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Climate and land use/land cover (LULC) changes alter ecosystem services that directly and indirectly affect human well-being. The impacts of management scenarios and different climate scenarios on water-related ecosystem services are uncertain in the context of future LULC and climate change interactions. Therefore, here, we analyzed the impact of future climate change and land management scenarios on water-related ecosystem services by 2030 in the Jianghuai Ecological Economic Zone (JHEEZ). Water yield and water purification were modelled for 2030, and the models were built on LULC scenarios and climate scenarios by using the Integrated Valuation of Ecosystem Services Trade-offs (InVEST) model. We used the Beijing Normal University Earth system model (BNU-ESM) for the representative concentration pathway (RCP) 4.5 and RCP8.5 scenarios, and we simulated four LULC scenarios using the future LULC simulation (FLUS) model. Four 2030 LULC scenarios, including rapid urbanization (RUS), farmland protection (FPS), ecological protection (EPS), and returning farmland to lakes scenario (RLS), were designed and compared with the year 2015 as the baseline. We found that the water yield of each LULC scenario under RCP4.5 had a decreasing trend: 10.41% (RUS), 12.43% (FPS), 13.69% (EPS), and 13.83% (RLS). However, the water yield increased under RCP8.5 and were 5.92%, 3.77%, 2.35%, and 2.18%, respectively. Water purification increased more in all LULC scenarios under the RCP8.5 than under RCP4.5. The water purification of all land-use scenarios from small to large was FPS, RUS, EPS, and RLS. Our results indicated that climate change had a greater impact than LULC on water yield, but LULC change had a greater impact on water purification. Our results provide scientific guidance for decision makers to develop better LULC policies to achieve sustainable water resource management in watershed-dominated regions. The integrated assessment approach to climate and land management also applies to other conditions to help achieve sustainable management.

Rainforests ensure fundamental water-related ecosystem services that are currently threatened by land-use change, in particular deforestation. Quantitative assessments of water-related ecosystem services have traditionally focused on the benefits linked to direct water availability for humans. Under this perspective, forests have been considered as water consumers, due to high interception and transpiration rates that reduce water flows available to downstream human activities. In contrast, their role as water suppliers through transpiration from tree canopies has often been neglected. Integrating this second perspective into assessments of water-related ecosystem services from forests and other land covers is key to providing a comprehensive support to decision-making processes on land-use change. In addition, specific indicators are necessary to incorporate the contribution of the different water balance components into ecosystem service assessment. In this paper, we investigate the use of water balance partitioning for the assessment of water-related ecosystem services. We use three water balance models (two existing ones and one developed in this study) and compare, via model simulations, water balance partitioning and water-related ecosystem services of a forested and a deforested area of the Brazilian State of Rondonia. Then, we propose a set of indicators that, based on the outputs of the models, provide a multidimensional characterization of different land-use types. Regardless of the model used, the values of these indicators for the selected case study consistently point out the key role of vegetation in regulating the water cycle. Forests act as effective indirect water suppliers for human activities and are key players in moisture recycling, thanks to high evapotranspiration rates (about 68% of total precipitation). Deforested areas, instead, act as direct suppliers of water flows for human activities due to higher drainage rates (about 50% of total precipitation). The proposed methodology helps highlight the importance of comprehensive water-related ecosystem services assessments. Moreover, the indicators quantitatively support the impact assessment of land-use change on the different processes involved in the water cycle and on human activities relying, directly or indirectly, on these processes.

Interventions in payment for ecosystem services (PES) programs can involve both collective and individual actions. This study explores the potential for the development of payment for water related ecosystem services (PWES) program in the Lake Naivasha basin, Kenya. Using a choice experiment approach, the willingness to accept compensation is estimated for three water-related ecosystem services (WES) attributes: one collective attribute (reforestation) and two individual attributes (environment-friendly agricultural practices and restoration of riparian land). Moreover, the preferences of upstream farm households are analysed with regard to sub-basins where a PWES program has already been implemented and sub-basins where it has not been implemented so far. For sub-basins where PWES has already been implemented, environment-friendly agricultural practices is the only significant attribute for local farmers' choice to improve WES. Reforestation and environment friendly agricultural practices are significant attributes for sub-basins where PWES has not been implemented so far. Farm households are willing to accept compensation but there appears to be heterogeneity in preferences for WES attributes. We find differences in farm households' preferences and values for collective and individual actions. Therefore, contrary to the current norm in PES interventions with a uniform compensation scheme, we recommend conservation payments to vary among ecosystem service providers.