In　this　work,　a　two-layer　depth-integrated　smoothed　particle　hydrodynamics　(SPH)　model　is　applied　to　investigate　the　effects　of　landslide　propagation　on　the　impulsive　waves　generated　when　entering　a　water　body.　In　order　to　deal　with　the　open　boundary　in　practical　engineering　problems,　an　absorbing　boundary　method,　based　on　Riemann　invariants　which　can　be　applied　to　arbitrary　geometries,　is　implemented.　In　order　to　examine　the　accuracy　of　the　proposed　formulation,　the　model　is　tested　against　both　available　laboratory　tests　and　numerical　examples　from　the　literature.　Then,　it　is　adopted　to　model　the　characteristics　of　the　impulse　waves　generated　by　the　Halaowo　landslide　in　the　Jinsha　River,　China.　The　results　provide　a　technical　basis　for　the　emergency　plan　to　the　Halaowo　landslide　and　benefit　the　disaster　prevention　policy,　which　helps　mitigating　future　hazards　in　similar　reservoir　areas.　©　2019,　Springer-Verlag　GmbH　Germany,　part　of　Springer　Nature.