Assessing Physicochemical Parameters and Trophic Status of Lake Hayq, South Wollo, Ethiopia

Abstract Lakes are one of the most important resources for human like tourism, irrigation and drinking. Hence lake water quality should be regularly monitored for better management of the water resources. The aim of the study was to assess the current physicochemical property and the trophic status of lake Hayq which is located in the norther part of Ethiopia. Using non probability with judgmental sampling method, eighteen water samples at six sampling sites were collected in pre wet season (May), wet (July) and post wet (December) of 2020. Both on site and laboratory analyze of water quality parameters were conducted. Data analyses used descriptive statix10 to summarize and analyze of the data, T-test for temporal variation and, GIS (IDW) interpolation was used for analyzing of spatial variation. The result shows, the mean value of temperature 27.3C°, turbidity 7.8NTU, SD 1.3m, pH 8.5, EC 908.83µs/cm, TDS 464.8mg/L, TP1.3mg/L, TN 21.84mg/L, DO 7.69mg/l, COD 13.33mg/l, BOD 6.40 mg/L and chlorophyll a 35µg/L. The comparison of result with fresh water guideline (EPA/USEPA) T, DO, pH and EC with in permissible limits and TDS, Tur, TP, TN, COD, BOD and CH-a was above permissible limits. The temporal variation of pollutions was statistically significant (p<0.05) in average dry and wet. GIS IDW interpolation shows significant color difference in spatially variation of parameters along lake shore. Trophic State index was TSI 76.7 and TLI 67.5 that indicates higher eutrophic level. Therefore, providing terrace, buffer zone, and silt trap are needed to reduce the overflow of pollution.