Integrated Drought Modeling For Texas Under Climate Change Impact With Implications For Water Resources Planning

Drought is a deficiency in the hydro climatic variable of interest that is experienced for an extended period of time. In many parts of the world, it is a normal, recurring feature of climate and is therefore inevitable. Adequate monitoring and planning is required for effective mitigation of droughts. The study area for this research is Texas, which has been a consistently drought prone state. There has been at least one serious drought in one part of the state or the other during every decade of the twentieth century. This trend is likely to increase in the coming years due to the effect of global warming and climate change. Taking into account the importance of water management under conditions of extreme climate, this study focuses on enhancing various aspects of drought modeling. The major goals include the development of an efficient means to quantify multiple physical forms of drought, formulation of scientifically robust drought planning regions, integrated multivariate hazard and vulnerability assessment under climate change impact, understanding the causal factors that might trigger a drought event in future, and development of an effective interface to convey the research results to decision makers. These goals were designed to bridge the gaps existing in the current drought research, which even though substantial, still fails to address some of the issues. The goals are addressed by developing a new multivariate drought index, use of copula to build the dependence structure of drought properties and subsequent plotting of multivariate risk maps, development of Drought Hazard Index (DHI) and Drought Vulnerability Index (DVI) for integrated risk analysis under climate change impact, and use of Directional Information Transfer (DIT) for grouping of homogeneous drought regions. A novel transfer entropy approach is adopted to analyze the cause-effect relationship between various hydro-climatic variables and drought properties, thus identifying the prominent future drought triggers. Finally, an efficient drought Decision Support System (DSS) is developed to convey the research results to decision makers through a number of statistical techniques and effective visualization. Ultimately, the study aims at developing a comprehensive framework for better understanding of droughts in Texas which will help decision makers to formulate a more effective adaptation and mitigation strategy in future