Impact assessment of flood spreading project on some physico-chemical properties and soil fertility, case study: Tigh Syah- Hashtbandi floodwater spreading in the Hormozgan Province

The flood water spreading is one of the suitable ways for the control and efficient use of flood water in arid and semiarid regions. By this way, the flood sediments are reused and soil fertility increased. The floodwater spreading is an suitable way to exploit deposits of nutrient-rich water that have some important uses include more fertile soil with nutrients supply. Floodwater spreading in the aquifer and sedimentation in surface soil cause large changes in soil characteristics on the surface and at the depth. This research is about Tigh Syah, Hashtbandi floodwater spreading network located in the 165 km in the South-east of Bandar Abbas on a shallow alluvial apron. In this plain, floodwater spreading plan began in 2005 with an area of 165 hectares. The purpose of this research was to study the changes in some features of the topsoil affected by floodwater and to compare its results with the control area. In this study three floodwater spreading network were implemented and in any network soil was sampled from 0-30 cm top soil and from three sections of upstream, middle and downstream of a control area. The study area was located in Tigh Syah in Hashtbandi, Hormozgan Province. For measuring changes on soil properties, 20 samples were selected from inside and outside of the station. The results were analyzed in a completely randomized design. Results of t test, showed that the average percentage of clay, silt, soil saturation moisture, organic carbon and electrical conductivity, total N, phosphorus and potassium were increased at the level of %1 (P≤ 0.01). Results also indicated that electrical conductivity and sand and pH were decreased (P≤ 0.01) in flood spreading area compared to control site. The results of this research indicates that in general, soil condition improves by floodwater spreading as a positive operation.