مجله اکو هیدرولوژی
سال هشتم شماره 3 (پاییز 1400)

Flood is defined as one of the most dangerous kinds of natural disasters which have caused massive damages, deaths, and economic conflicts on the Latian river basin. Participatory planning is one of the recent planning approaches that has been utilized by planners in a variety of fields such as urban planning, urbanism, environmental planning, and crisis management through the last decades. In this study, with the consideration of the recent investigations over this river basin, region specifications, habitants, and conditions of the Latian river basin, the effective variables of participatory planning were selected. Economical, social, governmental, cultural, and environmental variables were chosen as effective variables in participatory planning in flood management. These variables were then compared with each other, for which the Analytic hierarchy process (AHP) method was used to compare and rank the variables because due to the multiplicity of expert opinions and the complete stability, it is possible to calculate the weight of each variable using the data normalization method. After analyzing the data, which are the results of the opinions of 21 experts, it can be concluded that the economic variable with the highest weight is in the highest rank compared to other variables, the governmental variable is placed after the economic variable in the second rank, the social and cultural variable is in the third place after the governmental variable, and the environmental variable is in the fourth place after the social and cultural variable.

The erosion phenomenon and sediment transport are the most important hydrodynamic processes that effect watersheds, rivers, coasts, ports, dams, bridges, roads, farms, and civil facilities. Waz is one of the main rivers on the northern slope of Alborz in Mazandaran province. This river has a morphological dynamic behavior and affected by various factors including geology, slope, land-use, and the condition of hydraulic flow. The aim of this study was to assessing the bank of Waz River stability using BANCS model, which is include NBS and BEHI indexes. To assessing the rate of bank erosion in the Waz River, in a three kilometer interval, eight cross-section were selected using field impression and mapping the parameters e.g. side height and angle, bank-full width, bank-full average depth, the maximum average-depth of bank in bank-full, the curvature radius, and bank material based on NBS and BEHI models. Regarding the results for each cross-section based on bank erosion risk index, near bank shear stress and comparing with field surveys, the banks with more risk of bank erosion and more stable banks were determined. Besides, comparing the results obtained from BEHI and NBS models with field surveys showing more efficiency of BEHI model for the Waz River.

Abstract Despite the need to determine the threshold of sustainable use of rangeland ecosystems, especially in drought conditions, no significant progress has been made in recent years, and still time-consuming and costly sampling of species production in a period of 5 to 10 years is used. In this study, to determine and monitor the threshold of sustainable use of rangeland ecosystem, the satellite index and meteorological drought index has been used, while the satellite index was determined by field measurement of canopy cover in a one-year period 2018-2019 in part of the basin of the Karaj river watershed. In this regard, In 3, 6, 9 and 12 month time steps, And the maximum satellite index (NDVI) during the growth period in the target years was determined over a period of 20 years. The results showed that there is a correlation coefficient of about 60% between satellite index and plant density, and in the normal years the satellite index has a correlation coefficient of is about 70% with the index of meteorological drought and 9-month cumulative rainfall leading to the period of maximum growth. Using the permitted harvest coefficients, the operating thresholds for the allowable range of the satellite index were determined and eventually the value of satellite index (NDVI) for the sustainable exploitation of the rangeland was proposed as (0.07459 ± 0.00908) and (0.1799±0.0194) for dry and wet years respectively, is recommended.

Optimizing the piezometric wells in the groundwater monitoring network is important in terms of reducing maintenance costs and improving efficiency and increasing the speed of data updating. Statistical methods or PCA are commonly used to identify significant wells. In geostatistical methods, optimization is performed according to the location of the samples but the temporal information of the wells is not taken into account. In the PCA method, indicator wells are determined in terms of temporal information of wells. In this research, an approach based on a combination of these two methods is presented to consider the spatiotemporal information of wells. The present study was conducted by obtaining data from 47 wells related to the first aquifer of Sarab plain in 1397 in three main stages: 1- Exploratory spatial data analysis (ESDA), 2- Determining the priority of wells based on temporal information of the wells in the neighborhood by PCA method, 3- Investigating the surface accuracy changes by kriging method assuming the removal of wells with low temporal priority. The results showed that 9 wells of Sarab plain (19%) have relative importance less than 0.3. By removing these wells and evaluating the RMSE error in the deleted points, the value of these wells can be calculated with 46cm error through spatial autocorrelation information. Therefore, the removed wells do not enter much spatial information, and by removing them, it is possible to increase the accuracy of measuring the water level in other wells and save time and cost with the same accuracy.

Groundwater is an important source of exploitation in arid and semi-arid regions. For this reason, in order to maintain groundwater quality and its optimal management, it is important to know their spatial and temporal distribution and their monitoring and zoning should be considered as an important principle in the country's water resources planning. The aim of this study was to zoning the electrical conductivity of groundwater in the Mashhad plain aquifer using 5 methods of distance inverse geostatistics (IDW), local estimator (GPI), general estimator (LPI), kriging and cokriging and also evaluating the gene expression programming model in predicting this The parameter is using spatial data. For the present study, data from 122 observation wells in the aquifer area of Mashhad plain were used. To compare the methods used, two squares evaluation criteria were the mean squared error (RMSE) and the mean absolute error (MAE). The semi-variable plot in GS + showed that the electrical conductivity data fit best in the spherical model. The results of the present study showed that among the mentioned methods, the inverse distance method (IDW) with error rate RMSE=0.3 mos/cm and MAE=0.16 mos/cm and then the model of gene expression programming with RMSE=275.54 mos/cm MAE=223.15 mos/cm with the highest accuracy and local estimator method (GPI) with RMSE=996.11 mos/cm and MAE=755.56 mos/cm, had the least accuracy in this field.

Determining the potential of mineral springs is one of the important and essential issues in water resources management. In this study, the potential map of the spring for the management and planning of groundwater resources was performed using statistical models of frequency ratio (FR) and weight of evidence (WOE) in the Vazrood Watershed. For this purpose, 57 springs were identified randomly in the calibration (34) and validation (23) phases. In the implementation of both models, the effective factors in spring potential were used include: slope percentage and aspect, hypsometry, plan and profile, geology, land use, topographic wetness index, distance from fault, fault density, drainge density, distance from the river and the road. The results showed that the accuracy of the FR model was 84.4% and the accuracy of the WOE model was 77.2%. These results indicate a very good accuracy of these two models in determining the potential areas of springs in the Vazrood Watershed. According to the results, the accuracy of the FR model is also higher than the WOE model. Finally, 39.7% and 34.9% of Vazroud watershed in high and very high classes in terms of spring potential are in two models of WOE and FR models, respectively. Finally, the potential maps of the springs can be used to provide the basic infrastructure to clean the springs from human damage and the entry of investors to build a drinking water spring factory and ultimately the prosperity of the local economy of the Watershed residents of Vazroud.