Journal of Advanced Informatics in Water, Soil, and Structure
Volume:1 Issue: 1, Winter 2025

In this study, in order to investigate the trend of changes in precipitation and river flow in Dez basin, were used the river flow (1963-2019) and precipitation (1971-2019) values of stations in Dez reservoir basin in two monthly and annual scales. The distribution of precipitation pattern in the region was also investigated using precipitation concentration index (PCI) and for evaluation the trend of changes in studied values the modified Mann-Kendall test were used. The results of the trend of precipitation changes in the study area showed the decreasing trend of precipitation in all studied stations that due to the slope of the trend line, most of the decrease in precipitation in the studied stations occurred in March. These changes are evident on a monthly and annual scale. Decreasing changes in precipitation in the study area have started since 1991. Decreasing changes in precipitation have a direct effect on flow rate and have caused decreasing changes in flow rate in Tele Zang, Sepid Dasht Sezar, Tang Pang Bakhtiari and Tang Pang Sezar stations. On a monthly scale, the decreasing changes were more significant in the first half of the year (April to October) and March. According to the time of change point in the flow rate time series in the studied stations, it is possible to reduce the flow rate changes in Tele Zang, Sepid Dasht Sezar, Tang Pang Bakhtiari and Tang Pang Sezar stations are about 34, 23, 15 and 43% respectively.

Dams play a key role in supplying water demands, recharging aquifers, and controlling floods, and it is important to accurately study dam break as it could release a huge amount of water and impose catastrophic downstream losses and casualties. An advanced simulation of dam break allows for informing managers of possible losses and casualties to make efficient decisions and effectively manage the crisis. This study presents hydraulics analyzes of the dam break of Tabarakabad and Chahchaheh embankment Dams in Razavi Khorasan Province, Iran. The dam break parameters, flood routing, depth mapping, velocity mapping, primary flood arrival time, and submergible zones were studied for three dam break scenarios, including overtopping, piping, and instantaneous break (sabotage). Numerical analyses were performed in Mathematica environment. The combination of the numerical results and the BREACH model allow for identifying the worst gradual dam break situation through an iterative process and performing unsteady flow analysis in HEC-RAS. Furthermore, the computer code would allow for implementing analyses to determine the most important dam output hydrograph using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). In addition, flood maps under different scenarios were compared between minimum roughness and maximum roughness, discussing the hydraulic results. For risk analysis, a descriptive-analytical (quantitative-qualitative) method was proposed, and a questionnaire was designed. The proposed methodology, which was consistent with passive defense approaches, was implemented with the help of relevant experts and practitioners to assess,  and analyze the dam risks through the developed computer code. Finally, the dam break parameters, flood routing under the aforementioned scenarios, flood mapping, and a draft of the necessary measures were provided. It was found that Tabarakabad Dam had a larger degree of risk than Chahchaheh Dam, and its break would impose serious damage to the adjacent villages and the city of Quchan. However, the efficient operation of Chahchaheh Dam could strongly contribute to stabilization and avoiding break floods. The arrival time of dam-break flood wave to Quchan city was calculated 1 h and 30 min to 2 h, while the arrival time of dam-break flood wave to Chahchaheh Village was calculated 45-60 min after gradual break signs

Every year, significant amounts of funding from government allocations are allocated towards the restoration and conservation of qanats. However, due to insufficient information, some qanats have undergone reconstruction and maintenance despite not being a priority for restoration. Additionally, implementing modern and technical operations in qanat reconstruction requires thorough examination, studies, and design. Through comprehensive identification and supplementary studies, all aspects of the qanats can be assessed from upstream to downstream, and after designing, the initiative for fundamental qanat reconstruction can be taken. Prioritizing qanat reconstruction greatly facilitates this process. This research focus on the revival and restoration of qanats from both managerial and technical perspectives. Using the Analytical Hierarchy Process (AHP) method and Expert Choice software, 10 qanats from the plain group and 10 qanats from the mountainous group were prioritized in each perspective. The indicators used for prioritizing qanats included discharge, length, depth, chemical quality, rainfall, distance from waterways, population, and cultivated area .This research introduces a new scientific method for prioritizing the restoration and rehabilitation of qanats. Additionally, the method employed in this research selects qanats as a priority for rehabilitation and restoration, which can achieve desired irrigation with the allocated cost. In this study, the Boshrouye qanat in the plain group was prioritized for restoration and rehabilitation from both managerial and technical points of view, with weights of 0.17 and 0.163, respectively. Also, the Darmian qanat was prioritized for restoration and rehabilitation in the mountainous group from both managerial and technical perspectives, with weights of 0.265 and 0.219, respectively.

The Muskingum model, widely used in flood routing, is the first order differential equation. The accuracy of the routing storage equation of the model depends on correct parameter estimation and a numerical method employed for its solution. In the present study, different explicit numerical methods are used for solving the equation. These methods include Euler, modified Euler, Runge-Kutta 4th order and Runge-Kutta-Fehlberg. For optimal parameter estimation, Shuffled Complex Evolution (SCE) algorithm is adopted. The performance of different numerical schemes are studied by appropriate evaluation criteria. The methods are tested against three historical and well-known flood data from literature and a field data from Karoon River, Iran as a natural river. Results indicated a good performance of the SCE algorithm and the Runge-Kutta 4th order method in the flood hydrograph numerical simulations. Regarding the sum of squared deviations and for the flood data of Karoon River, the Runge-Kutta 4th order method yielded 18% better results than traditional Euler method in the field condition of a natural river. Similar results can be observed for the first case study, where the Runge-Kutta 4th order method yielded 178% better results than traditional Euler method. However, for second and third case studies the results of all considered numerical methods nearly are in a same level of accuracy. Therefore, it can be said that an appropriate numerical scheme for a hydrological flood routing problem can be adopted by considering the relationship between storage volume and weighted flow.

Drought is a natural and mysterious creeping phenomenon, and many believe that it has a complex mechanism and is less known than other natural disasters. Studying drought events is very important for natural and water resource management planning. One strategy to manage drought is to predict drought conditions using a probabilistic tool. The study aimed to predict the probability and severity of meteorological drought in Kashmar. To this aim, the monthly rainfall data of the Kashmar Synoptic Station was used to analyze a 30-year period (2017-1987). The drought status of Kashmar County was considered by drought duration of The Standardized Precipitation Index (SPI) at 1, 3, 6, 9, 12, 18, 24, and 48-month timescales. Next, using the Markov Chain, the transition probability matrix for the study area was carried out, and the probability of meteorological droughts was predicted for severity. The results of this study showed that the severest drought in Kashmar occurred in 2000 and 2009, with an SPI coefficient of greater than -3, while the highest precipitation occurred in 1993, with an SPI coefficient of 2.8. Then, the Markov chain model was used to calculate the balance probabilities for dry, wet, and normal periods at different time scales. The results showed that, on average, the stationary probability of dry, normal, and wet periods is 29, 30, and 41 percent, respectively. Consequently, it means that the region's climate conditions are often normal. As a result, given the critical situation of Kashmar County, the opportunity to reduce water stress and aquifer discharge can be exploited.

In this research, the objective is to study the process of contaminant transport and pumping in a laboratory model. A two-dimensional laboratory model was used in this research. The length, width, and height of the model respectively were 140 cm, 5 cm, and 57 cm. Chambers were provided on the left and right sides of the model to store water and create a constant hydraulic head. The material used in this model was glass beads, which act similarly to sand particles. Sampling tubes were installed at five points A to E along the length of the model and at three depths. Finally, at specific times after the contaminant release, a sample of the contaminant was injected and its concentration was analyzed. The research results showed that at a gradient of 0.05, the contaminant transport rate was significantly higher than at a gradient of 0.014. Therefore, the depth penetration of the contaminant is less at a gradient of 0.05 than at a gradient of 0.14. On the other hand, contaminant pumping at points C2 and D2 showed that pumping from point C2 more effectively reduced the contaminant concentration in the entire laboratory model. This holds for contaminants with other concentrations as well. Contaminant concentration and hydraulic gradient are two important factors in the amount of contaminant transport. Also, for effective contaminant pumping, the best location for pumping contaminated water is somewhere near the seepage site and in the path of the contaminant movement.

Today, climate change caused by the increase in greenhouse gases is considered one of the important global issues and has led to anomalies in the global climate system. Downscaling methods play a fundamental role in improving the accuracy of General Circulation model outputs (GCMs). Among these, statistical downscaling methods have more efficiency due to their easy and inexpensive calculations compared to dynamic downscaling methods and are used more. In this study, the results of two statistical downscaling models, LARS-WG and Change Factor (CF) or Delta, in simulating temperature and precipitation parameters under three emissions scenarios (RCP2.6, RCP4.5, and RCP8.5) shortly period (2021-2040) were considered based on observational data from the Golmakan synoptic station in the base period (1975-2005). To evaluate the accuracy of the mentioned methods in estimating the variables, statistical evaluation criteria such as Nash-Sutcliffe efficiency, Root Mean Square Error, and correlation coefficient were used. Ultimately, based on the research findings, the LARS-WG model showed less error in simulating minimum and maximum daily temperature and precipitation in the study area and performed better compared to the Change Factor method in climate prediction.