Analysis of factors determining the hydrodynamics of Agulu Lake: A multivariate linear model approach

Abstract

This study employs an approach providing interpretation and understanding of how much of the variations in the hydrologic flows of the lake are related to morphometry, climate, and human interferences. The morphometry of lakes, climatic, and anthropogenic factors regulate the amount of outflow originating from lakes. This paper analysed and discussed the key variables amongst a range of factors determining the outflow condition of Agulu Lake. The principal component analysis (PCA) has shown that, of the nine factors identified, four components surfaced which are independent of each other. Lake morphometry, hydrological input, temperature, and evaporation rate were shown to account for 96.231% of the variance in the hydrodynamic conditioning of the lake. We then evaluated the effects of the four components on the hydrodynamic processes by isolating from each of the four components, the component defining variables (CDVs) using a multivariate linear model. Using our model, we estimated lake outflow. We found a good linear correlation between the predicted and observed annual lake outflow (r=0.99, P<0.05). The assessment indices indicate that the model represented the observed data quite well with NSE=0.991, RSR= 0.097, and PBIAS=0.0396. This shows that the model is a good predictor of the lake outflow response in relation to the hydro-climatic-morphometric parameters permitting an accurate prediction of the lake outflow from the CDVs. This approach, which uses the CDVs in a multivariate linear model, enables us to quantitatively describe the lake's responses to climatic, morphometric, and anthropogenic changes within its catchment.