Assessment of remotely sensed drought features in vulnerable agriculture

Abstract

Abstract. The growing number and effectiveness of Earth observation satellite systems, along with the increasing reliability of remote sensing methodologies and techniques, present a wide range of new capabilities in monitoring and assessing droughts. A number of drought indices have been developed based on NOAA-AVHRR data exploiting the remote sensing potential at different temporal scales. In this paper, the remotely sensed Reconnaissance Drought Index (RDI) is employed for the quantification of drought. RDI enables the assessment of hydro-meteorological drought, since it uses hydrometeorological parameters, such as precipitation and potential evapotranspiration. The study area is Thessaly, central Greece, which is a drought-prone agricultural region characterized by vulnerable agriculture. Several drought features are analyzed and assessed by using monthly RDI images over the period 1981-2001: severity, areal extent, duration, periodicity, onset and end time. The results show an increase in the areal extent during each drought episode and that droughts are classified into two classes, namely small areal extent drought and large areal extent drought, respectively, lasting 12 or 13 months coinciding closely with the hydrological year. The onset of large droughts coincides with the beginning of the hydrological year, whereas the onset of small droughts is in spring. During each drought episode, the maximum occurs usually in the summer and they all last until the end of the hydrological year. This finding could justify an empirical prognostic potential of drought assessment.

Risk identification of agricultural drought for sustainable Agroecosystems

“…It is felt that it should also be mentioned that irrigation is a common agricultural practice during the warm season in the study area, which may affect drought analysis. Indeed, the purpose of the approach presented in this paper is to develop a remote-sensing methodology under conditions of existing agricultural practice, including irrigation, and the results have shown consistency, which has also been achieved in similar recent studies in the study area (Dalezios et al, 2012a;Kanellou et al, 2009aKanellou et al, , 2012.…”

“…At first, it should be mentioned that there is an on-going research effort on droughts in the study area of Thessaly. In a recent study on hydrological drought using the reconnaissance drought index (RDI) based on satellite and conventional data (Dalezios et al, 2012a), there are eight detected drought periods lasting 12 months each within the same 20-year study period. However, in this paper, which deals with agricultural drought using VHI, and for the same period, drought occurs every year during the warm season, namely from May to October.…”

“…There is an increasing trend for the use of remote sensing in drought assessment, mainly due to the growing number and efficiency of earth-observation satellite systems, along with the increasing reliability of remote-sensing methods (Dalezios et al, 2012a;Kanellou et al, 2012). Specifically, remote-sensing data and methods can be employed in several aspects of drought, such as vulnerability, damage assessment and warning.…”

“…Indeed, remote-sensing data and methods can delineate the spatial and temporal variability of several drought features in quantitative terms (Dalezios et al, 2012a). A description of some key features follows.…”

Long term and seasonal ground deformation monitoring of Larissa Plain (Central Greece) by persistent scattering interferometry

“…The increased water demand has been associated with severe extreme and persistent drought episodes in the last decades [2,5]. The dry conditions resulted in irrigation cutbacks, over-exploitation of ground-water and significant losses of crop fields.…”