Hydrochemical characteristics and irrigation suitability of surface water in the Syr Darya River, Kazakhstan

Weiyan Zhang,Long Ma,Galymzhan Saparov,Yongxiao Ge,Jilili Abuduwaili,Gulnura Issanova

doi:10.1007/s10661-019-7713-8

Abstract

The surface water hydrochemistry of the Syr Darya River in Kazakhstan was investigated at 39 locations to analyze regional hydrochemical characteristics and evaluate the irrigation suitability of the studied regions. The cations in the surface water are mainly Na+, Ca2+, and Mg2+, while the anions are mainly SO42−. The main hydrochemical type is Ca-Mg-SO4-Cl. From the perspective of natural factors, the hydrochemical characteristics in the study area are derived from the dual effects of rock weathering and evaporation-concentration; however, the influence of anthropogenic factors include industrial and agricultural production near the river and the inflow of urban domestic sewage on the hydrochemical characteristic is also present. The irrigation suitability evaluation of the surface water based on SAR, Na% and KI showed that the majority of the water is suitable for irrigation, and from the TDS content analysis, 71.43% of the samples are in a critical state, indicating that the influence of TDS concentration on irrigation suitability cannot be ignored. The results have practical significance for maintaining the sustainable use of water resources in the Syr Darya River.

Highlights

The hydrochemical characteristics of water are indicative of the climate and environment in the area where the river flows
The total dissolved solids (TDS) values indicated that the salinity of surface water in the study area varied between 342.00 mg L−1 and 4014.00 mg L−1, with a mean value of 1144.49 mg L−1, 94.87% of samples were above the limit of 500 mg L−1 which indicating the presence of slightly salinity and related to the problem such as hardness (Herojeet et al 2013), and approximately
From the average ion concentrations, the main anions were dominated by SO42−, followed by HCO3− and Cl−, and the least abundant anion was CO32−, the average content of SO42− in the study area was higher than the limit value of fishery 100 mg L−1 but lower than the standard value of drinking water 500 mg L−1, it will affect the safe of fishery; the main cations were dominated by Na+, Ca2+ and Mg2+, and the content of K+ was relatively small

Summary

Introduction

The hydrochemical characteristics of water are indicative of the climate and environment in the area where the river flows. 572 Page 2 of 17 main ion composition in water can be used to identify and control the basic processes affecting the chemical composition of the water, such as the weathering of rocks in river basins, the evaporation and concentration of water bodies, and the input of atmospheric compounds via precipitation (Han and Liu 2004; Sadashivaiah and Ranganna 2008; Dinka et al 2015) Anthropogenic activities such as irrigation have a great influence on the water salinity, many salts, and agrochemical loadings will affect the water quality with irrigation return flows (Isidoro and Aragüés 2007). 100% of the irrigated area in Kyzylorda and 67.8% of the area in South Kazakhstan is moderately or highly saline, which results in large-scale crop reductions (Murray-Rust et al 2017)

Methods

Results

Conclusion