Suspended sediment yield data could be used for estimating soil erosion in drainage basins. The objective of multiple regression analysis is to use the independent variables (values known) to predict the single dependent value selected by the researcher. In this research, eleven stations were selected in Gorganroud drainage basin according to area of upland catchments, geology, climate, vegetation cover, etc. The potential factors effective in suspended sediment yield were identified. Using the mean load within discharge data, 30 years mean suspended sediment load of each station was estimated. Multiple regression analysis was used to obtain the best statistical relationship between suspended sediment yield data and independent variables. According to the final model, the percentage of forest area density and mean annual discharge varies together and are in positive relationship with sediment yield. Inversely, the percentage of area of resistance and relatively resistant geological formation has negative effect on sediment yield. These three independent variables explain more than 96% of variation in mean suspended sediment load in Gorganroud basin and exhibit 19% standard error in their prediction.

Due to global warming, and its resulting changes in the frequency and amount of precipitation and temperature, there has been a great concern on climate change impacts by the scientific community. This study focuses on trend analysis of annual and seasonal rainfall (P), maximum temperature (Tmax) and minimum temperature (Tmin) time series from seven meteorological stations in Gorgranrood river basin during 1982-2011. Three statistical tests including, Mann-Kendall (MK), the Modified Mann-Kendall (MMK) test and Man Wintney (MW) were examined at 10% significance level. To quantify the slope we used Sen’s nonparametric estimator of slope. Both positive and negative trends were identified by all the tests. However, all negative trends were insignificant and only some positive trends were significant. Trend tests reveal that the median of slopes of seasonal series of Tmax, Tmin and P are located above zero line which is revealed that increasing trend is observed in most of the station Steepest positive slope of trend line of the Tmax is found in the spring then in summer time. Trend analysis has revealed strong seasonal variability of Tmin series. The highest number of stations with significant trends occurred in the Tmin while less significant trends were detected in the Tmax and P. There is a non-significant increasing rainfall trend in the basin. With regard to seasonality P, it is remarkable that positive significant trends were detected in few stations at both annual and seasonally time scale. In order to remove serial correlation, the trend-free prewhitening procedure has been applied and less number of positive trends has been again observed, highlighting that, in this case, serial correlation affect the results of Mann-Kendall trend test.

In recent decades, drastic land use changes in Golestan province caused to reduce a substantial amount of Hyrcanian forest. To investigate the changes, land cover maps produced using Landsat satellite imagery classification of sensors TM from 1984, 2012 and 2016 respectively used as input data in Land Change Modeler (LCM) to predict land cover changes in 2030. In order to assess the accuracy of modeling, statistics of relative performance characteristic (ROC), ratio Hits/False Alarms and figure of merit was used. In continue to investigate the role of land use changes in water yield as one of ecosystem services was discussed. The results show the accuracy of artificial neural network with the ROC equal to 0. 949, the ratio Hits/False Alarms equal to 57 percent and the figure of merit is equal to 11 percent. Land use change modeling results showed that from 1984 to 2012, The most prominent changes were related to reduction of forest cover. This process modeling using artificial neural network showed, from 2016 to 2030 forest cover will be reduced about 30361 hectares. The results of water yield study showed that runoff in the area, particularly in the East and North East area has increased. This increase in the amount of runoff occurred as a result of land use change on forest ecosystems to agriculture. Results of this study improve our understanding of hydrological consequences of land-use changes, and provide needed knowledge for effectively developing and managing land-use for sustainability and productivity in the Gorgan-rood watershed.

Introduction During the recent years, the occurrence of environmental hazards and the occurrence of harmful damages and significant losses caused by it has become a major challenge in most parts of the world. In order to reduce the effects of environmental hazards, consideration has been given to the resilience approach. Resilience is considered as one of the effective measures in the risk management process. It is also a community-oriented approach that improves the preparedness of local communities against instabilities caused by hazards. By knowing and understanding the level of resilience, it is possible to help reduce injuries and destructive effects with proper planning. Natural disasters reduce resilience in three ways. physical damage; including damage to residential, commercial uses, equipment and facilities. Economic damages; including loss of employment, business interruption, repair and reconstruction costs. Social harms; including the impact on people who need medical assistance and shelter. Among these natural hazards in Golestan province, we can mention facing natural disasters such as the flood of 2018. Therefore, the present research was carried out with the aim of determining the effective indicators in measuring the resilience of rural settlements in the Gorgan-rud watershed and determining the extent and importance of the social, economic and ecological resilience of the surveyed villages against the floods of the mentioned year. Materials and Methods The studied area is Gorganrood watershed, located in the heights of Golestan forest.  The current research is applied in terms of purpose and descriptive-analytical in terms of method. This research was done using two documentary and field methods using a questionnaire tool. The statistical population includes native residents, which consists of 126 villages and a total population of 22,942 households. Among the most populated villages in the upstream, central and downstream parts of the region, some villages were selected by two-stage cluster random sampling method based on the Cochran method. Finally, 10 populated villages and 200 heads of households were selected. The research questionnaires include three social-cultural dimensions (19 components), economic (5 components) and environmental-management (7 components). The content validity of the questionnaire was also confirmed by asking the opinions of the professors related to the subject, and then data was collected by using interviews and questionnaires. In the descriptive findings, only the individual characteristics of the respondents have been investigated. In the analytical findings, a sample t-test was used. To make statistical inferences, the mean resilience of the components was compared with the optimal mean. Kruskal-Wallis test was used in order to investigate the internal relationship between the effective macro-dimensions of the resilience of rural settlements in the face of crisis. The Kolmogorov Smirnov test was used to check the normality of the data distribution, the Friedman test was used to rank the items related to each index, and the Spearman test was used to analyze the correlation coefficients. Results and Discussion The results of the examination of 21 components in three economic, social and environmental dimensions showed, the social index with an average of 2.89 impact and the environmental index with an average of 2.30 had respectively the highest and the lowest impact on the resilience of the villages. Also, the highest mean of social index (3.09) was observed in Sadegh Abad village and the lowest mean (2.69) was observed in Bahlke Sheikh Musa village. The highest average of the economic index (3.36) was observed in Sahne Sofli village and the lowest average (2.49) was observed in Bahlke Sheikh Musa village. The highest average of the environmental index (2.42) was observed in Sadeghabad village and the lowest average (2.02) was observed in Aghabad village. Totally, the resilience of Sahne Sefali village had the highest level (2.89) in terms of the investigated indicators. The results of T-test samples and Kruskal Wallis of the studied villages indicated the existence of significant differences in all social-cultural, economic and environmental-management indexes (P<0.05). Also, the findings showed that the total resilience with a value of 2.65 was lower than the average and there was a significant difference between the villages (P<0.05). The results of prioritizing dimensions of resilience using Friedman's test also showed that socio-cultural factors had a higher priority than other indexes and environmental-management factors was in the last priority. Conclusion According to the results, it can be suggested that one of the most necessary activities for planning the current situation is to pay attention to the indicators that lead to increasing the level of resilience of the local watershed community. Therefore, considering that the calculated value of the resilience number is lower than the base limit (3) in different indexes, especially from the environmental-management aspect. Therefore, considering that the calculated value of the resilience number is lower than the base limit (3) in different dimensions, especially from the environmental-management aspect. Therefore, it is better to move towards creating resilient societies with high adaptive capacity by relying on crisis management. It will not be possible without recognizing and rooting the weaknesses of the society and the continuous communication of the responsible institutions and organizations with the local communities by social facilitators. At the same time, considering that the resilience of local communities against floods is a time-consuming and gradual process; establishing continuous interaction between villages with a higher resilience coefficient and villages with a lower rate in order to benefit from each other's experiences. It is suggested to hold workshops and training courses on preparedness to deal with possible floods to describe and implement them in the studied villages.

Background and Objectives: Climate change has changed meteorological parameters in different parts of the world. Drought and water scarcity may lead to crisis in many countries. Therefore, the study of the past meteorological parameters changes and their effect on river flow which is a key element of water supply is important. The purpose of this study was to investigate the relationship between temperature and rainfall parameters with base flow index using continuous wavelet transform and wavelet coherence in Gorganroud River Basin. Materials and Methods: At first, we used the base flow indices resulting from the Eckhart's two-parameter method and then the base flow index which is the portion of groundwater in river surface flow, was calculated at six gauge stations (Tamar, Lazoreh, Nodeh, Arazkooseh, Gorgan Dam and Taghiabad). The results illustrated that the lowest annual index found at Taghiabad gauge station with a value of 0. 30 and the highest yearly baseflow index found at Tamer gauge station with a value of 0. 66. Then, the annual trend of temperature and rainfall were investigated with base flow index of each station in Gorganroud River Basin during a period of 33 years (1981 to 2013) using continuous wavelet transform and wavelet Coherence. An analysis of wavelet coherence analysis showed a strong relation between temperature and rainfall with base flow. Results: Our analysis reveals the impact of yearly temperature and rainfall on the base flow index. Investigation of wavelet coherence between rainfall and base flow index showed that there is the highest correlation between 1-4 year period length, which indirect correlation was observed in the middle years of Gorgan dam and Taghiabad stations and positive correlation in other stations and the early and the end years of Taqiabad station. Similarly, a direct relationship exists between the rainfall and the base flow index in the 4-8 year period length, which are direct at Lazooreh and Nodeh gauge stations and indirect correlation in Tamer gauge station. Also, in the period length of 8 to 10 years, the high correlation between rainfall and base flow index were found at Arzokesh and Nodeh gauge stations with lower correlation at Sadgegran gauge station, which arrows direction indicated direct relationship. The analysis of the wavelet coherence between temperature and base flow index exhibit positive and high strength correlation at Gorgan dam gauge station in 2005 to 2009 in 3-4 year period length, at Lazorah gauge station in 2002 to 2006 with 4 year period length and at Taghiabad gauge station in 1984 to 1989 with period length of 1 to 5 years. Indirect correlations were found at Nodeh and Tamer gauge stations between 1987 to 1990 and 2011 to 2013, respectively, with a short 2-year and 3-year period length and Taqiabad gauge station between 1993 to 2000 and between 1992 to 2013 with a long-term period of 8 to 10 years. Conclusion: The rainfall relationship with the base flow index can be direct or indirect due to the watershed characteristics (e. g., human activities, soil, land-use, climate, hydrology, and geology). Also, in some stations there is a direct relationship in the periods and indirect relationship in the rest of the period. The relationship between the base flow index and temperature is also indirect in some of the stations.

Background and Objective Land use/cover changes (LU/LC) are considered as one of the most important issues in natural resource management, sustainable development and the environmental changes on a local, national, regional and global scale. Changing uses into each other and changing permissible uses into impermissible uses such as changing agricultural lands into residential regions or changing rangelands into eroded and low-yielding dry farming lands are always considered as importand issues in natural resources. Detection of the patterns of the land use changes and prediction of the changes in the future to carry out suitable planning for optimal utilization of uses in natural resource management reveal the need for modeling spatial and temporal changes of LU/LC. This study aims to assess the efficiency of the integrated model of Markov chain automatic cell (CAMarkov model) in simulation and prediction of spatial and temporal changes of Land use/Land cover (LU/LC) in Gorgan-rud river basin by applying threedimensional Pentius-Melinus analysis in calibration of land use changes by using three assessment indices of Quantity Disagreement, Allocation Disagreement and Figure of Merit as new indices in the assessment of the accuracy of CA-Markov model...

After the destructive floods in Golestan Province during the early seventies, numerous biomechanical practices were performed in order to the restoration of vegetation cover and affecting the runoff in the main cluster of Gorganrood river, so the extensive studies are necessaire for the evaluation of their results. The goal of this study was to evaluate the changes in some physicochemical properties of soils following biomechanical practices as compared with the control area in dasht kalpush that is one of the Gorgan-roud sub-catchments. After land units mapping, soil samples (75 samples) were taken from a land unit that has restored (furrowing and Atriplex spp plantation) and control areas. In each treatment (inside furrows and under the Atriplex spp canopy cover, between furrows and control area), five soil samples in five slope positions (summit, shoulder slope, back slope, foot slope, toe slope) were taken at the depth of 0-15 cm (totally 25 soil samples in each treatment) and in the laboratory, some physicochemical properties of soils were measured. Data analysis was performed using the ANOVA and the tukey test that was conducted with SPSS (18.0) software. The results demonstrated that the percentage of soil saturated moisture and soil stability have significantly decreased in the treatment of inside furrows compared with control treatment and the percentage of soil clay particles has significantly increased, either.