Akademik Veri Yönetim Sistemi
IRRIGATION AND DRAINAGE, cilt.52, sa.4, ss.343-353, 2003 (SCI-Expanded)
Soil productivity is affected by soil physical properties that play a crucial role in planning drainage systems. Improper planning of drainage systems can create high water table problems and, in turn, an unsuitable environment for plant growth. Therefore, drainage systems should be well planned and monitored regularly. It is very labor-intensive and time-consuming to determine the spatial and temporal changes in drainage parameters such as groundwater (GW) depth, elevation, hydraulic gradient and salinity by conventional methods over large areas. Geographic information systems (GIS) can be used to assess the spatial and temporal changes efficiently and rapidly. This study was conducted to determine drainage problem areas and to suggest the most suitable drainage systems for those areas by evaluating spatial and temporal changes in GW depth, elevation and salinity, with regard to drainage criteria used by the State Hydraulic Works (DSI) responsible for the development of land and water resources in Turkey. A pilot area of 8494 ha in the Lower Seyhan Plain, Adana, Turkey, was selected. The elevations and coordinates of 85 drainage observation wells were obtained from the existing maps with a scale of 1/5000 and 1/25 000, respectively. The GW depth and GW salinity data, the latter only available for July, were obtained from an archived long-term monthly data set of the 6th Regional Directorate of the DSI. Running ArcView 3.0a, the salinity, as well as the seasonal maps of the GW depth and elevation, were developed to assess the spatial and temporal changes. Results indicated that about 99.8% of the study area was suffering from various levels of drainage problems. Main, secondary and tertiary drainage canals in the region seemed to be malfunctioning due mostly to siltation and weed problems. GW fluctuation did not seem to be of great importance, indicating a need for a subsurface drainage system. It was concluded that some areas are likely to be prone to potential GW salinization risk during the peak irrigation season if in the future, irrigation water is sparingly used and irrigation efficiency is improved. The GW hydraulic gradient did not significantly change temporally, but it did change spatially. Copyright (C) 2003 John Wiley Sons, Ltd.