1 00:00:00,010 --> 00:00:04,650 Between 2000 and 2010, groundwater depletion 2 00:00:04,650 --> 00:00:08,770 caused by irrigation increased 22 percent. 3 00:00:08,770 --> 00:00:13,090 NASA scientists and colleagues used Earth observations and models 4 00:00:13,090 --> 00:00:17,090 to understand where this groundwater depletion is most severe. 5 00:00:17,090 --> 00:00:21,260 The most overexploited aquifers: the North and South Arabian, 6 00:00:21,260 --> 00:00:25,440 Persian, Western Mexico and Upper Ganges, 7 00:00:25,440 --> 00:00:29,950 all show evidence of groundwater depletion from irrigation. 8 00:00:29,950 --> 00:00:34,220 In drier countries like Kuwait, Iran and Saudi Arabia, 9 00:00:34,220 --> 00:00:38,330 crops require extremely large amounts of groundwater-depleting irrigation to grow. 10 00:00:38,330 --> 00:00:42,410 For example, rice grown in Pakistan causes eight times more groundwater depletion per unit 11 00:00:42,410 --> 00:00:46,510 than in India, where surface water resources are more plentiful. 12 00:00:46,510 --> 00:00:50,770 International trade moves these crops between countries, 13 00:00:50,770 --> 00:00:54,840 so in some cases, the countries consuming the most groundwater depletion-linked crops 14 00:00:54,840 --> 00:00:58,910 may have more water supplies, relatively speaking. 15 00:00:58,910 --> 00:01:03,050 However, importers of groundwater depleting-crops 16 00:01:03,050 --> 00:01:07,710 face a potential future food supply risk, as overexploited aquifers 17 00:01:07,710 --> 00:01:11,900 may not be able to continue providing water 18 00:01:11,900 --> 00:01:16,076 at current levels in the long-term.