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121.
净土保卫战和农业农村污染治理攻坚战是污染防治攻坚战的重要组成部分。本文对\"十四五\"及今后一个时期土壤、地下水和农业农村生态环境保护总体形势进行了分析,研究提出\"十四五\"目标指标、重点任务和政策措施的建议,提出坚持问题导向、目标导向,坚持分类施策、精准治污,以解决人民群众关心的突出环境问题为重点,实施一批源头预防、风险管控、治理修复重大工程,推进土壤、地下水和农业农村生态保护治理体系与治理能力现代化,为美丽中国建设提供坚实保障。  相似文献   
122.
Large area soil moisture estimations are required to describe input to cloud prediction models, rainfall distribution models, and global crop yield models. Satellite mounted microwave sensor systems that as yet can only detect moisture at the surface have been suggested as a means of acquiring large area estimates. Relations previously discovered between microwave emission at the 1.55 cm wavelength and surface moisture as represented by an antecedent precipitation index were used to provide a pseudo infiltration estimation. Infiltration estimates based on surface wetness on a daily basis were then used to calculate the soil moisture in the surface 0–23 cm of the soil by use of a modified antecedent precipitation index. Reasonably good results were obtained (R2= 0.7162) when predicted soil moisture for the surface 23 cm was compared to measured moisture. Where the technique was modified to use only an estimate of surface moisture each three days an R2 value of 0.7116 resulted for the same data set. Correlations between predicted and actual soil moisture fall off rapidly for repeat observations more than three days apart. The algorithms developed in this study may be used over relatively flat agricultural lands to provide improved estimates of soil moisture to a depth greater than the depth of penetration for the sensor.  相似文献   
123.
ABSTRACT: Most water-resouree investigations in semiarid basins of the Great Basin in western North America conclude that ground-water recharge from direct precipitation on the valley floor is negligible. However, many of these basins contain large areas covered by unvegetated, active sand dunes that may act as conduits for ground-water recharge. The potential for this previously undocumented recharge was investigated in an area covered by sand dunes in Desert Valley, northwestern Nevada, using a deep percolation model. The model uses daily measurements of precipitation and temperature th determine energy and moisture balances, from which estimates of long-term mean annual recharge are made. For the study area, the model calculated a mean annual recharge rate of as much as 1.3 inches per year, or 17 percent of the long-term mean precipitation. Model simulations also indicate that recharge would be virtually zero if the study area were covered by vegetation rather than dunes.  相似文献   
124.
Characterized by expensive housing, high socioeconomic status, and topographic relief, Upper Sonoran Lifestyle communities are found primarily along the Wildland-Urban Interface (WUI) in the Phoenix, Arizona metro area. Communities like these sprawl into the wildlands in the United States Southwest, creating a distinct urban fringe. This article, through locational comparison, introduces and evaluates a new field assessment tool for monitoring anthropogenic impact on soil–vegetation interactions along the well-maintained multi-use recreational trails in Upper Sonoran Lifestyle region. Comparing data from randomly selected transects along other multi-use trails with data from a control site revealed three key indicators of anthropogenic disturbances on soil–vegetation interactions: soil disturbance, vegetation disturbance, and vegetation density. Soil and vegetation disturbance displayed an average distance decay exponent factor of −0.60, while vegetation density displayed a reverse decay average of 0.60. Other important indicators of disturbance included vegetation type, biological soil crusts, and soil bulk density. The predictive ability of this new field tool enhances its applicability, offering a powerful rapid ecological assessment method for monitoring long-term anthropogenic impact in the Upper Sonoran Lifestyle, and other sprawling cities along the WUI.  相似文献   
125.
Preliminary surveys are used to prioritize between contaminated sites to select those to be investigated more thoroughly. The data-gathering steps are almost identical between countries; however, the assessment procedures differ significantly. In this study, we have investigated 21 contaminated sites assessed as belonging to the high-risk or the very high-risk class using the Swedish Methods for Inventories of Contaminated Sites (MICS). We then applied the US Preliminary Assessment (PA) method to the same sites and compared the results and conclusions from the two screening procedures. In both cases, all sites were recommended for further investigation and the two approaches seem to corroborate one another; however, the PA assessment scores and the preliminary MICS classifications did not correlate. The results obtained with the PA method were easier to explain than the final MICS classification. The PA method also seems more transparent and easier to standardize, although objections could be made regarding the weighting scheme, because the outcome in this study was entirely dependent on the surface exposure pathway. However, to examine this in greater detail, it is necessary to include sites with less contamination: The importance of preliminary surveys in the overall risk management process gives a strong motivation for such an evaluation. Generally, the lack of research and scientific support for the various assessment procedures in use suggests that there is a need for method development, standardization, and validation.  相似文献   
126.
    
Sewage sludge, or biosolids, produced in wastewater treatment plants (WWTP) can be used as an alternative to organic fertilizer in the agricultural field. However, it holds a large amount of anthropogenic chemicals, such as drugs and metals. The aim of the present study is to evaluate biochemical biomarker responses in earthworms (Eisenia andrei) exposed to soil presenting different sludge concentrations deriving from the largest WWTP in Southern Brazil. Treatments comprised 3%, 6%, 12%, 24%, 50%, and 75% of sludge incorporated to native forest soil, 100% of sludge and the control group (0%). Concentrations of different drugs, mainly of antibiotics, as well as high sulfur, magnesium, potassium, zinc, and phosphorus were identified in analyzed sewage sludge. Exposed earthworms were collected on the 7th, 14th, and 28th day of the experiment and subjected to analysis of lipid peroxidation levels (TBARS), acetylcholinesterase (AChE), catalase (CAT), and glutathione S-transferase (GST) activity. Treatments with 50%, 75%, and 100% of sludge were lethal to earthworms after 7 days. Based on biochemical tests performed in treatments with 3%, 6%, 12%, and 24% of sludge, the highest sludge concentrations (12% and 24%) and the longest exposure time (28 days) led to significant changes in biomarkers. Therefore, sewage sludge must be incorporated into the soil at concentrations lower than 3%, mainly due to changes in CAT, AChE, GST, and the resulting lipid damage observed at concentrations of 6%, 12%, and 24%.  相似文献   
127.
本文讨论了区域水资源的评价问题.无论是地表水、地下水,还是土壤水都是来源于大气降水,降水资源才是区域总水资源;同时讨论了区域水资源的平衡原理.降水资源转化了截留水、地表水、土壤水和地下水4项水资源.该文对这2种不同的水体进行了深入讨论,着重论述了土壤水资源的概念及其特征.并对潜水蒸发和水资源的价值问题提出了看法.  相似文献   
128.
土壤侵蚀是一种危害严重、分布范围广的生态环境问题,影响人与自然的和谐共存,以及各业生产的可持续发展。通过分析秦皇岛市土壤侵蚀特点、原因,提出综合治理土壤侵蚀的对策和措施,以期为今后该区土壤侵蚀防治与治理提供科学依据。  相似文献   
129.
石油烃对土壤和地下水的污染不断被重视,释氧材料作为一种强化生物修复技术正日益受到关注。文章介绍了释氧材料的发展史,阐述修复场地条件、地下水化学环境和材料释氧速率控制对修复效果的影响,并对该技术的发展进行了展望。  相似文献   
130.
目前,我国对石油工业领域环境保护立法,采取的是特殊行业规制与一般规制相结合的模式。总体上看,我国石油工业环境保护领域已建立起初步的法制框架,但仍须进一步完善立法、执法、制订应急预案和建立信息公开机制等。  相似文献   
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