Arid Zone Research ›› 2024, Vol. 41 ›› Issue (5): 776-787.doi: 10.13866/j.azr.2024.05.06

• Land and Water Resources • Previous Articles     Next Articles

Spatiotemporal evolution of water yield in the lower Malian River Basin

GAO Yayu1(), SONG Yu1, ZHAO Tinghong1(), GAO Jinfang2, HE Wenbo1, LI Zexia2   

  1. 1. College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou 730050, Gansu, China
    2. Gansu Institute of Soil & Water Conservation Sciences, Lanzhou 730020, Gansu, China
  • Received:2023-12-13 Revised:2024-01-30 Online:2024-05-15 Published:2024-05-29

Abstract:

This study examines water yield patterns in the lower reaches of the Malian River Basin, which are typical loess plateau gully areas in eastern Gansu Province, China. These areas are crucial for regional ecosystem health and understanding the temporal and spatial characteristics and response of water yield considering climate and land-use changes. Employing the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model, we quantitatively assess the spatial and temporal patterns of water yields across four years: 1990, 2000, 2010, and 2020. Spatial heterogeneity in water yield across the lower reaches of the Malian River Basin was assessed using geographic detection techniques. Analysis revealed a fluctuating trend in total water yield from 1990 to 2020, characterized by an initial decrease, followed by an increase, and finally another decrease. Compared to 1990, total water yield in 2020 declined by 5.9×107 m3 (25.43% reduction). Furthermore, spatial analysis revealed a distinct pattern in water yield distribution across the basin. Higher water yield was observed in the southern and marginal areas, whereas lower yield characterized the northern and central regions. Land-use type significantly influenced water yield capacity. Ranked from highest to lowest, the order was as follows: construction land>bare land>agricultural land>low-coverage grassland>high-coverage grassland>shrub land>forest land>open water. Moreover, a significant positive correlation was identified between water yield and precipitation, suggesting that precipitation plays a key role in water production. Conversely, a negative correlation emerged between actual evapotranspiration and altitude. Our analysis identified precipitation and actual evapotranspiration as the primary drivers of spatial variations and temporal changes in water yield, with q values ranging from 0.616 to 0.735 and 0.517 to 0.653, respectively. These findings provide valuable scientific evidence to support the development, utilization, and management of soil and water resources in the loess plateau of eastern Gansu.

Key words: InVEST model, water yield, spatiotemporal evolution, lower Malian River Basin