The influence of vegetation types on water yields in the Da Hinggan Mountains of China

Climate change and excessive water use are endangering water resources in many areas of the world. As a result there is an urgency to increase available water resources and to improve water supply using vegetation management in catchment areas. The objectives of this study were to determine the effects of four vegetation types (Quercus mongolica F.; QM), Larix spp. plantation; LP), Prunus sibirica L.; PS) and grassland; GL) on water yields by monitoring surface runoff, infiltration, canopy interception and evapotranspiration in the Da Hinggan Mountains, a semi-arid area of China. Surface runoff for each vegetation type was triggered by rainfall of at least 6.6 mm, with surface runoff significantly increasing with rainfall events over 15.8 mm. The QM forest had the highest amount of runoff (1.34 mm), followed by LP (1.06 mm), PS (1.01 mm) and GL (0.69 mm), this accounting for only 0.23% – 0.44% of the total water balance. Infiltration to a soil depth of 10 cm occurred with rainfall events with at least 13 mm, but the depth of infiltration rarely exceeded 30 cm during most rainfall events. More than half of the rainfall was taken up by vegetation during the growing season, with an order of LP > QM > PS > GL. Comprehensive analysis indicated that QM was the most appropriate vegetation for water conservation in this water-limited area, and this vegetation cover could effectively provide more water resources in the local area.