جستجوی مقالات مرتبط با کلیدواژه « water spreading » در نشریات گروه « آب و خاک »

Water spreading on the permeable areas is an appropriate strategy for flood control and efficiency. Determination of appropriate site for water spreading is one of the most important stages of such projects. In this paper, suitable areas for water spreading in Shabestar plain were determined based on four parameters including slope, permeability, transmissivity and unsaturated alluvium thickness. For this purpose, by using data of drilling logs from exploration and piezometric wells in the area, layer parameters information was prepared in geographical information system (Arc GIS 10 software) and then maps were combined together. The results showed that the maximum area of the aquifer with 192.794 square kilometers (40.1 percent), had suitable condition for water spreading and 146.512 square kilometers (30.5 %) of ​​the aquifer, had moderate condition. As well as 79.786 square kilometers (16.6 percent), had unsuitable condition for water spreading and 61.046 square kilometers (12.7%) of the aquifer had quite suitable condition.

The main aim of flood water spreading in Iran is to recharge groundwater. Understanding the effect and efficiency of such projects is one of the most important activities in managing and implementing water spreading. The purpose of this study was to investigate the effects of water spreading on groundwater resources in Kohdasht plain. Data and information required including precipitation rate, groundwater level and groundwater exploitation were collected and analyzed for a ten year period. First of all, in order to assess the three variables test of normality was performed and then all the data was normalized. The results showed that before implementing the water spreading project, fluctuations of groundwater were proportional to utilization of groundwater resources, showing a declining rate. After implementing the project, a turning point on groundwater level was observed. Also, another turning point was recognizable in hydrological year 1377-1378. In addition to overexploitation, drought affected the aquifer so dramatically that standard index in hydrological year 1371-1372 decreased from 0.3 to -1.5 in hydrological year 1377-1378.

Determination of suitable species is the most important factor in success of forestation in unfavorable conditions. One of the least costly and the shortest ways for introduction of adaptable species in an area is recognition of the plants that grow naturally. The objective in this study was to find out the effects of protection and water spreading operations on the quantitative improvement of Greek Juniper seedlings. In this study, the areas of water spreading station (Research station of Poshtkoh Water spreading) and an area in western section of water spreading station (an area as control) along the Poshtkoh watershed were chosen. The research was performed on counting of Greek Juniper (Juniper excelsa) in each of two areas. The ratio estimation method was used in a randomized systematic design in strips with the width of 50 meters and 200 meters apart for registration of qualitative parameters of Greek Juniper (Juniper excelsa). The total surface of areas was 600 ha and inventory with intensity of 16 percent has been done. This study showed that in spite of the less number of Greek juniper trees per ha in the station (0/104) in relation to the number of Greek juniper trees per hectare out of the station (0/666), the number of the Greek juniper seedlings in the station was eight times (8.34) more than the number of the Greek juniper seedlings out of the station. As to the effect of protection and water spreading operations on natural growth and increase of number of Greek Juniper seedlings in the station, forestation using this species in this area is recommended.