ABSTRACT

The purpose of this study is to investigate the quality of water resources for drinking, agricultural, and industrial uses, based on World Health Organization (WHO) standards, the Wilcox and Schoeller diagrams using Chemistry software, and the Langelier Saturation Index (LSI) and Ryznar Stability Index (RSI) in a section of the Masouleh Rudkhan River located in Guilan Province. Data from three hydrometric stations, Zudel, Kamadul, and Chamethqal, were used to assess water quality parameters, including pH, Ca, Mg, Na, EC, TDS, SAR, TH, Cl, SO4, and HCO3. By comparing the water quality variables with the World Health Organization standards, it was indicated that the water quality of the river in the study area was within the permissible range. According to the Willcox and Schuller quality indices, the river water was suitable for agricultural use and good for drinking purposes. Based on the Langelier and Ryznar indices, the available water resources were reported as corrosive. Therefore, to prevent irreparable damage, appropriate and comprehensive management is required, which can reduce excessive extraction of water resources through supply and demand management. Additionally, to preserve and protect these waters resources, further studies such as preparing quantitative and qualitative maps of the region's water resources using modern and accurate methods, are effective.

ABSTRACT
The purpose of this study is to investigate the quality of water resources for drinking, agricultural, and industrial uses, based on World Health Organization (WHO) standards, the Wilcox and Schoeller diagrams using Chemistry software, and the Langelier Saturation Index (LSI) and Ryznar Stability Index (RSI) in a section of the Masouleh Rudkhan River located in Guilan Province. Data from three hydrometric stations, Zudel, Kamadul, and Chamethqal, were used to assess water quality parameters, including pH, Ca, Mg, Na, EC, TDS, SAR, TH, Cl, SO4, and HCO3. By comparing the water quality variables with the World Health Organization standards, it was indicated that the water quality of the river in the study area was within the permissible range. According to the Willcox and Schuller quality indices, the river water was suitable for agricultural use and good for drinking purposes. Based on the Langelier and Ryznar indices, the available water resources were reported as corrosive. Therefore, to prevent irreparable damage, appropriate and comprehensive management is required, which can reduce excessive extraction of water resources through supply and demand management. Additionally, to preserve and protect these waters resources, further studies such as preparing quantitative and qualitative maps of the region's water resources using modern and accurate methods, are effective.

EXTENDED ABSTRACT

Introduction

Surface water is the most important water resources and plays a significant role in supplying water for various activities such as agriculture, industry, and drinking. There are various standards to assess drinking water quality. The Schoeller diagram can identify drinking water quality. To determine agricultural water quality, the Wilcox classification can be used. Also, to classify water for industrial uses, the Langelier Saturation and Ryznar Stability index are used. Numerous studies have been conducted on water resources quality such as; Cham Anjir River water quality, based on the Schoeller diagram, is good and acceptable for drinking, Tuo River water quality have high salinity and low alkalinity, which can be used for irrigation, while the Bian River water quality had high salinity and were suitable for irrigating plants with high salt tolerance. The purpose of this study is to determine the water quality of the Masouleh Rudkhan River at the Chamethqal, Zudel, and Kamadul hydrometric stations in the Masouleh Rudkhan watershed.

Materials and methods
In this research, data recorded at three hydrometric stations, Zudel, Kamadul, and Chamethqal, located in the Masouleh Rudkhan watershed in Guilan Province, were used. This study examined parameters such as pH, Ca, Mg, Na, EC, TDS, SAR, TH, Cl, SO4, and HCO3 were examined as key water resource quality parameters. The Zudel, Kamadul and Chamethqal stations are located upstream, midstream and downstream of the river. In assessing the water quality of the Masouleh Rudkhan River for drinking and agricultural purposes, Chemistry software was used, along with the Schoeller and Wilcox diagrams. River water quality is investigated using the World Health Organization standard and Langelier Saturation and Ryznar Stability Index for industrial use.

Results and discussion
It can be summarized that pH, Ca, Mg, Na, TDS, TH, Cl, SO4, and HCO3 are within a good range, EC is moderate, and SAR is at a low risk of alkalization. The Schoeller diagram indicates that the Masouleh Rudkhan River water quality is in good category for drinking purposes. The Wilcox diagram shows that the river water quality is slightly saline and suitable for agriculture. The results of the Langelier Saturation and Ryznar Stability Index indicate that the Masouleh Rudkhan River water quality is corrosive for industrial uses and can have an adverse effect on well equipment and water supply facilities. The results of this study consistent with the studies conducted by Akhourzadeh on the Dez River and by Izadi et al., on the Khorramabad River.

Conclusion
The following suggestions are provided for water resource management. Water supply and demand management can be reduced excessive water withdrawal from water resources. Due to the limited availability of water resources and increasing final cost of water extraction, allocating water resources to projects with the highest efficiency is essential. Economic comparison and prioritization of projects are of great importance. Preparing quantitative and qualitative maps of the region's water resources using modern and accurate methods is effective. The use of new irrigation technologies compatible with climatic and agricultural conditions should be carefully selected.

EXTENDED ABSTRACT

Introduction

Surface water is the most important water resources and plays a significant role in supplying water for various activities such as agriculture, industry, and drinking. There are various standards to assess drinking water quality. The Schoeller diagram can identify drinking water quality. To determine agricultural water quality, the Wilcox classification can be used. Also, to classify water for industrial uses, the Langelier Saturation and Ryznar Stability index are used. Numerous studies have been conducted on water resources quality such as; Cham Anjir River water quality, based on the Schoeller diagram, is good and acceptable for drinking, Tuo River water quality have high salinity and low alkalinity, which can be used for irrigation, while the Bian River water quality had high salinity and were suitable for irrigating plants with high salt tolerance. The purpose of this study is to determine the water quality of the Masouleh Rudkhan River at the Chamethqal, Zudel, and Kamadul hydrometric stations in the Masouleh Rudkhan watershed.

Materials and methods
In this research, data recorded at three hydrometric stations, Zudel, Kamadul, and Chamethqal, located in the Masouleh Rudkhan watershed in Guilan Province, were used. This study examined parameters such as pH, Ca, Mg, Na, EC, TDS, SAR, TH, Cl, SO4, and HCO3 were examined as key water resource quality parameters. The Zudel, Kamadul and Chamethqal stations are located upstream, midstream and downstream of the river. In assessing the water quality of the Masouleh Rudkhan River for drinking and agricultural purposes, Chemistry software was used, along with the Schoeller and Wilcox diagrams. River water quality is investigated using the World Health Organization standard and Langelier Saturation and Ryznar Stability Index for industrial use.

Results and discussion
It can be summarized that pH, Ca, Mg, Na, TDS, TH, Cl, SO4, and HCO3 are within a good range, EC is moderate, and SAR is at a low risk of alkalization. The Schoeller diagram indicates that the Masouleh Rudkhan River water quality is in good category for drinking purposes. The Wilcox diagram shows that the river water quality is slightly saline and suitable for agriculture. The results of the Langelier Saturation and Ryznar Stability Index indicate that the Masouleh Rudkhan River water quality is corrosive for industrial uses and can have an adverse effect on well equipment and water supply facilities. The results of this study consistent with the studies conducted by Akhourzadeh on the Dez River and by Izadi et al., on the Khorramabad River.

Conclusion
The following suggestions are provided for water resource management. Water supply and demand management can be reduced excessive water withdrawal from water resources. Due to the limited availability of water resources and increasing final cost of water extraction, allocating water resources to projects with the highest efficiency is essential. Economic comparison and prioritization of projects are of great importance. Preparing quantitative and qualitative maps of the region's water resources using modern and accurate methods is effective. The use of new irrigation technologies compatible with climatic and agricultural conditions should be carefully selected.