جستجوی مقالات مرتبط با کلیدواژه "lars wg" در نشریات گروه "اکولوژی"

In this research, the changes in the frequency intensity curve for the Zone No. 6 of Tehran municipality (Mehrabad synoptic station) under the influence of climate change were investigated by using the Abkhezr-Ghahreman relationship. The information related to the current research includes two categories: First category includes hourly rainfall data measured in order to derive IDF curves for the base period (1980-2020). The second category includes the predicted daily rainfall data for the near future (2021-2050) and the far future (2051-2100), which were obtained from the output of the LARS model. First, using EasyFit software, statistical analysis was done on the observational data and the best distribution (Gamble distribution) was selected and the corresponding IDF curves were extracted for different return periods. To extract the IDF curves under the influence of climate change, the general circulation model of the atmosphere HadGEM - ES from the series of CMIP5 models under RCP2.6, RCP4.5 and RCP8.5 emission scenarios was used. The results showed that the rainfall intensity in all rainfall interval duration and different return periods in all three scenarios have increased compared to the intensity duration frequency curve of the base period, and only for the near future (2021-2050) under the RCP 8.5 scenario, there is a decreasing trend compared to the base period will have. For example, interval duration of 4 and 24 hours for the return period of 10 years, the amount of precipitation intensity for the scenario RCP 2.6 and RCP 8.5 for the distant future (2051 -2100) is 7.05, 7.1 and 2.56, 2.58, respectively, while which for the base period (1980-2020) is 6.71 and 2.44, respectively, which indicates the increase in the intensity of maximum rainfall with the increase of the return period. It can be concluded that the maximum intensity of rainfall has increased in short-term time base and with the passage of time, the intensity of the maximum rainfall has decreased, and the IDF curves are affected by short-term rainfall.

Considering the importance of the effects of climate change on water resources, it is useful and necessary to study the behavior of the river, especially its discharge in future periods, to manage water resources and provide solutions to adapt to the phenomenon of climate change. The purpose of this study is to investigate the effect of climate change on the discharge of the Zolachai River in West Azerbaijan Province. For this purpose, using the LARS-WG model, the precipitation and temperature values of the Upper Chehriq meteorological station under different scenarios from 2021 to 2080 were predicted. Then, based on the microscale data of future precipitation and temperature, the volume of run-off output of the basin in future periods was simulated using the IHACRES rainfall-runoff model. The results of runoff forecast during future climatic periods showed that the average long-term annual run-off changes during the period 2080-2021 at the rate of 1.12 cubic meters per second (33.34%) under the RCP2.6 scenario, 1.17 cubic meters per second (0.67 33%) under the RCP4.5 scenario and 1.37 cubic meters per second (39.42%) under the RCP8.5 scenario compared to the base period.

The Climate change can be a major threat to biodiversity and ecosystem integrity. Therefore, prediction of hydrological behavior of watersheds for conservation and reconstruction of ecosystems is necessary. In this research SWAT semi-distribution hydrological model was used to evaluate water flow and water balance by changing climate in Latyan dam near Tehran during 1988-2014. Also, the output of the CMIP5 series model is under two scenarios RCP 2.6 and RCP8.5 for the near future using the model, LARS-WG was introduced into the mode.The result of stimulation for 2021-2050 showed that mean temperature increases by 0.75 C° for RCP 2.6 optimistic scenario and 1.45 C° for RCP 8.5 pessimistic scenario. In addition, rain was reduced by 2 % in RCP 8.5 and 5 % in RCP 2.6. The result for water flow showed that high level of water flow decreases by 2.4 cubic meter per second in May and increases by 1.49 in April. The water flow in RCP 8.5 scenario for May and June was greatly reduced which it can negatively affect level of water in dam until starting rain. Average evapotranspiration was increased by 3 mm in optimistic scenario and 8 mm in pessimistic scenario which it negatively affects the accessible water resource. Reduction of rain was predicted for two scenarios.