In the context of climate change, large-scale vegetation restoration projects have significantly altered hydrological processes. However, existing studies have primarily focused on the impact of the “Grain for Green” programme (GGP) on hydrological dynamics in arid areas, neglecting humid regions. To help close this gap, we simulated streamflow and sediment yield in the Three Gorges Reservoir Area (TGRA), an important ecological zone in China, using the SWAT + model. We differentiated the effects of the GGP and climate change on streamflow and sediment yield in different hydrological periods. The results show that sediment yield responds more intensely to variations in vegetation composition compared to water yield. From 2000 to 2020, reforestation has significantly reduced annual sediment yield by an average of 802.6 kg/ha. Climate change was identified as the main driver of the changes in runoff and sediment yield. Furthermore, the effects of reforestation exhibit seasonality, with runoff increasing during the dry season and sediment yield decreasing during the flood season. The GGP also reduces runoff and sediment yield extremes and promotes the stability of the water-sediment relationship. In addition, projections of future climate scenarios from 2025 to 2050 indicate an upward trend in total runoff and a downward trend in soil retention. This study provides insights into the impacts of the GGP and climate change on hydrological processes in humid regions and offers guidance for future development pathways.
ArnoldJGMoriasiDNGassmanPW, et al. (2012) SWAT: model use, calibration, and validation. Transactions of the ASABE55: 1491–1508.
2.
BaiRWangXLiJ, et al. (2024) The impact of vegetation reconstruction on soil erosion in the loess plateau. Journal of Environmental Management363: 121382.
3.
BiegerKArnoldJGRathjensH, et al. (2017) Introduction to SWAT+, a completely restructured version of the soil and water assessment tool. JAWRA Journal of the American Water Resources Association53: 115–130.
4.
BiegerKArnoldJGRathjensH, et al. (2019) Representing the connectivity of upland areas to floodplains and streams in SWAT+. JAWRA Journal of the American Water Resources Association55: 578–590.
5.
BrighentiTMBonumáNBSrinivasanR, et al. (2019) Simulating sub-daily hydrological process with SWAT: a review. Hydrological Sciences Journal64: 1415–1423.
6.
BryanBAGaoLYeY, et al. (2018) China’s response to a national land-system sustainability emergency. Nature559: 193–204.
7.
BunelRCopardYCarolineLB, et al. (2025) Impact of vegetation cover on hydro-sedimentary fluxes in the marly badlands of the southern alps (draix-bléone critical zone observatory, SE France). Geomorphology478: 109726.
8.
CaiDGeQWangX, et al. (2020) Contributions of ecological programs to vegetation restoration in arid and semiarid China. Environmental Research Letters15: 114046.
9.
Castellanos-OsorioGLópez-BallesterosAPérez-SánchezJ, et al. (2023) Disaggregated monthly SWAT+ model versus daily SWAT+ model for estimating environmental flows in peninsular Spain. Journal of Hydrology623: 129837.
10.
ChenXXuGZhangW, et al. (2019) Spatial variation pattern analysis of hydrologic processes and water quality in three gorges reservoir area. Water11: 2608.
11.
ChenHFleskensLBaartmanJ, et al. (2020) Impacts of land use change and climatic effects on streamflow in the Chinese loess Plateau: a meta-analysis. Science of the Total Environment703: 134989.
12.
ChenCGanRYangF, et al. (2022) Parameters optimization scheme and uncertainty analysis of runoff simulation based on SWAT model. Yangtze River53: 538–548.
13.
CookBIMankinJSMarvelK, et al. (2020) Twenty-First Century Drought Projections in the CMIP6 Forcing Scenarios. Earth’s Future, 8, e2019EF001461.
14.
DaneshiABrouwerRNajafinejadA, et al. (2021) Modelling the impacts of climate and land use change on water security in a semi-arid forested watershed using InVEST. Journal of Hydrology593: 125621.
15.
DerepaskoDWitingFPeñasFJ, et al. (2023) Towards adaptive water management—optimizing river water diversion at the basin scale under future environmental conditions. Water15: 3289.
16.
DudaPBHummelPRDonigianAS, et al. (2012) BASINS/HSPF: model use, calibration, and validation. Transactions of the ASABE55: 1523–1547.
17.
EekhoutJPVenteJD (2020) How soil erosion model conceptualization affects soil loss projections under climate change. Progress in Physical Geography: Earth and Environment44: 212–232.
18.
FrancesconiWSrinivasanRPérez-MiñanaE, et al. (2016) Using the soil and water assessment tool (SWAT) to model ecosystem services: a systematic review. Journal of Hydrology535: 625–636.
19.
GaoJZ (2024). In: National Tibetan Plateau DataC (ed) China Regional 250m Normalized Difference Vegetation Index Data Set (2000-2023). National Tibetan Plateau Data Center.
20.
GaoGHuangARanL, et al. (2024) Dam regulation on extreme streamflow-sediment relationships along the yangtze river basin. Science Bulletin70(6): 866–870.
21.
GebreAMBeleteMDBelaynehMZ (2024) Soil loss and sediment yield prediction in Lake hawassa sub-basin, central rift valley basin, Ethiopia. Air, Soil and Water Research17: 11786221241261823.
22.
HagemannSChenCClarkDB, et al. (2013) Climate change impact on available water resources obtained using multiple global climate and hydrology models. Earth System Dynamics4: 129–144.
23.
HattermannFFHuangSKochH. (2015) Climate change impacts on hydrology and water resources. Climate Services10: 9-19.
24.
HuangCZhaoDDengL (2022) Landscape pattern simulation for ecosystem service value regulation of three gorges reservoir area, China. Environmental Impact Assessment Review95: 106798.
25.
HuangCZhaoDLiaoQ, et al. (2023) Linking landscape dynamics to the relationship between water purification and soil retention. Ecosystem Services59: 101498.
26.
JanjićJTadićL (2023) Fields of application of SWAT hydrological model—a review. Earth4: 331–344.
27.
JianSZhaoCFangS, et al. (2015) Effects of different vegetation restoration on soil water storage and water balance in the Chinese loess Plateau. Agricultural and Forest Meteorology206: 85–96.
28.
LeoneMGentileFLo PortoA, et al. (2024) Setting an environmental flow regime under climate change in a data-limited Mediterranean basin with temporary river. Journal of Hydrology: Regional Studies52: 101698.
29.
LewisSLWheelerCEMitchardET, et al. (2019) Restoring Natural Forests is the Best Way to Remove Atmospheric Carbon. Nature, 568, 25–28.
30.
LiBYWangYC (2024) Impact of the grain-for-green programme and climate change on the soil erosion decline in the yangtze river, China. Journal of Geographical Sciences34: 527–542.
31.
LiZDengXWuF, et al. (2015) Scenario analysis for water resources in response to land use change in the middle and upper reaches of the Heihe River Basin. Sustainability7: 3086–3108.
32.
LiMDiZHDuanQY (2021) Effect of sensitivity analysis on parameter optimization: case study based on streamflow simulations using the SWAT model in China. Journal of Hydrology603: 126896.
33.
LiangXLettenmaierDPWoodEF (1996) One-dimensional statistical dynamic representation of subgrid spatial variability of precipitation in the two-layer variable infiltration capacity model. Journal of Geophysical Research: Atmospheres101: 21403–21422.
34.
LiangXGuanQClarkeKC, et al. (2021) Understanding the drivers of sustainable land expansion using a patch-generating land use simulation (PLUS) model: a case study in Wuhan, China. Computers, Environment and Urban Systems85: 101569.
35.
LiuZFXuZXHuangJX, et al. (2010) Impacts of climate change on hydrological processes in the headwater catchment of the tarim river basin, China. Hydrological Processes24: 196–208.
36.
LiuRWangJShiJ, et al. (2014) Runoff characteristics and nutrient loss mechanism from plain farmland under simulated rainfall conditions. Science of the Total Environment468-469: 1069–1077.
37.
LoweSA (2010) Sanitary sewer design using epa storm water management model (SWMM). Computer Applications in Engineering Education18: 203–212.
38.
LuoYWangHMeersmansJ, et al. (2021) Modeling soil erosion between 1985 and 2014 in three watersheds on the carbonate-rock dominated Guizhou Plateau, SW China, using WaTEM/SEDEM. Progress in Physical Geography: Earth and Environment45: 53–81.
39.
McFarlaneDStoneRMartensS, et al. (2012) Climate change impacts on water yields and demands in south-western Australia. Journal of Hydrology475: 488–498.
40.
MolinaAVanackerVBalthazarV, et al. (2012) Complex land cover change, water and sediment yield in a degraded Andean environment. Journal of Hydrology472: 25–35.
41.
NashJESutcliffeJV (1970) River flow forecasting through conceptual models part I—A discussion of principles. Journal of Hydrology10: 282–290.
42.
NepalDParajuliPBOuyangY, et al. (2023) Assessing hydrological and water quality responses to dynamic landuse change at watershed scale in Mississippi. Journal of Hydrology625: 129983.
43.
NFGA (2020) Twenty years of returning farmland to forests and grasslands in China (1999-2019). National Forestry and Grassland Administration12(4): 1492.
44.
NkwasaAChawandaCJMsigwaA, et al. (2020) How can we represent seasonal land use dynamics in SWAT and SWAT+ models for African cultivated catchments?Water12: 1541.
45.
NooriNKalinL (2016) Coupling SWAT and ANN models for enhanced daily streamflow prediction. Journal of Hydrology533: 141–151.
46.
QinPCXuHMLiuM, et al. (2020) Climate change impacts on three gorges reservoir impoundment and hydropower generation. Journal of Hydrology580: 123922.
47.
RockströmJMazzucatoMAndersenLS, et al. (2023) Why we need a new economics of water as a common good. Nature615: 794–797.
48.
ShiPChenCSrinivasanR, et al. (2011) Evaluating the SWAT model for hydrological modeling in the xixian watershed and a comparison with the XAJ model. Water Resources Management25: 2595–2612.
49.
SidleRCGomiTUsugaJCL, et al. (2017) Hydrogeomorphic processes and scaling issues in the continuum from soil pedons to catchments. Earth-Science Reviews175: 75–96.
50.
SongZHZhangXQXuJJ, et al. (2025) Vegetation greening promotes the conversion of blue water to green water by enhancing transpiration. Journal of Hydrology658: 133181.
51.
SunGZhouGZhangZ, et al. (2006) Potential water yield reduction due to forestation across China. Journal of Hydrology328: 548–558.
52.
SunWShaoQLiuJ, et al. (2014) Assessing the effects of land use and topography on soil erosion on the loess Plateau in China. Catena121: 151–163.
53.
TaylorKE (2001) Summarizing multiple aspects of model performance in a single diagram. Journal of Geophysical Research: Atmospheres106: 7183–7192.
54.
ThrasherBWangWMichaelisA, et al. (2022) NASA global daily downscaled projections, CMIP6. Scientific Data9: 262.
55.
TianjiaoFTianxingWKeesstraSD, et al. (2023) Long-term effects of vegetation restoration on hydrological regulation functions and the implications to afforestation on the loess Plateau. Agricultural and Forest Meteorology330: 109313.
56.
UniyalBKosaticaEKoellnerT (2023) Spatial and temporal variability of climate change impacts on ecosystem services in small agricultural catchments using the soil and water assessment tool (SWAT). Science of the Total Environment875: 162520.
57.
WallingtonKCaiX (2023) Updating SWAT+ to clarify understanding of In-Stream phosphorus retention and remobilization: SWAT+P.R&R. Water Resources Research59: e2022WR033283.
58.
WangHSunF (2021) Variability of annual sediment load and runoff in the Yellow River for the last 100 years (1919–2018). Science of the Total Environment758: 143715.
59.
WangSFuBJLiangW (2016) Developing policy for the yellow river sediment sustainable control. National Science Review3: 162–164.
60.
WangWChenLZhuY, et al. (2019) Is returning farmland to forest an effective measure to reduce phosphorus delivery across distinct spatial scales?Journal of Environmental Management252: 109663.
61.
WanggXiajLix, et al. (2021) Critical advances in understanding ecohydrological processes of terrestrial vegetation: from leaf to watershed scale (in Chinese). Chinese Science Bulletin66: 3667–3683.
62.
WangYLiuXLiJ, et al. (2022) Quantifying the spatial flow of soil conservation service to optimize land-use pattern under ecological protection scenarios. Frontiers in Earth Science10: 957520.
63.
WangZFuBWuX, et al. (2023) Vegetation resilience does not increase consistently with greening in China’s loess Plateau. Communications Earth & Environment4: 336.
64.
WeiCDongXHYuD, et al. (2022) An alternative to the grain for green program for soil and water conservation in the upper huaihe river basin, China. Journal of Hydrology: Regional Studies43: 101180.
65.
WuJGaoXJ (2013) A gridded daily observation dataset over China region and comparison with the other datasets (in Chinese). Chinese Journal of Geophysics Chinese Edition56: 1102–1111.
66.
WuQKeLWangJ, et al. (2023) Satellites reveal hotspots of global river extent change. Nature Communications14: 1587.
67.
XieDZhangYZhangM, et al. (2024) Hydrological impacts of vegetation cover change in China through terrestrial moisture recycling. Science of the Total Environment915: 170015.
68.
XiongLXuXRenD, et al. (2019) Enhancing the capability of hydrological models to simulate the regional agro-hydrological processes in watersheds with shallow groundwater: based on the SWAT framework. Journal of Hydrology572: 1–16.
69.
XuHTaylorRGXuY (2011) Quantifying uncertainty in the impacts of climate change on river discharge in sub-catchments of the yangtze and yellow river basins, China. Hydrology and Earth System Sciences15: 333–344.
70.
XuXBYangGSTanY, et al. (2020) Unravelling the effects of large-scale ecological programs on ecological rehabilitation of China’s three gorges dam. Journal of Cleaner Production256: 120446.
71.
YifruBAChungI-MKimM-G, et al. (2021) Assessing the effect of land/use land cover and climate change on water yield and groundwater recharge in east african rift valley using integrated model. Journal of Hydrology: Regional Studies37: 100926.
72.
YinSGaoGRanL, et al. (2023) Extreme streamflow and sediment load changes in the yellow river basin: impacts of climate change and human activities. Journal of Hydrology619: 129372.
73.
ZhangLWangJBaiZ, et al. (2015) Effects of vegetation on runoff and soil erosion on reclaimed land in an opencast coal-mine dump in a loess area. Catena128: 44–53.
74.
ZhangYZhongP-AChenJ, et al. (2017) Impacts of climate change and human activities on the three gorges reservoir inflow. Water9: 957.
75.
ZhaoJChengHCaoJ, et al. (2023) Orchestrated decline of Asian summer monsoon and Atlantic meridional overturning circulation in global warming period. The Innovation Geoscience1: 100011–100019.
76.
ZhouZCGanZTShangguanZP, et al. (2009) China’s grain for green program has reduced soil erosion in the upper reaches of the yangtze river and the middle reaches of the yellow river. The International Journal of Sustainable Development and World Ecology16: 234–239.
77.
ZhouYHuangQWuP, et al. (2024b) Seasonal variations in ecosystem service supply and demand based on the SWAT model: a case study in the guanting reservoir basin, China. Ecological Indicators158: 111552.
78.
ZhouJLiuQLiangL, et al. (2024a) Water constraints enhanced by revegetation while alleviated by increased precipitation on China’s water-dominated loess Plateau. Journal of Hydrology640: 131731.
79.
ZhuGDengLShangguanZ (2018) Effects of soil aggregate stability on soil N following land use changes under erodible environment. Agriculture, Ecosystems & Environment262: 18–28.
80.
ZhuHJiangZLiL (2021) Projection of climate extremes in China, an incremental exercise from CMIP5 to CMIP6. Science Bulletin66: 2528–2537.
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
