Regulation Of Land Use Transition In The Yellow River Basin With Water-Energy-Food And Ecosystem Services Oriented

The Yellow River Basin(YRB)spans across three major regions in China:the east,the middle,and the west,exhibiting significant differences in resource endowments and spatial mismatches in water,energy,and food resources.These disparities,coupled with extensive land use practices,have led to prominent ecological issues.Approximately46%of the YRB is situated in arid and semi-arid areas,where per capita water resources are less than a quarter of the national average,yet the development and utilization rate is double the ecological warning line.In terms of energy,seven out of the country’s fourteen large coal bases are distributed in the upper and middle reaches,while two are located in the lower reaches.Coal production accounts for over 70%of the national total,but the energy consumption per 10,000 yuan of GDP is twice the national average.Regarding food,the lower reaches support nearly 60%of the basin’s food production while only accounting for 26%of water resources.Uncoordinated or sloppy resource exploitation has severely impacted the YRB’s ecological environment:the upper and middle reaches suffer from ecological fragility,high water consumption,and pollution from energy development,leading to desertification that exceeds a quarter of the entire basin.Additionally,the lower reaches experience agricultural nonpoint source pollution due to excessive fertilization,and soil-water matching urgently requires optimization.Consequently,the coupling of water,energy,food,and ecological factors is challenging,significantly affecting land use transition(LUT)in the YRB and intensifying"triple contradictions":regional differences in resource endowment and imbalances in supply and demand create"mismatch"contradictions;"conflict"contradictions arise between land use,resource development,and ecological protection;and watershed governance as a whole and factor allocation present"fragmented"contradictions.Therefore,how to carry out regulating LUT in the YRB oriented to water-energy-food(WEF)and ecosystem services(ESs),and resolve the above-mentioned triple contradictions has become an important theoretical proposition and practical problem that must be solved for ecological protection and high-quality development in the YRB.However,LUT has long been portrayed from a spatial morphological perspective,with insufficient emphasis on functional aspects.The level of resource utilization and supply and demand of ESs related to WEF have not been fully considered,and the scale analysis seems to be relatively homogeneous,resulting in questionable scientificity of the related regulation strategies.To this end,this study selected the YRB as a research area from the perspective of the WEF nexus.Initially,based on spatial morphology,mapping analysis was employed to explore the spatio-temporal evolution characteristics of LUT and ecosystem service value(ESV).Next,the WEF association relationship was measured using a simultaneous equation model at the provincial scale.Then,from the municipal scale,the coupling coordination degree model and socio-ecological network analysis were employed to reveal the characteristics and mechanisms of coupling coordination between WEF and LUT.Furthermore,with the help of the In VEST model,supply and demand index,and four-quadrant model,the matching characteristics and patterns of three types of ESs related to WEF were explored across various scales of natural and administrative boundaries.Finally,a conceptual model and strategy for LUT regulation were proposed,focusing on the WEF nexus and ecological enhancement.The main conclusions of the study are presented as follows.(1)In terms of spatial patterns,the overall LUT of the YRB exhibited significant differences,and the spatial structure of"production-living-ecological"spaces within each secondary basin was relatively stable,with a pronounced zonality pattern.In terms of conversion types,the transition from agricultural production space to grassland ecological space dominated.Meanwhile,the scale,mode,and location of different types of transitions significantly impacted the watershed’s ESV.During the study period,the overall ESV increased from 10,976.59×10~8 Yuan in 2000 to 11,210.96×10~8 Yuan in2020,with a spatial pattern of"highest in the central and southwest,higher in the northeast and southeast,and lowest in the northwest."The transition from other ecological spaces and agricultural production spaces to grassland ecological spaces primarily drove the positive contributions,while their reverse transitions were the main sources of negative effects.Spatially,the range of ecological impairment zones had expanded,indicating that the overall ESV improvement in the YRB resulted from ecological enhancements in specific areas.Therefore,it is essential to prevent the inhibitory effects of the ecological impairment zones on the ecological preservation and appreciation zones.(2)Water consumption,energy consumption,and food production exhibited positive or negative effects,influenced by both internal characteristics and external interactions.Overall regression analysis revealed that crop sown area,food production,daily urban sewage treatment capacity,and the secondary industry proportion were the WEF system’s key positive factors,with positive influence coefficients of 1.317,0.268,0.255,and 0.237,respectively.In contrast,effective irrigation area and precipitation generated negative effects,with influence coefficients of-0.220 and-0.189,respectively.Temporally,the direction and degree of factors influencing the WEF nexus varied significantly,and the nexus among the three strengthened after 2010.Spatially,the WEF nexus displayed notable regional differences.The key factors in the upper reaches significantly impacted the energy and food subsystems,while factors in the middle and lower reaches had a more pronounced effect on the water resources subsystem.Robustness tests,conducted by replacing food production indicators,confirmed the reliability of the results,as the regression coefficients in the three equations matched the baseline regression outcomes.(3)The LUT and WEF measurement models were constructed from the perspectives of functional morphology and resource utilization,respectively,and their coupling and coordination mechanisms were analyzed.The two systems exhibited temporal and spatial differences.Both WEF and LUT composite indices showed an increasing trend;spatially,the WEF system displayed a distribution characteristic of"downstream>upstream>midstream,"while the LUT system followed a geographical gradient pattern of"downstream>midstream>upstream."Further calculations of the coupling coordination degree(CCD)revealed that the mean value of the CCD between WEF and LUT decreased overall but consistently maintained moderate coordination.Spatially,the CCD varied considerably between east and west,demonstrating a clear spatial clustering feature.Simultaneously,the complex network of multiple cores centered on provincial capitals emerged,with a spatial distribution pattern of"dense in the southeast and sparse in the northwest"becoming increasingly distinct.The association tightness among various cities decreased,and the"core-periphery"structural characteristics essentially formed.Additionally,the CCD of WEF and LUT was driven by a combination of natural and socioeconomic factors,with large disparities in the scales of action for different variables.Per capita GDP was the most critical factor driving the formation of the CCD association network.(4)There were significant differences in the supply and demand of various ESs within the YRB.Regarding supply,the spatial pattern of water yield presented a"high in the southwest and low in the northeast"distribution,while the spatial pattern of food production was the opposite.Carbon sequestration distribution aligned with forestland distribution.Demand for ESs was closely related to population density and economic development levels,with all exhibiting varying degrees of increase over time,and a spatial pattern of"high in the southeast and low in the northwest."The three ESs supply and demand indices within the entire basin were in a surplus state.However,supply and demand matching differ significantly at various scales,and trade-offs changed accordingly.They only exhibited significant correlations at the city scale.In terms of supply and demand matching patterns,both water yield and food production services were primarily characterized by low-low matching,while carbon sequestration services were dominated by high-low mismatch and low-high mismatch.The spatial patterns of hotspot and coldspot areas for different levels of ESs were relatively stable,featuring concentrated and contiguous distributions.Hotspot areas were mainly located in the western Qinghai-Tibet Plateau,while coldspot areas were concentrated around three major urban agglomerations centered on Zhengzhou,Jinan,and Ningxia.Consequently,18 ecosystem service supply regions and 27 demand regions had been delineated.(5)Based on the aforementioned research findings,LUT regulation strategies under the WEF nexus and ecological interconnections have been proposed.First,the theoretical feasibility of regulation was explained based on its connotation and core essence,leading to the construction of a conceptual LUT regulation model based on a double helix structure.Next,priority regulation areas were identified,considering the WEF and LUT coupling and coordination mechanisms.These areas included five types:priority promotion,key promotion,potential promotion,collaborative optimization,and moderate optimization.They accounted for 13.51%,20.27%,31.08%,17.57%,and17.57%of the region,respectively.Key promotion and potential promotion areas were concentrated and distributed in the middle and upper reaches of the basin.By integrating the supply and demand levels of the three ESs associated with the WEF nexus,14"zoning control-classification strategy-hierarchical governance"portfolio governance models were delineated.The predominant models were food production-ecological restoration-significant governance(18.92%),food production-ecological restoration-general governance(13.51%),and energy utilization-ecological conservation-minor governance(13.51%).Lastly,WEF and ESs were interconnected to establish differentiated LUT regulation objectives and pathways.From the perspectives of boundary articulation,resource endowment,and planning systems,LUT regulation strategies for the YRB,in terms of logical integration,complementary advantages,and governance models,were proposed.The innovation of this study lies in its systemic approach,which entails conducting research on the LUT regulation of the YRB,focusing on WEF and ESs.Specifically,the coupling and coordination mechanisms between WEF and LUT are revealed,serving as one basis for LUT regulation.By integrating natural boundaries and administrative borders,the supply and demand matching characteristics of three ESs related to WEF at multiple scales are clarified.The city level is identified as the most suitable governance scale,providing a second basis for LUT regulation.Based on these two foundations,an expandable LUT regulation model with a double helix structure is constructed to guide LUT regulation in the YRB and offer insights for optimizing land resource allocation in other regions.The paper has 82 figures,60 tables,and 332 references.