Why did the kingdom fall to pieces under scar?

[Deagonx]

Alright, in the first movie after Simba is exiled and Mufasa is dead, Simba hakuna matata style, and for WHATEVER REASON the lakes dry up, the trees die, and all the grass goes away. I mean, Scar wasn't exactly a forceful leader, but did the hyaenas like, drink the lake? I mean cmon now.

[KingKovu44]

It's a symbolic image to show how poor of a ruler Scar was.

[DGFone]

In Arthurian legend, there is the Fisher King, whose kingdom reflected upon the king's mood. You can say that Scar was part Fisher King, and part bad ruler. Because in the end, Scar did over-hunt the herds.

You can look at it this way: a regular African summer doesn't get much rain. The herds are over-hunted, so they leave. The plants and grasses no longer get eaten, overgrow to unsustainable levels and use up all remaining water. So the plants die as well.

And this is how a regular summer can turn into a severe drought if you exclude all symbolism (which even I think there is some).

[SophieCub]

Because he wasn't a good ruler...

[FlipMode]

You answered your own question, its all the Jenga effect, mess up one thing everything crashes down around it. Scar was a tyrant and literally just wanted the power and title "king". His failure as a ruler was the cause of it all.
By the way, lakes are not magically filled with water, the supply has to come from somewhere so it is possible that the king would be tasked with that, hence the drying up.

Also, in short - it is cinematic effect.

[TheLionPrince]

It was explained in The Lion King musical that the hyenas made the lionesses of the hunting party overhunt, because the hyenas under Mufasa's reign were starving, and turned to Scar as he promises they will "never go hungry again".

So, when Scar usurps the throne, the lioness have to hunt for themselves and a legion of hyenas, which would quickly dwindle all the Pride Land's resources. Not to mention the hyenas would also be thirsty as well, which will dwindle any water source in the Pride Lands. So, with more predators and less prey, then, the Circle of Life is unbalanced, so it would make sense for the Pride Lands to have droughted.

I could also say it is common for the African plains to experience a drought every once in a while. And in the story, "The Tale of Two Brothers" in The Lion King: Six New Adventures, a drought occurs even Ahadi, if he is the sovereign monarch, is a good king.

[pitbullangel]

yup. a land that gets no rest will die. and when evil takes over things get dark. And his refusal to move even when it was clear there was nothing left for them, just further shows how he knew nothing of running a kingdom, and all the kingly power in the world couldn't fill his belly let alone the whole pride and the hyenas (who were just takers and couldn't contribute anything to pride life). he was basically a lion with just a title of King and not a true leader.

[Auon]

Even though they do not feed and drink as much as lions, there were much more hyenas then lions while Scar ruled. That just completely ruined the balance of the pride lands, in turn ruining the kingdom.

[Regulus]

Lion + hyena overhunting -> less zebra, antelope, etc.

less herbivores -> plant life overpopulates

more plant life -> less available water

lions and hyenas fight one another for water -> strongest survive

dry ground -> fire starts and purifies land

heavy rain season + nutrient rich soil -> plant life returns

fewer predators + return of food supply -> herbivores return

...and thus the circle of life is restored.

[SweetNala]

The food supply (zebra herds and stuff) quickly was used up because both hyenas and lions had to eat. Without the herds the ecosystem died a bit. Also, the hyenas and the lions had to drink, and so there wasn't enough for everyone.
The weather is unexplainable, even Scar can't stop the weather. I suppose it reflected his mood.