A lot of water is wasting through the canals and ponds. The use of geosynthetic materials such as geomembrane liners¡ have been welcomed by farmers due to their low cost¡ rapid installation and low water seepage. In this research¡ seepage water lost in 7 ponds with HDPE geomembrane lined in Semnan province was studied. To determine water lost¡ ponding method was used. The results showed that in the pools that were lined with HDPE geomembrane¡ the amount of water seepage lost was 4.5 to 46 (meanly 25) mm/m2/day. Water seepage losses in the stone and cement of pools was 74.5 to 84 (meanly 80) mm/m2/day. So¡ water seepage in geomembrane lined pools in about 30% of ston-lined pools. Water seepage losses in Geomembrane lining¡ was 20 times less than ston-lined. High-speed¡ short implementation time¡ lower cost¡ greater durability and very good seal¡ are the most important reasons for accepting the Geomembrane covers. The biggest weakness of the Iranian Geomembranes plates was width low. Low width sheets¡ increased cost of the projects.

Geomembranes is a kind of geosynthetics that is used to control water losses in water storage ponds. and conveyance irrigation canals with a a fast growing rate. This lining material, in addition to the ease and speed of execution, can control water seepage losses completely. In this research, the role of execution and operation issues in control of water seepage losses in geomembrane linings was investigated. For this purpose, in 5 provinces of Alborz, Isfahan, Khouzestan, Semnan and Hamedan, 15 cases (ponds) were selected. All of these ponds were lined with HDPE geomembrane sheets with a thickness of 1.5 mm , made in Iran, with a lifetime of 8 years and ponds depth was 3 meters. Total water losses in these ponds were determined in three stages of one crop year. . Based on the results, the amount of water seepage losses from geomembrane lining is between 0.1 to 37.6 and on an average 13.9 liters/m2/day, which is about 125 times lower than the seepage losses in concrete lining. The lowest seepage losses were in Hamadan and Khuzestan provinces with 0.3 and 0.2 liters/m2/day ,respectively, and the highest value belonged to Alborz, Isfahan and Semnan provinces with 23.1, 16.2 And 29.6 liters/m2/day, respectively. Due to the uniformity of the geomembrane sheets and the geometric conditions of the ponds, the difference in the amount of seepage losses was found to be related to the quality of the execution and operation issues of geomembrane lining in the ponds. The most important issues in the ponds with high value of water seepage losses were the lack of attention to the slopes of the bed in design and execution, sediment accumulation and the need for dredging during operation, inadequate bed prepration and compaction, the presence of rocks and sharp objects under the lining, the formation of wave, the cuts due to the absence of under lining in the weld sides and the corners of the pond and human destruction during the lining.

Clogging of emitters is one of the main problems in subsurface drip irrigation. The objective of this study was investigation of effect of Geocomposite on wetting pattern in subsurface irrigation system. This research was conducted in lysimeters located at Shahrekord University research field. The study was conducted as a factorial experiment based on a completely randomized design with 10 treatments and three replications of three factors. The first factor of experiment was geocomposite shape with the same area on two levels (shape square with dimensions (4 × 4) square centimeters and rectangular with dimensions (2 × 8) square centimeters), the second factor was combination of geocomposite material on two levels (two layers of geotextile on both sides of Geonet and The second level, a layer of geomembrane and a layer of geotextile on both sides of geonet), the third factor of placement in the soil at on two position (horizontal and vertical) and emitter with envelopment (in two position horizontal and vertical) were used as control. The ground wet and wet the maximum of soil depth profiles were measured. The results was showed that geocomposite of shape square with dimensions (4 × 4) square centimeters for a layer of geomembrane and a layer of geotextile on both sides and how to align horizontally in the soil wet ground level by lowering the 21.55 percent and increased 17.1 percent wet the soil deep profile compared to control (emitter with envelopment horizontally in the soil) is the most effective and best conditions on wetting profiles.

The performance of geomembrane liners depends on proper design, installation, and maintenance. Geomembranes exhibit thermoplastic behavior, expanding and contracting significantly with temperature changes. This can lead to issues like wrinkling and uplift, which can compromise the liner's seepage control function. Proper maintenance is also essential, as geomembranes are sensitive to mechanical damage that can greatly reduce their effectiveness.In Iran, geomembrane lining of irrigation canals has been implemented in several projects, including the Moghan Irrigation Network. However, comprehensive studies on the performance and durability of these liners are lacking. This study aimed to evaluate the effectiveness of geomembrane liners in controlling seepage from Pumping channel No. 3 of Moghan, and identify any issues related to their design, installation and operation. The results can help guide the rational expansion and optimal utilization of geomembrane lining for improving agricultural water productivity in Iran.

Literature Review:

Geomembranes exhibit thermoplastic behavior, expanding and contracting significantly with temperature changes. Geomembranes layers have a high coefficient of thermal expansion, causing wrinkling or waves in parts of the liner when heated. Proper temperature is critical for seam welding to avoid inadequate bonding and uplift of the geomembrane on slopes. Long-term wrinkles can also become failure points. Proper maintenance is essential for the sustainable operation of geomembrane projects, especially for exposed liners. Preventing mechanical damage (intentional and accidental) is crucial for the liner's durability and effectiveness. Geomembranes are sensitive to intentional damage (cutting, burning, abrasion, impact, etc.) which can greatly reduce the liner's seepage control capacity.

The Moghan irrigation network, particularly Pumping Channel No. 3, has been a focal point for evaluating hydraulic performance, seepage control, and durability in irrigation systems. This channel, which spans 28 kilometers, is crucial for drawing water from the irrigation network and has a capacity of 2.3 cubic meters per second, serving approximately 3,500 hectares of agricultural and industrial land. Research conducted on this channel has employed the inflow-outflow method to measure average seepage rates, which were found to be around 46.86 liters per day per square meter. This rate is considered moderate compared to other geosynthetic-lined channels, highlighting the need for ongoing maintenance and monitoring to manage water loss effectively.Field inspections have revealed significant deterioration in the channel's walls and floor, leading to operational challenges. In 1999, significant repairs were made to three critical sections of the canal, covering 8 kilometers in total. However, these repairs proved insufficient, as severe damage reoccurred within two years of service. This situation emphasizes the necessity for robust construction practices and the potential benefits of using advanced materials, such as geomembranes, to enhance the durability and performance of irrigation channels. The research indicates that while immediate repairs can address some issues, long-term solutions are essential for maintaining the integrity of the irrigation infrastructure.Overall, the evaluation of Pumping Channel No. 3 illustrates the complexities and challenges faced in managing irrigation systems, particularly regarding hydraulic efficiency and seepage control. The findings suggest that integrating geosynthetic materials could significantly improve the channel's performance and longevity, thereby optimizing water resource management in the Moghan region. Continuous assessment and adaptation of maintenance strategies will be crucial in ensuring that the irrigation network meets the agricultural demands of the area effectively.

The average seepage rate along the canal reaches was 0.4686 liters per square meter per day. No sedimentation or damage was observed during field inspections. The results demonstrate the acceptable short-term effectiveness of well-installed geomembrane liners in controlling water losses. Properly designed and maintained geomembrane liners can significantly reduce seepage, improving agricultural water productivity. However, geomembranes require careful consideration in design, construction and operation to avoid issues like thermal wrinkling and mechanical damage that can compromise their seepage control function.

Controlling seepage from water storage and conveyance systems is essential in water-scarce countries like Iran. Geosynthetic liners, especially geomembranes, are rapidly expanding in Iran due to their unique waterproofing capabilities and other advantages like quick and easy installation. However, comprehensive studies on the performance of these liners are lacking. Rational expansion, proper utilization and optimal investment requires comprehensive evaluation of completed projects. This study's results indicate the acceptable short-term effectiveness of well-installed geomembrane liners in controlling water losses. Therefore, geomembrane liners can contribute to improving agricultural water productivity by significantly reducing seepage, if they meet waterproofing requirements. However, long-term performance and durability require further investigation.

Iran has limited water resources that require preservation and reducing water loss from reservoirs, especially in arid and semi arid regions. There are a number of methods available for to control water loss from reservoirs and canals. Concrete linings in water reservoirs and ponds are durable, but their efficiency is limited. Geomembrane sheets are another method of controlling leakage from water reservoirs. In this research, high density polyethylene was used to lining a concrete water reservoir to test its suitability for water proofing and chemical resistance. The benefits and drawbacks of this new lining material were investigated in the design, execution and operation stages. Subsequently, the effectiveness of this liner to control water loss was tested under different. The results showed that a geomembrane liner over a concrete lining requires special consideration during design, installation and maintenance and accessories such as pipes and sumps to reduce excessive stress on the liner. The analysis of water leakage from the liner showed that proper design and installation of the liner and accessories reduce water loss about 38% and limit leakage to 16.9 mm/day/m2.

The concrete canvas product consists of three main parts: the three-dimensional (3D) substrate with the cement mixture, the geo-membrane layer and the desired adhesive to connect the geo-membrane layer to the three-dimensional substrate. The three-dimensional layer is generally made of polyester, polypropylene and other engineered polymer had good mechanical and chemical properties, and has different thicknesses, suitable for various applications. This three-dimensional layer is designed in such a way that it has different textures on both sides so that the cement is poured into the space of the three-dimensional layer on one side and nothing spills out of the other layer. In the next step, this process is completed by connecting the geo-membrane layer to it. In industrial application; the geo-membrane layer formulation (including polymer-based resin, emollient, impact curing, filler, etc.) is designed in such a way that in addition to moisture insulation properties, mechanical strength and good chemical resistance to moisture dilute alkaline and acidic environments. In this way, a desired adhesive with desired formulation (including adhesive base resin, solvent, activator and type of catalytic additive, etc.) was selected for connecting of geo-membrane to 3D substrate. To achieve a suitable product, in addition to the geo-membrane layer, the adhesive selected to connect the geo-membrane layer to the three-dimensional substrate must have the appropriate viscosity to be able to completely cover the three-dimensional substrate and cause the two layers to be fully connected to each other. . If the adhesive used cannot create a suitable coating on the geo-membrane layer, by penetrating the fluid around the adhesive, it will weaken and thus destroy the entire coating layer and thus separate the layered concrete layers. In this way, one of the main disadvantages of concrete canvas produced by conventional methods is the separation/layering of the coating layer from the concrete canvas substrate due to thermal and mechanical stress, which weakens the adhesive connecting the layer to the substrate which creates practical problem for this product. In this work, the polymer casting technology based on polyvinyl chloride paste was used to cover a concrete canvas and the properties of the product were investigated. In this method, the polymer paste is coated on the three-dimensional substrate in one step without using (geo-membrane / adhesive) by Dr. Blade knife in a certain thickness. The results showed that the fabric concrete made based on the PVC paste casting method, has good sealing, mechanical and chemical resistance and has good resistance against layering. The results showed that the fabric concrete product obtained from the polymer casting method based on (resin / polyvinyl chloride paste) in terms of mechanical strength, showed acceptable properties compared to the geo-membrane layer and the overall fabric concrete product and also in terms of chemical properties (resistance to various solvents), it has a much better resistance than the sample made by conventional methods (geo-membrane / adhesive). This product (concrete canvas) has also shown better resistance to water leakage against the sealing of the product, the overall product made by the polymer casting method.

With the deployment of the belt on the land, increasing population and the need for new water resources, the need for better exploitation of all available water resources, including groundwater, surface runoff from rainfall is required. For efficient and effective use of rainwater, the role of catchments in supplemental irrigation have been reviewed by several professors and have been approved of. Therefore, in this article, calculation of the amount of water collected from the annual rainfall on the cover of greenhouses or in case of need and calculating the level of isolation required to meet the water requirements of the plants (with regard to methods to prevent evaporation of water collected) has been carried out. And the exclusion of the most critical regions of the Khorasan Razavi province, lack of access to adequate water supplies and the high life Geomembrane panels, rain water harvesting has very clear economic justifications. On the other hand, the dry land without the proper use of the method and construction of greenhouses, increasing land productivity and output and employment in the region are affected. In this way, according to the water requirement of plants grown in the greenhouse to collect rainwater in the upper level of the house and part of the adjacent land (according to the average rainfall in Mashhad and the amount of water extracted from), which is insulation for Geomembrane in pools of water for irrigation at the right time to reaffirm the measures used. Yet the implementation of this technique requires testing on health and long-term water quality monitoring will.

In this study, the amount of water losses in 7 irrigation canals in plains of Zaiandeh-rood, Moghan and Kerman, with the same specifications of HDPE geomembrane lining with the same age, were evaluated. For this purpose, the losses of water in the canals was determined by input-output method in three stages. At the same time, the amount of evaporation using a class A pan installed in next canals, was determined. to calculate seepage losses, the amount of evaporation losses were deducted from the total losses. Based on results, the amount of efficiency efficiency was between 95.9 to 99.7 and in averagewas 98.9 percent. The total losses in the canals was determined between 3.3 to 13.8 and averagely 11.5 lit/s per kilometer. From total losses, between 3.3 (Zaiandeh-rood) to 16.2 (Kerman) and in average 7.1 percent was due to evaporation and the remainder was due to seepage losses from geomembrane lining. The seepage losses in evaluated canals was between 0.03 (KC in Kerman plain) 0.16 (EC4 in Zaiandeh-rood ) and an average of 0.1 m3/m2/day (17 times lower than the concrete lining). The results of this study showed remarkable impact of geomembrane lining in control of water losses from irrigation canals and its advantages compared to conventional concrete lining.

An investigation was carried out on the sustainablity and growth rate of Rutilus frissi kutum larvae in polyethylene tanks in Ghazian Aquaculture Research Station, Guilan Province. The results were compared to those recorded for the currently used tanks including fiberglass and glass aquariums. Three treatments each with three replications were designed and the tanks were stocked with 30 fishes, with an average initial weight of 650 to 746 mg. The tanks were filled with 70 liters of water and the experiment was conducted for 60 days. The fish were fed with concentrated food during the rearing period. The fish showed an increase rate of 625.88, 643.54 and 659.48 mg in fiberglass, aquarium and polyethylene tanks, respectively. No significant difference was observed in the indices special growth ratio (SGR), food conversion ratio (FCR) and weight gain (P>0.05). The research indicated that the high-density polyethylene tanks made are more suitable for Rutilus frissi kutum culture than fiberglass and aquarium tanks.

Technosols are modified soils affected by human activities. This study investigated genesis, classification and physicochemical properties of four pedons of Technosols developed on refused oil refinery materials and compared them with two unpolluted pedons. Mineralogical studies showed smectite as a dominant clay mineral with other clay minerals. These clay minerals adsorb oil compounds in their interlayer spaces and reduce their mobility and decomposition. Different micromorphological features resulting from oil compounds in soils, including depletion zones, types of coatings (quasi and hypocoating) and features due to horizontal and vertical movement of oil compound in soil showed dynamics of oil compounds and their effects on soil forming process. The refused petroleum compounds decrease pH and increase organic carbon, amorphous form of Iron in soils. Taking into account the presence of high amounts of gypsum and carbonate in polluted soil, the studied soils were classified as Typic Calcigypsids in Soil Taxonomy but in WRB system, due to the presence of impermeable geomembrane within 100 cm of soil surface, they were classified as Linic Technosols, showing the more precision of WRB system in their classification.