UN estimates the amount of debris in the Gaza Strip at 37 million tonnes in mid-April, or 300 kilogrammes per square metre
Three ahead at the start of the final round, the 27-year-old finished on seven under par 277 after carding a 68.
Thailand's Jasmine Suwannapura was second, two shots off the pace.
Popov was in tears even before she hit the final putt, and was overcome with emotion as she left the final green at Royal Troon.
"I haven't talked about it before but I had a lot of health issues in my early time on Tour. After a couple of years it was finally diagnosed as Lyme disease," she said.
"It is something that sticks with you, but I am very careful with my nutrition and working out. But it took a lot of personal research and now I feel pretty good."
The tournament was played behind closed doors due to the coronavirus and Popov admitted it was a strange sensation.
"Walking down 18th was strange with no crowds. But it was so beautiful.I though it looked like Lord of the Rings.
"Sometimes grandstands and huge galleries mean you can't see the course properly. So it was a different kind of nice."
Popov, who had never even won a major Tour event, made a shaky start, hitting her opening tee shot into a bunker and going on to make a bogey five.
But with her German boyfriend Max as her caddie, she bounced back with birdies from inside 10 feet at the second and third and never wavered.
She made another birdie at the sixth and vital back nine birdies at the 15th and 16th helped seal the deal.
Three ahead with three to pay, she could almost enjoy the final walk.
"I can hardly get anything out of my mouth," said Popov as she clutched the trophy.
"I nearly quit playing last year - thank God I didn't.
"I was so nervous today and this is just unbelievable. I have had to face many obstacles on the way, but I knew what I was capable of achieving.
She added: "I am just so grateful to my boyfriend for keeping me calm."
Suwannapura did her best to ruin the fairytale.
The 27-year-old two-time LPGA Tour winner got to within a shot after a magnificent run of four birdies in a row from the fourth.
And after bogeys at the 11th and 13th, she again applied the pressure with back-to-back birdies at the 16th and 17th.
But it was only good enough for second place, two ahead of Australian Minjee Lee, who finished outright third after a 69.
Popov, unlike so many players, managed to fit in a reasonable amount of golf during the coronavirus hiatus.
She won three times on the Cactus Tour in Arizona in April and May - her final win coming at Troon North in Scottsdale.
She only qualified for the Women's British Open with a top 10 finish at the Marathon Classic at the start of the month - and arrived in Scotland on Tuesday after competing on the Symetra Tour in the US.
Before Sunday she had won just $108,000 (91,498 euros) on the LPGA Tour; now she has added the top prize of $675,000.
Park Inbee, the seven-time major champion, had a good early run with four birdies in a row from the fifth.
She went on to shoot a joint best of tournament 66 and finished in fourth place on one under par.
Popov joins two German men as major champions - Bernhard Langer won the 1985 and 1993 Masters, while Martin Kaymer claimed the 2010 PGA Championship and 2014 US Open.
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