Accurate values of electric dipole (E1) amplitudes along with their uncertainties for a number of transitions among low-lying states of Mg${}^{+}$, Ca${}^{+}$, Sr${}^{+}$, and Ba${}^{+}$ are listed by carrying out calculations using a relativistic all-order many-body method. By combining experimental wavelengths with these amplitudes, we quote transition probabilities, oscillator strengths and lifetimes of many short-lived excited states of the above ions. The uncertainties in these radiative properties are also quoted. We also give electric quadrupole (E2) and magnetic dipole (M1) amplitudes of the metastable states of the Ca${}^{+}$, Sr${}^{+}$, and Ba${}^{+}$ ions by performing similar calculations. Using these calculated E1, E2 and M1 matrix elements, we have estimated the transition probabilities, oscillator strengths and lifetimes of a number of allowed and metastable states. These quantities are further compared with the values available from the other theoretical studies and experimental data in the literature. The present data will be useful for the astrophysical observations, laboratory analysis and simulations of spectral properties in the above considered alkaline-earth metal ions.

镁低洼状态之间许多跃迁的电偶极（E1）振幅准确值及其不确定性${}^{+}$，钙${}^{+}$，Sr${}^{+}$和Ba${}^{+}$通过使用相对论的多阶多体法进行计算来列出。通过将实验波长与这些振幅相结合，我们引用了上述离子的许多短寿命激发态的跃迁概率，振荡器强度和寿命。还列举了这些辐射性质的不确定性。我们还给出了Ca的亚稳态的电四极（E2）和磁偶极（M1）幅度${}^{+}$，Sr${}^{+}$和Ba${}^{+}$离子通过执行类似的计算。使用这些计算出的E1，E2和M1矩阵元素，我们估算了许多允许状态和亚稳态的跃迁概率，振荡器强度和寿命。将这些数量与其他理论研究和文献中的实验数据得出的值进行比较。目前的数据将对上述被认为是碱土金属离子的天体观测，实验室分析和光谱特性的模拟有用。