Accurately　depicting　the　highly　nonlinear　hydraulic　properties　of　soil　is　critical　for　predicting　pore-water　pressure　distributions　and　evaluating　the　stability　of　vegetated　slopes.　Accordingly,　semi-analytical　solutions　are　proposed　for　calculating　pore-water　pressure　distributions　and　slope　stability　in　an　infinite　multi-layered　slope　considering　both　hydrological　and　mechanical　effects　of　vegetation.　The　solutions　have　the　advantage　of　depicting　the　highly　nonlinear　hydraulic　properties　of　soil,　both　with　and　without　roots,　using　a　multi-exponential　function.　After　verifying　the　solutions,　parametric　studies　are　conducted　to　investigate　influential　factors　on　pore-water　pressure　distributions,　including　root　architecture,　root　volume　ratio,　root　depth　and　the　combination　of　different　soil　layers　in　landfill　cover.　It　is　found　that　compared　to　the　multi-exponential　function,　the　single-exponential　function　commonly　used　in　published　solutions　significantly　underestimates　negative　pore-water　pressure　induced　by　root　water　uptake　by　up　to　65　kPa　under　drying　conditions,　because　it　fails　to　depict　soil　hydraulic　properties　accurately.　When　root　reduces　the　hydraulic　conductivity　of　unsaturated　soil,　larger　negative　pore-water　pressure　induced　by　root　water　uptake　within　root　zone　could　be　observed　under　drying　conditions,　while　the　trend　reverses　under　wetting　conditions.　The　effects　of　root　architecture　and　root-induced　changes　in　the　hydraulic　conductivity　of　unsaturated　soil　on　pore-water　pressure　distributions　become　more　significant　as　the　root　volume　ratio　increases.　Under　drying　conditions,　root　water　uptake　induces　the　largest　negative　pore-water　pressure　near　the　ground　surface　in　the　three-layer　landfill　cover,　compared　with　the　cover　with　capillary　barrier　effects　and　single-layer　cover.　The　derived　solutions　can　be　used　to　guide　engineering　practices　of　vegetated　slope　and　landfill　cover.　©　2025　Elsevier　Ltd