If the contour lines are not numerically labeled and adjacent lines have the same style (with the same weight, color and type), then the direction of the gradient cannot be determined from the contour lines alone.
A fal iyaka tan win taɣelit war eššelan tolas iyaka tan win sider olahan ichikil ( olahan tazzayt , dumu d ichikil) dihen asatoɣ wan gradient war addobat ad ej ɣur iyaka tan win taɣelit ɣas