Study On Land Use Change And Ecological Risk Effect In Typical Transect Of Hebei Province

With the rapid expansion of economic development and urbanization,human disturbance to the land use structure has become increasingly tight,and the weakening of land functions and ecological environment problems have intensified.The reason is that the land use structure has changed.Land use change is of great significance as a basic study of terrestrial transects and global environmental change.The Typical Transect in Hebei is deep in the hinterland.It is an important ecological function protection area such as the water conservation and the soil conservation around Beijing and Tianjin.It is also a sensitive area for important wetland protection and coastal salinization.Therefore,based on the selection principle and basis,the Typical Transect of Hebei is set as the research area.According to the “pattern-process-effect” as the main research line,the land use change law driving factors between 1995 and 2017 is studied through the remote sensing data of multiple time-phase land use.Further clarify the spatial and temporal characteristics and the cause analysis of land use ecological risk by constructing landscape ecological risk index,and put forward feasible suggestions for the unreasonable land use pattern and ecological environment problem of the Transect,in order to provide the regional ecological environment for the sample area.Construction provides technical support and scientific basis.The specific results are as follows:(1)The land use change characteristics of the Typical Transect in the Hebei Province are significant.The whole of the Transect is in the development stage.The reduction of cultivated land and wetland is the main trend of forest land,grassland,artificial surface and other land use.The artificial surface and grassland increase the most,which are 466.19 hm2 and 102.10 hm2 respectively,and the cultivated land and wetland decrease the most.They are 428.92 hm2 and 180.72 hm2 respectively.From the perspective of land use trends and state changes,forest land is in equilibrium,grassland,cultivated land and wetland are in an unbalanced state,and other land and artificial surfaces are in an extremely unbalanced state.From the analysis of spatial transfer characteristics the main types of land transferred to each time are cultivated land and wetlands,and the land transferred to the land is mainly artificial surface and other land.It shows that the contradiction between economic development and ecological environment protection of this Transect is more prominent.(2)The land use change in the 22 a typical Transect in Hebei is obviously affected by natural factors and socio-economic factors.The topographic factor is the basic factor,which affects the spatial pattern distribution of land use,and the hierarchical level is significant.The grassland and forest land are mainly distributed in the elevation range of 500-1500 m,the slope is 6-25 °,and the terrain gradient increases first.The reduced situation;cultivated land,artificial surface and wetland are mainly distributed below the elevation of 100 m,the slope is within 0-2 °,and gradually decreases with the increase of terrain gradient;the fluctuation of other land before and after the change is large,and with the terrain gradient rise is gradually decreasing.From the perspective of socio-economic factors,economic development,population increase and industrial structure are the main factors affecting land use change,and the regional land use type transfer with rapid economic development and rapid population increase is mainly cultivated land or wetland→ artificial surface and wetland→ the transformation of cultivated land is the main factor,and the imbalance of the overall industrial structure development of this Transect zone is another major factor affecting land use change.(3)The characteristics of land use ecological risk effects between 22 a in Hebei typical Transect are significant.From the perspective of ecological risk level,the low,medium and high ecological risks showed a continuous decreasing trend,and the low and high ecological risk levels continued to increase.From the perspective of different topographic gradients,the low ecological risk is dominated by mountainous hilly areas with an elevation of 1000 m and a slope of 15 ° or above.The conversion of forest land is the main reason for the decrease of the area;the lower ecological risk is the elevation of 500-2000 m and the slope 2-25 ° is the main area,and the grassland transfer is the main reason for the increase of the area;the medium ecological risk is mainly in the range of 0-100 m and 500-1000 m,and the slope is 0-6 °,which is a transitional area.Frequent;high and high ecological risk is below 100 m in elevation and 0-2 ° in slope.The decrease of cultivated land and wetland and the increase of artificial surface are the main reasons for the change.From the perspective of ecological risk transfer characteristics,the shift from low to high ecological risk level is much larger than that from high to low level,and most of them are adjacent transfer.The highest → high ecological risk level has the highest transfer rate,mainly cultivated land or wetland→ artificial surface and wetland→ cultivated land conversion.From the correlation between the change of land use type and the change of ecological risk grade,the low ecological risk grade has higher correlation with forest land and grassland,and the high ecological risk grade has higher correlation with cultivated land and artificial surface land.(4)Put forward targeted recommendations based on the ecological risk effects caused by land use change and their causes.The low and low ecological risk zones are located in the hilly areas of the mountains and are the core protection areas of the Transect.Development and destruction should be strictly prohibited.The middle ecological risk zone is a transition zone,which is mainly distributed in the Yuxian Basin and the piedmont slope plain area of Yuxian County.It is necessary to optimize the land use structure by adjusting the agricultural industrial structure,and it is strictly forbidden to open ecological forests such as forests and grasses,and selectively implement policies about returning farmland to forests and grasslands.The high and high ecological risk areas are mainly distributed in the plain area,which is mainly concentrated in cultivated land,urban built-up areas and wetlands.The existing cultivated land patches are optimized and combined to strengthen the agricultural modernization construction;urban population,economy and other needs should be developed according to local conditions and jointly built to create a green and smart city.In addition,it is imperative to restore and control Baiyangdian and its tributaries.In summary,this paper reveals the land use change law and its driving factors of Typical Transect the Hebei Province,and further expounds the ecological risk level and cause analysis of land use,which is important significance for scientifically optimizing the land use structure of Typical Transects in Hebei and establishing an ecological security pattern.