Ecological water requirement accounting of the main stream of the Yellow River from the perspective of habitat conservation

The Yellow River Basin is of great significance to China's economic and social development and ecological security. The Yellow River Basin is not only an important ecological barrier but also an important economic zone. In this article, natural hydrological conditions were taken as a reference, a habitat simulation model of the key sections of the Yellow River was constructed based on the MIKE 21 model, and an ecological water requirement assessment method for river ecological integrity combined with habitat simulation and features of the hydrological reference group was established, which took account of the survival and reproduction of indicator species. The suitable flow rates for the spawning period (i.e., April to June) of Silurus lanzhouensis in Lanzhou (LZ) and Cyprinus carpio in Longmen (LM) were 350-720 and 260-400 m(3)/s, respectively. Therefore, high pulse flow with a low flow peak should be guaranteed in mid- to late April. The peak flow should be at least approximately 1,000 m(3)/s to ensure that fish receive spawning signals, with a high pulse flow process occurring 1-2 times in May to June. The annual ecological water requirement of the Lanzhou and Longmen section was 9.1 x 10(9)-11 x 10(9) and 4.7 x 10(9)-11.3 x 10(9) m(3). The model quantitatively simulated the changes in ecological water requirement of indicator fishes in key sections of the Yellow River, and an effective and realistic tool for ecological water requirement accounting of the Yellow River was provided.