Wetlands are critically impacted by a variety of pollutants, primarily due to their position at the terminus of both surface and subsurface water flows. This study aims to assess the eutrophication status of Zarivar Wetland, situated in Kurdistan Province, Iran. To evaluate the eutrophication levels, the research employed the Iranian Water Quality Index for Surface Water Resources-Conventional Parameters (IRWQI_SC) and the Carlson’s Trophic State Index (TSI) during two sampling periods in July and September 2021. The findings indicate that in July, the wetland exhibited an upper-mesotrophic condition, with an average Carlson index value of 52.2, while in September, it transitioned to both upper-mesotrophic and eutrophic conditions, reflected by an average Carlson index value of 60.17. The zoned map of the eutrophication index identified domestic sewage from Marivan city as a significant contributor to elevated eutrophication levels in the southeastern region. Additionally, runoff from irrigated agricultural lands, orchards, and domestic wastewater from surrounding villages contributed to heightened eutrophication in the northeastern and eastern areas of the wetland. A comparative analysis of water quality between July and September 2021 revealed IRWQI_SC values ranging from 3.57 to 9.72 in July and from 2.63 to 4.72 in September, categorizing them as relatively good and good, respectively. To safeguard Zarivar Wetland, it is recommended to implement measures that prevent livestock waste discharge into the wetland, manage urban and rural sewage systems, control agricultural runoff, and optimize fertilizer application practices.

The extensive exploitation of water resources in Chaharmahal va Bakhtiari province has led to a destructive impact on the water balance and quality of the region. In order to evaluate water quality of the study area, water quality parameters from 132 wells were analyzed to prepare spatial distribution maps of the IRWQI index. To analyze spatial and temporal rainfall anomalies, the SPI index was spatially interpolated using the ordinary Kriging method. Principal component analysis was used to investigate the relationship between water quality parameters. The suitability of data for PCA was evaluated by the Kaiser–Meyer–Olkin and Bartlett tests. Additionally, water balance components of the study area, including surface runoff and ground water, were simulated using the WetSpass-M model. According to the results of the IRWQI index, 54 wells, mostly located in built-up and agricultural lands, had poor quality․ Investigation of the average groundwater quality during the years 2007 to 2017 shows that the trend of groundwater quality decreased. Comparison of drought and water quality maps showed similar patterns so that in areas with extreme drought, water quality was bad. The highest and lowest recorded concentrations for nitrates were related to built-up and rangeland lands with concentrations of 35 and 21 mg/l, respectively. Comparison among land use classes showed that in the rangelands, groundwater quality was better and nitrate level was lower compared to agricultural and built-up areas. Overall, the results of this study show that water quality can be affected by land use types and water balance components.

Wood finger joints are widely used in both structural timber and high-quality furniture due to their ability to create long, continuous members from shorter pieces. The mechanical performance of these joints depends not only on the wood species but also on the geometry of the interlocking teeth and the quality of the adhesive bond. This study explores how the geometry of finger joints affects the tensile behavior and fracture characteristics of beech (Fagus sylvatica L.) and oak (Quercus robur L.). Specimens with varying tooth dimensions were tested using a 50 kN universal testing machine from Shimadzu. Key metrics such as ultimate tensile load, effective cross-sectional area, cohesive stress, energy required to cause failure, and fracture energy (G_c) at 0.5, 1.0, and 2.0 mm displacements were systematically measured. The results revealed that beech specimens achieved ultimate tensile loads up to 21,320 N and cohesive stress of 204 MPa, while oak reached 21,631 N with a cohesive stress of 239 MPa. Fracture energy (G_c) values ranged from 0.036 N/mm for beech to 0.051 N/mm for oak, depending on joint geometry. Results show that both the type of wood and the tooth design, including width and length, play a decisive role in joint performance. In general, longer teeth and larger bonded areas improved tensile capacity and increased resistance to fracture. These findings offer deeper insights into the fracture mechanics of hardwood finger joints and provide practical guidance for optimizing glued connections in furniture and structural timber. The collected data can also support accurate modeling, quality assurance, and numerical simulations in future studies.