ntrl dsstr s th vry hrmfl mpct n scty r cmmnty brght by ntrl phnmnn r hzrd. Sm xmpls f ntrl hzrds ncld vlnchs, drghts, rthqks, flds, ht wvs, lndslds - ncldng sbmrn lndslds, trpcl cyclns, vlcnc ctvty nd wldfrs. ddtnl ntrl hzrds ncld blzzrds, dst strms, frstrms, hls, c strms, snkhls, thndrstrms, trnds nd tsnms.
ntrl dsstr cn cs lss f lf r dmg prprty. t typclly css cnmc dmg. Hw bd th dmg s dpnds n hw wll ppl r prprd fr dsstrs nd hw strng th bldngs, rds, nd thr strctrs r.
Schlrs hv rgd th trm "ntrl dsstr" s nstbl nd shld b bndnd. nstd, th smplr trm dsstr cld b sd. t th sm tm, th typ f hzrd wld b spcfd. dsstr hppns whn ntrl r hmn-md hzrd mpcts vlnrbl cmmnty. t rslts frm th cmbntn f th hzrd nd th xpsr f vlnrbl scty.
Nwdys t s hrd t dstngsh btwn "ntrl" nd "hmn-md" dsstrs. Th trm "ntrl dsstr" ws lrdy chllngd n 1976. Hmn chcs n rchtctr, fr rsk, nd rsrc mngmnt cn cs r wrsn ntrl dsstrs. Clmt chng ls ffcts hw ftn dsstrs d t xtrm wthr hzrds hppn. Ths "clmt hzrds" r flds, ht wvs, wldfrs, trpcl cyclns, nd th lk.
Sm thngs cn mk ntrl dsstrs wrs. xmpls r ndqt bldng nrms, mrgnlztn f ppl nd pr chcs n lnd s plnnng. Mny dvlpng cntrs d nt hv prpr dsstr rsk rdctn systms. Ths mks thm mr vlnrbl t ntrl dsstrs thn hgh ncm cntrs. n dvrs vnt nly bcms dsstr f t ccrs n n r wth vlnrbl ppltn.