جستجوی مقالات مرتبط با کلیدواژه "قزل اوزن" در نشریات گروه "آب و خاک"

Ghezel Ozan River Basin is one of the important basin in Iran, which supply people grains requirements. The amount of potential reference crop evapotranspiration (ET0) was evaluated with RCP4.5 (low emission) and RCP8.5 (high emission) scenarios on the horizons 2030, 2050, and 2070. The output of four GCM models in CMIP5 and the LARS-WG6 statistical downscaling were used. In this study, the daily historical records of six synoptic stations (namely Zanjan, Mianeh, Khalkhal, Zarrineh, Qorveh, and Bijar) from 1989-2016 were used. Differences of mean ET0 time series in the base and future time periods were tested using the t-test method in three-time scales (i.e. monthly, seasonal, and annual scales) at 5% significance level. Trends of ET0 in the proposed three-time scales were analyzed in the base and 2021-2080 periods with both RCP scenarios using the Mann-Kendall (MK) method at 5% significance level. The effect of significant autocorrelation coefficients was eliminated in MK method. The slope of trend lines was estimated by Sen’s estimator. Results showed in the whole basin, based on the RCP4.5 scenario in the horizons of 2030, 2050, and 2070, the amount of ET0 will be increased by 1.8%, 3.7%, and 5.7%, respectively. These records were about 1.7, 5.4, and 9.1 percent using the RCP8.5 scenario, respectively. The most increase in ET0 was observed for July. The annual ET0 values would be increased in the future in all stations. The mean differences of ET0 in June, July, August, summer, and annual time series with respect to the base time period were significant for all the stations and for all the future periods (under two RCP scenarios). In the future period, according to the both scenarios at all stations, the annual ET0 trend was upward.

Accurate planning for adaptation to climate change is very important in each region. In this study, using the meteorological data of the six synoptic stations in the Ghezel Ozan basin in the period 1989-2016, and by employing the four GCM models, under the two scenarios RCP4.5 and RCP8.5, data were generated for the horizons 2050. Then, some parameters such as the air temperature, precipitation, potential evapotranspiration (ET0), precipitation deficit (PD) during the growing season, dryness intensity were calculated. ET0 was calculated by Pristeley-Taylor (PT) and Penman-Monteith (PM) methods. Then, ET0 obtained from the PT method was calibrated using four Artificial Intelligence methods (namely Eureqa Formulize, ANN, ANFIS and SVM) with PM method for each station. For spatial analysis, three geostatistical methods namely IDW, Kriging, and Cokriging were utilized. The results indicated an increase of 0.9 - 2 ºC in mean air temperature and an increase in precipitation between 27 and 49 mm will be experienced in the future period. Furthermore, ET0 and dryness intensity will be increased at all the stations. The increase in average PD (in the whole basin) will be about 6% to 9%. In average, the rate of increase in agroclimatic indices in the RCP8.5 scenario will be about four percent more than the RCP4.5 scenario. Among the methods of interpolation, the modified Cokriging based on DEM (Digital Elevation Model) showed the more suitable one among others. The length of the growing season will be elongated from 15 to 35 days. No significant changes will be occurred for dryness period. The spatial variation of future climate variables is expected to be not changed comparing the base period.

Water contaminants concentration is important based on water usage in different sections such as domestic, agriculture, and industry, and etc. QzlOuzanRiver has a wide range of potentialities in a variety of economic fields including water transmission, agro-industry, development of organic farming, tourism, and etc. The river reaches the Sefidrood Reservoir after crossing 8 provinces. Recently, an increasing trend in water salinity has been observed in tributaries. In this regard, the water quality in the river and four of its tributaries has been monitored. In order to determine contribution of each pollutant sources, a mathematical model, the Qual2K, has been applied. Results indicated that the contribution of flow in four tributaries, which four of its tributaries are located in the Province of Zanjan, to water salinity of the QzlOuzan River, is significant. The Goorani River with 28.6 percent and the Chesb River with 0.3 percent of pollution load contributed the highest and the least salt load of the QzlOuzan River, respectively.