ABSTRACT
Drought events with varying intensity are usually reported from every part of the globe. The spatiotemporally varying climatic factors such as rainfall, temperature, evaporation, and soil moisture are triggering droughts of different intensities. It is very difficult to estimate these varying parameters with traditional field measurement. This chapter provides an overview of how remote sensing and the geographical information system (GIS) can be used for the monitoring, assessment, and forecasting of drought phenomena. The recent advancements in the field of remote sensing techniques provide capabilities to estimate hydrological parameters important for drought studies, such as rainfall, evapotranspiration (ET), soil moisture, land surface temperature (LST), and vegetation status at reasonable spatial and temporal scales. Those sensors that can be used to derive such parameters are discussed in detail. With the advancement of computing technology, the capabilities of GIS have also improved. In each section, can be utilized to extract information at the required spatial or temporal scale is depicted through descriptive figures. Examples of GIS application in deriving various indices using remote sensing inputs are also given. The capabilities of geospatial technology in the field of hydrological modeling are also presented. A list of global, national, and regional drought 218monitoring, assessment, and early warning system has been provided. Certainly, remote sensing data and the GIS technique can be effectively used to develop a decision support system with respect to monitoring, assessment, and forecasting of drought.
