Investigating land use changes and trends of hydro morphological indicators on the area and volume of the Ovan Lake's water zone based on the time series of Landsat data

One of the most important approaches to preserve and restore wetlands, is identifying environmental changes from past to present and developing an integrated management plan to control these changes and decision-making to provide solutions for improving the condition of these valuable ecosystems. Ovan Lake, as one of the beautiful and touristic landscapes in the forbidden hunting area of Eastern Qazvin, has distinct mountain habitats and various species of wildlife. By employing remote sensing techniques for a 30-year period, the process of changes and land use in the hydrological unit leading to Ovan Lake were identified and the trend of their changes was obtained quantitatively in this research. Then, the effect of the related hydromorphological indicators on the area and volume of the lake was investigated. The results showed that, according to the Modified Normalized Difference Water Index (MNDWI), the average area of the lake water zone was 8.15 hectares over the past eight years and based on univariate regressions, its hydrological regime is mainly related to two important factors of precipitation and evaporation. According to the univariate regressions demonstrate a significant relationship between the lake's hydrological regime and precipitation/evaporation rates. The evaporation parameter also showed a logical trend during the statistical years, so that the area and volume of the water zone of the lake has decreased by the increase of evaporation from the free surface of the water. Also, the results of multivariate regression between lake water volume and rainfall and evaporation components showed that the lake volume is more correlated with rainfall. But in contrast, evaporation changes with a greater slope or rate.