▁Most ▁of ▁the ▁area ▁is ▁thus ▁covered ▁in ▁thin ▁grass es ▁pun ctu ated ▁by ▁th orn y ▁shr ubs ▁such ▁as ▁Ba ob ab , ▁Fa id her bia , ▁and ▁Kar ita . ▁Those ▁areas ▁that ▁have ▁higher ▁ra inf all — s outh ▁of ▁ 1 0 & 7 2 9 ▁N ▁and ▁the ▁Mand ara ▁Mountains — have ▁th icker ▁grass es ▁and ▁more ▁and ▁larger ▁trees . ▁Here ▁the ▁shr ubs ▁have ▁thick ▁b arks ▁to ▁with stand ▁the ▁fires ▁that ▁sometimes ▁rav age ▁the ▁area ▁during ▁the ▁dry ▁season . ▁The ▁frequently ▁flo oded ▁Log one ▁Valley ▁and ▁the ▁per imeter ▁of ▁Lake ▁Ch ad ▁also ▁support ▁th icker ▁and ▁t aller ▁fields ▁of ▁grass es . ▁ ▁Human ▁activities ▁such ▁as ▁burning ▁of ▁fields , ▁cho pping ▁down ▁trees , ▁and ▁over gra zing ▁of ▁cattle ▁have ▁ex ac erb ated ▁the ▁problem ▁of ▁desert ification ▁in ▁the ▁Far ▁North . ▁In ▁response , ▁the ▁Cam ero onian ▁government , ▁with ▁aid ▁from ▁various ▁non - g overn ment al ▁organis ations , ▁ ▁has ▁begun ▁Operation ▁Green ▁Sah el . ▁The ▁project ▁a ims ▁to ▁reverse ▁the ▁effects ▁of ▁desert ification ▁by ▁re int rodu cing ▁trees ▁to ▁the ▁region . ▁ ▁Dem ograph ics ▁ ▁S ett lement ▁patterns ▁In ▁larger ▁towns ▁and ▁cities , ▁such ▁as ▁Mar ou a , ▁houses ▁tend ▁to ▁follow ▁the ▁modern ▁model ▁of ▁concrete ▁walls ▁and ▁metal ▁roof . ▁Though ▁house ▁construction ▁diff ers ▁from ▁people ▁to ▁people