| As the main water source of Xiong’an New Area,Baiyangdian Basin is an important water resource protection area and an ecological barrier,which is of great political and ecological significance,so Baiyangdian Basin is chosen to be the research subject of this study.The basic data include the remote sensing images,DEM data and Economic Yearbook statistics in the years of 2003,2008,2013 and 2018.Based on 3S technology,landscape ecology principles and mathematical models,from the perspectives of the whole basin scale and different county type scales(Xushui District for the plain county,Tangxian County for the county between mountains and plains,Laiyuan County for the mountainous county)and the East-West belt transect scale,this research analyzes the landscape structure characteristics and landscape pattern dynamics(2003-2018),makes a prediction of Landscape structure change trend in 2023 based on CA-Markov Model,summarizes the driving force factors of landscape pattern evolution via Principal Component Analysis,and evaluates and predicts the habitat quality with the In VEST model.The results are as follows:(1)In the year 2018,forest landscape has the largest area,and the smallest area goes to the area of water.The specific area ranking is forestland>farmland>construction land>grassland>unused and other land>water.The plain county is dominated by two types of landscapes,farmland and construction land.The mountainous county mainly has forestland and grassland.The county between plain and mountain has four types,farmland,forestland,grassland and construction land.The landscape structure of the East-West belt transect and the whole basin are basically the same,but the proportions are different from the three types of counties.(2)Landscape structure had been changing in different degrees from 2003 to 2018.In terms of the the whole basin,the area of farmland and forestland dropped year by year,while construction land,unused land and other land kept increasing.The grassland area fell from 2003 to 2013 and climbed slightly from 2013 to 2018,and the water area experienced an opposite trend as the grassland,climbing from 2003 to 2013 and falling slightly from 2013 to 2018.As for the plain county,the farmland area showed a decreasing trend,while the forestland,construction land,water,unused and other land areas recorded an increasing trend.The grassland had a similar trend as the whole basin.In regard to the county between mountains and plains,The farmland and forest decreased,and the construction land,unused and other land increased.The grassland and water area had a similar trend as whole basin.As to the mountainous county,Forestland area dropped,while grassland,construction land,water area,unused and other land climbed.In respect to the East-West belt transect,farmland and forest land experienced a downward trend,while the construction land increased.Grassland and water area had the same trend as the whole basin.The unused land and other land increased continuously from 2003 to 2013 and decreased slightly from 2013 to 2018.(3)Based on the three research scales,the changes of the landscape patterns show the following trends:The number of patches and the landscape fragmentation increased,while the mean patch area and the maximum patch index decreased,the control of large patches to the watershed became weaken gradually;the shapes of the patches were increasingly irregular,complicated and unstable.The degree of landscape heterogeneity was increasing.However,in the same topography area,different landscape types were of different pattern characteristics,and there was also some difference in the spatial pattern of different topography areas of the same landscape type.(4)Based on the CA-Markov model,the landscape pattern in 2023 is predicted as follows(the future social and political factors not included):the whole basin will see the decrease of the farmland and forest land and the increase of other types of landscapes;the East-West belt transect area will witness the decline of the farmland,forestland and water area and the climb of the others;the plain county will experience the fall of farmland and the rise of the others;the county between mountains and plains will record the descent of farmland,forestland and water area and the ascent of the others;the mountainous county will suffer the fall of forestland and the rise of the others..(5)Four principal components,namely,economy,society,population and nature were extracted,which are the main driving factors affecting landscape pattern changes.The changes of landscape patterns are highly positively correlated with per capita GDP,consumption level of urban residents and local financial revenue,and highly negatively correlated with the composition of the primary industry.The changes show a positive correlation with the farmland area,grain output and minimum living security of urban and rural residents and negative correlation with the natural population growth rate.(6)The results of habitat quality analysis by means of In VEST model are as follows:From the scale of the whole basin,the mean habitat quality indices of Baiyangdian basin and East-West belt transect area showed a declining trend from 2003 to 2018.From 2003 to 2018,the number of grids in the lower and higher grades of habitat quality increased,while the number of grids in the middle and the highest grades decreased.From the perspective of county scale,the mean values of habitat quality in plain county from 2003 to 2018 decreased.The number of middle grade grids in the habitat quality of plain county increased,while that of other grades decreased.The mean habitat quality indices of the county between mountainous and plains were stable at first and then gradually decreased.The mean habitat quality indices of mountainous county kept stable.In the county between mountains and plains and mountainous county,the number of the low level and relatively high grids were increased,and the number of medium and the highest grids declined.The predicted results of Baiyangdian basin showed the habitat quality of 3 scales will decrease compared with the year 2018.The mean habitat quality of plain county will decease the most sharply and the mountainous county will decrease relatively slightly. |
PDF Full Text Request