11:00 AM - 1:00 PM
[HTT15-P06] LUCC and Groundwater Change Quantification in a Hyper-arid Region
- A case study in New Valley, Egypt
As one of the world’s hyper-arid areas, Egypt's New Valley Governorate has faced a severe water problem. Monitoring the trend of land use land cover (LUCC) changes in New Valley has essential reference significance for regional environmental and water resource management. Thus, this study constructed and analyzed time-series LUCC maps to identify the LUCC changes (LUCCs) over extensive periods across the oases of New Valley and understand the change trends.
The analysis of LUCC from 1986 to 2019 in the oases of New Valley utilized Landsat multi-temporal images and OBIA (object-based image analysis) algorithm on eCognition 10.0. After revealing the LUCC changes in the study area, we quantified the primary water consumption pattern (i.e., [irrigation] for agricultural use) for estimating the consequence of agricultural area on water consumption in the study area. The overall changes in irrigation water usage were calculated using Egypt's agricultural area and the total agricultural water consumption, combined with the agricultural land area of the study area.
The analysis of groundwater utilized two GRACE mascon solutions from 2002 to 2021 in the New Valley. The Groundwater usage in New Valley for 2002–2021 was extracted.
The OBIA method that we extended in this study can effectively and reliably monitor the changing LUCC trend of New Valley oases.
Through the change detection and spatial analysis, our research shows that each class in three oases is increasing. Irrigation water usage also showed an increasing trend, while GWS of new-valley continuously decreased. For aquifers, no correlation was found between the atmospheric hydrological fluxes and the GWS in the NSAS, as expected for a fossil aquifer.
The total agricultural irrigation water use from 2002 to 2021 is consistent with the reduction in GWS calculated by GRACE. Although there are some gaps, the overall result is reasonable considering population water, a small amount of industrial water, and wells dug by farmers that are not counted. This research provides an essential reference for regional environmental management and water resource management in New Valley, Egypt.
The analysis of LUCC from 1986 to 2019 in the oases of New Valley utilized Landsat multi-temporal images and OBIA (object-based image analysis) algorithm on eCognition 10.0. After revealing the LUCC changes in the study area, we quantified the primary water consumption pattern (i.e., [irrigation] for agricultural use) for estimating the consequence of agricultural area on water consumption in the study area. The overall changes in irrigation water usage were calculated using Egypt's agricultural area and the total agricultural water consumption, combined with the agricultural land area of the study area.
The analysis of groundwater utilized two GRACE mascon solutions from 2002 to 2021 in the New Valley. The Groundwater usage in New Valley for 2002–2021 was extracted.
The OBIA method that we extended in this study can effectively and reliably monitor the changing LUCC trend of New Valley oases.
Through the change detection and spatial analysis, our research shows that each class in three oases is increasing. Irrigation water usage also showed an increasing trend, while GWS of new-valley continuously decreased. For aquifers, no correlation was found between the atmospheric hydrological fluxes and the GWS in the NSAS, as expected for a fossil aquifer.
The total agricultural irrigation water use from 2002 to 2021 is consistent with the reduction in GWS calculated by GRACE. Although there are some gaps, the overall result is reasonable considering population water, a small amount of industrial water, and wells dug by farmers that are not counted. This research provides an essential reference for regional environmental management and water resource management in New Valley, Egypt.