Abstract:

To master the coordination situation of the collaborative governance of water resources, sediment and pollution in small watershed, the index system was constructed from subsystems of water management, sediment and soil erosion control, and non-point source pollution prevention and control with the small watershed in Ying River source area as the example, and the coupling coordination degree model was adopted to study the synergistic effect of the three subsystems in 2006, 2009, 2012, 2015 and 2018. The results showed that there was significant difference of the effect of each index from the three subsystems on the coupling system; and there was a coupling relationship of mutual influence and restriction among the three subsystems, which made the comprehensive evaluation index of the coupled system show a changing trend of ‘declining- rising- slowly declining—rising'. The variation trend of coupling degree and coupling coordination degree were basically the same, except the decrease in 2009 and 2015, it basically showed a slowly rising trend. The coupling degree was lower than 0.8 in 2006 and 2009, but above 0.8 in other years, indicating that the coupling level of the three subsystems was relatively high, which made the coordination degree of the coupling system rise slowly from intermediate to advanced and then to high quality, which was conducive to the in-depth development of ecological clean governance in the watershed. Therefore, it would be beneficial to increasing the synergistic control level of water resources, sediment and pollution in this area by relying on scientific and technological progress, vigorously developing water-saving agriculture, reducing the application amount of chemical fertilizer and pesticide, improving land use structure, reducing man-made soil and water loss, and increasing the rate of water quality and sewage treatment.

Key words: water source management, sediment and soil erosion management, non-point source pollution prevention, coupling coordination