Sharp Expansion of Intensive Groundwater Irrigation,Semi-Arid Environment at the Northern Bekaa Valley Lebanon

This research focuses on the sharp expansion of groundwater irrigation in the Northern Beqaa, using Landsat satellite images and other auxiliary GIS relevant data sources. Topographic maps were used to assess the location and size of the irrigated area in the early 1960s as the initial years of agriculture expansion analysis. The first available Landsat image of the area was of the year 1972 followed with a series of accessible Landsat images until 2009. In the 1960s, agricultural practices were only limited to areas of surface water resources and open channels next to urban settlements. In the Early 1980s, farmers discovered the agricultural potential of the area. Only 3% of the area was cultivated before the 1970s. The cultivated area reached about the 20% in late 1990s. Weather conditions, shallowness of groundwater tables, low fuel costs and market opportunities have led to an agricultural boom in the area considered as prone to desertification and of low productivity by national authorities. The area is however poorly understood from its hydro geological characteristics and exposed to intensive and unsustainable use of its natural resources.

Effects of different irrigation methods on micro-environments and root distribution in winter wheat fields

The irrigation method used in winter wheat fields affects micro-environment factors, such as relative humidity（RH） within canopy, soil temperature, topsoil bulk density, soil matric potential, and soil nutrients, and these changes may affect plant root growth.An experiment was carried out to explore the effects of irrigation method on micro-environments and root distribution in a winter wheat field in the 2007–2008 and 2008–2009 growing seasons.The results showed that border irrigation（BI）, sprinkler irrigation（SI）, and surface drip irrigation（SDI） had no significant effects on soil temperature.Topsoil bulk density, RH within the canopy, soil available N distribution, and soil matric potential were significantly affected by the three treatments.The change in soil matric potential was the key reason for the altered root profile distribution patterns.Additionally, more fine roots were produced in the BI treatment when soil water content was low and topsoil bulk density was high.Root growth was most stimulated in the top soil layers and inhibited in the deep layers in the SDI treatment, followed by SI and BI, which was due to the different water application frequencies.As a result, the root profile distribution differed, depending on the irrigation method used.The root distribution pattern changes could be described by the power level variation in the exponential function.A good knowledge of root distribution patterns is important when attempting to model water and nutrient movements and when studying soil-plant interactions.

Use fuzzy interface systems to optimize land suitability evaluation for surface and trickle irrigation

In this study fuzzy logic system was used for optimization parametric evaluation system in surface and trickle irrigations.This study was performed on a surface area of 5175 ha in fathali region located in Ardabil province of Iran.It was indicated that for trickle and surface irrigation respectively an area of about 2941.35 ha(56.77%)and 159.81 ha(3%)of the lands is“highly suitable”and an area of about 246.43 ha(4.7%)and 312.69 ha(6%)is“moderately suitable”.About 797.1 ha(15.4%)and 2744.17 ha(53.02%)were respectively“marginally suitable”for trickle and surface irrigations.“Currently not suitable”suitability included about 737.58 ha(14.2%)and 1746.05 ha(33.7%)and“Permanently not suitable”suitability matched 458.54 ha(8.86%)and 212.28 ha(4.1%)in the zone under study.According to the results,there is a major difference between the“highly suitable”lands obtained through the two methods and the area of“highly suitable”lands in the trickle method is about 18 times of the area of“highly suitable”obtained through the surface irrigation method.As a result,considering the gradual changes of soil parameters,fuzzy evaluation leads to more accuracy compared to the parametric non fuzzy method.By and large,it can be said that fuzzy method,shows higher qualities about the suitability of lands for trickle irrigation.