Spatial And Temporal Evolution Of Habitat Quality In The Yellow River Delta And Multi-scenario Simulation

The Yellow River Delta is affected by the interaction of various natural factors such as the changes of the Yellow River water and sand,coccyx oscillation and sea level rise,seawater intrusion,etc.The habitat condition is very complex.In recent years,the increasing intensity of human activities such as urban construction,industrial and agricultural production,and resource exploitation has directly led to strong changes in regional land use patterns,while habitat fragmentation,weakened ecological functions,and fragile ecosystems have come to the fore,and regional habitat quality is seriously threatened.To quantify the state of habitat quality in the Yellow River Delta under the influence of land use changes,this study assessed the dynamic evolution of habitat quality in the Yellow River Delta from 2000 to 2020 with the help of land use classification data and the In VEST model on the basis of deciphering land use information in the Yellow River Delta,and then predicted 2030 based on the MOP-PLUS model Yellow River Delta natural development prospect,economic priority scenario,ecological priority scenario,and synergistic development scenario land use demand and spatial pattern,and predict the future scenario habitat quality status of the Yellow River Delta under different development goals based on the predicted land use spatial distribution data,with the main conclusions as follows:(1)In terms of land use quantity changes and type shifts,the Yellow River Delta is dominated by non-wetlands from 2000 to 2020,and the non-wetlands always maintain a high growth rate during this time period,natural wetlands have a decreasing trend,and the initial scale of meadow marshes is larger,but their area shrinks severely.In the type difference of land use quantity change,the land use motive of artificial wetland,especially salt field and breeding pond,is higher,and the motive of urban construction land is also higher.In terms of the direction and intensity of land use transfer,the vast majority of patches have no land use type change from 2000 to 2020,and the land use pattern of the Yellow River Delta is relatively stable.Among the natural wetlands,mudflats are more commonly occupied by farming ponds,and meadow marshes are mainly occupied by cultivated land and farming ponds.Natural wetlands are not easily transferred to nonnatural wetlands,and the transfer of land use types basically occurs within natural wetlands,mainly the mutual transfer of mudflats and meadow marshes.(2)From the spatial and temporal evolution of habitat quality,the overall habitat quality of the Yellow River Delta was relatively good from 2000 to 2020,but showed a significant downward trend,and the regional differences in habitat quality increased.To facilitate the habitat quality analysis,the habitat quality classes of the Yellow River Delta were divided into five classes: poor,relatively poor,moderate,relatively good and good.In terms of the structure of habitat quality classes,the habitat quality classes with the largest proportion of area in the Yellow River Delta and the largest change in area from 2000 to 2020 are " relatively poor" and " good".The increase and decrease of these two habitat quality classes are the structural reasons for the decrease of habitat quality in the Yellow River Delta.In terms of the dynamics of habitat quality at the county level,from 2000 to 2020,there were significant differences in habitat quality among counties,and the mean values of habitat quality were ranked from high to low: Hekou District,Kenli District,Dongying District,Lijin County,and Guangrao County.The habitat quality of each county decreased to different degrees during this time period,among which the habitat quality of Hekou District was the most impaired,followed by Kenli District and Dongying District,while the habitat quality of Lijin County and Guangrao County had a weaker foundation and decreased to a smaller extent.In terms of the direction of habitat quality class transfer,most of the habitat quality class transfer occurred in the transfer in and out of adjacent classes,for example,the class "poor" was mainly transferred out to "relatively poor".In terms of the distribution of habitat quality classes,the distribution of habitat quality classes in the Yellow River Delta has significant land and sea differences.The center of gravity of "poor" and " relatively poor" grades is farther away from the ocean and inland.The centers of gravity of "moderate"," relatively good" and "good" grades are close to the coastline,and the distance from the ocean decreases in succession.On the trajectory of the shift of the center of gravity of habitat quality,the center of gravity of "good" grade moves northward from 2000 to 2020,and the quality of habitats in the coastal areas of the northern Yellow River Delta with good quality continues to improve,while the grade of " relatively good " shifted to the southeast,indicating that the habitat quality in the western coastal habitat quality base has declined.(3)In terms of the multi-scenario differences in habitat quality,the economic priority scenario has the lowest mean habitat quality value,followed by the natural development prospect and the synergistic development scenario,and the ecological priority scenario has the highest habitat quality value.Combining the scale of urban and rural construction land expansion in the four scenarios,the synergistic development scenario has more built-up area expansion compared to the natural development scenario,but the difference in habitat quality levels between the two scenarios is small,indicating that the ecological priority scenario does not cause greater damage to habitat quality while taking into account economic benefits.The proportion of "moderate" and " relatively good" grades in the synergistic development scenario and the ecological priority scenario has increased,which increases the possibility of habitat quality improvement in the medium and long term.In terms of the spatial distribution of habitat quality change areas,the areas of habitat quality reduction in all four scenarios were scattered,mainly in the former built-up areas,salt fields and the boundary of aquaculture ponds,while the areas of habitat quality improvement were mainly concentrated in the northeastern part of the study area.In terms of the direction and magnitude of habitat quality changes,compared with 2020,the probability of areas with significantly reduced habitat quality is higher in the economic priority scenario,the probability of moderate improvement in habitat quality in the study area increases in the synergistic development scenario,but at the same time the probability of significant decrease in habitat quality will also increase,and the probability of moderate or mild improvement in habitat quality will increase significantly in the ecological priority scenario.