Integrative modeling of hydrological, ecological, and economical systems for water resources management at river basin scale

摘要

An integrated hydrological, ecological, and economical model (HEE) was developed at basin scale to evaluate the interactions among resources, agriculture, and rural development. Hydrological module in the integrated model was adapted from SWAT, the Soil and Water Assessment Tool, to simulate the water balance in terms of soil moisture, evapotranspiration, streamflow, and groundwater table change. Ecological module was integrated into the hydrological module to compute the ecosystem production of biomass and yield for different land use types. Economical module estimated the monetary values of crop yield and other ecosystem services. The model was implemented in a holistic approach, and able to produce simulation results at daily time steps with a spatial resolution of hydrological response unit (HRU). The integrated model was calibrated by data for the period of 1983-1991, and run for the period of 1986-1995 with the calibrated parameters for the upper and middle parts of the Yellow River basin, a semi-arid area in northwest China. The average efficiency of the model in simulating monthly streamflow was 0.63 during the calibration period, which indicated an acceptable calibration. Preliminary simulation results revealed that water use in the study area had largely reduced the streamflow in many parts of the area except for that in the riverhead. Spatial distribution of biomass, crop yield, and water productivity showed a strong impact of irrigation on agricultural production. In general, the simulation results from this study indicated that the model was capable of tracking the temporal and spatial variability of pertinent water balance variables, ecosystem dynamics, and regional economy, and provided a useful simulation tool in evaluating long-term water resources management strategies basin scale.