Effect of the proposed construction of Poyang Lake Hydraulic Project on the habitat suitability for Tuber-eating Birds at different water levels

Poyang Lake is the largest wintering habitat for migratory birds in Asia. In the last decade, the Lake has experienced early-occurring and prolonged dry season that has deteriorated the lake′s ecological status. To tackle this issue, the Chinese government has proposed the construction of the Poyang Lake Hydraulic Project. However, there is no quantitative study on the impact of the Hydraulic Project on wintering migratory bird habitats. The habitats of the Tuber-eating Birds including Grus leucogeranus, Grus vipio, and Cygnus columbianus, etc. were studied. The 3 S technology combined with ecological knowledge were used to build a suitability evaluation model for the habitat of the Tuber-eating Birds on the ArcGIS platform. Then, we used the suitability evaluation model combined with a two-dimensional hydrodynamic model to generate the habitat suitability map of the Tuber-eating Birds, with and without the presence/operation of the hydraulic project. During the hydraulic project dispatch period, the period of stable water level was selected. Based on the Xingzi water level without the hydraulic project, we explored the habitat suitability changes of Poyang Lake in different water levels, with and without the presence/operation of the hydraulic project. The impact of the hydraulic project on the suitability of the Tuber-eating Birds habitats was quantitatively studied. The results showed that the scheduling rule of the hydraulic project were scientific. The scheduling rule had little impact on the habitat of the Tuber-eating Birds in the early winter, but still sacrificed some of the areas suitable for the Tuber-eating Birds in the late winter. The region of hydraulic project to Duchang station was significantly negatively affected by the hydraulic project. In the nature reserves at all levels, the northern provincial migratory bird nature reserve was most significantly negatively affected, and the area will reduce the area of 18.01-39.80 km~2 suitable for the Tuber-eating Birds. However, the operation of the hydraulic project could increase the soil water content, making it easier for the Tuber-eating Birds to eat and increase the food richness. Our study can provide a scientific reference for the future water environment planning and ecological management of the Poyang Lake.