Impact of surface irrigation practices on groundwater level and water quality in North West Amhara Region, Ethiopia

Alebachew Enyew Tiruye; Pakorn Ditthakit; Dessalegn Tegegn; Fasikaw Atanaw Zimale; Seifu Admassu Tilahun

doi:10.20372/pjet.v1i2.1407

Alebachew Enyew Tiruye Amhara Regional Agricultural Research Institute, Adet Agricultural Research Center, Ethiopia
Pakorn Ditthakit School of Engineering and Technology, Walailak University, Nakhon Si Thammarat 80160, Thailand
Dessalegn Tegegn International Water Management Institute
Fasikaw Atanaw Zimale Faculty of civil and water resource engineering, Bahir Dar University, Bahir Dar, Ethiopia
Seifu Admassu Tilahun Faculty of civil and water resource engineering, Bahir Dar University, Bahir Dar, Ethiopia

DOI: https://doi.org/10.20372/pjet.v1i2.1407

Keywords: Groundwater, Koga, nutrient concentration, surface irrigation

Abstract

Natural resources are degraded continuously due to rapid population, global climate change, poor management, and misunderstanding of the nature of resources. Changes in groundwater level and water quality caused by irrigation practices (overwater application and use of high chemical fertilizers) are currently observed problems. This study focused on the impact of surface irrigation practices on groundwater level and water quality. To investigate the impact of irrigation practices on groundwater quality, a total of 72 groundwater samples were collected from irrigated and non-irrigated fields, and groundwater levels were recorded based on monthly intervals. The concentration of nitrate (NO^-3), phosphate (PO₄), and potassium (K) were analyzed in the laboratory following the standard procedures of photometer methods respectively. One-way ANOVA was used to analysis the data. The result showed that a huge amount of chemical nutrients was deposited in the groundwater wells located in the irrigated area as compared to wells located outside the command area. Similarly, the water levels rose in the irrigated area and the water levels decline outside the irrigated area. This indicates that overwater use and high chemical dose application had a significant effect on groundwater nutrient concentrations and water level changes. For all nutrients, the peak value occurred in April and July for irrigated and non-irrigated areas respectively due to the effect of groundwater recharge long-term event. In conclusion, poor surface irrigation management, an overdose of nutrient application, and unforeseen biological activities aggravate the degradation of groundwater quality and water level changes in irrigated agriculture.