| Weibei dryland area in Shaanxi Province is an important grain production base in northwest China.The contradiction between human and land is prominent and it is easily influenced by external factors.It is a typical area that urgently needs to build an ecological security pattern.With the progress of urbanization and industrialization,the ecological land in this area is gradually decreasing,soil erosion is serious,the ecological service function is declining,and the scope of ecologically fragile areas continues to expand.In order to improve the level of ecosystem service and optimize the ecosystem service function,it is particularly important to quantitatively analyze the temporal and spatial evolution law of regional ecosystem service function and its response mechanism to land use change,and it has a positive effect on the construction of ecological security barrier and the optimization of land spatial pattern in Weibei dry plateau area of Shaanxi Province.In this paper,Arc GIS software is used to analyze the spatial and quantitative evolution law of land use pattern in Weibei dry plateau for a long period of time.Based on the analysis results,PLUS model is used to mine the main driving factors in the process of land use type transfer,and the spatial pattern of land use in future multi-scenarios is simulated and analyzed.Based on InVEST model,the changes of ecosystem service function in the study area from 1980 to 2020 and from 2020 to 2035under different development scenarios are estimated.The main conclusions are as follows:(1)During the study period,the spatial pattern of land use in Weibei dryland of Shaanxi Province changed obviously.By analyzing the land use types,it was found that a certain amount of cultivated land and forest land were converted into construction land from 1980 to2020,the construction land increased by 69.51%,and the water area decreased the most(129.80 km~2).In the next 15 years,under the natural development situation,the cultivated land area will decrease by 608.49 km~2,and the construction land area will increase by over 25%in the southeast and southwest areas of the study area,while the areas of other land types will generally show a stable trend with a small change.Under the situation of giving priority to economic development,the area of woodland and grassland decreased by 567.24 km~2,and the area of construction land increased obviously.In the situation of ecological priority development,the area of cultivated land with low ecological value is obviously reduced(290.73 km~2),and the lost cultivated land is basically converted into woodland and grassland.(2)From 1980 to 2020,the area of low-grade habitat in the study area expanded by 462.55km~2,and the overall situation was declining year by year.The degraded areas of habitat quality are mainly concentrated in Yan’an city in the northeast of the study area,and the improved areas are distributed in strips near water sources and relatively high altitudes.From 2020 to2035,in the situation of economic priority development,the area of low-grade habitat quality area is 20787.41 km~2,and its volume is obviously higher than other development situations.(3)During the study period,the carbon storage decreased by 7.85×10~6 Mg,and the carbon fixation capacity decreased year by year.The areas with high carbon reserves are concentrated in the areas with complex terrain and sparse population in the study area,while the areas with reduced carbon reserves are scattered in the whole study area in a point way,and there is no obvious aggregation phenomenon.In 2035,except for the natural situation,the carbon storage in other development scenarios declined to varying degrees.(4)Based on the analysis of hot spots,it is found that from 1980 to 2020,the cold spots with extremely significant landscape ecological risk value in the study area decreased obviously,and the range of hot spots with extremely significant ecosystem service value expanded continuously.The study on the changes of landscape ecological risk shows that the stability of ecosystem has decreased year by year,the high-risk areas have been expanding,the landscape fragmentation has increased,and the self-repair ability of ecosystem has gradually declined.By analyzing the changes of ecosystem service value,it is found that the service functions of the ecosystem in the study area are declining,and the ecosystem service value has decreased by 377 million yuan,of which the loss value of cultivated land type is the highest(592 million yuan).The study can provide new ideas for the analysis of the relationship complexity and background dependence among ecosystem service value,landscape ecological risk and ecosystem service function,help to support healthy and sustainable ecological environment management decision,and provide scientific basis for the protection of land and resources. |
PDF Full Text Request