Background Rapid urbanization has resulted in the reduction of other types of land due to the large number of urban construction sites, and has an impact on the value of regional ecosystem services. Relevant research may provide information for regional sustainable development and policy decision-making.

Methods Taking Cixi county on the south shore of Hangzhou Bay in China as the study area, this work utilized 3 periods' (in the year of 2005, 2010, and 2015) remote sensing data and extracted the information of land use in the 3 periods to analyze the change of land use as well as the change of ecosystem services value (ESV) due to the rapid urbanization in Cixi county. ESV was calculated by the modified model from R. Costanza.

Results 1) From 2005 to 2015, land use changes in Cixi county showed a large decrease in tidal flats, and its area decreased by nearly 40.4%. Most of the tidal flats were transformed into dry lands, and a few were converted into paddy fields. The increase in construction land was the most significant, with an average annual increase of 11.3 km². The expansion of construction land increased the fragmentation of other land types. 2) Among the various types of land use in Cixi county, the ESV of tidal flat was much higher than that of other land types. In 2005, the ESV of tidal flats accounted for 60.2% of the entire Cixi area. In the past 10 years, the ESV in Cixi County has continued to decline, reaching 10.02×10⁸Yuan. The main reason for this was the sharp drop in tidal flats. 3) Over the past 10 years, the ESV lost due to the expansion of construction land up to 7.30×10⁸ Yuan, accounting for 73% of the total ESV reduction, and the ESV loss from various land use types during 2005 to 2010 was higher than that of 2010-2015. Regarding the structure of ESV loss, the amount of lost ESV due to the conversion of tidal flats into construction land amounted to 4.60×10⁸ Yuan, accounting for 62.9%, followed by occupied water area, the loss ESV accounted for 23.6%, and the remaining land types had a relatively small impact on ESV.

Conclusions Overall, there is a negative correlation between the urbanization level and the ESV in Cixi County. The expansion of construction land and the reduction of tidal flats affected by urbanization is the main reason for the ESV loss.