Spatiotemporal Variations in Water Quality under Land Use/Land Cover in the Khabur River

One of the most pressing water quality issues in semi-arid regions, where seasonal pressures and anthropogenic impacts reduce river flows, affects ecosystem health and human well-being, as well as sustainable water management. Thus, the research investigated spatiotemporal changes in Khabur River water, including physicochemical parameters and heavy metals, with correlations drawn from probable land use/land cover in that geographic area. Ten sites spaced ~13 km apart over a 130 Km stretch were sampled once a month for a year. In situ measurements were made for water temperature, pH, electrical conductivity, and total dissolved solids, while laboratory parameters included dissolved oxygen, turbidity, major ions, nutrients, and the heavy metals Ag, Al, As, B, Ba, Li, Sr, and Cd. Land-use/land-cover changes percentages were calculated for each site within a 500-meter buffer using ArcGIS Pro. The results showed that temperature, pH, and EC varied between (7.1-31.1°C), (7.4–8.9), and (344.62 µS/cm), respectively, while the mean value of TDS was (172.59 mg/L), showing a clear seasonal variation. Heavy metal Boron ranged from (1-3.01), exceeding the WHO guideline limits. Concentration of some heavy metals was decreased by the presence of forests and shrublands, whereas cropland, bare land, and sediments enhanced levels of Level of heavy metals such as Cd, B, Sr, and Ag. Most variables exhibit a marked seasonality factor, though their spatial gradients are seemingly quite specialized as the spatial scale increases. The physicochemical qualities that determine water quality are mainly governed by the interaction of hydrological regimes and the impact of land-use/land-cover changes (LULC) on metals and nutrients. Therefore, sustainable land management coupled with constant monitoring should be instituted immediately.