Impacts of land use change and climate change on hydrological services- a case study in Taiwan

Abstract:

Water is the most important natural resource, providing a wide range of fundamental functions –hydrological services-- to both humanity and ecological systems alike. Unfortunately urbanization and climate change can compromise hydrological services. In this paper, we consider the impacts of both land-use change and climate change on hydrological services. Our study area includes the entire extent of the Datuan river watershed, which is located in the northern part of Taiwan. We used CLUE-s model to predict future land-use change. We then used the InVEST model to calculate hydrological services, such as water yield, nitrogen retention, phosphorus retention, and sediment retention. Finally, we analyzed the impacts of land use change and climate change on hydrological services. We used the IPCC fifth assessment report (AR5) scenarios of RCP4.5 and RCP8.5 as a component of near future land-use changes and future precipitation regimes. The results indicate that while water yields will be significantly affected by climate change, nitrogen retention and phosphorus retention will be significantly affected by land use change. Whereas both projected land-use change and climate change will have little impact on projected sediment retention. All in all, impact analysis indicates that both land-use and climate change will not only have huge impacts on overall hydrological services, particularly water yield, but also the distribution of such services.