Testing a Conceptual Lumped Model in Karst Area, Southwest China

Peng Shi,Zhicai Zhang,Xi Chen,Simin Qu,Xinxin Ma,Mi Zhou,Xueyuan Qiao

doi:10.1155/2013/827980

Abstract

Karst aquifers are known for their heterogeneous physical properties and irregular complex flow patterns which make it a challenge to describe the hydrological behavior and to quantitatively define the distribution of river flow components using hydrologic models. In this paper, a conceptual lumped hydrologic model, Xin’anjiang model (XAJ), was applied in Sancha River, which is a karst basin in southwest China, for the simulation of streamflow. The performance of XAJ model was evaluated based on the model’s ability to reproduce the streamflow and baseflow. Percentage of bias (PBIAS), Nash-Sutcliffe efficiency (NSE), coefficient of determination (R2), and standard deviation (RSR) were calculated between the simulated and measured flow for both calibration and validation period. The low PBIAS and RSR (2.7% and 0.367 for calibration period, 1.3% and 0.376 for validation period) and the high NSE andR2(0.866 and 0.866 for calibration period, 0.858 and 0.860 for validation period) indicate that the model structure and parameters are of reasonable validity. Furthermore, streamflow was separated to baseflow and surface flow using the “baseflow programme,” and the calculated results indicate that the model could also reproduce the response of baseflow in such karst system.

Highlights

Karst terrain accounts for about 15% of the world’s land and is home for around 1 billion people [1]
The low percent bias (PBIAS) and RSR (2.7% and 0.367 for calibration period, 1.3% and 0.376 for validation period) and the high Nash-Sutcliffe efficiency (NSE) and R2 (0.866 and 0.866 for calibration period, 0.858 and 0.860 for validation period) indicate that the model structure and parameters are of reasonable validity
As a result, modeling the response of karst aquifers and water storage in such systems becomes an important challenge and is an important step to estimate the sustainable yield of karst aquifers as well as to evaluate future climatic or anthropogenic impacts on the sustainability of groundwater resources in these systems

Summary

Introduction

Karst terrain accounts for about 15% of the world’s land and is home for around 1 billion people [1]. Conceptual lumped models (LPM) are based on the conceptualization of the karst aquifer as a whole; that is, dependent variables are not a function of spatial position, and physical relationships are not considered explicitly but are represented in general terms through the conceptualization of the aquifer Due to their simplicity, LPMs are useful for the interpretation of data when it is neither possible nor justified to use distributed parameter models [26]. Albeit based on a simplified physical interpretation of the processes which transform inputs into outputs, Xin’anjiang conceptual lumped models are sufficient to help define the nature and behavior of the karst contribution to river flows and the impact of future change on karst water resources. (3) analyzing the hydrological behavior in karst area Southwest China

Methods and Materials

Methods

Findings

Conclusion