RESUMO
Rivers originating in the Tibetan Plateau are crucial to the population in Asia. However, research about quantifying seasonal catchment memory of these rivers is still limited. Here, we propose a model able to accurately estimate terrestrial water storage change (TWSC), and characterize catchment memory processes and durations using the memory curve and the influence/domination time, respectively. By investigating eight representative basins of the region, we find that the seasonal catchment memory in precipitation-dominated basins is mainly controlled by precipitation, and that in non-precipitation-dominated basins is strongly influenced by temperature. We further uncover that in precipitation-dominated basins, longer influence time corresponds to longer domination time, with the influence/domination time of approximately six/four months during monsoon season. In addition, the long-term catchment memory is observed in non-precipitation-dominated basins. Quantifying catchment memory can identify efficient lead times for seasonal streamflow forecasts and water resource management.
RESUMO
How to solve the pollution problem of water environment in river network is a hot issue in the world. Artificial floating island is an efficient way to deal with water pollution. Taking Jiashan, Zhejiang, China, as an example, Lattice Boltzmann method (LBM) is used to simulate the law of hydrodynamics and pollutant transport in river network. Lattice Boltzmann equations are established in both artificial floating island and non-artificial floating island sections, and the river network boundary is automatically identified. The simulation results have high accuracy and are more suitable for the establishment of complex boundaries. On this basis, combined with the genetic algorithm (GA) module, the location of the artificial floating island is optimized, and the retention ratio of the pollution in optimized layout of artificial floating island is between and 2.4 and 7.2%. The research results of this paper can provide theoretical reference for the selection and location of artificial floating island in practical engineering.
Assuntos
Rios , Poluição da Água , Simulação por Computador , China , AlgoritmosRESUMO
Heavy metals are often stored in the sediment of lakes or reservoirs and are easily released to the overlying water in the case of strong wind, which greatly affects the water environment of lakes or reservoirs. The conventional investigation of heavy metals in lakes has been relatively extensive, but there is no numerical model for heavy metals released into overlying water with suspended sediment under hydrodynamic action. In this paper, laboratory experiments were carried out, and it is found that the concentration of heavy metals (Cr, Cu, Cd) often begins to stabilize after the concentration of total suspended solids (TSS) reaches a stable level. With the increase of flow velocity (3.2 to 14 cm/s), the final equilibrium concentration of TSS, Cr, Cu, and Cd will also increase from 174 to 1102 mg/L, 0.72 to 1.14 µg/L, 2.34 to 10.45 µg/L, and 0.13 to 0.35 µg/L, respectively. Based on lattice Boltzmann method (LBM), a numerical model of heavy metal released into overlying water under hydrodynamic conditions is established. Compared the simulated data with measured data, the average [Formula: see text] of LBM model can be reached at 0.827, higher than 0.711 of traditional simulation model. The development of the numerical model is conducive to the prediction of lake or reservoir environment and also provides a theoretical basis for heavy metal treatment in reservoirs.
