majid khazayi; Iman Saleh; reza bayat; Shokr allah Absallan
Abstract
The concept of water productivity is to produce the best and most products by spending the lower amount of water. in this study water productivity was investigated with field surveys, field measurements and remote sensing analysis. For this purpose, in the first stage, water resources condition of the ...
Read More
The concept of water productivity is to produce the best and most products by spending the lower amount of water. in this study water productivity was investigated with field surveys, field measurements and remote sensing analysis. For this purpose, in the first stage, water resources condition of the Basht aquifer investigated. in the next step, the cultivated area of Basht aquifer was investigated using Sentinel-2 satellite images in Google Earth Engine. Then, the agricultural condition of the aquifer investigated through questionnaire by farmers and experts. In the next step, the water requirement of the current cultivation pattern was calculated by the Penman-Monteith method. Finally, by evaluating the products in terms of productivity indicators, the water productivity of different products was determined. Penman-Monteith method calculations indicated that the water requirements of the aquifer dominant crops, including Citrus fruits, wheat, barley, corn, rapeseed, watermelon, branches, legumes and alfalfa respectively were 9170, 5630, 4821, 7863, 5411, 9291, 20234, 5225, 14083 cubic meters per hectare, respectively. In total, the amount of water consumed by the agricultural products in aquifer Basht is 45 million cubic meters, that approximately equivalent to 1 cubic meter per square meter of the aquifer cultivation area and and this amount is much more than the aquifer agriculture programmable water (17 million cubic meters).
Rahim kazemi; Bagher Ghermezcheshmeh; Reza Bayat
Abstract
IntroductionResearch on low flow is important, not only from a fundamental point of view but also in terms of sustainable water resource management. Optimum water resources management is one of the most crucial challenges of the 21st century, and due to population growth and climate change, water supply ...
Read More
IntroductionResearch on low flow is important, not only from a fundamental point of view but also in terms of sustainable water resource management. Optimum water resources management is one of the most crucial challenges of the 21st century, and due to population growth and climate change, water supply in the future will probably depend on sustainable water sources. The World Meteorological Organization (WMO) introduces low flow as a flow of rivers that continues during the dry period of the climate. Low flow is affected by climate changes, topography, geology, soil, and human activities. The geographical location and climatic conditions of Iran cause a lack of rainfall and water scarcity. Therefore, the recognition and analysis of sustainable water resources is the main component in the surface water resources management of Iran. This research has been done with the aim of investigating the characteristics of scientific publications regarding low flow research in Iran and the world and providing a perspective of the current situation and direction of future research.Materials and methodsThe data relating to low flow research in environmental; agricultural and biological sciences were retrieved from the Science direct database in the period 1999 to 2022 and SCImago Journal Rank indicator (SJR) from https://www.scimagojr.com as well as scientific information database of Jihad Daneshgahi (SID) and data from Iranian Research Institute for Information Science and Technology (IranDoc). A total of 22875 publications were obtained and with following aspects analysed intensively:(1) Distribution of international low flow-related publications (2) low flow-related publications from Iran; (2) distribution of subject categories; (3) core journals; (4) distribution of Iranian articles related to low flow; (5) frequency of low flow-related articles in Middle East and countries around Iran; (6) research trends. Bibliometric techniques, including citation analysis, five-year impact factor, JCR classification, coverage period and h-index were used to evaluate and interpretation of the results.Results and discussionThe results showed that the general trend of global scientific publications in low-flow research was with a positive slope and a growth rate of 1.52%. Also, the trend of international publications from Iran had a positive slope with a 0.94 coefficient of determination and a growth rate of 1.60%. The results of the subject classification of publications at the global level showed that most publications with 85.75% belong to research papers and the least amount to conference papers and editorials. International papers originating from Iran were of the first order of importance to publications with 90.04%, which has a larger share of the total papers than global papers. The results of the analysis of the most important keywords related to low flow showed that more than 72% of the titles of papers and theses were assigned to "base flow" and "flow duration curve (FDC) keywords ".ConclusionsThis research is a systematic bibliographic analysis of texts related to low flow research publication. By summarizing and analysing the growth curve of publications, it can be concluded that the total number of international publications related to low flow research corresponds to the theoretical fitting line and shows the proportionality of the potential of low flow research in the world with the actual amount. The general result of the analysis of international publications from Iran shows a high potential for low flow research in Iran and indicates a change in the attention of the Iranian scientific community to the publication of articles on the topic of low flow at the international level.
Majid Soufi; Reza Bayat; Afshin Partovi
Abstract
Some parts of “morpho-climatic classification of Iran's gullies” national project in Soil Conservation and Watershed Management Research Institute, refer to the amount of produced sediments and reclamation measures for their management and the amount of damages resulting from their development. ...
Read More
Some parts of “morpho-climatic classification of Iran's gullies” national project in Soil Conservation and Watershed Management Research Institute, refer to the amount of produced sediments and reclamation measures for their management and the amount of damages resulting from their development. The results of this research indicate that Iran's gullies are categorized in two classes, small (<1 m) and medium gullies (1-10 m). One meter of gully has produced 19 m3 of sediment. Generally, they are distributed in rainfed lands and rangelands with loam, sandy loam and clay loam soil textures. The most important causes of gully formation and development are rangeland destruction, rangeland change to cropland and garden, and non-proper road and culvert construction. The present research showed that more than 50% of Iranian gullies had no management and reclamation measures, so that in 90% of some provinces and 30-50% in other areas, no management measures have been taken. More mechanical measures such as loose rock dams, rock and cement dams and gabions dams with the aim of sediment trapping are taken in Iran's provinces. Most measures are taken in small gullies, but just a few in medium ones. Management measures for prevention of gully formation are negligible in rainfed lands and serious attention is recommended to be paid to the design and construction of culverts and roads in mountainous and steep areas. Biological methods, blankets and rip-rap methods are used less in Iran. Demolition and abandoned old Ab-anbars had a role in have gully formation and development.
Reza Bayat; Afsaneh Alinejadian; majid soufi; abbas maleki; Omidali Akbarpour
Abstract
Recognition of influential factors is required for management of gully erosion. The purpose of this study was gully classification and determining the most effective variables on the soil loss in the Fath Abad, Buin Zahra in Qazvin Province. Twenty four gullies were selected, surveyed and recorded by ...
Read More
Recognition of influential factors is required for management of gully erosion. The purpose of this study was gully classification and determining the most effective variables on the soil loss in the Fath Abad, Buin Zahra in Qazvin Province. Twenty four gullies were selected, surveyed and recorded by GPS, and their morphologic characteristics including length, width and depth were measured. Surface soil samples were taken from headcut and were analyzed for texture, EC, pH, organic matter and some anions and cations. Indices related to the form of watershed were extracted from the digital elevation model which derived from UAV image processing. The Ward method was used for cluster analysis of gullies and their properties. Factor analysis, the correlation between factors and multivariate regression were performed to determine important and effective factors on the formation of gullies in SPSS. The results of the research indicated that gullies have vertical headcuts, trapezoidal cross-sections and linear general plans. The average depth of headcuts, depth at 50% of the gully length and the average gully length were 0.4, 0.6 and 25 m, respectively. Soil texture was loam and average soil texture components including sand, silt and clay were 30, 46 and 24%, respectively. The mean EC and pH of the samples was 8 dSm-1 and 8.4 respectively. Linear correlation between the total volume of soil loss and other gully characteristics showed that the average cross section, average gully lower width and upper width, sand content, average gully depth and total length have meaningful correlation coefficients greater than 0.6 at 1% percent level. Also, multivariate regression results showed that the most effective factors on soil loss by gully erosion were saturation percentage, sand content, roundness coefficient, basin length and area respectively, which had more effect on soil loss prediction, which entered into the loss prediction equation.
