用降水径流法推求设计径流的分析

由于多年平均降水量与高程关系密切,直接利用降水径流综合公式,就能快速准确地计算出设计流域的多年平均径流量,避免了移用参证站径流系数带来的分析误差。     

西藏怒江流域高寒草甸气候生产潜力对气候变化的响应

根据西藏怒江流域9个气象站1980-2008年年平均气温、年降水量资料,采用Miami模型研究该流域高寒草甸气候生产潜力的地域分布以及年代际变化。结果表明,近29年西藏怒江流域气候生产潜力中上游主要受温度条件的制约,中下游主要受降水条件的制约,气候生产潜力与年降水量和主要生长季平均温度显著正相关。总体上气候生产潜力的分布存在较大的地区差异,下游地区明显高于上游地区。过去29年,由于温度的逐年升高,伴随降水的增加,气候生产潜力呈逐渐增加趋势,且增幅较明显。整个怒江流域未来90年(2011-2100年)有向“暖湿型”气候方向发展的趋势,降水将成为该流域气候生产潜力的主要气候限制因子,总体上气候生产潜力呈增加趋势,但增幅不大,未来气候对该流域畜牧业发展和生态环境改善有利。     

青海湖流域气候变化对草原生态环境的影响

利用青海湖流域草原牧场气候资料和牧业生态统计资料,分析青海湖流域同德高原牧区气候变化特征及其对天然牧草生物量、草地生态环境和畜牧业的影响,发现同德地区气候变化的显著特征是:年平均气温、秋季、冬季、春季、夏季每10年升温趋势分别为0.37℃、0.23 ℃、0.50～0.88℃、0.11～0.35℃和0.10～0.33℃;年降水量每10年以10.5 mm的趋势减小,90年代是降水量最少的时期.气温年际变化趋势呈上升趋势,增温速度均大于全国增温速度.20世纪70年代之后持续偏暖.温度变化的倾向率均为正;草地年干燥指数变化呈显著上升趋势,使牧区草场产草数量和质量下降,劣等牧草、杂草和毒草的比例越来越高,草场生产力进一步下降.气象因子对草地生物量和生态环境的影响温度大于降水;降水对生态环境的影响主要表现在降水量的年际波动和年内各季节分布的差异上.当前存在的草原退化现象主要应归咎于不合理的人为活动.     

锡林河流域降水量时空动态及对NDVI的影响

以锡林河流域为研究对象,基于1960～2015年间锡林浩特气象站降水日值资料,运用Mann-Kendall非参数统计检验等方法,开展不同时间尺度降水量趋势分析和突变检验;利用2008～2015年锡林浩特气象站及流域内CMADS站点对锡林河流域年降水量进行空间插值,分析多年平均降水量空间变化规律;通过对比典型水文年各月份降水量与NDVI的变化关系,揭示NDVI空间异质性。结果表明:时间上,年均降水量和汛期平均降水量均呈不显著下降趋势,春、夏、秋三季降水变化均不显著,而冬季呈显著上升趋势(P0.05);空间上,年降水量呈现由东南向西北减小趋势,典型水文年月降水量与各月NDVI呈显著相关(R~2=0.733,P0.01),尤其丰水年内各月降水量与月NDVI的相关系数介于-0.76～0.99,二者呈现良好的一致性。     

内蒙古通辽市科尔沁区近50年气温降水变化趋势分析

运用内蒙古通辽市科尔沁区1961年1月-2010年12月的气温与降水资料,对科尔沁区近50年来的气候特征作了分析。结果表明,近50年来,科尔沁区气温呈上升趋势,特别是20世纪90年代以来增温十分明显;2007年是50年来气温最高的一年;50年来的气温分为冷、暖两个阶段,1989年以前为冷期,之后为暖期;降水量波动明显,总体呈下降趋势,50年平均减少58mm。     

内黄县气温和降水变化特征及对农业生产的影响分析

利用内黄县气象观测站1961～2005年气象观测资料,分析了近45a气温、降水变化特征及对农业的影响。结果表明:年平均气温呈明显的波动上升趋势;春季平均气温大致呈波浪式上升趋势;夏季平均气温总体呈缓慢下降趋势;秋季是四季中气温演变最平缓的一个季节;冬季气温变化是四季中气温变化最大的季节,气温呈曲线明显上升趋势。年平均降水量变化趋势不明显,年际波动大;春季降水量总体呈下降趋势,仅在80年代有小幅度的上升;夏季降水量除80年代异常减少外,总体也呈下降趋势;秋季降水量则表现为两头多,中间少;冬季降水量在近几年呈上升趋势。温度、降水的变化对农业生产有利也有弊。     

大柴旦近30 a农业气候资源变化特征分析

本文通过大柴旦地区近30 a农业气候资源变化特征分析,以期在气候变暖的大背景下充分利用农业热量资源,为藜麦在该地区的推广种植提供理论依据。利用大柴旦地区逐日气象资料,运用气候倾向率、M-K及累积距平突变检验等方法对1991~2020年作物生长期(4~9月)平均气温、≥0℃积温、≥10℃积温及降水等要素主要变化特征进行分析。发现大柴旦近30 a生长期平均气温、≥0℃活动积温及≥10℃活动积温变化整体呈显著增加趋势;平均气温、≥0℃活动积温及≥10℃活动积温分别于1998年、1998年及1997年发生突变,在1997年生长期≥0℃和≥10℃的活动积温累积距平曲线同步经历了一次显著的波动,1997年之后呈上升趋势,至今未见明显下降趋势;生长期≥0℃活动积温持续天数为179 d,≥10℃活动积温持续天数为119 d,以上表明该地区作物生长期光照充足,热量资源充沛;生长期降水量占全年降水量的87.4%;降水量以倾向率为9.9 mm/10 a的趋势增加;但自然降水不能满足藜麦发育水分需求,需采用大田灌溉的方式来解决。     

1961～2020年三江源地区候降水变化特征分析

利用1961～2020年三江源地区14个气象站点的逐日降水量资料,利用一元线性回归、累积距平变异系数等方法分析了三江源地区候降水量变化特征.结果表明:1961～2020年三江源地区候降水量总体呈增加趋势,候降水变化明显分为两段,20世纪60年代到21世纪00年代初期,为降水偏少期,21世纪00年代中期以后,为降水偏多期...     

青藏高原东北边缘牧区气候变化及其对畜牧业的影响

利用青藏高原东北边缘的甘南高原牧区草原牧场气候资料和牧业生态定位观测资料及统计资料,分析青藏高原东北边缘的甘南高原牧区草原牧场气候变化特征及其对畜牧业的影响.结果表明,青藏高原东北边缘的甘南高原牧区大部分区域降水量年际变化呈下降趋势,降水量的年际变化存在6～7、15 a的年周期振荡特征.气温年际变化趋势呈上升趋势,增温速度均大于全国增温速度.20世纪70年代之后持续偏暖.草地年干燥指数变化呈显著上升趋势,使牧区草场产草数量和质量下降,劣等牧草、杂草和毒草的比例越来越高,草场生产力进一步下降.由于冬、春季气温升高,降雪减少,牧区雪灾趋于减少,牲畜死损率呈明显的下降趋势.幼畜成活率1984年之后持续在一个较高水平上.     

新疆伊犁河流域牧草气候生产潜力的时空变化特征分析

利用新疆伊犁河流域1961-2007年历年逐月气温、降水资料,运用迈阿密模型、桑斯维特纪念模型计算新疆伊犁河流域近50年的牧草气候生产潜力。结果表明,流域气候生产潜力为4083.75~8415.42kg/(hm²·a),潜力较大,不同气候区有所差异。平原区气候生产潜力较小,且稳定性较差,丘陵区和山间盆地区气候生产潜力较大,山间盆地区同时也具有较好的稳定性。与气温相比,降水量是限制流域牧草气候生产潜力的主导因素。近50年来,气候生产潜力变化较大,总体呈上升趋势,尤其是2000年以来,增加幅度变大。     

Scrapie in goats in Cyprus

Ovine scrapie was first recorded in Cyprus in 1985. Subsequently four dairy goats kept in two mixed flocks with affected sheep developed characteristic clinical signs similar to those seen in sheep. Fifteen goats from the two flocks were examined histologically and neurological lesions consistent with a diagnosis of scrapie were found in the four animals and in three others which had subsequently developed early neurological signs. These lesions were similar to those of naturally-affected sheep although neuronal degeneration and vacuolation were more severe in some cases.     

Heartworm in dogs in Canada in 1984

In late December 1984, 1853 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1984 and 35% of them responded. Veterinarians reported that 97,794 dogs were blood-tested to check for microfilariae and 1417 dogs (1.45% of those tested) were found with heartworm. Another 34 dogs were amicrofilaremic, but were diagnosed as having heartworm disease, to give the total number diagnosed in 1984 as 1451 (1.48%). Heartworm was reported from all provinces except Prince Edward Island and Newfoundland but most (1310) of the cases were in Ontario. In Quebec, 126 cases were reported mostly from west of Montreal.

Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 27% of the cases were observed with clinical signs of heartworm disease and 72% had a history of not having left Canada. Southwestern Ontario continued to be the primary focus of the infection.

     

Heartworm in dogs in Canada in 1983

In late December 1983, 2 800 veterinarians across Canada were sent a questionnaire in order to assess the status of heartworm disease in Canada in 1983 and 26% of them responded. Veterinarians reported that 59 504 dogs were blood-tested to check for microfilariae and 771 dogs (1.30% of those tested) were found with Dirofilaria immitis. Heartworm disease was diagnosed in all provinces except New Brunswick and Newfoundland but most (733) of the cases were in Ontario.

Heartworm disease was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 31% of the cases were observed with clinical signs of heartworm disease and 64% had a history of not having left Canada. Southwestern Ontario continues to be the focus of the infection and most of the dogs there had not left the province previously.

     

Heartworm in dogs in Canada in 1991

In late November 1991, 1883 clinics in Canada were sent a questionnaire to assess the status of Dirofilaria immitis in dogs in 1991 and there was a 60.0% response. There were 344,031 dogs tested for heart-worm (HW), 627 were found infected and the prevalence of HW infection was 0.18%. There were 417 dogs with HW in Ontario, 116 in Manitoba, 38 in Quebec, 53 in British Columbia, three in Alberta, and one in Nova Scotia. In British Columbia, all of the infected dogs but one were from the Okanagan valley which, as from 1991, is a new focus of infection in Canada. Most dogs with HW had not been on preventive medication in 1990, and the prevalence among dogs tested and unprotected was 0.59%. That prevalence was considerably higher in endemic areas. Companion dogs, over three years of age and maintained primarily outdoors in rural areas, were most frequently infected. One cat was diagnosed with D. immitis and 33 dogs had Dipetalonema reconditium.     

Heartworm in dogs in Canada in 1985

In late December 1985, 1485 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1985 and 44% of them responded. Veterinarians reported that 137,300 dogs were blood-tested to check for microfilariae and 1210 dogs were found with heartworm. Another 36 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number diagnosed in 1985 as 1247 (0.91%).

Heartworm was reported from all provinces except Prince Edward Island, Newfoundland and Saskatchewan but most (1126) of the cases were in Ontario. Southwestern Ontario continued to be the primary focus of the infection in Canada. From Quebec, 91 cases were reported mostly from and around Montreal. From Manitoba, 19 cases were reported from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 28% of the cases were observed with clinical signs of heartworm disease and 78% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1988

In late November 1988, 1581 small and mixed animal clinics and institutional veterinarians across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1988, and 46% of them responded. Veterinarians reported that 181,577 dogs were blood-tested for heartworm disease and 367 dogs were found with D. immitis microfilariae. Another 60 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1988 as 441 (0.24%).     

Heartworm in dogs in Canada in 1989

In late November 1989, 1732 clinics and institutional veterinarians were sent a questionnaire to assess the status of Dirofilaria immitis, and 51.7% responded. Of 247,716 dogs tested, 394 had D. immitis microfilariae and 51 were amicrofilaremic for a total of 445 cases and heartworm prevalence of 0.17%. Most (408) of these dogs had no preventive medication and the prevalence among dogs tested and unprotected was 1.01%. That prevalence was considerably higher in endemic areas. Thirty-seven dogs with heartworm had preventive medication. Heartworm was most frequent in companion dogs over three years of age maintained outdoors in rural areas. About 75% of the cases had never left Canada, 26% had clinical signs and 125 were not treated.

Heartworm was reported from British Columbia, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland, but 383 cases were in Ontario. South-western Ontario was the primary focus of infection. There were 33 cases in Quebec and 24 in Manitoba, mainly found in and around Metropolitan Montreal and Winnipeg respectively.