What is a food?A food is a natural event that can have far reaching efects on people and theenvironment. A food is too much water in the wrong place!What causes / factors of foods?Causes of food.(Contd.)The river has overtopped its banks and spilled onto the food plain.Eceptionall! heavy rainMonsoon wet seasonEssential for rice growing"ut bad if there is too much rain.Dam Collapses #os Angeles $.%.A.Humans to lameAs cities !et "i!!er there is more impermea"le concrete and tarmac. The rain can#t soa$ into the !round.&epal 'deforestation(ore people(ore farmland needed%rees cut do&n%erraces made on hillsides'andslides and more run(o)(ore risk of foodin!)igh Tides can cause the sea to food the land in a storm surge.Hurricanes cause storm surges too!e.g. *lorida $.%.A.%sunami *loodin!%ubmarine earth+uakes cause giant tidal wavese.g. %.E. Asia ,--.Desi!n Criteria for food protective "uildin!s /rotecting our houses and propert! from serious foods is a big challenge facing lots of researchers and companies all over the world. There are presentl! two main innovations to deal with it0 foating houses and food'shield houses.a. Cone(shape "asement". +aft "asement*loatin! housefoating house is a building that can foat on the water due to the inherent buo!antforces in a food. *rom an environmental view1 it seems reasonable because it uses a natural energ! force to solve the eact same naturall!'occurringproblem. These foating houses can generall! be divided into two t!pes according to their diferent modes of movement.Elevation on *illElevation on fow'thru wallsElevation b! poles1 piers1 or columns(ethods to Elevate "uildingsElevation on *illElevation on *illFillThis house looks like a normal house1 but inside the inhabitable areas begin on the 2rst foor. The ground foor is reserved for storing supplies that have the least conse+uences if the! sufer food damage.Elevation on *ill Elevation on *ill 3aising the level of the ground with 2llThis alternative uses a man'made hill. The soil concerns are the same as mentioned before1 but the slopes can be ad4usted according to a geotechnical engineers recommendation."uilding on a decrease hillThis alternative is a combination of building in habitable areas above the "*E and building on a hill. The direction of the food should enter at the side of the garage1 where the conse+uences of food damage are minor.Elevation on *ill Elevation on *ill $suall! limited to three or four feet in height*ill placed in 5 la!ers and compacted 6789 proctor:Etend 2ll ;- around structure%ide slopes ; vertical to ;.8 hori?& %)?@>&A =?&%T3$=T>?& BETA>#% ?* *#??B /3?&E "$>#B>&A%)ouse built on elevated foundation walls*low through crawl spaceElevation on /osts or /ilesElevation on /osts or /iles/osts or columns are wood1 steel1 concrete1 or masonr! supports./iers are vertical structural members supported b! concrete footings./iers/osts%torage TanksAbove ground tanks ma! be anchored or elevated up to 8'feet from grade."elow ground tanks must be anchored1 re+uire engineered installation.*loodproo2ng C (inor Accessor! %tructuresFPEOpenings to allow floodwaters to flow in & outExisting Pre-FIRM Residential StructureFPEFPEAfter Substantial ImprovementACACUtilityBoxElevate on fill or crawl requiredBEFOREAFTER=A%E %T$BD' "A&A#ABE%)=A%E %T$BD' "A&A#ABE%)Bangladesh Flooding July/August 2004CausesoftheAnnualMonsoonSeasonalFlooding:September2004: Monsoon rains have hit Bangladesh . ClimaticTerrestrial ProcessesHman !cti"ity n su!!er the land is "ar!er than the sea!a#ing $%& '()SS*() so the smmer #onsoon $inds +ring !oist air off the sea , really "etn "inter the land is -old !a#ing ./. '()SS*(). 0he dry "inds +lo" out fro! the land to the sea.Climatic Causes: (ando! variations in the intensity of monsoon rains -ause the flooding. Bangladesh has a tropical monsoon-type climate, with a hot and rainy summer and a dry winter. The climate is one of the wettest in the world. Most places receive more than 1,525 mm of rain a year, and areas near the hills receive 5,080 mm . Most rains occur during the monsoon !"une#$eptem%er..istori-al re-ords to 12314 sho" that a ma%or &lood cold be expected e"ery se"en years and a catastrophic one e"ery ''()0 years. More detailed re-ords sin-e 1564 sho" the "orst flooding sin-e then o--urred in 15244 15324 1533 and 15534 "hen 20 7er-ent of the -ountry "as su+!erged in the !ost serious flood Bangladesh had ever seen. Then 2004: 0he !ighty Brah!a7utra river4 s"ollen +y rain and a .i!alayan +urst da!4 has flooded huge s"athes of north ndia and Bangladesh4 #illing do8ens and for-ing !illions to see# refuge on higher ground. &our days of constant rain have caused floods in parts of Bangladesh, as in this village 100'm north of (ha'a.Himalayan Sno$ #elt *)very su!!er/angotri gla-ier4 in the ndian .i!alayas4 feeds the /anges river. 0he gla-ier is retreating an average 26 !etres yearly.Terrestrial Processes+,elie& ,ain&all in the Himalayan #ontains &eeds the ri"ersMost of Bangladesh sits astride the deltas o& a series o& large ri"ers flo"ing fro! i!the .alayas4 and a+out a third of the -ountry floods every year during the !onsoon.)oughly 80 percent of the landmass is made up of fertile alluvial lowland called the Bangladesh *lain. 0his !eans that it is 7rone to severe and heavy flooding. Flooding irrigates -ro7s and adds fresh silt to 7adi fields !aintaining the fertility.Most of Bangladesh is +elo" 10 !etres a+ove sea levelHman !cti"ity + -lobal .arming leading to sea le"el rise/ The flow of water coming from the +imalayas # which is huge # depends on the differential of height.,-hen the sea level is higher, the flow of that water will %e restricted. $o when you hear now of Bangladesh %eing a flood#prone country # it will %e a much more flood#prone country in future., 0he e9tra-tion of ground"ater for irrigation had lo"ered the "ater ta+le and cased the land to sbside +y a+out 2.6!.0he ground"ater -ontains naturally high levels of arseni-:0he use of "ater u7strea! for irrigation and storing "ater in reservoirs has redced the amont o& silt deposited so the level of the land has not +een +uilt u7.'eo7le live on river sand+an#s -alled Chars.n-reased a!ounts of rbanisation has led to higher 7ea# flo" on the rivers "ith !u-h shorter lag ti!es and a greater fre;uen-y of floods. */ So 0e&orestation in the .i!alayas has in-reased leading to in-reased run off