Study on water and salt balance of plateau salt marsh wetland based on time-space watershed analysis

Abstract

We analysed the eco-hydrological characteristics of the Bojiang Haizi River basin, which is the location of the Erdos Larus Relictus Nature Reserve plateau salt marsh wetland. The study found that the restoration of the plateau salt marsh is more of a water quality problem than a water quantity problem. Simply maintaining the balance of water volume without considering water quality will destroy the original stable ecosystem. Therefore, water balance analysis was conducted for the overall water resources in the basin on the basis of simulated data of the Soil and Water Assessment Tool module. We examined remote sensing and water quality monitoring data via geographic information system-3D technology to meet the requirements of water quality and quantity in wetland restoration. We established the hydrological dynamic relationship model of lake storage capacity-elevation-area-salinity and found that the lake presents an alternating cyclic rule of salt accumulation and dilution during seasonal changes. This pattern is an important guarantee for the healthy and sustainable development of the salt marsh wetland. Lastly, the survival salinity of the organism was selected as the target salinity (5 g/L), and the corresponding target water amount was simulated as 20.17 × 106 m3; the target lake area was 9.48 km2. Through an analysis of three water transfer scenarios, we found that under the optimum balance condition between water quantity and salt concentration, simulating the water transfer mode in precipitation replenishment is an effective means to restore the wetland during breeding season. The findings of this study may improve our understanding of the eco-hydrological characteristics of plateau salt marsh wetlands and help managers protect and restore water balance using water–salt dynamic models.