Impact of land use change on the water conservation service of ecosystems in the urban agglomeration of the Golden Triangle of Southern Fujian, China, in 2030

The water conservation service of an ecosystem is the basis and a guarantee for the sustainable development of water resources. It is continually affected by the disturbance and influence of human activities. Land use change caused by humans is one of the main influencing factors and has substantial and enduring impacts on the water conservation service of an ecosystem. In this study, the InVEST model was used to simulate water conservation scenarios for the urban agglomeration of the Golden Triangle in Southern Fujian, China, for 2015 and 2030. The results showed that the amount of water conservation in the urban agglomeration of the Golden Triangle in Southern Fujian would decline by 0.24×10~8 m~3 by 2030. The comparison shows that the effect of land use change on water conservation are mainly manifested in the following four aspects: changed area, changing direction, the intensity and the compensatory effect. Firstly with regards to changed area, the amount of water conservation and the size of the area of land use had changed were positively correlated, but the variance in the amount of water conservation and the area of land use change were not positively correlated. Secondly, with regards to changing direction, the natural ecosystem and the agricultural ecosystem were more conducive to water conservation than the urban ecosystem and the water ecosystem. Thirdly, the degree of impact that land use change had on water conservation is ordered from strong to weak, the order is woodland, other land, grassland, cultivated land, construction land, and water area and tidal flats. Finally, the size of the compensatory effect when area had changed, which is based on the differences in water conservation capacity and area of land subjected to land use change, meant that the decline in water conservation caused by the loss of cultivated land, woodland, grassland and other land could not be fully compensated by the area increase in construction land, water area and tidal flats.