DataSheet1_Investigating Anzali Wetland Sediment Estimation Using the MPSIAC Model.pdf

The adverse effects of upland erosion impact the Anzali Wetland in Iran. The Modified Pacific South-west Inter Agency Committee model (MPSIAC) was used to estimate the sediment yield in the watershed. The watershed was divided into twelve sub-watersheds based on the geomorphologic features and waterway orientations (Sw0-Sw11). To investigate the effect of different factors on erosion and sedimentation, data were digitized using ArcGIS software. The effective factor weights were determined using the MPSIAC model, and the total sediment yield was calculated for each sub-watershed. Results showed that the amount of particulate sediment in the critical sub-watersheds Sw6 and Sw9 was 777.9 and 730.2 t km−2. yr−1, respectively. Based on erosion and sedimentation results, the sub-watershed erosion was prioritized as Sw6> Sw9> Sw4> Sw1> Sw0> Sw5> Sw2> Sw8> Sw3> Sw11 > Sw7> Sw10. Both model inputs (precipitation) and outputs (sediment) at different parts of the watershed were assessed via point observations data. Comparison of correlation values reveals that the correlation between the simulated and sampling values was strong in sub-watershed 1 (R2 < 0.8). EF, RMSE, nRMSE, CRM, and MAE were 0.23, 16.74 tons per year, 5.05%, 0.55, and −3.6, respectively, which indicates the model’s high performance in Sw0. Areas with insufficient cover and bare soil showed a high correlation with the final erosion model. Thus, land-use classes, such as dense vegetation and good pastures, correspond to areas with low erosion. Conversely, bare soils and poor pastures were located on the eroded flats.

伊朗安扎利湿地（Anzali Wetland）受到高地侵蚀的负面影响。研究采用改良型太平洋西南部跨机构委员会模型（Modified Pacific South-west Inter Agency Committee model，MPSIAC）估算该流域的产沙量。研究团队依据地貌特征与水道走向，将该流域划分为12个子流域（Sw0-Sw11）。为探究不同因子对侵蚀与沉积过程的影响，研究人员借助ArcGIS软件完成了数据数字化工作。通过MPSIAC模型确定各有效侵蚀因子的权重，并计算了每个子流域的总产沙量。结果显示，关键子流域Sw6与Sw9的颗粒泥沙量分别为777.9与730.2吨·平方千米⁻¹·年⁻¹。基于侵蚀与沉积评估结果，各子流域的侵蚀优先级排序为Sw6>Sw9>Sw4>Sw1>Sw0>Sw5>Sw2>Sw8>Sw3>Sw11>Sw7>Sw10。研究通过点位观测数据，对流域不同区域的模型输入项（降水）与输出项（泥沙）开展了评估。相关性对比结果表明，子流域1的模拟值与采样值间相关性较强（决定系数R²<0.8）。纳什效率系数EF、均方根误差RMSE、归一化均方根误差nRMSE、相关系数偏差CRM以及平均绝对误差MAE分别为0.23、16.74吨/年、5.05%、0.55与-3.6，上述指标表明该模型在Sw0子流域中表现优异。植被覆盖不足区域与裸土区域与最终侵蚀模型呈现出较高的相关性。因此，茂密植被与优质牧场等地类对应侵蚀程度较低的区域。反之，裸土与劣质牧场则分布在侵蚀严重的平坦区域。