Abstract:
Objective The construction and operation of high-speed railway, an important transportation infrastructure in China, will inevitably influence the surrounding environment by causing land use change, habitat quality change, biodiversity disturbance, etc. However, the degree and scope of such influence and other relevant scientific issues need to be further studied.
Methods With good ecological background, Wulongquan Town in Jiangxia District, Wuhan City, is taken as the research area of this research. This research adopts the InVEST model to analyze the temporal and spatial evolution of habitat quality in the research area during the periods from 2000 to 2010, from 2010 to 2020, and from 2000 to 2020, and to explore the influence of the Beijing − Guangzhou High-Speed Railway (the Railway) on habitat quality along the Railway.
Results Research results are as follows: 1) There exist time differences in the conversion of land use type in the research area. The change of land use type on both sides of the Railway before and after the construction of the Wuhan section of the Railway is mostly influenced by the conversion of cultivated land: during the period from 2000 to 2010, mainly forest land, wetland and water body were converted into cultivated land, and during the period from 2010 to 2020, cultivated land was converted into other land use types. 2) Before and after the construction of the town area and core area of the Wuhan section of the Railway, the overall habitat quality is first poor and then excellent: the expansion of construction land leads to a continuous increase in the area of areas with poor habitat quality, while the area of forest land and water body with good habitat quality decreases first and then increases, thus improving the overall habitat quality. The change of land use mode along the Railway greatly influences the habitat quality. The area with unchanged habitat quality is mainly the construction concentration area in the northwest of the core area. The proportion of areas with poor habitat quality is the largest, mainly in the middle of the core area and distributed in patches. The areas with improved habitat quality are distributed in the middle of the core area and the water body area near the Liangzi Lake. 3) The variation characteristics of habitat quality in the core area are consistent with those in the town area. During the period from 2000 to 2020, the construction of the Railway had a significant influence on the habitat quality in the core area along the Railway, accompanied by the deterioration of the overall habitat quality and the improvement of wetland habitat quality in some waters.
Conclusion 1) The change of land use pattern along the Railway greatly influences the habitat quality along the Railway. During the township construction period of the Wuhan section of the Railway, a large number of forest lands, wetlands and water bodies were converted into cultivated land, while after the construction of the Wuhan section, the area of forest lands and water bodies increased significantly, and most of them were converted from cultivated land, reflecting the change tendency of land use type along the sample section of the Railway along with the construction of the sample section, and the results of the continuous improvement of greening and of the adoption of positive measures for improving the ecological environment such as “returning farmland to forest” along the sample section upon completion of the construction thereof. Although the habitat quality along the Railway has improved after the Railway enters the operation period, the damage to habitat quality caused by the construction of the Railway may be irreversible. The change of the proportion of habitat quality grade is also different, but it is basically consistent with the change degree of land use type, proving that the change of land use type may reflect the change of habitat quality. 2) Different land use types and structures on both sides of the Railway have different impacts on the habitat quality on both sides: With the increase of distance away from the Railway, the habitat quality on the west side of the Railway becomes increasingly improved, while the opposite is true on the east side. The change trend of habitat quality on the west side of the core area is simple, and the habitat quality of the core area “decreases first and then increases” with the increase of the distance away from the Railway. On the east side, the change of habitat quality index is quite complex, and the overall change shows the trend of “increasing first and then decreasing”, opposite to that on the west side. The habitat thresholds on the west side are about 400 m, 1,400 m and 2,600 m, and those on the east side are about 1,600 m and 2,200 m, respectively. There are differences in the habitat thresholds on both sides, for which the main reason is that the west side of the Railway is featured by simple land use type and relatively uniform spatial distribution, while the east side is close to water with complex boundary influencing factors. Through the analysis of land use type change in the sample section of the Railway in Wulongquan Town, Wuhan, this research explores the internal causes of changes in the ecological quality along the Railway. The accuracy of the results of this research needs to be continuously corrected on the basis of long-term field investigation, recording and monitoring. The research may provide a reference for the research on influence rules and restoration suggestions with respect to a high-speed railway for a certain time of period after the high-speed railway is built, including ecological protection, ecological restoration, biodiversity protection, township construction and land use type conversion along the high-speed railway.