa kpo nu enumake kloe abe tsidzɔƒe si le wowóm ene, tɔdzisasrã siwo wotsɔ anyi wɔe siwo le tɔdzisasrãwo dzi la vuvu vivivi le miniti 20 va ɖo 90 me, tsikpeta siwo me tsikpewo le la ɖea gbeɖuɖɔ siwo yɔ fũ kple kpewo ɖe go toa togbɛwo me, eye tomebɔmb ƒe tsiɖɔɖɔɖɔƒewo ɖea tɔsisi siwo me aɖi le si xɔa ame me la dona.
| Dodokpɔ ƒe Ƒomedodo | Alesi Mɔxenua Do kpo Nui | Breach Formation ƒe Duƒuƒu | Tsiɖɔɖɔ ƒe Ƒutsotsoea ƒe Dzɔdzɔme | Nuxlɔ̃amedzesi Siwo Woŋlɔna Klasik Hafi Woadze anyi |
|---|---|---|---|---|
| 1. Kɔkrit ƒe Aɖaka, Nuheŋusẽ, alo Buttress Dam ƒe Dodokpɔ (alo Anyigbaʋuʋu ƒe Ʋuʋudedi ƒe Ƒutsotsoewo ƒe Tame) . | Xɔtuɖoɖo ƒe gɔmeɖoanyi ƒe gbagbã, anyigbaʋuʋu ƒe gbagbã, kpe si le abutment ƒe gbagbã, alo todzinyigba gã aɖe si ge ɖe tsita la me eye wòkɔ ƒutsotsoe gã aɖe ɖe tɔdzisasrãa ƒe ta dzi. | Enumake va ɖo < miniti 10 (kɔkrit gli blibo alo monolith ɖea mɔ zi ɖeka). | Tsi ƒe gli si le tsitrenu kloe (si kɔkɔ meta 10 va ɖo 50+ le bali gbadzawo me) si le zɔzɔm sesĩe 40 va ɖo 80 km/h (25 va ɖo 50 mph). | Anyigbaʋuʋu sesẽ aɖe si le ʋuʋum; gbagbãƒe yeyewo alo kɔkrit ƒe ƒuƒoƒo siwo mesɔ o le tɔdzisasrãa ƒe mo; tsi siwo ƒe nyaƒoɖeamenu sesẽ siwo le tu dam tso kpe si wotsɔ ƒo xlãe le afisi tɔdzisasrãa do go kple balia ƒe gli le. |
| 2. Anyigba alo Agakpewo ƒe Tɔdzisasrã & Tɔdzisasrã ƒe Dodokpɔ (Overtopping alo Internal Piping) | (a) Overtopping: Tsiɖɔɖɔ ƒe tsiwo kɔ ɖe anyigba ƒe ta si le etame dzi eye wokpa do si le abe V ene ɖe megbe togbɛa dzi. (b) Piping / Internal Erosion: Tsi toa pɔmpi si woɖi, lãwo ƒe do, alo anyigba ƒe ƒuƒoƒo dzi vaseɖe esime xɔa tame mu. |
Aɖabaƒoƒo 15 va ɖo gaƒoƒo 3 ne overtopping alo muddy piping si le dɔ wɔm dze egɔme ko (si le du dzi ŋutɔ ne V-notch la le kekem ɖe enu). | Tsi si le dzi yim kabakaba, si ƒe amadede nye tsokolet-blɔ kple anyigba si vuvu, si ɖoa eƒe kɔkɔƒe le miniti 15 va ɖo 60 me eye wònɔa kɔkɔƒe gaƒoƒo alo ŋkeke geɖe ne tsi si le tsidzraɖoƒea le sisim. | Ke si me ʋuʋudedi le si le ʋuʋum le afɔbidɛ si le anyime la gbɔ; do siwo me tsi megena ɖo alo gbagbãƒe didi siwo le tɔdzisasrã/tɔdzisasrãa ƒe mɔ si le etame dzi; ati siwo le ʋuʋum le tɔsisia ƒe togbɛ si le anyime; tsi si le sisim ɖe ta la dzi. |
| 3. Glacial Lake ƒe Tsiɖɔɖɔ (GLOF) / Jökulhlaup . | Togbɛwo dzi tsikpe siwo le ƒoƒom kabakaba la wɔa ta gãwo le kpe gbadzɛ kple tsikpe gbogbo siwo meli ke o (terminal moraine dams) megbe alo le tsikpetowo te. tsikpe/kpe ƒe ahomya si le sisim ɖe ta la me, tsidzadza gã, dzoxɔxɔ dome, alo dzoto ƒe dzoxɔxɔ si le tsikpe te te ye ʋãe. | Aɖabaƒoƒo (moraine-tɔdzisasrãa ƒoa xlãe eye wòƒuna enumake; tsikpetoa gbãna). | Gbe gbadzɛ siwo ƒe sisi sɔ gbɔ akpa (si ade 60% kpewo, kpe gbadzɛwo, tsikpe gbadzɛwo, kple atiwo le woƒe lolome nu; woƒe kpekpeme \(1.8\text{ va ɖo }2.2\text{ g/cm}^3\)) si zɔna sesĩe 20 va ɖo 60 km/h (12 va ɖo 37 mph) kilometa ewo le towo ƒe baliwo me. | Gbeɖiɖi sesẽ alo dziɖegbe ƒe ɖiɖi le towo dzi (kpe/tsikpe ƒe ahomya); todzitɔsisi si me kɔ nyuie le dzɔdzɔme nu ƒe ƒutsotsoe si me ʋuʋudedi le/si me ƒu kplakplakpla; anyigbaʋuʋu si wokpɔ to bali me anyigbaʋuʋu ƒe dzesiwo dzi. |
| 4. Mine Tailings Dam ƒe Mumu (Tsi ƒe Dodokpɔ) . | Tɔdzisasrã siwo wotu le dzigbe gome siwo wotu kple tomenukuƒe gbeɖuɖɔ siwo wotsɔ ƒo ƒu (tailings) to static alo seismic liquefaction me: kasia anyigbaʋuʋu si dze abe sesẽ ene trɔna zua tsi sesẽ le nuteɖeamedzi alo tsidzadza gã aɖe me. | Ɣeyiɣi kpui aɖe (< miniti 1) evɔ womaƒoe do ŋgɔ o. | Aɖi ƒe ƒutsotsoe si me aɖi le ŋutɔ (silica si wofli, gayibɔ/akɔbli/sika ƒe gbeɖuɖɔ, arsenic, mercury, lead, alo cyanide ƒe ʋuʋudedi) si ɖia baliwo ɖe mu si le abe kɔkrit ene ƒe meta geɖe si tsia sesĩe alo nɔa ke gbagbe me. | Teƒe siwo tsi xɔdzo ("avifafa"), ʋuʋudedi, alo ɖa ƒe gbagbã le xɔtaxɔe ƒe tailings ƒe togbɛ dzi; tsi si me mekɔ o le tsidzɔƒewo; inclinometer/radar ƒe ɣlidodo siwo wowɔna le wo ɖokui si. |
Dziɖuɖua ƒe tɔdzisasrã kple tɔdzisasrã ƒe nuxlɔ̃ame kpata ƒe seƒewo gɔmesese¶
In the United States (National Weather Service / FEMA / US Army Corps of Engineers), Canada, the United Kingdom (Environment Agency), the European Union, and Himalayan/Andean GLOF monitoring networks, authorities use standardized escalation tiers. Knowing the difference between a Watch and an Emergency Warning tells you whether you have hours or seconds:
- Dam / Levee Watch (Advisory or Condition B: Potential Failure Developing):
- What it means: Floodwaters behind a dam or levee are approaching dangerous capacity, auxiliary spillways are discharging at maximum rate, or engineers have discovered a structural defect (such as seepage or minor slumping) that could lead to failure if conditions worsen.
- What you must do NOW: Pack your emergency Go-Bag, load mobility-limited family members, infants, and pets into your vehicle, move livestock to high pasture, and evacuate the inundation zone early while roads and bridges are still completely dry.
- Flash Flood Warning for Dam Failure / Levee Breach (Condition A: Imminent or Active Failure):
- What it means: The dam or levee is actively failing right now or is guaranteed to breach within minutes. Wireless Emergency Alerts (WEA) on mobile phones will sound a loud alarm tone with the header "FLASH FLOOD WARNING: DAM FAILURE" or "EXTREME EMERGENCY: EVACUATE TO HIGH GROUND."
- What you must do NOW: Drop everything and move to high ground immediately. Do not pack possessions; grab only the people next to you and climb out of the valley floor.
- High-Volume Spillway Release Warning (Non-Breach Controlled Flood):
- What it means: To keep an earthen dam from overtopping and collapsing completely during historic rainfall (such as during a hurricane or atmospheric river), dam operators are forced to open the emergency floodgates or auxiliary spillway to release massive volumes of water down the river channel.
- What you must do NOW: Evacuate all low-lying riverfront homes, campgrounds, and floodplains immediately, as river levels can rise 3 to 10 meters (10 to 33 feet) in a single hour even though the dam itself has not broken.
Flood Wave Arrival Time, Velocity, and Impact Force by Distance Downstream¶
Understanding how a dam-break wave or GLOF transforms as it travels down a canyon helps you estimate how many minutes you have to climb to safety:
| Distance Downstream from Dam / Glacial Lake | Typical Wave Arrival Lead Time | Typical Wave Front Height (Narrow Canyon vs. Wide Valley) | Peak Flow Velocity | Structural Destructive Power |
|---|---|---|---|---|
| 0 to 5 kilometers (0 to 3 miles) (Immediate Gorge / Tailrace Zone) | 1 to 8 minutes (Almost zero technological warning time) | 10 to 30+ meters (33 to 100+ feet) in canyons; 4 to 10 meters (13 to 33 feet) on flats. | 35 to 65+ km/h (22 to 40+ mph) | Total obliteration: Scours soil down to bare bedrock; sweeps away reinforced concrete bridges, power plants, and every building in the channel. |
| 5 to 20 kilometers (3 to 12 miles) (Middle Valley Reach) | 10 to 35 minutes | 5 to 15 meters (16 to 50 feet) in gorges; 2 to 6 meters (6.5 to 20 feet) on floodplains. | 20 to 40 km/h (12 to 25 mph) | Catastrophic: Carries thousands of snapped trees, boulders, and vehicles as battering rams; demolishes wood and brick houses and overtops highway bridges. |
| 20 to 50+ kilometers (12 to 31+ miles) (Lower Floodplain & Alluvial Fan) | 40 minutes to 3+ hours | 1.5 to 4 meters (5 to 13 feet) spreading kilometers wide across flat land. | 8 to 20 km/h (5 to 12 mph) | Severe inundation: Floods first and second stories of buildings, buries towns in 1 to 3 meters of mud, and cuts off all road egress for days. |
How to spot a failing earthen dam or levee: The "Clear vs. Muddy Seepage" rule¶
Millions of people live directly behind earthen flood control levees, canal embankments, farm stock dams, or hydroelectric earthfill dams. If you are inspecting a levee or earthen dam during high water, civil engineers use one simple visual test to distinguish harmless water seepage from a deadly impending breach:
- Clear Water Seeping Slowly = Watch Closely, Low Immediate Breach Risk: When water stands high against an earthen levee for days, the soil becomes saturated and clear water often sweats or trickles slowly out near the bottom toe. If the water is crystal clear and flow rate is steady, the soil skeleton inside the levee is holding firm (engineers often ring a clear seep with a horseshoe collar of sandbags simply to raise the back-pressure head).
- Muddy, Dirty, Silt-Laden Water Gushing or Bubbling = EVACUATE IMMEDIATELY (Active Piping): If the water bubbling out of the ground or flowing out of the back slope of the dam is cloudy, brown, muddy, or piling up a cone of sand and gravel like a miniature volcano (a "sand boil"), the rushing water is actively washing the dirt core out from inside the dam. Hidden beneath your feet, an underground tunnel (pipe) is eating its way backward toward the reservoir. Once that tunnel breaks through to the river side, pressurized reservoir water enlarges the hole in seconds, collapsing the top of the levee and unleashing a full-depth breach. Never walk onto a slumping or boiling levee, never try to plug a gushing muddy boil by throwing dirt into the hole, and call 911 / 112 / 999 while evacuating.
The Upstream Landslide-Dam Trap in Mountain Canyons
After a major anyigbãʋuʋu, dzobibi, alo tsidzadza gã aɖe le tonyigbawo dzi, kpe kple anyikpe tɔn miliɔn geɖe ƒua du tso bali aɖe ƒe gli dzi zi geɖe eye woxea todzitɔsisi aɖe keŋkeŋ, si wɔnɛ be anyigbaʋuʋu ƒe tɔdzisasrã si meli ke o nɔa anyi ɣeyiɣi kpui aɖe. Ne èle tɔsisi aɖe ƒe go kemɛ dzi le todzitɔsisi aɖe to eye nède dzesii be tɔsisia ƒe tsi ƒe kɔkɔme ɖiɖina zi ɖeka va ɖoa tsidzadza me le ahom sesẽ aɖe me alo le emegbe la, MÈGAZO ɖe tɔsisia to o eye MÈGANƆ wò balia me aƒe o. Tɔsisi me tsi ma si bu la le megbe yim va zu ta gã aɖe si le anyigba ƒe ʋuʋu ƒe mɔxenu si le dzigbe gome la megbe; le gaƒoƒo alo ŋkeke aɖewo megbe la, ta la ato anyigba si le gbadzaa la dzi, atsoe le aɖabaƒoƒo ʋɛ aɖewo ko me, eye wòana tsi kple kpe gbadzɛwo ƒe gli si gblẽa nu le ame ŋu la naƒo ɖe tɔsisi ƒuƒu si le ɖiɖim la dzi. Miʋu yi teƒe kɔkɔwo eye miaƒo ka na dɔwɔƒe siwo kpɔa nudzɔdzɔ kpatawo gbɔ enumake be woagblɔ tɔsisiwo ƒe sisi kpata.
Agbetsitsi ƒe dzɔdzɔmeŋusẽŋununya ne wolée le gota alo le ʋu me¶
Ne èlé wò le bali aɖe me esime tɔdzisasrã ƒe gbagbã alo GLOF ƒutsotsoe aɖe va eye màte ŋu aɖo balia ƒe gli si le etame la gbɔ le ɣeyiɣi nyuitɔ dzi o:
- Tia dzɔdzɔme togbɛ si dzi ʋuʋudedi le ɣesiaɣi wu xɔ ÐESIASI si amegbetɔ tu: Dzɔdzɔmekpe si do meta 10 (afɔ 33) si woɖe ɖe go alo togbɛ si me ke le si wotsɔ seke ɖo anyigba gɔ̃ hã mate ŋu agbã to tsiɖɔɖɔ ƒe ƒutsotsoe me o, gake xɔ si nye dziƒoxɔ 3 si wotsɔ anyikpe tu si bɔbɔ nɔ balia titina la ate ŋu ana eƒe gɔmeɖoanyiwo nagbã eye wòamu ɖe tɔʋua me.
- Ne togbɛ aɖeke meli o (tsiɖɔɖɔ ƒe teƒe gbadzaa) la, tia xɔ si sɔ si me woaɖe amewo le le tsitrenu:
- Gblẽ: Aƒe siwo nye dziƒoxɔ ɖeka, xɔ siwo wotsɔ ati tu, aƒe siwo wotsɔna ʋuna/mɔzɔʋuwo, xɔ siwo wotsɔ anyikpe tu siwo ŋu womedo ŋusẽe o, gadzraɖoƒewo, kple ʋuwo.
- Tolia: Xɔ si wotu ɖe dziƒoxɔ geɖe dzi (** dziƒoxɔ 3+) si wotsɔ kɔkrit si wokɔ alo gakpo si wotsɔ tu xɔtunuwoe (abe kɔdzi, yunivɛsitixɔ, ʋutɔɖoƒe si wotsɔ kɔkrit tu si nye dziƒoxɔ geɖe, alo egbegbe amedzrodzeƒe ene). Ʋu yi dzisasrã 3 lia alo esi kɔkɔ wu eye nànɔ xɔa ƒe akpa si le anyime si didi tso fesre siwo dze ŋgɔ ƒutsotsoe siwo gbɔna ƒe ŋusẽkpɔɖeamedzi gbɔ.
- Mègatre ɖokuiwò ɖe dziƒoxɔ si wotu me si me fía alo xɔtaxɔ ƒe ʋɔtru mele o me gbeɖe o: Ne tsi si le dzi yim zi dziwò be nàlia xɔ aɖe ƒe atrakpuiwo la, mègalia dziƒoxɔ si wotu me gbeɖe o negbe ɖe fesre si dzi woate ŋu ato ado le, xɔtaxɔ ƒe ʋɔtru, alo fía/sledgehammer kpekpe aɖe si ate ŋu agbã ati tame ƒe nutsyɔnu kple xɔtaxɔe la li hafi. Ame alafa geɖe siwo tsiɖɔɖɔ gblẽ nu le la nyrɔ ɖe woawo ŋutɔ ƒe xɔtaxɔ tame ƒe akpa si le ete.
- Ne wokplɔe yi tsia me: Mègadze agbagba mèga kpɔ be yeaƒu tsi atsi tre ɖe tsi si le sisim ŋu alo tsi tre ɖe tsi si le zɔzɔm kabakaba me o (wò afɔwo dada ɖe tsiɖɔɖɔ ƒe tsi si me kpewo le me la léa wò afɔ ɖe kpe gbadzɛwo dome esime tsiɖɔɖɔa ƒoa wò akɔta yia ŋgɔ, si ƒoa wò ɖe tsi te: afɔ ƒe mɔ̃). Mia wò akɔta eye wò afɔwo nafia asi tɔsisia ƒe anyime eye nàlée ɖe te sesĩe be nàxe mɔ ɖe kpewo kple ati siwo le tsia dzi nu, nàtsɔ wò ŋutilã aɖo tɔdziʋu ƒe dzogoe si nye dzidzenu 45 ɖe ƒuta ƒe ʋuʋudedi alo togbɛ si te ɖe ŋuwò wu, eye nàƒu du ayi ƒuta le ɣeyiɣi si me nèƒo tsi si le blewu wu le balia ƒe akpa si le eme la dzi.
Ðoɖowɔwɔ do ŋgɔ: Alesi nàxlẽ wò nutoa me Tɔdzisasrã ƒe Tsiɖɔɖɔ ƒe Nɔnɔmetata kple GLOF ƒe Afɔku ƒe Nɔnɔmetata¶
Ne èle tɔsisi ƒe bali me, ƒuta polder, alo togbɛwo ƒe bali me, le dɔ wɔm, alo ƒu asaɖa anyi me la, tsɔ miniti 10 do ŋgɔ na nudzɔdzɔ kpata aɖe nàtsɔ akpɔe ɖa be yeƒe lãme gblẽ hã:
- Kpɔ Dukɔa ƒe Tɔdzisasrãwo ƒe Nudzraɖoƒe kple Tsiɖɔɖɔ ƒe Nɔnɔmetatawo:
- United States: Di United States Asrafowo ƒe Mɔ̃ɖaŋudɔwɔlawo ƒe Habɔbɔ Dukɔa ƒe Tɔdzisasrãwo Ŋuti Nuŋlɔɖi (NID) (
nid.sec.usace.army.mil) alo wò dukɔa ƒe tɔdzisasrã ƒe dedienɔnɔ ƒe mɔnu (abe California DWR Dam Breach Inundation Maps ene) be nàkpɔ ablɔ ɖesiaɖe dzi Sunny-Day Breach kple Flood-Induced Breach ƒe tsiɖɔɖɔ ƒe dzogoe eneawo tututu kple ƒutsotsoewo ƒe vavaɣiwo (e.g., "aɖabaƒoƒo 15 ƒe ƒutsotsoewo ƒe vava ƒe nɔnɔme" tsɔ wu "gaƒoƒo 2 ƒe vava ƒe nɔnɔme"). - United Kingdom & Europe: Kpɔ UK Nutome Dɔwɔƒe ** Tsiɖɔɖɔ ƒe Nɔnɔmetatawo le Tsidzraɖoƒewo** (
check-for-flooding.service.gov.uk) alo dukɔa ƒe dukɔmeviwo takpɔkpɔ ƒe tsiŋutinunya ƒe mɔnuwo. - Alpine & Mountain Nutowo (Himalaya, Andes, Alps, Rockies, Alaska, Iceland, New Zealand): Kpɔ nutome anyigbaŋutinunya me numekuku Glacial Lake Inventory kple GLOF Hazard Maps hafi nàzɔ to alo aƒu asaɖa anyi ɖe tsikpetowo ƒe baliwo me; mègatu agbadɔ ɖe kpe gbadzɛ alo tɔsisi ƒe akpata si le tsikpe bali aɖe me gbeɖe o, le dzomeŋɔli zã si me ŋdɔ ʋuna le gɔ̃ hã me.
- De dzesi Afɔtoƒe Eve Siwo Le Tsitrenu: Do go le wò ŋgɔgbe ʋɔtrua nu eye nàde dzesi mɔ si dzi woato afɔ kabakaba wu (to afɔzɔlawo ƒe atrakpui, togbɛwo dzi mɔ, alo mɔ si dzi woato atso mɔ si dzi ʋuʋudedi le dzi) si lia tsi tre ɖe tɔsisia gbɔ va ɖo kɔkɔƒe si le tsiɖɔɖɔ ƒe liƒo si woɖo ɖe anyigbatata dzi la tame. Srɔ̃e kple wò ƒomea be nàzɔ edzi ale be amesiame nate ŋu akpɔe le viviti me keŋkeŋ le elektrikŋusẽ ƒe nutsotso me.
Nya siwo wobiaa amewo enuenu¶
How fast does a dam-break flood wave or Glacial Lake Outburst Flood (GLOF) travel, and can I outrun it in a car down the valley highway?
In a steep mountain canyon or narrow river valley below a dam or glacial lake, the flood wave travels at 30 to 65 kilometers per hour (20 to 40 miles per hour), and on flatter floodplains it still advances at 10 to 25 kilometers per hour (6 to 15 miles per hour). Trying to outrun the wave by driving downstream along a winding valley road that follows the river is often a fatal mistake: a single traffic jam, washed-out bridge, or rockslide traps you directly in the path of the wall of water; instead, you should always travel perpendicular (at a 90-degree angle) away from the river straight up the nearest valley hillside, on foot if necessary.
Why does a Glacial Lake Outburst Flood (GLOF) happen even on a clear, sunny summer day with zero rain?
As mountain glaciers shrink and retreat due to warming temperatures, meltwater collects in massive deep lakes trapped behind unstable piles of loose gravel, boulders, and buried ice cores called terminal moraines. On a warm, sunny afternoon, a huge slab of overhanging glacier ice or sun-warmed cliff rock high above the lake can suddenly calve off and plummet into the water; this impact generates a giant displacement wave inside the lake that splashes over the loose moraine dam, slices it open within minutes, and unleashes millions of tons of water and boulders down the valley under blue skies.
What is a "sand boil" behind a levee, and why is it so dangerous?
A sand boil occurs when high-pressure river water finds a weak seam or sandy layer underneath an earthen levee and tunnels through to burst upward on the dry landward side, creating a bubbling fountain surrounded by a ring of deposited sand that looks like a miniature volcano. If the water trickling out is clear, the levee core is still intact; however, if the sand boil is gushing muddy, brown, silt-filled water, the underground flow is actively washing out the structural dirt foundation of the levee (internal piping erosion), meaning the entire levee wall above it can collapse into a catastrophic breach within minutes.
Why is a mine tailings dam collapse even more deadly than a regular water reservoir dam failure?
A mine tailings dam does not hold plain water; it holds millions of tons of wet, pulverized rock flour, heavy metals, and chemical processing sludge left over from mining iron, copper, gold, coal, or phosphate. When a tailings dam suffers liquefaction failure, the resulting flood wave has the density of wet cement (roughly twice as heavy as water), demolishes reinforced concrete bridges and buildings effortlessly, and then solidifies or remains as deep, inescapable quicksand across the entire valley floor, making swimming impossible and burying survivors alive.
What does it mean if a mountain river suddenly dries up or drops to a trickle during or right after a heavy rainstorm or earthquake?
If a normally rushing mountain river suddenly drops to a trickle during a storm or after an earthquake, it is a classic warning sign that a massive landslide, rockfall, or avalanche has crashed into the canyon upstream and temporarily plugged the river channel (creating a natural landslide dam). Behind that unstable pile of dirt and rock, the river is rapidly filling a deep temporary lake; once the water overtops the blockage (often within hours), the entire dirt dam gives way at once, sending a devastating wall of water and boulders down the dry riverbed. Evacuate to high ground immediately and alert emergency authorities.
Why shouldn't I walk out onto the dried mud flats after a dam-break or tailings flood wave passes to look for my belongings?
Freshly deposited flood silt, glacial rock flour, and mine tailings behave as thixotropic non-Newtonian fluids (quicksand): a thin crust dries on top in the sun and looks solid enough to walk on, but underneath lies 1 to 5 meters (3 to 16 feet) of water-saturated liquefiable mud. The moment a person steps onto the crust, the vibration liquefies the mud underneath and sinks them waist- or chest-deep in seconds, where suction force makes it impossible to pull your legs out without specialized rescue boards and fire department winches.
Wolé ŋku ɖe dzɔtsoƒewo ŋu¶
- Dukɔa ƒe Dɔwɔƒe si Kpɔa Nudzɔdzɔ Kpatawo Gbɔ (FEMA, United States) kple United States Asrafowo ƒe Mɔ̃ɖaŋudɔwɔlawo ƒe Habɔbɔ (USACE): Dukɔa ƒe Mɔfiamewo na Tɔdzisasrãwo ƒe Dedienɔnɔ: Ðoɖowɔwɔ Kpata na Tɔdzisasrãwo tɔ (FEMA P-64), Dukɔa ƒe Tɔdzisasrãwo Ŋuti Nuŋlɔɖi (NID), kple Levee Seepage and Sand Boil Field Manual.
- United States Anyigbaŋutinunyalawo ƒe Dɔwɔƒe (USGS) kple Dukɔa ƒe Atsiaƒu kple Yame ƒe Dɔwɔƒe (NOAA / NWS, United States): Anyigbaʋuʋu-Sisi, Anyigbaʋuʋu-Dam ƒe Dzodzo, kple Dam-Break Flood Wave Hydraulics kple Nuxlɔ̃ameɖoɖowo.
- Dukɔwo Dome Towo ƒe Ŋgɔyiyi si Wowɔ Ðekae (ICIMOD), Dukɔ Ƒoƒuawo ƒe Dɔwɔƒe si Kpɔa Afɔkuwo Dzi Ðeɖe Akpɔtɔ (UNDRR), kple Xexeame ƒe Yame ƒe Nɔnɔme Ŋuti Habɔbɔ (WMO): Nuxlɔ̃ame Kaba ƒe Ðoɖowo Kple Amewo Ƒe Ʋuʋu ƒe Mɔfiamewo na Tsiɖɔɖɔ Siwo Le Tsidzadza Ta (GLOFs) le Hindu Kush Himalaya, Andes, kple Europa Alps-towo dzi.
- International Commission on Large Dams (ICOLD) and United Nations Environment Programme (UNEP): Global Industry Standard on Tailings Management (GISTM) and emergency evacuation lessons from catastrophic tailings dam liquefaction failures.
- Nutoa me Dɔwɔƒe (United Kingdom): Tsiɖɔɖɔ ƒe Nɔnɔmetatawo kple Nutome Kpata ƒe Ðoɖowɔwɔ ƒe Mɔfiame na Tɔdzisasrãwo ƒe Tsiɖɔɖɔ ƒe Nutowo.