نشریه مدیریت جامع حوزه های آبخیز
سال سوم شماره 2 (پیاپی 8، تابستان 1402)

Without a doubt villagers can play an effective role in improving their social, environmental and economic conditions. They also have an important and sensitive role in watershed areas and cooperation in watershed management activities. This stady aime to identify the factors affecting the indicators and sub-indicators of reducing the level of people's participation in natural resources and watershed activities, to know the expectations and needs of the local community, and finally to provide scientific and technical solutions order to increase the level of public participation in Sarabbagh region of Abdanan city. The influential indicators in this research include four economic, social, design-executive and educational-promotional indicators with 12 sub-indices determined and categorized.

This research was carried out as a survey using questionnaires, interviews and numerous meetings with community members and local experts. For this purpose, the factors affecting the non-participation of villagers in watershed management activities were identified and classified based on the literature review, questions from experts, as well as referring to the area and face-to-face interviews with residents. Then, questionnaires of paired comparisons and Likert were prepared as measuring tools and the relibility of the questionnaires was confirmed based on experts' opinions. Finally, after determining the sample size by Cochran's formula and completing the questionnaires, using the fuzzy AHP and the Friedman test, the indicators and sub-indices affecting the lack of sustainable participation of the people in the watershed management plans of the investigated catchment were prioritized. SPSS software was used for data analysis and Cronbach's alpha was used to check the validity of the questionnaire.

Based on the history of investigation in the study area and similar areas, unfortunately, the evidence indicates that most local communities do not know about the implementation and exploitation of watershed projects and natural resources in their living and production areas. The field surveys conducted in the study area showed that from the point of view of experts and local communities, the economic factor is the most important factor in the non-participation of local communities in watershed management activities. In Sarabbagh catchment, economic, design and implementation indicators play a greater role in people's non-participation than educational, promotional and social indicators. From the point of view of the experts, the sub-index of ignoring people's income as a direct economic incentive and not paying attention to non-governmental organizations have the maximum and minimum importance in people's non-participation, respectively, with an average rank of 9.35 and 3.69. From the point of view of the local communities, the sub-indices of ignoring people's income as a direct economic incentive and not paying attention to non-governmental organizations have the maximum and minimum importance in the non-participation of the people, respectively, with an average rank of 9.02 and 4.68

In general, one of the most important measures that can be taken in order to remove the obstacles to the participation of local communities in watershed projects is to identify, categorize and rank the factors that cause their non-participation in these projects. Prioritizing the factors affecting people's non-participation is a fundamental step in the cycle of people's management of watersheds and proper management of watersheds. The general result of the survey of local communities indicates that participatory management increases the capabilities and optimal productivity of other facilities and resources in the catchment. Implementation of multi-purpose watershed projects and taking into account the interests of the watershed residents, as well as the participation of local communities in the various stages of monitoring, studies, needs assessment, implementation, and maintenance of watershed projects can cause economic motivation, attention to the local force in the implementation of projects, employment, and active participation of the people in the mentioned stages. Attention and emphasis on the issue of trust of the local community and increasing the amount of social trust in the General Administration of Natural Resources and Watershed Management are among the factors that can reduce or eliminate the obstacles of non-participation of the local community in the implementation and exploitation of watershed and natural resources projects.

Climate change has a significant impact on water resources and environment, which are reflected in agriculture, society and economy. Using general circulation model (GCM) with statistical downscaling models is a method of climate change assessment. Due to the location of Abadeh in semi-arid region of Fars province and Iran, population growth, industrial and mining development, and getting to the sustainable agriculture, evaluation of climate change impacts on meteorological parameters seemed necessary. The aim of this study is to assess meteorological parameter variations of precipitation, minimum and maximum temperature under climate change condition in order to use them in water resources management of water consumptions, and to decrease the negative impacts of climate change on different parts of the environment in Abadeh region.

In this study, the effect of climate change on meteorological parameters of minimum temperature, maximum temperature, precipitation was assessed, using HADCM3 as general circulation model and LARS-WG5.5 statistical model for downscaling, in Abadeh station for the base time period of (1993-2017). After assessment of model for parameters simulation, using model fitness criteria, daily value of minimum temperature, maximum temperature and precipitation were simulated for A1B, B1 and A2 scenarios. Then, the results were analysed.

Evaluation of the model showed that rainfall forecasting had the maximum error, and minimum and maximum temperature were simulated with more precision. Comparison of the mean and standard deviation of observed and simulated monthly precipitation of Abadeh station in the (1993-2017) base time period showed that the mean of simulated precipitation is more than the observed precipitation in March, April, August and September. The standard deviation of monthly simulated precipitation is more than the observed one in February, March, April, August and September. Comparison of the observed and simulated monthly minimum temperature of Abadeh station in the (1993-2017) base time period showed that the mean of simulated monthly minimum temperature is the same as the observed one in most of the months. The standard deviation of simulated monthly minimum temperature is less than the observed one in all of the months. The future trend of maximum temperature is the same as minimum temperature.After model assessment, the parameters were forecasted for the next three periods of 2011-2030, 2046-2065 and 2099-2080, under three gas emission scenarios of B1, A1B and A2. Comparison of forecasted parameters over three periods, with the based period values, showed that in the 2011-2030 time period, the precipitation value increases in three scenarios of A2, A1B and B1, respectively. In the 2046-2065 time period, the precipitation increases in all scenarios too, with the same order of 2011-2030 time period, but the variation of scenarios is different. In the 2080-2099 time period, precipitation value increases in B1 scenario, but decreases in the other two scenarios. Comparison of forecasted minimum temperature over three future periods, with the base time period values, showed that in all of the time periods, minimum temperature value increases in the three scenarios of A2, A1B and B1, respectively. The percent of increase will be more from 2011-2030 period to 2046-2065 time period and, to 2080-2099 time period. The future trend of maximum temperature is the same as minimum temperature.

The precipitation, minimum and maximum temperature for the next 70 years were forecasted, using HADCAM3 as a GCM model and LARS-WG for statistical downscaling. Results showed an increase in minimum and maximum temperature in all months and seasons of the three time periods. Precipitation increases in 2011-2030 time period and 2046-2065 time period in all of three scenarios of A2, A1B and B1. Precipitation decreases in most of the scenarios of 2080-2099 time period. These all verify climate change in Abadeh region. The increase in evapotranspiration, water requirement of crops, and the decrease of water storage are some of the climate change effects, which need management to reduce damage on water resources, agriculture and environment, using the obtained results. Climate change assessment of the other stations of Fars province and other regions of Iran is suggested for comprehensive planning readiness.

Today, climate change and the subsequent alteration in precipitation patterns have caused floods, which have overshadowed urban management. The financial and human losses caused by urban floods have significantly increased, and there are no signs of their reduction. Urban flooding occurs when the amount of precipitation exceeds the capacity of the drainage channel network, which lacks sufficient capacity. Two main factors contribute to the exacerbation of damage caused by urban floods. The first factor is population growth and the expansion of urbanization. The second factor is heavy rainfall caused by climate change, which plays an essential role in intensifying and accelerating the hydrological cycle, potentially altering the amount and frequency of precipitation. This factor impacts the probability of flooding, runoff volume, and peak flow. It is particularly pronounced in arid and semi-arid areas where rainfall is typically brief but intense. One critical urban infrastructure is the runoff collection network, which is subject to increased wear and tear due to the growth of impervious surfaces. Changes in rainfall patterns resulting from climate change have amplified the occurrence of urban floods, which makes essential the use of new approaches such as low-impact developments (LIDs).

In this research, the runoff collection network of district 10 of Tehran Municipality was simulated, and its performance was evaluated under current and future conditions. This district is located in the relatively dense fabric of Tehran metropolis, has a population of 327,000 people, and covers an area of 807 hectares. The simulation and evaluation of the runoff collection network's performance, using the vulnerability and reliability indices, necessitate a precise model with detailed information. To accomplish this, SWMM version 5.1 software was used for simulating the runoff collection network. The study area was divided into 285 sub-catchments to allow for more detailed simulation of the sub-channels. Information such as slope, area, and the percentage of impervious space was incorporated into the catchment data using ArcMap software version 10.3.1. The sub-catchment width parameter was calculated by dividing the sub-catchment area by its greatest length, employing Q-GIS software, and then applied to the sub-catchments. The LARS-WG model was also employed to generate the micro-scale output of climate models exponentially. To simulate the network under current conditions, historical precipitation data from Mehrabad synoptic station was used. For simulating future conditions, precipitation data from the climate models presented in the sixth climate change report were employed. Among the climate model predictions, the scenario with the highest projected rainfall was chosen as the pessimistic scenario. Subsequently, low-impact development tools (LIDs) were employed to enhance the network's performance against climate change. Specifically, swale and permeable pavement, which are recognized as two of the most common and efficient LIDs, were selected and implemented under three different scenarios.

The runoff collection network of district 10 in Tehran municipality was simulated under current and future conditions using the SWMM hydraulic model. Initially, the SWMM simulation model was applied to the current rainfall conditions, considering various return periods. The results indicated that the total runoff volume for the 2, 5, and 10-year return periods was 45.9, 51.14, and 59.7 thousand cubic meters, respectively. This increase in runoff volume led to an increase in vulnerability from 10.4 to 12.2 percent and a decrease in reliability from 97.5 to 95.8 percent. In the second stage, the runoff collection network was simulated under future conditions using climate change data from the SWMM model. Previous studies' findings were used to determine the most suitable climate model for the sixth climate change report. The top 5 climate models were identified, and the model with the highest precipitation was selected as the pessimistic scenario. The simulation results for the network under future conditions revealed an increase in runoff volume, reaching 64.04 and 72.18 thousand cubic meters for the 5 and 10-year return periods, respectively. Consequently, the vulnerability index increased to 12.7 and 13.9 percent for the 5 and 10-year return periods, respectively. Meanwhile, the reliability index stood at 95.3 and 94.3 percent during the same return periods. Then, two low-impact development tools of swale and permeable pavement were selected to improve the network performance and were introduced to the pseudo-model under three scenarios. The results showed that after the use of LIDs, the total runoff volume decreased by an average of 10.5% in the first scenario, an average of 17% in the second scenario, and an average of 21% in the third scenario. This reduction in water flow volume caused the vulnerability index to decrease by 8.3% and the reliability index to increase by 98.9%.

In this research, the stormwater collection network of district 10 of Tehran Municipality was simulated using the SWMM software under current and future conditions. The network simulation under current conditions was based on the precipitation data from Mehrabad synoptic station, while the simulation under future conditions used precipitation data from climate model outputs of the sixth climate change report. After simulating both scenarios, the performance of the network was evaluated. The simulation results indicated that as the return period increased, the vulnerability index increased, while the reliability index decreased. The impact of LIDs on the network was further investigated through a re-simulation with LIDs incorporated under three scenarios. The results showed that the implementation of LIDs improved the network's performance, leading to a reduction in vulnerability and an increase in reliability. Furthermore, the results demonstrated that LIDs had better efficiency in improving the performance of the stormwater collection network under lower return periods. It is recommended that future studies use optimization methods to better implement these LID tools, aiming to reduce costs and enhance their effectiveness.

Water stresses are one of the most important issues that the world is facing today. Following the increase in population, climate, and land use change, Iran is also facing serious challenges in achieving sustainable water management on basin scale. In recent decades, climate and land use changes at the level of watersheds have had adverse effects on socio-environmental and economic issues. The case considered in this study is the Tajan watershed, located in Mazandaran province, northern Iran. This watershed is crucial in terms of ecosystem services (runoff generation, sediment delivery) for the residents living in the area and the Caspian Sea, which consists of the terminal part of the watershed. Temporal analysis of trends in hydro-climatic data is important to increasing our knowledge about the variations of such variables over time.

Tajan watershed with an area of 3,970 square kilometers is located in the northern part of Iran, which discharges the generated runoff into the Caspian Sea. Contrary to other watersheds, the amount of rainfall decreases with increasing altitude (i.e., the gradient of precipitation is negative with the change in altitude). An analysis of the temporal trend of the precipitation and discharge was conducted using the long-term monthly data (50 years from 1971 to 2021) collected in four rain gauges and two hydrometric stations. The rescaled adjusted partial sums (RAPS) index, non-parametric Mann-Kendall test, and Sen’s slope method were adopted to reveal the changes in precipitation and discharge data. Moreover, the state of land use changes in 37 years (1984-2021) were extracted using the Maximum Likelihood Classification method on the satellite images.

The results of this study showed that the trend of discharge does not match the rainfall, because during the 30 years of 1969-1999, the rainfall data of the studied stations had a decreasing trend with an average slope of -0.463 mm/year, while the discharge in watershed outlet indicates an increasing trend with an average slope of +1.02 cubic meters per second per year. On the other hand, during the period between 1999-2021, despite the positive trend of precipitation data with an average slope of +0.343 mm per year, the discharge shows a decreasing trend with an average slope of -2.249 cubic meters per second per year. By examining the state of land use changes in 1984 and 2021, the results indicate a decrease of 16 and 11 percent of areas for pasture and forestlands and an increase of 110 and 670 percent of irrigated lands and urban areas. The findings of this research showed that the trend of temporal changes in the discharge of sub-basins does not follow the rainfall, and the main factor in reducing the runoff generated in the Tajan watershed is the land use changes over the studied catchment.

The following conclusion could be drawn upon an evaluation of the temporal changes in rainfall and runoff data in the Tajan watershed: 1) the change of land use in the study area from forest to agricultural and urban areas caused an increase in the volume of runoff generated in the watershed. 2) The construction of the Shahid Rajaei reservoir dam in the study area has caused a change in the discharge trend of the mainstream. This affects the region's ecosystem as well as the morphology of the river channel that passes through the city of Sari. 3) The hydrological response of the studied watershed is not only influenced by climatic factors, the human activities (e.g., land use change and damming) has significant contribution. The authors suggest future researchers conduct more extensive research on the effect of dams on the hydromorphological characteristics of the downstream river.

According to global data, flood is one of the most important natural disasters, which has the highest number of occurrences and a high volume of coverage. Therefore, it has extensive damage and consequences that cause destruction all over the world every year. Watershed management can be very important and effective in preventing floods and their damage. The analysis of watershed projects is one of the most fundamental measures that is carried out for the long- term planning in relation to executive plans and natural resources management. The loss of water and soil resources in watershed has been increasing in recent decades due to irrational exploitation of resources. This problem leads to a decrease in the useful life of dam reservoirs, a decrease in the production, and loss of the country’s capital, while intensifying the occurrence of floods and increasing sediment generation and deprecation of equipment and structures. The construction of watershed structures played an obvious and significant role in reducing erosion and consequently preventing these sediments from entering the reservoir, which is the supplier of the major part of the drinking water in Ilam city. In the current study, an assessment of the impacts of watershed management implementations of Gol-Gol, Ilam province watershed has been done using HEC-HMS.

Gol-Gol watershed is located in Ilam province, in Ilam and Malekshahi county as one of the sub-basins of Ilam dam. Gol-Gol watershed has geographic coordinates of 46°  to 46°  east longitude and 33°  to 46°  north latitude. Its area was estimated to be 24950 hectares. The maximum and minimum height of the Gol-Gol watershed is 2605 and 1076m above sea level, respectively. The average rainfall is 570.6 mm and the average temperature is 16.8 . In this study, first, all the data and related maps were collected and the HEC- HMS hydrological model was calibrated and validated using the observed rainfall and runoff data. In this stage, the data of 2004-2005 period were used for calibration and the data of 2006 were used for the validation. Also, the effectiveness of the hydrological model in simulating the flood hydrograph in the calibration and validation stages were evaluated using peak flows, average flows, Nash-Sutcliffe efficiency and correlation coefficient. Then, a daily event with a return period of 25 years and time steps of 10 minutes was selected to investigate the effects of watershed implementation, and their results were analyzed in this stage as two main scenarios (the presence of a watershed structure and the absence of a watershed structure).

The calibration results showed that the maximum observed flow rate is 90 m3/s, while the simulated flow rate is 89.7 m3/s. The correlation coefficient and dispersion of the data used in the calibration stage were 80% and the NSE was 79%, which show the acceptable results of the simulation. Then, the results were validated using the optimized parameter of the model during the one- year period of 2006. The maximum observed flow rate was 67.7 m3/s and the simulated value was 67.1 m3/s. The efficiency index of the model was obtained with a correlation coefficient of 77% and a cliff settlement factor of 76%. Based on the results of the calibration and validation of the model and the low percentage of difference between the observed and simulated flow rate in the used events, it was determined that HEC- HMS model has the necessary efficiency to simulate the Gol-Gol watershed basin. In addition, the evaluation of the effect of watershed structures on the flow rate results showed that in the first scenario (the presence of a watershed structure), the simulated peak flow was calculated as 137 m3/s, but the calculations showed the value of 114.2 m3/s for the second scenario (the absence of a watershed structure).

This study was performed with the aim of evaluating the effect of watershed management measures on runoff in the Gol-Gol watershed, using the HEC-HMS hydrological model. In order to check the effect of the proposed devices, the flood behavior was simulated for the existing events. The criteria of peak discharge and flood volumes were determined for evaluation and their values were calculated for two situations before and after watershed measures. The results of the statistical comparison showed that these measures have a significant effect on reducing runoff and discharge in the study area. The calibration results also showed that the curve number parameter is one of the most sensitive and effective parameters on runoff. Since the numerical value of this parameter depends on the hydrological group of the soil of the region, land use, hydrological status of the region and previous soil moisture status, these factors can be controlled by management measures. The evaluation phase of watershed structures and their efficacy on the flow resulting from a storm with a return period of 25 years showed a decrease of 22.8 m3/s of he maximum flow, which can finally be concluded that the creation and construction of watershed structures is the best solution to prevent floods in this area, which confirms the effect of structures on reducing floods.

Climate change is one of the most important issues in the world, which has great effects on ecosystems and their diversity. One of the most important factors of climate change is the increase in temperature and change in the precipitation pattern, which affects the distribution of plant species. The use of species distribution models is one of the most reliable techniques for investigating the impact of climate change on the distribution of plant species. One of the methods of plant distribution modeling is using the maximum entropy model. This model uses environmental conditions such as temperature, precipitation, and geographic altitude as inputs, and based on that, plant distribution is predicted. This model predicts the probability of species distribution in the new environment based on the theory of maximum entropy and based on the available data. In this model, based on the information we have about species distribution in different environments, a probability distribution is obtained for species distribution, which has the highest entropy. However, for the best prediction of the distribution of the species, we need to have detailed information about the biophysical, ecological and environmental characteristics of the species in question. In this method, instead of trying to model all aspects of the species and the environment, only the available information about the distribution of the species is used. In this study, the effect of climate change on the distribution of valerian (Valeriana sisymbriifolia) species is predicted using the maximum entropy model in Isfahan province.

In this study, the effect of climate change on the prediction of the distribution of Valeriana sisymbriifolia species in Isfahan province was investigated using MaxEnt model. For this purpose, 50 points of presence of example in May 2022 in different regions were first registered by GPS device by random sample method and after collecting environmental data including 10 climate changes and 3 physiographic changes, the effect of climate change on the distribution of the plant species Valeriana sisymbriifolia in Isfahan province was investigated using the entropy machine model and in the time periods of 2020, 2050 and 2100, under two scenarios: SSP2 and RCP4.5. To study the effect of climate change on the distribution of Valeriana sisymbriifolia plant species in Isfahan province, new climate scenarios including SSP (Shared Socioeconomic Pathways) and RCP (Representative Concentration Pathways) scenarios were used. The SSP scenarios in the GFDL-ESM4 general circulation model correspond to a combination of paths in which the economy, population, and politics will change in the future. The RCP scenarios in HadGEM2-CC general circulation models also correspond to different levels of future greenhouse emissions.

The results showed that the distribution of Valeriana sisymbriifolia species in Isfahan province will decrease from 3.07% to 0.047% under RCP4.5 scenario in 2020 to 2100. Also, the distribution of this species under the SSP2 scenario showed that from 2020 to 2100, the distribution of the species and its favorable habitat will decrease from 3.74% to 1.554%. In fact, under both studied climate scenarios, the ideal habitat of valerian has decreased and will be completely lost in some areas. The entropy machine model showed that there are several factors affecting the distribution of valerian including slope, rainfall in the coldest season of the year, annual rainfall and altitude. Also, this model obtained Auc=0.95 in the evaluation, which shows the excellent prediction of the entropy model in predicting species distribution.

According to the output maps from the MaxEnt model and also according to the influence of important variables in this process, it can be concluded that the distribution of the species in question is decreasing under the influence of climate change in successive years. In addition, according to the response curves of the species in terms of physiography, as the slope and height increase in the area in question, the amount of distribution of the Hyacinth species also increases. Also, according to the field observations, it can be said that the species in question is observed in the slope and at very high altitudes, such that during sample collection the species in question was present at an altitude of 3000 meters, and the reason for this can be attributed to the strong roots of the plant, which creates the ability to reproduce in rocky conditions. On the other hand, because other species do not tolerate the same conditions, their presence decreases and the competition it decreases for the Hyacinth species. The response curves of the species to changes in rainfall also show that the more the annual rainfall and the rainfall in the cold months, the more likely the presence of the species will be, such that the more the annual rainfall exceeds 250 mm, the more likely it will occur.