遥感与地理信息系统技术在洪湖市湿地钉螺分布研究中的应用

血吸虫(Schistosoma)是一种寄生虫,可以寄生在人体或动物体内,主要依靠钉螺(Oncomelania hupensis)繁殖.遥感技术作为一种监测手段,辅助地理信息系统空间分析,可以有效地对钉螺分布区进行监测和数据提取.运用阈值提取和空间分析的方法,对2001年洪湖市钉螺栖息地的分布情况进行了分析和研究.在归一化植被指数为0.2～0.3和穗帽湿度指数为7～13的阈值下,提取出可疑钉螺栖息地分布的数据,根据实际钉螺分布图对其进行精度评价,其正确率达到86.20%.82.77%的可疑钉螺栖息地分布在沟渠之中,这说明沟渠具有适合钉螺生长的最佳环境条件.遥感与地理信息系统技术相结合的研究方法对洪湖市钉螺分布监测具有可行性,可以作为血吸虫防治工作的新方法.     

A Comparative Study of Distribution of Heavy Metal Concentrations in the Pomacea insularum Collected from Polluted and Unpolluted Sites of the Freshwater Ecosystem in Malaysia

The snails (Pomacea insularum) were collected from polluted and unpolluted sites at Juru River and the Universiti Putra Malaysia Lake, respectively. Besides the shells, the soft tissues of snails were dissected into 6 different parts: intestine, operculum, foot, pennial sac, lung sac and the remainder. They were analyzed for the concentrations of Cu, Cd, Zn, Pb, Ni and Fe. The present study found 6 interesting points. First, all the metal levels found in the different parts of P. insularum collected from Juru River were significantly (p<0.05) higher than those in the snails of unpolluted lake. These results were also supported by the sediment data in which the Juru River sediment had significantly (p<0.05) higher levels of metal than those in the unpolluted lake. Second, the high levels of Cd and Pb were found in the shell of P. insularum, indicating that it is a potential biomonitoring material for these metals. Third, intestine accumulated elevated levels of Zn, Ni and Fe and thus is a potential biomonitoring organ for the 3 metals. Fourth, high levels of Cu were found in the lung sac and this phenomenon could be related to this metal binding to metallothionein in this organ. Fifth, elevated level of Pb found in the soft tissues of P. insularum indicated that this snail is not suitable for human consumption since its pollution level was higher than the food safety guideline for Pb. Sixth, there was no significant difference (p>0.05) between the different sizes (small sizes: 30.5-33.2 mm; large sizes: 37.7-40.4 mm) of P. insularum. The first 5 points supported the use of different soft tissues of P. insularum as biomonitoring organs of heavy metal pollution in the freshwater ecosystem in Malaysia although further validation is required.     

山丘型抑螺防病林的营建模式

<正>山丘地区地理和自然环境因素复杂,血吸虫治理难度大,治理时应根据钉螺分布的特点,采取分类分模式治理。据调查,山丘地区钉螺的分布和数量以荒坡、沟渠和河滩等处密度较大,为血吸虫病生态防治的重点地段;四旁(田边地坎、溪沟两旁、房前屋后、道路两旁)钉螺分布密度次之,但这些区域人畜活动更为频繁,应作治理的主体区域。依据血吸虫生物发育规律和     

适合钉螺、血吸虫生长发育的气候条件变化

根据有关研究成果,分别取日平均气温5.87℃和15.17℃为钉螺和日本血吸虫生长的下限温度,取3846.28 d·℃和842.95 d·℃为其有效积温指标。以1986年为分界点,利用1950-2003年气象台站日平均气温资料,计算了80%保证率下,5 d滑动平均气温稳定通过5.87℃和15.17℃的起始日和结束日以及历年有效积温,借助ArcGIS8.3模块分析了钉螺和血吸虫生长发育季节气候条件的变化。结果表明：气候变化使大部分地区钉螺和血吸虫生长发育季节延长,生长发育速度加快。气候变化可能使钉螺感染季节延长,感染率增高。     

斯氏并殖吸虫第一中间宿主拟钉螺属一新种记述 (中腹足目, 盖螺科)

为调查斯氏并殖吸虫拟钉螺宿主,现场采集螺标本,进行形态分类和生态考察及螺体寄生虫检查.发现拟钉螺属(Tricula)一新种,命名为建欧拟钉螺(Tricula jianouensis sp.nov.),螺壳高3.125 mm,壳宽1.600 mm,体螺层高1.125 mm,壳口长径1.275 mm,壳口宽径0.925 mm.螺口外缘翘起呈铲状;轴缘与外缘形成较窄夹角,内唇嵴明显高出,与体螺层间有一沟状隙.齿舌每一横列有7枚齿,齿式:2-1-2/2-2·3-1-3·11(14)·14(15).该螺充当斯氏并殖吸虫第一中间宿主,斯氏并殖吸虫尾蚴感染率为0.11%.     

未来气候变化对湖北省钉螺潜在分布的影响

利用最大熵模型,结合地形、植被、气象等环境因子,模拟了湖北省钉螺在基准期（1986-2005年）的分布,预测了RCP2.6、RCP4.5、RCP8.5这3种未来情景下2021-2040年、2051-2070年和2081-2100年湖北省钉螺潜在分布风险。结果表明,基于主导环境因子建立的最大熵模型的受试者工作特征曲线（ROC）下的面积（AUC）平均值达到0.894±0.024,可用于未来气候变化情景下湖北省钉螺的潜在分布研究。3种排放情景下钉螺潜在分布低、中风险区范围相对基准期分别扩大了4.5%和1.6%,无风险区范围缩小了9.3%;伴随着未来可能的气候变化,钉螺潜在分布中、高风险区向北移动。     

依靠科学技术 促进林业血防工程建设

<正>党中央、国务院历来高度重视血吸虫病防治工作,2004年5月13日国务院下发关于进一步加强血吸虫病防治工作的通知,同年5月20日在湖南岳阳召开了全国血防工作会议,文件提出了“建立抑螺防病     

滩地人工林营林措施对钉螺种群的影响

通过对滩地不同经营措施的杨树人工林内钉螺种群影响的长期定位观测和分析研究,结果显示：①在低海拔淹水时间达60天的滩地,采用挖沟抬垄整地是确保人工林造成功和有效抑螺的重要措施;②在幼林阶段,采用林农复合经营是抑螺防病林经营的有效措施;③随着林木的生长,树木对林地环境的改善强度加大,其对钉螺种群的抑制效果逐渐加强,使钉螺种群密度保持较低的水平。因此,对钉螺滋生的滩地采取针对性的造林技术和措施,即可增加林地的经济产出,更为重要的是可有效抑制钉螺的种群数量,同时辅以对家畜的管理,可使林地内的感染性钉螺隆至零,达到了滩地利用与抑制钉螺的双重目标。     

山丘区流域治理与兴林抑螺

血吸虫病是危害人类生命健康十分严重的寄生虫病．流行区域广泛。据世界卫生组织统计．全世界约74个国家．2亿人受其危害,是发展中国家的主要寄生虫病之一。中国是受害人数最多,钉螺分布最广的国家。截至2003年底,全国有433个流行县（市、区）,已有260个县达到传播阻断标准,63个县达到传播控制标准。目前,全国钉螺分布面积达222万hm^2,累计血吸虫病人1200多万例。据卫生部门统计,中国目前血吸虫病尚未得到控制的地区主要集中在长江流域的湖南、湖北、江西、     

运用证据权重法进行阳性钉螺-地理因子的空间关系研究(英文)

Schistosomiasis is a serious public health problem in the middle-lower Yangtze River Basin in China. Study of spatial variation of snail distribution that is related to microgeographic factors can help to choose pertinent measures for snail extinguishment and environment rebuilding. This paper studied the theoretical architecture of weights-of-evidence approach. The case study was made for spatial relation between the occurrence of infected snails and geographic factor combinations in Waijiazhou marshland of Poyang Lake region in China. The multievidence data came from the geographical factor combinations by crossing operation of vegetation coverage grade layer, cattle route distance grade layer, and special environment layer (181 combinations in total) in GIS. The calculation of weight contrast index shows that high vegetation coverage, cattle route distance of <45 meters, and special geographic factor “ground depression” had direct spatial relation with the occurrence of infected snails. The verification by crossing operation in GIS indicated 72.45% of the infected snails concentrated on the areas of positive weight contrast index (sequenced in an order of weight contrast index from high to low), demonstrating the high efficiency of the model established in finding infected snails according to the geographic factor combinations that can be explicitly discerned in the study area. Supported by a the National Natural Science Fundation of China (No. 30590370), the Research Project “Spatial Simulation of Schistosomiasis Susceptible Areas in the Poyang Lake Region” Sponsored by Science Research Plan 2007 of Jiangxi Normal University (Natural Science Category).