If the asset account Land increased, what's the likely effect on Cash?

if cash is used to purchase land then reduce cash(asset) and increase land (asset), if the land is increased due to revaluation then increase equity by the revaluation reserve amount (i.e. new value of land - carrying value of land) as per IFRS.

if land is purchased through cash then cash will decrease in other words it will be credited

If the reason for this increase is due to the purchase of new land and pay for it, so cash account will be decreased.

It will not effect the cassh account. Because revaluation of land doesnt effect cashh at all. THe entry for revaluation is:

Land A/C                                 Dr

Revaluation surplus a/c       Cr