JWSS - Journal of Water and Soil Science

Understanding the quality of groundwater resources, which are the largest available freshwater reservoir, is one of the needs in planning and developing water resources. The purpose of this research was to study the quality changes of groundwater resources in the upstream aquifers of Zayandehrood Dam (1995-2016) and to evaluate water quality in terms of drinking and agricultural consumption and evaluation of IRWQIGC. For this purpose, EC, TDS, SAR, PH, TH, Cl, CO₃, Ca, Mg, Na, K, HCO₃ and NO₃ parameters and heavy elements including zinc, copper, lead, cadmium and arsenic were investigated from laboratory samples. In the upstream aquifers of the Zayandehrood Dam, the water classification was mainly agricultural in the C2-S1 range, and it was generally acceptable in the drinking classes. The amount of heavy elements was allowed. The average amount of nitrate in the Chehelkhaneh, Damanehdaran, Boein-Miandasht and Chadegan aquifers was calculated to be 43.77, 48.08, 35.53 and 26.36 mg / l, respectively, and the maximum nitrate levels in these areas, however, were often exceeded. Nitrate zoning and IRWQIGC were performed by the kriging method. The lowest index values, which fell into relatively poor classes, were in the south and southwestern parts of Boein-Miandasht and south and south-west of the Chehelkhaneh, and in the central parts of Damanehdaran, and the south of Chadegan.

Soil erosion is one of the most serious environmental issues in the world, causing soil degradation, reduction of land productivity, increasing flood, water pollution and pollutions transportation; it is also a serious threat to sustainable development in the world. Therefore, the soil conservation and the prevention of soil erosion and use of conditioners as the nanoclay can be considered as a solution to improve   land productivity and protect environment. The present study was, therefore, conducted to address the effect of the application of montmorillonite nanoclay with three rates of 0.03, 0.06 and 0.09 t ha^-1 on changing runoff and soil loss variables under laboratory conditions. The results showed that the nanoclay with the rate of 0.03 t ha^-1 could decrease the runoff coefficient, soil loss and sediment concentration with the rate of 40.65, 88.38 and 82.19 percent, respectively. The average of soil loss in control treatment and conservation treatments of nanoclay with various rates was measured to be 3.76, 0.44, 1.33 and 3.16 g, respectively. Also, the results showed that the most sediment concentration was the control treatment with the rate of 5.84 g l^-1 and the conservation treatments with nanoclay in the applied rates was 1.04, 3.47 and 2.96 g l^-1, respectively. Also, the results showed that the nanoclay effect was significant on changing the soil loss and sediment concentration at the level of 99 percent. Finally, due to the effect, the use of this conditioner in natural conditions and investigation of the effects on environment and aggregates stability are recommended.