Research on the cumulative effect of multiscale ecological compensation in river basins: A case study of the Minjiang River Basin, China

A program of ecological compensation (EC) is an effective means to solve the potential unfairness caused by the difference in environmental quality between the upper, middle, and lower reaches of river basins, alleviate the conflict of economic interests between regions. By constructing an EC accounting model, this study defines the carbon emissions of construction land as the consumption of ecological services to avoid the problem of lower EC in the upper reaches than the middle and lower reaches when only the ecosystem service value (ESV) is used as the compensation basis. We calculate the cumulative EC standards in the basin from 2000 to 2018 at the county, major functional oriented zone, and basin section scales, divide the subjects unto those provide EC and the subjects receiving EC, and finally introduce the comparative ecological radiation force to simulate the direction and scale of the ecosystem service flow (ESF) of the subjects receiving EC. The findings of this study are as follows: (1) The ESV of the Minjiang River Basin shows a downward trend in time and a spatial distribution pattern of high in the north and southwest parts and low in the middle and southeast parts. (2) Carbon emissions from construction land in all counties (cities and districts) in the Minjiang River Basin show an upward trend in time and a spatial distribution pattern of high in the middle part and low in the north and south parts. (3) The cumulative EC standard in the Minjiang River Basin from 2000 to 2018 is 279.401 billion CNY, which indicates ESV spillover. On the county scale, 22 subjects receive EC and 23 subjects providing EC. The subjects receiving EC are generally located in the southwestern parts of the upper and lower reaches, and the subjects providing EC are concentrated in the national key development zone in the middle reaches. (4) The ESF goes from north to south in the upper reaches, towards the north and south sides in the middle reaches, and towards the east and north in the lower reaches. Our findings provide an important reference for EC practices in the Minjiang River Basin.