Variation Characteristics of Main Climate Factors in the Upstream of Wei River in Recent 39 Years

Wei River is an important river which affects the industrial and agricultural production,people's life in Guanzhong district of Shaanxi and the east of Gansu.To study the variation characteristics of main climate factors in recent 39 years in the upstream of Wei River,we analyzed the variation characteristics of climate factors by using the data in 11 meteorological stations in the upstream basin of Wei River during 1971-2009.The results showed that the precipitation presented the decline trend in the basin,and the temperature rose in 0.3 ℃/10 a trend.The temperature increase trend was 0.4 ℃/10 a in winter,spring and wasn't obvious in summer,autumn.The potential evapotranspiration presented the yearly increase trend in recent years.The precipitation decreased,and the temperature rose.Moreover,the potential evapotranspiration strengthened.It wasn't favorable for the healthy run of ecological system in the upstream,downstream basins and aggravated the shortage degree of water resources.

THE DRIVING FORCES OF LAND USE/COVER CHANGE INTHE UPSTREAM AREA OF THE NENJIANG RIVER

ABSTRACT: Based on the Landsat 5 and Landsat 7 TM images, the land use/cover change was detected in the upstream area of the Nenjiang River between 1995 and 2000. With the spatial analysis techniques of GIS, the maps of land use degree and its change within this period were produced. To identify the causes of changes, elevation and slope were regarded as the main natural influencing factors and were transformed from coverage format to grid format within GIS. The Thiesson polygon method was used to the spatial allocation of socio-economic factors including human population, livestock numbers, mechanizing power of farming and the nearest distance from the changed pixel to the trunk stream and to main settlements, thereby the spatial relationship between land use degree change and socio-economic factor variation was analyzed. According to results of the spatial correlation, the determinants of changes in land use/cover, i. e. elevation, slope, population density change, livestock increase were extracted quantitatively in this area. At last, the spatial multi-linear regression model of land use degree change was developed as follows: △ La = 11. 037-4. 512 * eleva-tion-0. 298 * slope + 0. 292 *△ population + 2. 596 *△ livestock.

Downstream effects of reservoirs in areas suffering from water deficiency-the case of Hutuo River, China

The Hutuo River is located in the semi-arid areas in China. Due to fat of water resources in these areas, changes in flow regime, mainly reduction in runoff downstream from the reservoirs, have been tremendous. As a result of decrease in flow power and sediment load, the post-dam river showed a less change in channel morphology and the change varied reach by reach. Comparatively, the channel shrinkage may contribute to the flood disasters in the lower reaches of the river in recent years. An obvious increase of channel's hydraulic roughness, the main cause for reduction of flood transmission capacity of the channel, is attributed to vegetation encroachment in the channel. The effects of reservoir construction on ground water level and other environmental aspects are also discussed in the paper.

Comparative Assessment of the Upstream and Downstream Water Qualities of River Tano in Ghana

River Tano, located in the Brong Ahafo region of Ghana, has a number of socio-ecological functions. Anthropogenic activities such as farming, washing, and discharge of industrial effluents into the river pose serious threat to human health. In view of this, water quality campaign was carried out for a period of 12 months by taking samples from the source and the downstream end of the river and analysing for some physico-chemical parameters. The results showed that most of the physico-chemical parameters such as pH, fluoride, nitrite, manganese and temperature were not within the regulatory safe limit. Although the levels of total alkalinity, total iron, ammonia and phosphate kept fluctuating along the course of the river, the difference were not statistically significant apart from fluoride and phosphate which showed significant difference between the upstream and downstream levels. This may be attributed to anthropogenic activities such as farming and washing in the river which implies that human activities have impacted slightly on the water quality. It is recommended that the relevant stakeholders should come together to enforce the environmental laws regarding protection of water bodies and do continuous monitoring for early detection of any change in quality of the River Tano.

Torrent risk zonation in the Upstream Red River Basin based on GIS

This paper explores the methodology for compiling the torrent hazard and risk zonation map by means of GIS technique for the Red River Basin in Yunnan province of China, where is prone to torrent. Based on a 1：250,000 scale digital map, six factors including slope angle, rainstorm days, buffer of river channels, maximum runoff discharge of standard area, debris flow distribution density and flood disaster history were analyzed and superimposed to create the torrent risk evaluation map. Population density, farmland percentage, house property, and GDP as indexes accounting for torrent hazards were analyzed in terms of vulnerability mapping. Torrent risk zonation by means of GIS was overlaid on the two data layers of hazard and vulnerability. Then each grid unit with a resolution of 500 m- 500 m was divided into four categories of the risk： extremely high, high, moderate and low. Finally the same level risk was combined into a confirmed zone, which represents torrent risk of the study area. The risk evaluation result in the upper Red River Basin shows that the extremely high risk area of 13,150 km^2 takes up 17.9% of the total inundated area, the high risk area of 33,783 km^2 is 45.9%, the moderate risk area of 18,563 km^2 is 25.2% and the low risk area of 8115 km^2 is 11.0%.

Analysis on hydrochemical characteristics of groundwater in strongly exploited area in Hutuo River Plain

The Hutuo River alluvial-proluvial fan is located in North China Plain, and groundwater is the main source of water supply for agriculture and domestic water. Shijiazhuang depression funnels due to the long-term excessive exploitation are the bottleneck of the regional economic development. Analyzing the chemical characteristics of groundwater under the condition of strong human activities, can provide a scientific basis for further study of strong groundwater mining area environmental change. 143 groups of shallow groundwater samples are collected during the period of 2007-2008. In this paper, the hydrochemical characteristics of groundwater in the Hutuo River Plain area are analyzed systematically, using hydrogeochemical theory, combined with statistical methods and hydrochemical methods. Results are shown as follows: HCO_3^- and Ca^(2+) are major anion and cation. The variation coefficients of K^+, Ca^(2+), Mg^(2+) and HCO_3^- between 0.25 and 0.52, which means small and stable relatively. The variation coefficient of are Na^+, NO_3^-, Cl-, SO2-4 were large(0.89-1.01). They are sensitive and vulnerable to environmental change affect. Due to the impact of human activities, from the top to the edge of the alluvial-proluvial fan, the hydrochemical types of groundwater change from single to multiple, followed by HCO_3^-Ca·Mg, HCO_3·SO_4-Ca·Mg, HCO_3·SO_4·Cl-Ca·Mg, HCO_3·Cl-Ca·Mg and other types.

Impacts of water and soil erosion in upstream watershed of Nenjiang River

Making a brief analysis of the water and soil loss present situation in Daxing＇anling area which locates to the upstream region of Nenjiang River, and giving the water and soil loss of this area that have been made near 20 years, as well as the factors of the water and soil loss. According to the factors corresponding prevention measure and forecast model have been put forward, make a brief introduction to this model in this article. It is helpful to improve the local soil conservation and sustainable development.

Orientation and community participation of ecological development: a case study of Hutuo River in Shijiazhuang City,China

Entrusted to by Shijiazhuang municipal Party committee and government, Shanghai Tongji University fin- ished “The General Planning of Ecological Development Project of Hutuo River in Shijiazhuang City”. It aims to build Hutuo River into a wind-breaking and sand-fixing barrier and ecological protect district in the north of Shijiazhuang based on the recovery of natural ecology to improve the environment of Shijiazhuang city. It also intends to develop the district lightly and build it into a nature beauty spot and big park. After the construction for several years, the general environment of this district has been greatly improved. But during the development, the man-made landscapes are highlighted excessively, which deviates from the construction of nature landscape. The currency of constructing big leisure park gradually comes into being, so the recovery of nature ecological is slow. So, this paper intends to make the orientation to ecological development of Hutuo River in Shijiazhuang city and puts forward the community participation to promote the future development of ecotourism in Shijiazhuang.

Impact of Tidal River Management (TRM) for Water Logging: A Geospatial Case Study on Coastal Zone of Bangladesh

Bangladesh is a floodplain dominated country. Coastal delta areas of Bangladesh convey multiple impacts of climate change worth-hit. Most of the rivers carry a huge amount of sediment from upstream piedmont area. The river bed rises due to insufficient upstream water supply. Similarly, the deposited sedimentation creates a large number of sandbars inside the river. That’s why, water logging and siltation turn into a serious problem in the south-western region of Bangladesh, especially in Satkhira, Khulna and Jessore district. In the middle of September, 2011 the Tidal River Management (TRM) project approved at the study site for four years to develop the water logging problem with basic consideration of silt management. In this circumstance, this study focused on the consequences of the TRM on water logging in the coastal area of Bangladesh. Primary and secondary data have been used. Geospatial analyses have been used following the NDWI in Arc GIS for water logging area detestation using Landsat Enhance Thematic Mapper (ETM) and Landsat Operational land Image (OLI) satellite images. The geo-spatial analysis denoted, about 5090 acres of agricultural land and about 729 acres of homestead land have been water logged during TRM implementation period.

A study on the relationship between vegetation pattern and environment in the upstream of Minjiang River,China

The vegetation pattern in the upstream of Minjiang River,and its relationship with environment factors,such as landscape position(elevation,slope,aspect),precipitation and temperature and soil are analyzed in this paper.The data used in this paper were based on the landscape map derived from 1994 TM imagery.The results were as follows:1)dominant landscape types were forest,shrub land and grassland,which were very similar in terms of area ratio(32.87%,31.85%and 28.44%,respectively);2)the patch shape of conifer forest and mixed forest was complicated while that of broad-leaved forest and cultivated land was simple;3)the fragmentation of conifer forest and mixed forest was serious in contrast with low fragmentation of broad-leaved forest and cultivated land;and 4)closed scrub and grassland had a high contagion and good connectivity while mixed forest had a lower contagion and bad connectivity.In addition,the vegetation distribution pattern of upstream of Minjiang River was closely related with elevation and temperature,but the relationship between vegetation and precipitation was not statistically significant.

Three Gorges Project——key to harness and develop Yangtze River

The upper Yangtze upstream ofYichang with a drainage area of1,000,000 km^2 brings an average annualrunoff to Yichang by 450 km^3 of river water,the drastic variation and uneven distributionof which often causes severe floods for fer-tile alluvial plains of middle and lower Yang-

基于PLUS模型的2030年滹沱河流域山区段生态承载力时空格局多情景预测

为探讨滹沱河流域山区段当前及未来不同发展情景下生态承载力的时空变化,应用植被净初级生产力改进的生态足迹模型测算分析了流域2015—2020年生态承载力的时空格局变化,并借助经过精度验证的PLUS模型对2030年区域自然发展、经济发展及生态保护三种发展情景下的生态承载力时空格局进行预测。结果表明:2015—2030年滹沱河流域山区段单位面积生态承载力整体格局变化不大,但内部空间分异明显,整体呈东南及西北区域单位面积生态承载力高,而东北、西南部区域单位面积生态承载力低的特点。2015—2020年区域生态承载力总量由1.0780×10^(6)bhm^(2)增加到1.0796×10^(6)bhm^(2),呈上升趋势;2030年自然发展和经济发展情景下区域生态承载力总量分别为1.0783×10^(6)、1.0782×10^(6)bhm^(2),与2020年相比呈下降趋势,草地向耕地的转移、林地向建设用地的转移是生态承载力下降的主要原因;2030年生态保护情景下生态承载力总量为1.0802×10^(6)bhm^(2),与2020年相比呈上升趋势,耕地向林地、草地转移是区域生态承载力增加的主要原因。各类用地的生态承载力总量由高到低依次为草地>耕地>林地>建设用地>水域,生态保护情景有益于林地、草地生态承载力总量的增加,经济发展情景有益于耕地和建设用地生态承载力总量的增加,水域生态承载力总量在各种发展情景下变化较小。生态保护情景更有利于未来生态承载力的增加,符合区域未来发展方向。严格控制草地向耕地的转变以及林地向建设用地的转变,继续实施退耕还林、还草生态工程,加强区域废弃矿山生态复垦的力度,将会提高区域未来生态承载力,实现区域生态安全及经济、社会、生态的可持续发展。

滹沱河石家庄段浅层地下水回补过程中磺胺类抗生素污染特征及风险评价

为识别地下水回补过程中磺胺类抗生素(SAs)的污染特征及风险水平,于2020—2021年分2期采集滹沱河补水沿线16口浅层监测井的地下水样品,采用固相萃取-超高效液相色谱串联质谱法,测定分析地下水中20种SAs的浓度水平及分布特征,并利用风险熵值法进行生态及人体健康风险评价。结果表明,地下水中SAs总体污染程度较低,回补初期地下水中共检出7种SAs,按检出率大小依次为磺胺甲恶唑(93.75%)、磺胺嘧啶(37.50%)、磺胺氯哒嗪(18.75%)、磺胺吡啶(18.75%)、磺胺甲氧嘧啶(6.25%)、磺胺脒(6.25%)、磺胺醋酰(6.25%),平均检出浓度最高的为磺胺嘧啶(29 ng/L)和磺胺甲恶唑(9.2 ng/L)。在优质南水北调水回补的混合稀释作用下,地下水中SAs检出率和检出浓度呈明显下降趋势。历史污水处理厂排放及农业畜禽养殖污染是造成局部区域下水中SAs污染的主要原因。地下水中磺胺甲恶唑和磺胺嘧啶在回补初期属于中等生态风险,且磺胺嘧啶对人体健康具有中等风险。回补后期各SAs评价均无明显生态风险和健康风险。

应用于鱼道设计的玉曲河流域裸腹叶须鱼游泳能力探究

探究西藏玉曲河流域裸腹叶须鱼(Ptychobarbus kaznakovi)的游泳能力,可为珍稀鱼类资源保护及鱼道设计提供理论参考。以体长(BL)18~27 cm的裸腹叶须鱼为研究目标,在野外场景下分别测试其感应流速、临界游泳速度、突进游泳速度和持久游泳速度。结果表明:(1)裸腹叶须鱼的感应流速为(0.17±0.01)m/s,平均相对感应游泳速度为(0.78±0.07)BL/s;临界游泳速度为(0.92±0.16)m/s,平均相对临界游泳速度为(4.33±1.20)BL/s;平均突进游泳速度为(1.28±0.39)m/s,平均相对突进游泳速度为(5.81±1.81)BL/s;(2)流速(V)对裸腹叶须鱼的持续游泳时间(T)有显著性影响,持续游泳时间均随设定流速的递增而明显下降,耐力关系可拟合为:lgT=-5.30V+6.39,游泳速度(V_(s))、鱼道总长度(d)和鱼道内最大流速(V_(f))关系式为:V_(f)=V_(s)-d×10^((5.3Vs-6.39));(3)裸腹叶须鱼的趋流率(P_(re))与流速(V)拟合关系式为:P_(re)=14.23V-2.51,得出95%裸腹叶须鱼的趋流速度为0.18 m/s;(4)以裸腹叶须鱼为主要过鱼目标时,建议鱼道进口的设计流速为0.9~1.3 m/s,进口的主流长度为2~4 m,鱼道出口流速不低于0.2 m/s,鱼道池室主流流速为0.2~0.8 m/s。结合鱼类在竖缝处的不同上溯模式和持久游泳速度,推荐池室主流长度最大应为5.5 m,竖缝处最大平均流速为1.1 m/s,鱼道长短隔板沿水流方向的最大间隔为0.4 m。研究结果可为玉曲河鱼道关键部位的长度设计和流速要求提供基础数据支撑。

台风风暴潮与上游洪水耦合作用下温州飞云江感潮河段潮水位模拟研究

在全球气候急剧变化的背景下,沿海地区风暴潮发生的频率与受灾程度逐渐增加,特别是受风暴潮与上游流域洪水共同影响下的河口感潮河段区域。尽管现有风暴潮模型也引入多种不同的边界设置,但提供的边界条件有限,且无法满足当前国内复杂水工程的概化需求。为此,文章以飞云江流域为研究对象,通过耦合上游流域水动力模型IFMS与海洋风暴潮模型ADCIRC模式,充分发挥二者各自的优势,构建河口感潮河段洪水演进模型,实现飞云江感潮河段潮水位时空模拟。该模型不仅有效地考虑了河口海洋处风暴潮上溯对感潮河段区域洪水演进的影响,也考虑了流域上游洪水对该区域的影响。首先,采用2016年台风“鲇鱼”对模型进行验证,模拟结果与实测系列吻合度较高,误差满足基本要求。然后,对台风“杜苏芮”和“卡奴”影响下的瑞安、马屿、碧山六桥及洞头4个潮位站的洪水过程进行模拟,结果显示4个站点的洪峰误差值均低于0.30m,纳什系数大于0.80,表明该模型能较好地反映高低潮位变化,可应用于河口感潮河段防灾减灾中。最后,还分析了上、下游边界的驱动作用对感潮河段3个站点(瑞安、马屿、碧山六桥)潮水位预测的影响,证明了下边界对3个站点的潮水位预报影响比上边界的影响大。研究成果不仅为河口感潮河段洪水模拟提供了一种新方法,而且通过分析给出提升模型模拟精度的方向。

急弯河段新建船闸上游引航道通航条件研究

在急弯河段已建枢纽上新建船闸工程,船闸布置受限因素众多,通航条件复杂。为分析船闸引航道通航水流条件,建立袁河石洲枢纽1:80正态物理模型,开展急弯河段船闸上游引航道通航水流条件试验,对比隔流堤不同长度口门区的流速分布,同时结合自航船模试验分析船闸口门区通航条件。结果表明,延长隔流堤对减小口门区横向流速峰值、改善流态作用明显;隔流堤延长250 m时,石洲船闸上游引航道最高通航流量可达到规范要求的20 a一遇洪水。

长江王家洲崩岸治理及护岸效果分析

通过分析长江上下三号河段近期河势变化趋势,由于受上游河势变化影响,王家洲岸坡易发生崩塌后退,需实施整治工程。为解决王家洲崩岸问题,对崩岸段采取岸坡防护加固措施。工程实施后,结合新近护岸测图,对该区域水文和地质进行了研究,分析了河道演变,并采用了平面法、横断面法和冲淤分析法,综合分析王家洲护岸工程实施后的效果。结果表明:护岸工程的实施保障了岸坡的稳定,历经多次洪水考验。实际说明护岸段近岸河床及岸坡相对稳定,护岸效果较好,并结合工程实践经验,提出后续建议和保护措施。

上游水库实际调度对桓仁水库入库洪水影响分析

本文以浑江流域2010年两场洪水为研究背景,分析桓仁水库上游中小型水库实际调度对桓仁水库入库洪水的影响,得出以下结论:在2010年7月28日—8月3日7天洪水过程中,上游4库的调度运行使桓仁水库入库水量增加1306万m3,占桓仁水库同期来水量的1.12%,整个洪水期,上游水库的调度使桓仁水库入库总水量有所增加。在2010年8月27日—9月2日7天洪水过程中,上游4库的调度运行使桓仁水库入库水量减少670万m^(3),占桓仁水库同期来水量的0.71%,上游水库的调度使桓仁水库入库总水量有所减少。应用此研究成果可提高浑江流域水文预报的精确度,研究成果为同类调度提供参考。

万家寨引黄南干线滹沱河连通工程对沿岸土壤盐渍化的影响

本研究以万家寨引黄南干线滹沱河连通工程天然输水河道长畛河、阳武河为研究区域,调查和评价工程未建设前土壤盐碱化现状水平,在此基础上,按照土壤环境影响评价导则,采取土壤盐化综合评分预测方法,定量预测应急输水期对沿河两岸土壤环境盐化的影响,为工程建设可持续利用提供依据。

气候变化和人类活动对滹沱河上游流域水文干旱演变的影响

基于滹沱河上游流域1961−2018年逐月径流数据和逐日气象数据,采用ABCD水文模型和以时间为解释变量的GAMLSS模型,构建时变标准化径流指数,综合考虑变点分析、气候变化和社会发展的不同阶段,将研究时域划分为自然期(1961−1979年)、影响期1(1980−1997年)和影响期2(1998−2018年)3个阶段,进而基于干旱指数关于时间的线性变化率量化气候变化和人类活动对非平稳水文干旱演变的影响.结果表明:在2个影响期的四季和年尺度上,非平稳水文干旱均表现为缓解趋势;在影响期1,气候变化和人类活动在季和年尺度上均以缓解水文干旱为主,但人类活动以53.22%~89.11%的贡献率占主导地位;在影响期2的四季和年尺度上,气候变化以50.72%~72.68%的贡献率主导了水文干旱的缓解趋势,而人类活动则以−49.27%~−27.32%的贡献率加剧了水文干旱;人类活动与气候变化导致的干旱指数序列在影响期2的3个月和12个月尺度下均呈现出显著负相关,这说明进入21世纪之后,人们对水循环的干预较20世纪更科学合理.