Spatio-temporal Pattern Of Urban Water Resources Based On The Demand Field Theory In Zhejiang Province

Nowadays,human activities impact on the earth surface system has become one of the research hotspots.With rapid urbanization,artificial disturbance not only have impacts on urban areas,but also have profound effects on the earth surface system.These critical processes directly or indirectly affect human activities through feedbacks.The coastal region of southeastern China is regarded as one of the areas,which have abundant water resources.However,under the background of rapid urbanization,the contradiction between supply and demand of water resources in coastal urban areas has become an obstacle for the urbanization.Research on spatial-temporal evolution of water resources demand in this area will help to analyze the interaction between human and water resources.And it also has certain theoretical and practical significance to the further development of urban areas.In this study,based on the theory of urban water demand field,we selected cities at county level from 2002 to 2016 in Zhejiang.The composition and distribution of urban"water charges" have been studied in this paper.The quantitative analyses of urban "water field" and its gradient were carried out.Studies on the spatio-temporal pattern of urban"water field" and the different of urban "water field" types are essential to understand the natural and human factors as driving forces to the evolution of urban "water field".The main results of this paper are given as following:(1)Spatially,urban "water field" intensity in the north area or coastal area is stronger than south area or inland area.The direction of urban "water field" flow is from the mountainous area,the underdeveloped areas or the areas with large precipitation to the plain area,the developed areas or the areas with little precipitation.Within the time window of our study,the urban "water field" intensity in study area was increasing.The core of urban"water field" in Zhejiang was located on the areas around Hangzhou Bay.(2)regional variations of The urban "water field" of Zhejiang has a significant hierarchy structure and obvious regionality.The urban hierarchical structure is higher,the water demand field intensity,the attraction of water resources and the influence on the surrounding areas is stronger.On the other hand,different regions have different evolution types.Cities in different spaces have different strength and speed of "water field" evolution.(3)Under the scale of our study,macro-scale distribution of urban "water field" is affected by the natural conditions such as topographic feature,river system and precipitation.While the mesoscale or micro-scale indicated that the social factors such as policies,economic and so on had a significantly influence on urban water field.At the current stage,the influence of human factors is greater than natural factors.Economy is certainly plays a critical role of the urban "water field" evolution.Industrial structure readjustment and government guidance also have a positive influence on the urban "water field".(4)The pattern of evolution of urban "water field" is affected by many factors.It reflects the comprehensiveness,complexity,systematization and integrity of urban "water field".At the same time,urban "water field" also has spatio-temporal heterogeneity and continuity.Under the background of urbanization,the relationship between human activities and water resources in geospatial space can be an organic system.In the system,human activities under the guidance of appropriate man-land relationship is the key factor for its sustainable development.