Zida zapamwamba zobowola nyundo

HFD pamwamba nyundo kubowola pang'onoamagwiritsidwa ntchito makamaka pofufuza za geological, mgodi wa malasha, kusunga madzi ndi mphamvu yamadzi, nsewu waukulu, njanji, mlatho, zomangamanga ndi zomangamanga, etc.