The researchers used satellite data to estimate how much water crops use each day. They combined Landsat and MODIS data to calculate water consumption on clear days and used a model to fill in the gaps on cloudy days. The method was tested in Guantao County and showed good results, with an error margin of 0.86 mm per day. They found that winter wheat uses the most water when it's maturing, while summer maize needs the most water in the middle of its growing season. Temperature and soil moisture levels were the main factors affecting water consumption for both crops. This study shows that the model can effectively monitor crop water use in North China by combining satellite data and considering environmental factors.