Evaluation of Water Quality in Ialomita River Basin in Relationship with Land Cover Patterns

The paper reviews the state of water quality in Ialomita River Basin (IRB), Romania, between 2007 and 2018 using the land use/land cover and basin-specific conditions effects on sediments and nutrients load. On-site monitoring was performed in two control sections of the Ialomita River, one in the upper part of the basin (near Targoviste city) and the second near the discharge into the Danube (downstream of Tandarei town). The statistical averages of water parameters for 10 years' monitoring in the control section that is close to the Ialomita River discharge in Danube were pH = 7.60 (range: 6.41-8.40), NH4-N = 1.20 mg/L (0.02-14.87), alkalinity = 4.12 mmol/L (1.34-6.27), NO3-N = 2.60 mg/L (0.08-17.30), PO4-P = 0.09 mg/L (0-0,31), dissolved oxygen (DO) = 8.87 mg/L (2.72-15.96), BOD5 = 5.50 mg/L (0.01-74.71), suspended solids (TSS) = 508.32 mg/L (15.2-4457), total dissolved salts (TDS) = 733.69 mg/L (455.2-1053), and river discharge = 38.60 m(3)/s (8.22-165). Expected mean concentration and soil and water assessment tool (SWAT) modeling have been employed in the GIS environment to extend the approach to large spatial patterns within the basin. The estimated average specific emission on the total area for nitrogen was 3.2 kg N/ha, and 0.3 kg P/ha for phosphorus highly influenced by the agricultural activities. The results are useful to raise awareness regarding water-quality degradation and the need to stop and even reverse such trends for local and national sustainable development.