| چکیده انگلیسی مقاله |
1- Introduction
Currently, continued drought and accelerated desertification in the Sistan region have led to sandstorms and created environmental and humanitarian crises. This has not only devastated the region's ecosystem but also faced significant challenges to the lives of its residents. In addition, the consequences of these destructive phenomenon cause a lot of damage to urban and rural facilities and infrastructures. The most important factors affecting wind erosion in arid areas include low humidity, poor vegetation, destruction of soil structure (Physical and chemical) and flat land surface. In response to the dehydration crisis and the limitations of biological measures, as well as the prevalence of high erosive winds, increasing soil roughness by creating barriers to control the movement of soil and flowing sand is a practical approach to prevent the destructive consequences of wind erosion in this region. Hence, this research aims to investigate the effect of furrow on increasing soil roughness to control sand movement and reduce sediment transport in the wind erosion centers of the Nimroz City.
2- Methodology
The study area located in the west of Hamon Lake with geographical coordinates between 61°8 ' 40" to 61°8 ' 46" east longitude and between 31°9 ' 24" to 31°9 ' 29" north and at an altitude of about 473 meters above sea level. The average annual precipitation of the study area is less than 50 mm, which often falls sporadically in the winter. Regarding topography, the studied area has a low slope and is free from low and high elevations. Moreover, this area due to severe erosion is one of the active dust sources in IRAN. The experiment had been conducted in a randomized complete block design with 42 treatments in 3 replications. The treatments included: type of soil roughness (furrow and control), Distance of sediment traps (1m, 16m, 31m, 46m, 61 and 76m) and times (March, May, June, July, August, September, October). Using tractor and furrower blade, the farrows were built in such a way that they were perpendicular to the wind direction. Sediment traps were set up in each treatment at a height of 0.18 cm above the soil surface. After each sand storm, samples were collected to analyze the sediment particle size and granulometry parameters such as Mid-average, Kurtosis, Skewness, and sorting. To analysis the mean of parameters among different land uses were used the Duncan test.
3- Results
The result showed that under the type of soil roughness there is a significant difference in the amount of aeolian sediment (P<0.05). Thus, the amount of sediment in the control area is equal to 454.2 grams, which has decreased to 68.3 grams with the construction of the furrow and the increase in the roughness of the soil surface. Beside that, the findings indicate the amount of sediment trapped is different in the experimental treatments too (P<0.05). So that with the increase of wind speed during the months of July and August and (with an average wind speed of 25.1 and 2.23 m/s, respectively) the amount of sediment in the furrow area at intervals of 1, 16, 31, 46, 61 and 76 m was associated with an average decrease of 4.7, 4.8, 6.4, 7.3, 8.6 and 1.14 times compared to the control area. According to the obtained results, the mean and average values of aeolian sediment in the control area are equal to 2.04 phi (equal to 235 microns) and 2.18 phi (equal to 220 microns), respectively. While, by furrow construction the median and mean values of particles size turned to 3.28 phi (105.11 microns) and 3.55 phi (88.39 microns), respectively. According to result the sediment texture in control area is in the sandy-loamy class, which with a decrease of 1.6 times of sand and an increase of 2.6 and 1.1 times of clay and silt has been changed to the loamy class in furrow area.
4- Discussion & Conclusions
In this research, we investigated the effect of furrow construction on soil roughness to control sand movement and reduce erosion in the erosion zone of Nimroz City. As results depicted, under the effect of furrows construction, the amount of sediment trapped decreased by 6.4 times compared to the control area (P<0.05). Also, the particles size of aeolian sediment in the control area were equal to 235 microns, which in the furrows area has decreased to 88.39 microns. This process implies that the increment of soil roughness along contour lines, directly alters the wind flow and decreases the destructive power of the wind and consequently sediment transport potential.
Overall, the construction of furrows in the erosion zone of the Sistan region, which is mostly devoid of vegetation and has flat topography, by increasing the roughness of the ground surface, caused the sand movement significantly decreased. In addition, this practice is adapted to harsh weather conditions in the Sistan region and can implemented with minimal facilities in fragile areas. Additionally, due to the scattered rainfall in these areas, the furrow system acts as a rainwater catchment system to collect the runoff and provide a suitable condition for restoring vegetation and consequently stabilizing and controlling erosion zones in these areas.
|
| نویسندگان مقاله |
معین جهان تیغ | Moien Jahantigh
Department Soil Conservation and Water Management, Sistan Agriculture and edition Natural Resources Research Center, AREEO, Zabol, Iran
بخش تحقیقات حفاظت خاک و آبخیزداری، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی سیستان، سازمان تحقیقات، آموزش و ترویج کشاورزی، زابل، ایران
منصور جهان تیغ | Mansour Jahantigh
Department Soil Conservation and Water Management, Sistan Agriculture and edition Natural Resources Research Center, AREEO, Zabol, Iran
بخش تحقیقات حفاظت خاک و آبخیزداری، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی سیستان، سازمان تحقیقات، آموزش و ترویج کشاورزی، زابل، ایران
|