different yields. It can be seen, for instance, that a 1Mt gurface burst vill give 0.03 MPa at about 4900 m distance from ground zero, r,rhile the same explosion 2500 n above ground will give tha! overPres- sure at just over 6000 m ground zero distance.4000 2000 5000 6000 7000 Distance from ground zero (m)lMt 0,03 l4Pa ( 4,4PSI ) 0. I [4Pa ( 14. 5 PSi ) / I lz+ n nl MPa /4 4 DCI\ I kt 0.'l llPa I(l4.5 PSr) |,.1,,A/ 35 /392lngli sh Annex : 3ec -Lt-! trees of various sizes and kinds in a forest and locaf vari ations in the.overpressures due to terrain effects, it is crear that the damage picture from blastt^rill in most cases J'ook very complex, Apart from a totally demolished region arolrrdgfound ZeTO fO]' a IOv al+i1- ,,1- cir }."--r ^-h- ^\'i---c ^l^-6r r^ rPa'r; Zero SUCh aSbridses or 'einrorced ".;;;;;; ;;;rilil;';;;; ;'i;ft '.0..^,,""iu"a"#u!"a "r,".."" other objects further ar+ay, such as buildings of liglrter ccnstruci,ion, r,rill havecollapsed compleLely. Under these circulsLances and having in mind the random natu-Teof indirect blast injuries, it is clearly irnpossibre to give a precise 'distance ofsurvival'" fTom b-Last for human beings from a nue-Lear bur sL of somc particular yield and height. I'or rough estimates some studies asslnne that the nurnbel of rmprotected.people in a popu-l-ated area who survive in an area covered by at least 0.035 Mpa(o-35 atrn or 5 PST) equafs the mrmber of peopre kilIed in areas receiving less thanI r-pr nr-nv-raoo',-o p--re b-Last fatalities are cons.i,lerr.r,l r ^ ha orrarvl-oriw ineirta 0.035 xfPa circle. For nilitary personnel and equiFment or people in shelters otherovelpressufe dannage criteria - depending on the protection assured - of couxse haveto be assrnaed. B. Thermal radiation and its effects fherrnal radiation
**Analysis**
The text appears to be discussing the effects of a nuclear explosion on the environment and human populations. It specifically mentions blast waves, overpressures, and thermal radiation, which suggests a focus on the immediate consequences of a nuclear event. The text also touches on the complexity of damage caused by a nuclear blast and the difficulty in predicting survival rates.

**Category**
Health, Science and technology