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111.
Deriving hillslope sediment budgets in wildfire-affected forests using fallout radionuclide tracers 总被引:3,自引:1,他引:2
W.H. Blake P.J. Wallbrink S.N. Wilkinson G.S. Humphreys S.H. Doerr R.A. Shakesby K.M. Tomkins 《Geomorphology》2009,104(3-4):105-116
Information on post-fire sediment and nutrient redistribution is required to underpin post-fire catchment management decisions. Fallout radionuclide budgets (210Pbxs, 137Cs and 7Be) were derived to quantify soil redistribution and sediment yield in forested terrain following a moderately severe wildfire in a small (89 ha) water supply catchment in SE Australia. Application of these techniques in burnt terrain requires careful consideration of the partitioning of radionuclides between organic and mineral soil components. Beryllium-7 and 210Pbxs were shown to be closely associated with ash, litter and soil organic matter whereas 137Cs was more closely associated with subsurface coarse mineral soil. Comparison of the three tracer budgets indicated that the dominant sediment source areas were ridgetops and steep valley sideslopes, from which burnt surface material was conveyed to the stream network via pre-existing gullies. Erosion was predominantly driven by sheetwash, enhanced by soil water repellency, and modified by bioturbation which both supplies subsurface sediment and provides sinks for erosive overland flow. Footslope and riparian zones were not important sediment source areas. The estimated event-based (wildfire and subsequent rainfall) sediment yield is 58 ± 25 t km− 2, based on fallout 7Be measurements. The upper estimate of total particulate phosphorus yield (0.70 kg ha− 1) is more than 10 times that at equivalent unburnt sites. This illustrates that, soon after fire, burnt eucalypt forest can produce nutrient loads similar to those of agricultural catchments. The tracer budgets indicate that wildfire is an important control on sediment and phosphorus inputs to the stream network over the decadal timeframe and the pulsed nature of this release is an important concern for water quality management. 相似文献
112.
Catastrophic and dangerous inflows to salt mines in Poland as related to the origin of water determined by isotope methods 总被引:2,自引:0,他引:2
Tritium, 14C, δ13C, δ18O and δD measurements indicated as early as 1973 the existence of inflows of modern meteoric water to the Wapno salt mine
in a Zechstein diapir. In spite of these early warnings, the continuation of improper exploitation led, in 1977, to sudden
flooding of the mine followed by catastrophic land subsidence. The lesson learned from that catastrophe, as well as the results
of isotope investigations performed in the Inowrocław salt mine, led to the decision to flood the mine artificially in order
to avoid a similar land subsidence. The Kłodawa mine was not regarded to be in danger of flooding due to a thick clay cap.
In fact, a large number of usually short-lasting water occurrences had the isotopic composition characteristic for evaporated
ocean water. However, since 1956 an inflow has existed with δ18O and δD values close to that of pre-Quaternary saline waters and brines in the Mesozoic formations adjacent to the diapir.
Two other inflows have recently occurred with the initial δ18O and δD values of modern waters. As a consequence, the mine is regarded to be in danger, and the exploitation of salt in
the areas of inflows has been stopped. The Wieliczka mine, southern Poland, exploits Miocene salts overthrusted together with
the Carpathian flysch from the south. The most dangerous and catastrophic inflows were caused by human errors. Isotope data
show the water to be of glacial or Holocene age stored in Tertiary, slightly cemented rocks of low permeability, which neighbor
the mine from the north. Owing to specific geology, the mine has survived for a long time, in spite of relatively large and
long-lasting inflows. However, its existence is in permanent danger.
Received: 7 March 1997 · Accepted: 17 November 1998 相似文献
113.
Water contamination and remedial measures at the Troya abandoned Pb-Zn mine (The Basque Country, Northern Spain) 总被引:1,自引:0,他引:1
This article describes a case of contamination of a karstic aquifer by abandoning an underground mine exploiting sulphide
ore body. To exploit the ore, the aquifer was drained and the water level declined about 230 m, drying up the spring that
had drained the aquifer up to that moment. When the mining activity ceased, the piezometric level recovered and contaminated
water began to flow out from a mine adit. The water is high in sulphates and dissolved Fe, although the pH is neutral. When
this water reached the nearby creek, the fish population was eliminated, principally due to the presence of toxic metals and
the precipitation of Fe hydroxides. The contamination originated in an area of the partially flooded mine rooms where the
ore is in contact with both air and water. The acidity generated by pyrite oxidation is neutralized by calcite dissolution.
Presently, the mine water is diverted to the old tailings pond which functions as an aerobic wetland. This action has allowed
the fish population in the creek to be restored.
Received: 20 January 1999 · Accepted: 15 March 1999 相似文献
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月亮田矿南四采区构造成因及找煤应用 总被引:1,自引:0,他引:1
利用地质力学原理,对月亮田矿南四采区的构造发肓规律及展布特点进行综合分析,认为该区地质构造成因是由繁到简并成带状分布,从而成功地找到了经济可采煤层。 相似文献
118.
赞比亚谦比西铜矿水文地质条件和疏干方案研究 总被引:3,自引:0,他引:3
分析了赞比亚谦比西铜矿水文地质条件的特点及其对矿山防治水的影响。提出了与当地习惯做法不同的本中段为主疏干、放水工程非均匀布置的治水方案 ,以及保证方案得以成功实施所应采取的措施。 相似文献
119.
通过1∶5万矿山地质环境调查和遥感解译手段,对日照市矿山进行了全面的调查,查明各类矿山546处,主要集中在莒县和五莲县境内。除莒县刘官庄煤矿外,其余全部为露天开采矿山,主要选用直接开挖的方式,不仅破坏了地表环境,而且矿山生产活动产生的固体废弃物占用了大面积的土地。该文根据矿山地理位置及开采方式的不同,将相同类型的多个矿山划分为同一治理区,针对不同治理区的特点,采取科学有效的治理方法,建立健全矿山地质环境监督管理机制,切实解决矿山地质环境问题,改善生态环境。 相似文献
120.