Estimation of suspended sediment and dissolved solid load in a Mediterranean semiarid karst stream using log-linear models

Abstract

Many models have been developed to predict the sediment transport in watercourses. This paper attempts to test the effectiveness of log-linear models (LLM) to estimate the suspended (S-LMM), dissolved (D-LLM), and total suspended (T-LLM) load into a Mediterranean semiarid karst stream (the Argos River basin, in southeast Spain). An assessment of the supposed validity of each model and a leave-one-out cross-validation were carried out to determine their degree of statistical robustness. The T-LLM model showed higher prediction accuracy (R 2 ¼ 0.98, RMSE ¼ 0.15, and PE ¼ ±5.4–6.6%) than the D-LLM model (R 2 ¼ 0.97, RMSE ¼ 0.16, and PE ¼ ±5.5–6.8%) or the D-LLM model (R 2 ¼ 0.77, RMSE ¼ 0.71, and PE ¼ ±101–493%). In addition, different model variants, according to two flow patterns (FP1 ¼ base flow and FP2 ¼ rising water level), were developed. The FP2-SLLM model provided a very good fit (R 2 ¼ 0.94, RMSE ¼ 0.34, and PE ¼ ±25.3–61.5%), substantially improving the results of the S-LLM model.