Multisite Monthly to Daily Naturalised Streamflow Disaggregation Using Daily Flow Pattern Hydrograph

Abstract

Conservation and preservation of environmental wildlife and fisheries became an important criterion in this era. Therefore, the environmental protection flow standards for major river basins and estuaries have been established in the state of Texas enacted by federal laws. The environmental flow issues can be addressed effectively and efficiently on a daily time step, and thus, a new technique, daily flow pattern hydrograph, is developed and implemented for disaggregating monthly naturalised streamflows to daily while preserving monthly volumes. Constitution of flow pattern hydrograph emphasises numerous issues such as the impact of water resources development at upstream, comparative analyses of available flows, geology, hydrology, the geographical location of gaging stations, etc. The previous parametric and nonparametric studies dealing with streamflow disaggregation methods mostly preserve spatial and temporal statistical characteristics such as variance, skewness and maximum and minimum values. This study has been conducted from the perspective of capturing low flows, and therefore a statistical parameter, duration curve, also known as flow frequency metric, is employed to evaluate and analyse the result. This study is performed for the Trinity River basin located at the state of Texas. However, this technique can be employed in any other river basin irrespective of its shape, and size.