A Discussion of Surface Water Resources in Tangshan at Present Conditions
现状条件下唐山市地表水资源量探讨

Under the impact of intense human activities,the runoff process we observed can't reflect the natural regimes of water resources,so the impact of human activities should be eliminated.The method which calculates the volume of water resources for water resources assessment is based on this idea.In the process of it,the volume of the water resources of the hydrometric stations which cann't represent the natural run-off and analyse the consistency of the natural run-off series should be dealt with.The consistency analysis method adopted by the Second National Water Resources Assessment is used to analyze the consistency of the water resources series in Tangshan.The result indicates that the surface water resources before and after 1970 or 1980 are different from each other.The main reason is due to the change of land cover,e.g.,water conservancy projects,excessive use of both surface water and groundwater for economic production and domestic life,vegetation restoration,construction of water and soil conservation project cosmically and constructing cropland.The surface water resources series before dividing point are corrected to make them consistent with present conditions using consistency correction method.The volume of surface water resources before correction is 1.462 billion m3 as the land cover change resulted in the fluctuation of surface water resources was not taken into account.However,the volume after being corrected is 1.297 billion m3.The decrease scale of the surface water in mount-ainous area is greater than that in plain area.This is mainly associated with vegetation rehabilitation and water and soil conservancy in mountainous area.The consistency of the corrected result putting forward in this paper is very well,which reflects the actual volume of surface water resources under present conditions.The result is more rational than that before correction.This study lays a solid foundation for clarifying the volume of the surface water resources and for the water resources planning in Tangshan.