Chemical indicators of anthropogenic impacts in sediments of the pristine karst lakes

The anthropogenic impact on the pristine karst lakes was investigated using combination of specific parameters, including multielemental analysis of major inorganic constituents (Al, K, Fe) and trace metals (Li, Ag, Cd, Sn, Pb, Bi, Cr, Co, Ni, Cu, Zn and Sb), polycyclic aromatic hydrocarbons (PAHs) and anionic surfactants of linear alkylbenzene sulfonate (LAS) type. The study was performed in the Plitvice Lakes National Park, situated in a sparsely populated area of the northwestern Dinarides, central Croatia. Dated cores of recent sediments from the two biggest lakes, Lake Prosce and Lake Kozjak, were analysed for the selected contaminants using highly specific methods, involving inductively coupled plasma mass spectrometry (ICP/MS), gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS). The concentration of inorganic constituents reflected primarily the geological background of the area as well as geomorphological and geochemical characteristics of the Plitvice Lakes. Due to the higher terrigenous input, the concentration of all elements was significantly higher in the Lake Prosce. The concentration of toxic metals was relatively low in both lakes, except for Cd (>1 mg kg⁻¹) and Pb (up to 40 mg kg⁻¹). The vertical profiles of these metals suggested that elevated concentrations of Cd were of natural origin, derived from the erosion of the Jurassic dolomite bedrock, while Pb was predominately of recent anthropogenic origin. A similar distribution pattern, suggesting the same prevailing mechanism of input, was observed for pyrolytic PAHs. The characteristic diagnostic PAH ratios revealed that higher PAHs prevailingly originated from the combustion of biomass and fossil fuels. LAS, which represent highly specific indicators of untreated wastewaters, were found in rather high concentrations in the recent sediment layers (up to 4.7 mg kg⁻¹), suggesting that contaminated household and hotel wastewaters reach the Lakes, very probably by leaking through the porous karst rocks.     

贵州喀斯特地貌区聚落的垂直分异探讨

喀斯特自然环境的垂直性导致了喀斯特地区的聚落存在垂直空间分布的现象.掌握喀斯特地貌区聚落的垂直分异规律对区域城镇规划和社会主义新农村建设有重要意义.本研究以喀斯特面积分布最广的贵州省为研究区域,选取三个具代表性的典型地貌类型区,运用GIS相关软件和分析方法,通过对等高线数据的空间转换和与居民点数据的叠置等技术得到各个研究区的居民点在不同高程、坡度和坡向上的分布情况,依此分析喀斯特高原盆地区、高原山地区、高原峡谷区聚落的垂直分布特点.研究结果表明,三种地貌类型区的聚落垂直分布有一定的特点和规律可循,且不同喀斯特地貌类型下的聚落有不同的垂直空间分布特点;喀斯特地区聚落垂直分异与区域喀斯特地貌密切相关,表现在地貌垂直空间差异越大,聚落垂直空间差异越大;并且,垂直性加剧了喀斯特聚落空间差异的复杂性.最后得出结论,垂直分异是喀斯特聚落空间分布的主要特点,喀斯特地貌是形成喀斯特地区聚落垂直分异规律的前提条件.     

Interregional comparison of karst disturbance: West-central Florida and southeast Italy

The karst disturbance index (KDI) consists of 31 environmental indicators contained within the five broad categories: geomorphology, hydrology, atmosphere, biota, and cultural. The purpose of this research is to apply the KDI to two distinct karst areas, west Florida, USA, and Apulia, Italy. Through its application, the utility of the index can be validated and other important comparisons can be made, such as differences in the karst legislations implemented in each region and the effect of time exposure to human occupation to each karst terrain. Humans have intensively impacted the karst of southeast Italy for thousands of years compared to only decades in west-central Florida. However, west-central Florida's higher population density allows the region to reach disturbance levels comparable to those reached over a longer period in Apulia. Similarly, Italian karst is more diverse than the karst found in west-central Florida, creating an opportunity to test all the KDI indicators. Overall, major disturbances for southeast Italy karst include quarrying, stone clearing, and the dumping of refuse into caves, while west-central Florida suffers most from the infilling of sinkholes, soil compaction, changes in the water table, and vegetation removal. The application of the KDI allows a benchmark of disturbance to be established and later revisited to determine the changing state of human impact for a region. The highlighting of certain indicators that recorded high levels of disturbance also allows regional planners to allocate resources in a more refined manner.     

县市域边界地区协调发展研究——以浙江省尖山-南北湖地区为例

随着经济全球化进程的加快,区域协调发展的要求变得日益迫切。作为地理微观区域,县市域边界地区的协调管理尤其困难,在相关研究中还容易被忽略。以CBRs理论为指导,结合浙江省尖山-南北湖地区协调发展实例,对县市域边界地区协调发展的机制进行深入分析,构建了发展机制框架体系。尖山南北湖地区是典型的微观跨边界地区,在空间、功能上都具有协调发展的基础。由于行政体制的分割,现有的规划更加关注自身发展的需求,缺少区域整体统筹发展的眼光,造成了产业定位相互冲突,交通衔接不畅,生态环境共同保护意识不到位等问题。通过对问题的分析,在协调发展机制框架基础上,提出协调发展规划方案,以期通过规划的手段使问题得以解决和落实,希望对微观区域的协调发展研究有所启迪     

Management issues in a Tasmanian tourist cave: potential microclimatic impacts of cave modifications

Caves can be difficult to navigate and often require physical modification to allow easy access for visitors. Single entrance caves double the access impact of each visitor. Visitors in tourist caves have direct physical effects such as the introduction of concrete and steel structures; transport of mud, dust, and nutrients; installation of lights and the exhalation of water vapour and carbon dioxide into the air. Indirect physical effects include alteration of the microclimate, both through physical modifications that change the ventilation regime and through the presence of visitors leading to changes in temperature, humidity and CO2 within the cave environment. Anthropomorphic changes to cave physical environments to aid access or to reduce backtracking can have adverse effects on the internal microclimate of cave systems with subsequent changes to the cave environment affecting the quality of decorations and cave art and the diversity of cave fauna. Although often stated that caves operate at or near a constant temperature, closer examination indicates that cave temperatures are neither static nor constant. The degree of variation depends largely on the structure and physical characteristics of the cave. Air temperature and humidity gradients between the inside and outside cave environment can result in air density differences, which create airflow, which will in turn affect the cave microclimate. As part of the development of a management framework for King Solomons Cave, Tasmania, a study of the microclimate was carried out on behalf of Tasmanian Parks and Wildlife Service. Analysis of the variables showed significant differences in air temperature within each site and between sites. These differences range from 4 degrees C variation at one site to 0 degrees C at another site. The data were used to model potential airflow between the cave and the external environment. Results indicate that part of the cave is dominated by airflow between the chimney and the cave entrance leading to microclimatic fluctuations, while stable climatic conditions occur at the end of the cave. Future management strategies that propose a passage from the chamber to the surface via the current end zone would create a potential for airflow induced microclimatic change, leading to a change in both the temperature and moisture regimes, necessitating the construction of an airtight double door system.     

广西会仙岩溶湿地典型抗生素污染特征及生态风险评估

为确定会仙岩溶湿地不同介质中抗生素的污染特征及来源,利用液相色谱串联质谱联用仪分析了磺胺类(SAs)、氟喹诺酮类(FQs)和四环素类(TCs)三大类20种抗生素的含量.结果表明,研究区内水土介质监测的抗生素中共检出12种,检出浓度范围为n.d～106 ng·L~(-1),其中,甲氧苄氨嘧啶(TMP)的浓度最高.各环境介质中,以养殖用水和地表河水中检出的抗生素种类相对较多,分别为10种和8种,溶潭水和土壤中则检出的抗生素种类较少.因子分析结果显示,会仙湿地水体中的典型抗生素来源可归为两类,一类以受外源污染为主,从而导致地表河水中磺胺氯达嗪(SCP)、磺胺嘧啶(SDZ)、磺胺甲恶唑(SMZ)、诺氟沙星(NOR)、氧氟沙星(OFL)检出浓度较高,一类受湿地内养殖污染,从而造成水土介质中磺胺二甲基嘧啶(SMD)、甲氧苄氨嘧啶(TMP)和金霉素(CTC)检出.水体中检出的抗生素主要受溶解氧(DO)影响,此外,甲氧苄氨嘧啶(TMP)、恩诺沙星(ENR)和强力霉素(DOX)与NH~+_4存在一定的协同污染关系.风险评估结果表明,恩诺沙星(ENR)处于高风险的范围内,磺胺甲恶唑(SMZ)、诺氟沙星(NOR)和氧氟沙星(OFL)处于中等风险,中等风险的抗生素主要集中在地表河水中,高风险抗生素则在养殖用水中.整体来看,研究区水体中抗生素存在一定的风险.因此,针对这一现象应减少存在生态风险抗生素的使用,并对有潜在风险的抗生素加以防范.     

土地利用变化对西南喀斯特土壤团聚体组成、稳定性以及C、N、P化学计量特征的影响

土壤团聚体稳定性和养分化学计量特征对土地利用变化的响应研究,以及对当前脆弱生态环境保护与修复具有重要意义.为探明西南喀斯特山地土地利用方式变化对土壤团聚体组成、稳定性与C、 N、 P养分化学计量特征的影响规律,选取了西南喀斯特典型区域为研究区,针对7种主要土地利用方式建立了系列样地,开展了土壤团聚体组成与稳定性、团聚体C、 N、 P含量与计量比特征研究.结果表明,土地利用变化显著影响了土壤团聚体稳定性.玉米地和撂荒地的土壤团聚体稳定性相对较高,草地和裸地的团聚体稳定性相对较低,土壤团聚体稳定性总体随土层增加呈现降低趋势.不同土地利用方式土壤团聚体C、 N和P含量存在显著差异.疏林地和撂荒地土壤团聚体C和N含量较高,草地土壤团聚体C和N含量较低,裸地和撂荒地土壤团聚体P含量相对较高.土地利用变化对土壤团聚体C、 N和P计量比也存在明显影响.乔木林地、疏林地和撂荒地土壤团聚体C∶N相对较高,草地土壤团聚体C∶N最低;乔木林地和疏林地土壤团聚体C∶P较高,明显高于其他土地利用方式;乔木林地、疏林地和灌木林地土壤团聚体N∶P较高,明显高于裸地和撂荒地.喀斯特土壤团聚体组成和稳定性与土壤C、 N...     

长江山区航道雾的时空分布特征分析

利用长江航道局布设在长江航道沿线重庆段39个人工雾情信号台近3 a的雾情观测资料,详细分析了重庆段航道雾的时空分布特征,并基于以上雾情及整个长江山区航道（宜宾到宜昌）逐里程的经度、纬度、水道宽度、河面弯曲度、河道变化剧烈度、河道支流岔道等6类地理信息因子,采用神经网络方法模拟了长江山区航道雾情综合指数的地域精细化分布。统计结果显示：长江山区航道雾总体上呈现冬多夏少的季节特点,但也有冬少夏多或四季比较平均的情况存在;大多数雾情形成于0～8时,结束于8～12时,其中大雾开始早、结束晚、持续时间长;重庆段航道雾空间分布差异较大,涪陵的蔺市到丰都段、万州的黄花城分布最多,年均大雾30～50次,最少的安坪至夔峡段年均不到5次。模拟结果表明,利用地理信息因子及神经网络法基本可以模拟出重庆段航道雾情分布状况,此方法推广应用,可获取整个长江山区航道雾情的精细化分布,输出结果与航道雾情资料分析及实地考察调研结果在分布趋势上比较接近,但由于试验存在局部误差收敛及因子选择局限性问题,因此模拟结果还不能完全代表航道雾情的实际分布状况,模拟试验还需更多资料及影响因子加入     

重碳酸盐胁迫下3种能源的生理特性及无机碳利用能力对比研究

以诸葛菜、芥菜型油菜和续随子为研究对象,通过模拟喀斯特高浓度HCO-3(10mmol/L)逆境,将植物生理生化、地球化学技术应用生物质能源领域,用于喀斯特边际土地能源植物的筛选。在210d的实验期内,定期测定三种植物叶片中脯氨酸、丙二醛、叶绿素、叶绿素荧光、光合日变化、碳酸酐酶活力、叶片稳定碳同位素组成和生物质产出。通过对比发现,HCO-3胁迫条件下,诸葛菜、芥菜型油菜较续随子更为敏感,但续随子的生长易受低温影响。结果表明,诸葛菜以较高的喀斯特适生性、高碳酸酐酶活力而表现出最高的无机碳利用能力,综合诸葛菜适宜的生物质产出可推荐其作为喀斯特边际土地生物质能源植物。     

中国八大经济区域5月与7月CO地面浓度时空分布规律研究

利用2013年5月与7月全国76个城市CO地面小时浓度连续自动监测数据,分析了我国八大经济区域春(5月)、夏(7月)季CO地面浓度的时空分布规律.结果发现,76个城市春夏季CO浓度日变化基本一致,1 d中CO最低浓度出现于傍晚17:00左右,但各个区域峰值出现的时间略不同,多数地区出现于早晨8:00—10:00,南部沿海地区出现于凌晨1:00;CO地面浓度季节变化明显,5月CO地面浓度高于7月,但西北地区7月CO地面浓度高于5月;西北地区和长江中游地区春夏季CO地面浓度变化差异大,南部沿海地区季节变化小;黄河中游和北部沿海等地区CO地面浓度相对较高,东北地区CO地面浓度较低.机动车尾气排放是造成CO空间分布差异的原因之一.