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Monitoring the Performance of Mine Site Reclamation
Published in Bruno Bussière, Marie Guittonny, Hard Rock Mine Reclamation, 2020
Bruno Bussière, Thomas Pabst, Vincent Boulanger-Martel, Marie Guittonny, Benoît Plante, Carmen Neculita, Sylvette Awoh, Mamert Mbonimpa, Isabelle Demers, Abdelkabir Maqsoud, Adrien Dimech, Pier-Luc Labonté-Raymond
These methods use a radioactive source for θ measurement; the most used method is the neutron probe. The neutron probe method is based on the measure of the mobile neutrons which are slowed down or thermalized by an elastic collision with hydrogen particles in the soil and water. The neutron probes use the property of preferential deceleration by the hydrogen atoms to determine θ of a soil. These hydrogen atoms are mostly associated to water molecules, and consequently the deceleration of the neutrons is related to the soil moisture. A calibration curve must be determined between the neutron probe count ratio and the volumetric water content. The main advantage of the neutron probe method is the accuracy of the measurements with a good calibration curve. However, the use of these techniques involves the handling of a radioactive source, the drilling of access tubes, and a specific calibration for each soil.
Sustaining the ecological functions of the Litani River Basin, Lebanon
Published in International Journal of River Basin Management, 2023
T. Darwish, A. Shaban, I. Masih, H. Jaafar, I. Jomaa, J. P. Simaika
Lebanon possesses 39% of territory as arable lands and 29% as irrigable land (Byiringiro, 2013). However, the country is land-scarce (700 m2 capita) and before 2010 water availability was 980 m3 capita year–1 against a water demand of 220m3 capita year–1 (Shaban, 2011), but following the Syrian crisis it currently dropped to less than 700 m3 capita year–1 (Jaafar et. al. 2016). Nevertheless, water supply from the public sector is below 35% of water demand (Shaban, 2011). Water share for agriculture is high (70%), with indications of decrease during the last decade (AQUASTAT, 2020). Total water withdrawal for agriculture is still below the needed requirements to irrigate about 400,000 ha of irrigable lands (Figure 2). Studies using neutron probe and 15N on potato, the second crop by area in Bekaa, showed water use efficiency in fertigation using drip irrigation reaching 80% versus 40% for macro sprinkler irrigation with higher fertilizer N recovery in localized irrigation technique (Darwish et al., 2003). However, more than 60% of lands are still irrigated with traditional techniques with low application efficiency. The explosion in population in recent years due to the refugee influx multiplied the problem of pollution which is the major problem in the LRB, including the Qaraoun Reservoir and extends even to groundwater.
Evaluation of nutrient beneficial management practices on nitrate loading to groundwater in a Southern Ontario agricultural landscape
Published in Canadian Water Resources Journal / Revue canadienne des ressources hydriques, 2020
Sara Esmaeili, Neil R. Thomson, David L. Rudolph
Parcels A and B are divided into 3 and 8 agricultural fields, respectively. In the research efforts of Bekeris (2007) and Koch (2009), groundwater recharge and nitrate mass load were estimated at various locations (called ‘monitoring stations’ or ‘stations’) within these fields that represent a variety of topographic, geologic, and agricultural management conditions. Each station was equipped with a minimum of one monitoring well and one neutron probe access tube for soil water measurements. At several of the stations, clusters of capacitance moisture probes and soil temperature probes were also installed. In addition, seven soil coring campaigns were conducted over a three-year period at each station. The coring depth generally correlated with the total depth of the neutron probe access tube. These cores were subsampled at intervals ranging from 0.1 to 0.3 m, and the bulk soil nitrate concentration and water content was determined (Bekeris et al. 2007). Water content was determined gravimetrically and the bulk soil nitrate concentration was estimated using the colorimetric method described by Tel and Heseltine (1990). The total nitrate mass within the vadose zone was estimated for the cored interval and compared over time during the course of the field studies to document changes resulting from the BMP implementation (Rudolph, Devlin, and Bekeris 2015).
Evaluating the Economic Water Productivity underfull and deficit irrigation;the case of sesamecrop (Sesumum indicum L.)in woreda Kafta-Humera,Tigrai-Ethiopia
Published in Water Science, 2019
Soil moisture measurement is one of the critical activities that should be taken into consideration when irrigation is needed to be conducted. The American Society for Testing and Materials (AMET) (1980) suggested that the gravimetric and neutron probe soil moisture measurements are some of the methods widely used in estimating the soil moisture of soil. In this study, due to the lack of accessibility of the neutron probe, the second method which is the gravimetric method of estimating soil moisture of soil was used. This method was applied to the oven dry of soil samples. The other physical parameters that had a high contribution in this study are; the field capacity (FC) and permanent wilting point (PWP). FAO (1989) suggested that for determining the field capacity (FC) and permanent wilting point (PWP), both the pressure plate laboratory test mechanism and Walker and Skogerboe (1987) curve that correlated soil texture, field capacity, permanent wilting point, and volumetric water content were used.