REMOTE SENSING AND EMPIRICAL METHODOLOGIES TO ASSESS GREEN WATER FOOTPRINT IN RIVER BASIN SCALE

摘要

Fresh water, a scarce natural resource, is essential in every aspect of life. However, it seems to be the most affected environmental component by human activity. Overpopulation, overconsumption, pollution and climate change effects, in conjunction with issues such as conflicting water uses and increasing needs of human kind for fresh water, have led to the deterioration of water quality as well as its quantity, a fact that has a significant impact on the environment and the global ecological status. For this reason, it is urgent that we adopt tools and processes that will improve the current situation.In this paper, empirical and remote sensing methodologies will be applied and compared to estimate the green component of water footprint (WF), in a period of four years, for three main land uses in a river basin: croplands, woodlands and pastures. The Water District of Western Peloponnese (GR01) which consists of two river basins was selected as the area of interest. Empirical methods were employed for estimating the contribution of evapotranspiration (ET) in green WF. In particular, the "Blaney - Criddle" approach was employed on croplands and pasture and the "Hargreaves" approach on woodlands (Marini et al., 2015). The analysis of the multitemporal remote sensing datasets was based on the MODIS Surface Resistance and ET (MOD 16) Level 4 product (Mu et al., 2011). The preliminary results which derived from the analysis and the quantitative comparison are presented so as to evaluate the green WF estimation obtained from the empirical and remote sensing approaches in a river basin scale.