Water Harvesting Research (Apr 2021)
The Effects of Gravelly Filters on Soil Moisture in rainwater Catchment Systems
Abstract
Rainwater harvesting system is one of the approaches to an adaptation to climate change and global warming. Rainwater harvesting has been resulted in diversification of water resources and will lead to increase water security. Optimum utilization of rainfall in arid and semi-arid plains ranging in sloping surfaces is very important. In areas where rainfall distribution during the season is not commensurate with the water needs of trees and plants, the water harvesting system and sand filters installed at the end of the system can lead to water infiltration into the rhizosphere of plant roots. The aim of this project is to investigate the performance levels of insulation, semi-insulating, and natural (With or without gravelly filters) range land to expansion of water supply around the seedlings dry almond in Isfahan province. To do this, 48 plots with dimensions of 7 * 4 meter with three treatments of insulation coating, semi-insulation, and natural cover with gravel filters and without gravel, filters were constructed at the end of rainwater level systems in three replications on the slope with a slope of 18%. At the bottom of each plot, a soil profile with dimensions of 1 * 1 * 1 meter was created to dig a seedling-planting hole with the aim of increasing the soil moisture. At this stage, materials such as rotten manure and straw, as well as nylon coating were used to increase water penetration and more moisture retention in the soil. In order to investigate the effect of the mentioned factors in increasing soil moisture, almond seedlings were planted in the system and simultaneous data on plant growth and soil moisture were recorded at two depths of 30 and 50 cm. Changes in pit moisture were measured at specific time intervals and finally statistically analyzed. Statistical analysis showed that among the treatments used, the treatment of adding 25% by volume of soil of seedling planting hole with rotten manure plus straw and straw and nylon with insulation cover and gravelly filter had the maximum volumetric moisture at a depth of 50 cm.
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