Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Engineering
Developing A Regional Land Use Drought Index In Florida, Chi-Han Cheng, Fidelia Nnadi
Developing A Regional Land Use Drought Index In Florida, Chi-Han Cheng, Fidelia Nnadi
2011 Symposium on Data-Driven Approaches to Droughts
Drought is a natural phenomenon that occurs when a significant decrease of water availability during a significant period of time and over a larger area. Drought indices can be a useful tool to assess and respond to drought. However, current drought indices could not fully show the land use effects and they have limitation in data sources. ENSO influence the climate of Florida; where El Niño years tend to be cooler and wetter, and La Niña years tend to be warmer and drier than normal in the fall through the spring, with the strongest effect in the winter. Both prolonged …
On The Physics Of Droughts, M. Levent Kavvas
On The Physics Of Droughts, M. Levent Kavvas
2011 Symposium on Data-Driven Approaches to Droughts
By means of a simple general circulation model of the northern hemisphere the interaction of atmospheric and hydrologic processes during droughts will be analyzed at continental scale. It will be shown by numerical solutions of this model that the mechanism leading to droughts is a non-linear positive feedback mechanism in the sense that it feeds on itself. Imposing a temperature wave over western USA for a short period on the order of few months induces geophysical conditions in that region which tend to reduce the hydrologic water storage for a period on the order of years. The mechanisms for returning …
A Look At 20th Century Droughts, Vijay P. Singh, Ashok K. Mishra
A Look At 20th Century Droughts, Vijay P. Singh, Ashok K. Mishra
2011 Symposium on Data-Driven Approaches to Droughts
Droughts exercise a profound effect on the social and economic fabric of nations. Many nations of the world experienced droughts encompassing the full spectrum of severity, areal extent and duration. The result has been that the economic development was hampered and many countries have not yet recouped fully from the ravages of droughts. The first decade of the 21st century has also witnessed varying degrees of droughts across the globe. Therefore, we ask the following questions: (a) Do droughts affect every part of the world? (b) Are there similarities in major droughts around the world? (c) Are climate change and …
Probabilistic Assessment Of Drought Characteristics Using A Hidden Markov Model, Ganeshchandra Mallya, Shivam Tripathi, Sergey Kirshner, Rao S. Govindaraju
Probabilistic Assessment Of Drought Characteristics Using A Hidden Markov Model, Ganeshchandra Mallya, Shivam Tripathi, Sergey Kirshner, Rao S. Govindaraju
2011 Symposium on Data-Driven Approaches to Droughts
Droughts are evaluated using drought indices that measure the departure of meteorological and hydrological variables such as precipitation and stream flow from their long-term averages. While there are many drought indices proposed in the literature, most of them use pre-defined thresholds for identifying drought classes ignoring the inherent uncertainties in characterizing droughts. In this study, a hidden Markov model (HMM) [1] is developed for probabilistic classification of drought states. The HMM captures space and time dependence in the data. The proposed model is applied to assess drought characteristics in Indiana using monthly precipitation and stream flow data. The comparison of …