2020 Volume 76 Issue 5 Pages I_409-I_414
Human activities have become one of the most crucial factors of the natural water cycle. This research is to assess the impact of human activities, especially land use and vegetation changes on the natural hydrological factors in the Loess Plateau, a region suffered the most severe soil erosion over the world. Since 1999, the government starts the water conservation project, forest and grass land increased significantly to replace most of the field land to more than 35%. Three stations at Loss Plateau are used to analyze water cycle parameter changes simulated by the land surface model H08 under the same climate and different land use scenarios. Four parameters of the model were optimized and validated by the observation discharge data from 1980 to 2014 at the three stations. The results showed good accuracy and validity of H08 applied in the region and simulations were conducted under optimized parameters. Results show that the returning farmland to forest and grass project can greatly both decrease and delay the flood peak, because by replacing farmland with forest the ability to contain water and sediment of soil dramatically increased.