مجله ترویج و توسعه آبخیزداری
پیاپی 38 (پاییز 1401)

Nowadays, the management of atmospheric water resources is one of the practical solutions to reduce the effects of drought and climate change. In fact, there is a significant source of potable water in the atmosphere, which is more than important due to the limited fresh water resources on the surface of the earth and on the other hand, long droughts. The purpose of this article is to investigate the effects of atmospheric water resources management on the runoff entering Zayandeh Rood Dam. For this purpose, the precipitation statistics of all stations affecting the Zayandeh Rood Dam and the volume of daily runoff entering the dam during the period of weather adjustment were obtained. Using the statistical method of factor analysis, firstly, the relationship of each station with the runoff entering the Zayandeh River Dam was investigated, and after determining the stations with greater influence, using SPSS software, the relationship between the rainfall on the same day and 7 days later in the form of a matrix with the runoff. The entrance to the Zayandeh Rood dam was investigated and finally the impact of the air conditioning operations in the Zayandeh Rood catchment area and the water entering the dam was estimated. The results showed that during the statistical period under review, 2.1 million cubic meters were added to the volume of water entering the Zayandeh Rood dam as a result of the weather adjustment operation.

Water storage dams are considered as strategic constructions of every country. The issue of soil erosion in the watershed of the mentioned dams and the transfer of produced sediment to the reservoir of the dams is one of the issues that is always raised regarding these types of dams. Cheshme Ashegh dam in Fars province is one of the mentioned dams. In the present study, erosion and sediment studies and estimation has been carried out for the first time in this watershed by RUSLE and MPSIAC models as well as the regional analysis method for the aim of design and implementation of suitable conservation measures as well as making policy and plan for soil conservation in the watershed of the dam and preventing the production and transfer of sediment to its reservoir. The results of this research showed that, based on the MPSIAC and RUSLE models, the amount of special sediment is estimated by 1.58 and 3.17 ton/ha/y, respectively. Considering that the result obtained from the regional analysis method based on Gozoon station, the amount of special sediment is estimated by 3.5 ton/ha/y, it can be said that the result of the estimation obtained from the RUSLE model is closer to the amount calculated from the regional analysis method. Therefore, it can be said that the results obtained from the RUSLE model are more efficient than the MPSIAC model for estimating the amount of sediment and future soil conservation measures in the Cheshme Ashagh Dam watershed.

Land use planning and sustainable management of natural resources require knowledge of land use changes and their secondary effects on the hydrological regime. The purpose of the present study is to investigate land use changes and river flow using Landsat 8 and IRS digital data in the distance between two hydrometric stations of Rodan Watershed Bridge to Brentin. First, the geometric and atmospheric correction of the images was done in ENVI 5.3, and then land use classification was done for the years 2000 and 2018, and the land use transition matrix was prepared. Mann-Kendall test was used to investigate the discharge changes in 2000-2018 years, at the two mentioned stations, and the results were significant at the 95% level. For spring 0.001 and summer 0.021, the negative trend was significant; while, no significant negative trend was observed for autumn 0.88, winter 0.561 and annual 0.072. According to the results, the change of the hydrological regime and the negative slope of the monthly, seasonal and annual discharge of the upstream station has caused the change of land use in the downstream, and the most land use change is related to mix agricultural-horticultural and garden lands. The lands of mix agricultural-horticultural have decreased from 123.25 to 116.18 and garden lands increased from 4.65 to 14.72 square kilometers. Also, land use change has caused a change in the hydrological regime and a steepening of the negative slope of the monthly, seasonal and annual discharge of the downstream station compared to the upstream station.

Soil erosion and related problems i.e. sedimentation are associated with significant issues and problems on the environment and agriculture, including economic losses, reduction of water quality, storage capacity of reservoirs and agricultural production, among which watershed activities play a prominent role in reducing the amount of soil erosion and sediment yield. For this purpose, in the present research, the watershed management activities were evaluated on the amount of sediment yield, using the Connectivity Index in the Gonbad paired catchment of Hamadan province. In this regard, firstly, the estimation of the continuity index was conducted in the erosion plots installed in the control and impacted watersheds during the events that led to sediment production. Then, a regression relationship was established between the data of the Connectivity Index and the erosion plots sediment yield using the Connectivity Index in order to estimate the rate of sediment yield of control and impacted watersheds. Finally, the impact of watershed practices on the degree of sediment yield was measured by comparing the estimated sediment in control and impacted areas using the Connectivity Index. The results showed that the average amount of sediment produced in the sample and control sub-basins is 0.003 and 0.005 tons per hectare, respectively, that is, the amount of sediment in the sample sub-basin is 45% less than the control sub-basin, and this difference is due to the effect of watershed management operations in the sample sub-basin.

The core idea of spatial data infrastructures (SDI) is based on "Design". The word "design" bears a deep philosophical meaning as it becomes a complicated yet practical tool owing to the confluence of experts from different disciplines, and not one particular science area, to borrow the people a grant of recognition/understanding and problem-solving. The primary purpose of developing an SDI is to design a designer; that is, it can design the recognition pattern and a suitable management strategy of the dynamic world for the end-users based on the input disseminated transdisciplinary data and information. Such a secondary (yet as important) design is underpinned by the synergistic conglomeration of data and information, eventually increasing the collective wisdom and co-intelligence in a society. Current research sets out to assess the applicability of designing a provincial SDI framework for the agriculture and natural resources sectors, availed by organizational coordination and the notion of crowdsourcing. Due to swift growth in farmers and, on the other hand, watershed stakeholders as a larger management unit, attaining a holistic grasp on the existing and potential strengths and weaknesses to assist such a sizeable beneficial spectrum would only be surmounted by producing and developing an SDI. Integrating SDIs with game engines would create an interactive environment, leading to a better understanding of the environment and the involved processes and converting data & information into knowledge and wisdom.

Unhealthy and low-quality water resources, by affecting human health, may lead to many acute and chronic diseases. Therefore, water resources management, especially groundwater, which is one of the main sources of water used in cities and villages, is very important. In the present study, groundwater quality data of Yazdekan plain were collected and analyzed to investigate the existing situation of the groundwater for the last two decade (2001-2021). For this purpose, graphical methods (Piper, Schuler, Durov and Stiff diagrams and anionic / cationic time series) and some of qualitative evaluation indices (permeability and Kelly indices, SAR and Magnesium Hazard, sodium percentage and sodium carbonate residue) were used. According to the results, the water type of the Yazdekan Plain groundwater, evaluated magnesium bicarbonate and according to the TDS amount, was evaluated as unsuitable for drinking. Based on the Piper diagram, high salinity was observed. According to Schuler's diagram, this aquifer is classified as "unsuitable for drinking". The values of the indices were calculated as PI:48.1, KI:0.5, MH:77.7, SAR:492×10-3, Na%:28.6 and RSC:3, which indicate the high risk of magnesium and sodium carbonate residue, but in terms of permeability, potassium and sodium percentage, was observed in the appropriate class. Considering the not very desirable condition of this aquifer quality, there is a need for detailed planning to prevent the deterioration of the existing situation and in the next step to provide solutions to improve the quality of this aquifer.

Proper management of water and soil resources in a watershed requires recognition the potential of sediment production and runoff. In addition, every year thousands of tons of fertile soil from different lands of the country are unavailable due to soil erosion, and due to the wastage of water and accumulation in sedimentation areas, causes considerable damage. In this regard, the control of soil erosion and flood refers to the ability of ecosystems to conserve soil and water. Therefore, the current research is planned with the aim of evaluation the effectiveness of implementing watershed projects (1376- 1397) on the amount of soil erosion and flood discharge in Chehlkhaneh watershed. Soil erosion and flood discharge were estimated respectively using the MPSIC SCS method. The results showed that the implementation of watershed projects has led to the reduction of soil erosion and sediment (4.30 and 1.80 ton/h) compared to before the implementation of watershed operations (6.05 and 2.30 ton/h). Also, with the increase of the return period of floods, the effectiveness of watershed projects in controlling of watershed flood and reduction of discharge and flood volume increases.