What was Saddam Hussein's outcome against the Kurds?why did he destroy the kurdish lands
The reason that Saddam Hussein was trying to persecute the Kurds is because he saw them as a potential threat to his power. Saddam did not want anyone to compete with him for power during the time that he was the ruler of Iraq.
The Kurds seemed to Saddam to be a dangerous group. This is partly because they are ethnically not the same as the Arabs who make up most of Iraq's population. In addition, there are Kurds in many of the countries that surround Iraq and the Iraqi Kurds feel as much loyalty to them as to Iraq. So Saddam worried that the Kurds would threaten the stability of his rule. He especially worried about this when the Kurds supported Iran in the Iran-Iraq War of the 1980s.
As to outcomes, the Kurds have not been destroyed. Many feld Iraq to other countries, though.
There was another reason Saddam Hussein committed genocide against the Kurds in the 1980s, and was generally brutal to them throughout his reign, oil.
The northern city of Kirkuk is near one of Iraq's richest oilfields. To get the Kurds out of the way, he systematically encouraged Arab Iraqis to move there and expelled Kurds from their homes, this solidified his hold on the city and the oil.
The Kurds have always wanted independence, and so they had (have) their own armed militia to fight Saddam's army with, called the PKK. Hussein also wanted to remove this threat to his control. It is one of the reasons he used poison gas against the Kurds in repeated attacks during the 1980s, killing an estimated 180,000 of them.