1- , Yazd University
2- Yazd University
3- Esfahan Regional Water. Esfahan, Iran
4- Soil Conservation and Watershed Research Institute
2- Yazd University
3- Esfahan Regional Water. Esfahan, Iran
4- Soil Conservation and Watershed Research Institute
Abstract: (681 Views)
Background: Many countries around the world have been affected by land degradation, primarily caused by soil erosion and sediment deposition. This has led to a decline in soil productivity, alterations in water quality, and a reduced capacity to mitigate natural disasters, such as floods. Beyond the direct economic impacts, soil erosion has severe environmental consequences, including the loss of nutrients, degradation of soil's chemical, physical, and biological properties, reduction in soil fertility, soil compaction, decreased permeability, deteriorated water quality, loss of wildlife habitats and biodiversity, changes in landscape features, desertification, an increase in greenhouse gases, and global warming. These changes also contribute to climate change, elevation of riverbeds, and a reduction in their carrying capacity .Watershed management practices, such as biological, mechanical, and bio-mechanical interventions—including seeding, planting, mulching, gabion construction, and piling—are effective in reducing erosion and runoff. One such method, paving, is a traditional resource management technique that has been less researched. It is recognized as indigenous knowledge in many parts of Iran and has been used for a long time as a method derived from experience and local wisdom. Unfortunately, despite its widespread use, this method has been under-researched within the context of watershed management and natural resource conservation. The effectiveness of paving has been largely demonstrated through local experience rather than scientific investigation .Paving is a watershed management practice that controls soil erosion and runoff by modifying the length and steepness of slopes. This research aims to investigate the hydrological response to rainfall events on plots of 2 meters by 10 meters in both paved and unpaved lands within the Kol Sheikhi watershed, part of the Parsian Dam headwaters, and the Tang Bawan watershed, part of the Zohra River headwaters, in Mamsani City. To achieve this, suitable locations for nine plots in paved lands and nine plots in unpaved lands were identified across three study sites with varying soil textures. Runoff was measured after each rainfall event was completed. The core of this research is based on field activities, including the collection of data from 10 rainfall events, and the measurement of runoff volumes in the three study areas, encompassing 18 plots, during the years 2020 to 2021.
Methods: Suitable locations for the experimental design were identified following a detailed review of geological maps, soil science data, vegetation cover, and slope characteristics of the study areas, along with extensive field surveys and an evaluation of the history of platform construction in the region. A total of 18 plots were established across three regions and three sub-watersheds, with nine plots located on lands with platforms and nine plots on lands without platforms. Each plot measured 10 meters in length and 2 meters in width, and the precise coordinates for their construction were recorded. The total volume of runoff generated after each rainfall event was measured using graduated containers. Runoff measurements were conducted for 10 natural storm events that occurred between January 26, 2018, and May 11, 2019. Finally, for statistical analysis, the data were compiled into a database using Excel 2016. Various descriptive statistics related to runoff were calculated using SPSS 21 software.
Results: The results from the first, second, and third study sites demonstrated a decrease in the runoff volume in paved areas compared to unpaved areas by 8.88%, 3.28%, and 15.6%, respectively. Additionally, a t-test revealed a significant difference (p ≤ 0.01) in the average runoff
volume between paved and unpaved lands across the study sites. During the maximum recorded rainfall event of 118 mm, the minimum runoff volumes were observed at the second, first, and third sites, with values of 6.5, 2.67, and 0.52, respectively. These sites, characterized by the "Pabdeh-Gorpi" and Aghajari formations, which are critically sensitive to erosion and sedimentation, showed the highest efficiency in controlling these processes.
Conclusion: Platforms are among the most significant human interventions in terrestrial ecosystems, designed to create new surfaces for cultivation on sloped terrains, reduce runoff and soil erosion, harvest and store rainwater, and accumulate biomass by enhancing crop production, and restore ecosystems. These structural modifications fundamentally alter land morphology, leading to changes in water infiltration, runoff generation, and ultimately impacting the entire water cycle from individual platforms to slope, catchment, and landscape scales. The scientific community has been studying the ecological, hydrological, and hydrogeological effects of platforms in terraced landscapes for several decades. Given the research gap in understanding the impact of these erosion and runoff control operations both in the country as a whole and in the target area specifically, this study examined the variability of hydrological components, such as runoff and soil loss, in paved and unpaved vineyards and pomegranate orchards under natural torrential conditions .The findings suggest that implementing such measures in runoff management programs—aimed at increasing moisture retention and preserving soil—can boost production and net income for land users. This can be achieved by involving local communities through subsidy plans, encouraging participation by offering free banking facilities, and institutionalizing these practices as part of the local culture. Paving, as a low-cost method, shows potential for improving formations that are sensitive to runoff, erosion, and sedimentation.
Methods: Suitable locations for the experimental design were identified following a detailed review of geological maps, soil science data, vegetation cover, and slope characteristics of the study areas, along with extensive field surveys and an evaluation of the history of platform construction in the region. A total of 18 plots were established across three regions and three sub-watersheds, with nine plots located on lands with platforms and nine plots on lands without platforms. Each plot measured 10 meters in length and 2 meters in width, and the precise coordinates for their construction were recorded. The total volume of runoff generated after each rainfall event was measured using graduated containers. Runoff measurements were conducted for 10 natural storm events that occurred between January 26, 2018, and May 11, 2019. Finally, for statistical analysis, the data were compiled into a database using Excel 2016. Various descriptive statistics related to runoff were calculated using SPSS 21 software.
Results: The results from the first, second, and third study sites demonstrated a decrease in the runoff volume in paved areas compared to unpaved areas by 8.88%, 3.28%, and 15.6%, respectively. Additionally, a t-test revealed a significant difference (p ≤ 0.01) in the average runoff
volume between paved and unpaved lands across the study sites. During the maximum recorded rainfall event of 118 mm, the minimum runoff volumes were observed at the second, first, and third sites, with values of 6.5, 2.67, and 0.52, respectively. These sites, characterized by the "Pabdeh-Gorpi" and Aghajari formations, which are critically sensitive to erosion and sedimentation, showed the highest efficiency in controlling these processes.
Conclusion: Platforms are among the most significant human interventions in terrestrial ecosystems, designed to create new surfaces for cultivation on sloped terrains, reduce runoff and soil erosion, harvest and store rainwater, and accumulate biomass by enhancing crop production, and restore ecosystems. These structural modifications fundamentally alter land morphology, leading to changes in water infiltration, runoff generation, and ultimately impacting the entire water cycle from individual platforms to slope, catchment, and landscape scales. The scientific community has been studying the ecological, hydrological, and hydrogeological effects of platforms in terraced landscapes for several decades. Given the research gap in understanding the impact of these erosion and runoff control operations both in the country as a whole and in the target area specifically, this study examined the variability of hydrological components, such as runoff and soil loss, in paved and unpaved vineyards and pomegranate orchards under natural torrential conditions .The findings suggest that implementing such measures in runoff management programs—aimed at increasing moisture retention and preserving soil—can boost production and net income for land users. This can be achieved by involving local communities through subsidy plans, encouraging participation by offering free banking facilities, and institutionalizing these practices as part of the local culture. Paving, as a low-cost method, shows potential for improving formations that are sensitive to runoff, erosion, and sedimentation.
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