Background Baiyangdian-Daqing River basin is a momentous water source and ecological barrier in Xiong'an New Area and plays important roles in regional ecology. The distribution pattern of water producing function and the special spatial distribution pattern of water conservation capacity in this area were revealed, which provides a basis for determining priority protection area, planning water conservation forest, and improving water producing capacity of the basin.

Methods Taking Baiyangdian-Daqing River basin as the study area, we quantitatively evaluated water yield and analyzed water conservation using the water yield module of InVEST model. Then, the spatial distribution difference of water conservation under different conditions was obtained by geostatistical method. Water conservation was normalized to identify the importance level of regional water conservation function.

Results According to InVEST model calculation, the present situation of water production in Baiyangdian-Daqing River basin is 3.58×10⁹ m³, the present situation of water conservation is approximately 1.71×10⁸ m³, and the average water yield is 83.91 mm. Basin water production and water conservation show obvious spatial heterogeneity. The spatial distribution characteristics of water production and water conservation are consistent, which increases slowly from the Tai-hang Mountains in the northwest to the shallow mountain area in the middle of the basin, and then decreases gradually from the shallow mountain area to the plains in the southeast of the basin. Geostatistical results show that water conservation capacity of different land cover types is significantly different, and the order of water conservation capacity from high to low is shrub > arbor > mixed forest > farmland> grassland > construction land > bare soil > bare rock. The normalized results indicate that low and moderate grade area of water conservation covered the largest area, which accounted for 60% of the study area, while the high importance area of water conservation is located in the hilly area, the importance level of shallow mountain area lower than hilly area. The importance and potential of the conservation function of the basin are comprehensively evaluated based on the natural conditions of the basin and related researches. The results show that the central hilly area has abundant rainfall, is little affected by human activities, and is covered with a large area of bare soil and shrubs, which has great water storage potential.

Conclusions Thus, the spatial distribution of water yield and water conservation function is not uniform due to the influence of precipitation difference, landform, land use, human disturbance, and other factors. Baiyangdian-Daqing River basin is a key link in the eco-city construction of Xiong'an New Area. Through comprehensive evaluation of the conservation function of the basin, the allocation of water resources in the basin is optimized to enhance the sustainable utilization of water resources, and to improve the service efficiency of the ecosystem, and accelerate the clean watershed treatment.