采礦專業(yè)畢業(yè)設(shè)計外文翻譯--關(guān)于煤層沼氣的一些經(jīng)常出現(xiàn)的問題-采礦工程(完整版)
【正文】 ity of CBM product water and its effect on soil: Coal bed methane product water has a moderately high salinity hazard and often a very high sodium hazard based on standards used for irrigation suitability. Irrigation with water of CBM product water quality on range or crop lands should be done with great care and managed closely. With time, salts from the product water can accumulate in the root zone to concentrations which will affect plant growth. Saline conditions stunt plant growth because plants must work harder to extract water from the soil. The sodium hazard of CBM product water poses additional threats to certain soil resources. Sodic irrigation water causes soil crusting and impairs soil hydraulic conductivity affecting water availability and aeration, important to crop growth and yield. Upon wetting soils with swelling clay, sodium causes the degree of swelling in the clay to increase, causing dispersion and migration of clay particles. Current research at Montana State University shows water with sodium levels equal to that in typical CBM product water of Montana can degrade the physical and chemical properties of heavier, clay soils, making such soils pletely unsuitable for plant growth. The risk of sodium has been observed in other soil textures. Jim Oster (personal .) observed crusting, poor soil tilth, hardsetting and aggregate failure on a sandy loam soil irrigated with water EC ~ 1, SAR ~ 7. Minhaus (1994) saw irreversible and severe reduction in infiltration on sandy loam soil with long term irrigation under high SAR water followed by monsoon rain. There are many factors in addition to soil textures that affect infiltration rates. Mineralogy, lime, sesquiozides, organic matter content, cultivation, irrigation method, wetting rate, antecedent water content and time since cultivation all play a roll in infiltration of soils. The only way to be certain of the impacts of saline/sodic irrigation water on the soil is to periodically sample and test the irrigation water and the soil. The quality of CBM product water and its effect on plants: Disposal of the large quantity of CBM product water into stream channels and on the landscape poses a risk to the health and condition of existing riparian and wetland areas. The high salinity and sodium levels in the product water may alter riparian and wetland plant munities with the replacement of salt intolerant species with more salt tolerant species. It is well recognized that encroachment of such noxious species as salt cedar, Russian olive, leafy spurge is enhanced by saline conditions. Will CBM development reduce flow to streams, springs and wells? As a result of the large amount of water being pumped from the coal seam aquifers, there is concern of impact to springs and streams and to the level of water in drinking, and livestock wells. The answer to t
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