Spatial-temporal Variation Characteristics of Water Quality in the Lower Reaches of the Nenjiang River

As an important river in the western part of Jilin Province,the lower reach of the Nenjiang River is an important wetland water source conservation area in Jilin Province.Within the watershed,it governs the Momoge Wetland,the Xianghai Wetland,and the Danjiang Wetland in Jilin Province.The main problem in the lower reaches of the Nenjiang River is the uneven distribution of water resources in time and space,and the intensification of land salinization.Zhenlai County and Da an City in the Nenjiang River Basin have sufficient surface water resources,with surface water as the drinking water source.Baicheng City and Tongyu County have scarce surface water resources,and both use groundwater as their domestic water source.The main polluted section in the basin is the Xianghai Reservoir,and the annual water quality evaluation is Class V.However,the water quality of the Tao er River,the main stream of the Nenjiang River,is significantly better than that of the Xianghai Reservoir.In order to better study the water environmental pollution situation in the Nenjiang River basin,monitoring data from five sections of non seasonal rivers in the basin from 2012 to 2021 were selected for studying water quality.This in-depth exploration of the water pollution status and river water quality change trends in the Nenjiang River basin is of great significance for future rural development,agricultural pattern transformation,and the promotion of water ecological civilization construction.

Relationship between spatio-temporal evolution of soil pH and geological environment/surface cover in the eastern Nenjiang River Basin of Northeast China during the past 30 years

To illuminate the spatio-temporal variation characteristics and geochemical driving mechanism of soil pH in the Nenjiang River Basin,the National Multi-objective Regional Geochemical Survey data of topsoil,the Second National Soil Survey data and Normalized Difference Vegetation Index(NDVI)were analyzed.The areas of neutral and alkaline soil decreased by 21100 km^(2)and 30500 km^(2),respectively,while that of strongly alkaline,extremely alkaline,and strongly acidic soil increased by 19600 km^(2),18200 km^(2),and 15500 km^(2),respectively,during the past 30 years.NDVI decreased with the increase of soil pH when soil pH>8.0,and it was reversed when soil pH<5.0.There were significant differences in soil pH with various surface cover types,which showed an ascending order:Arbor<reed<maize<rice<high and medium-covered meadow<low-covered meadow<Puccinellia.The weathering products of minerals rich in K_(2)O,Na_(2)O,CaO,and MgO entered into the low plain and were enriched in different parts by water transportation and lake deposition,while Fe and Al remained in the low hilly areas,which was the geochemical driving mechanism.The results of this study will provide scientific basis for making scientific and rational decisions on soil acidification and salinization.

Assessment of temporal and spatial variations in surface water quality using multivariate statistical techniques: A case study of Nenjiang River basin, China

Assessment of temporal and spatial variations in surface water quality is important to evaluate the health of a watershed and make necessary management decisions to control current and future pollution of receiving water bodies. In this work, surface water quality data for 12 physical and chemical parameters collected from 10 sampling sites in the Nenjiang River basin during the years(2012-2013) were analyzed. The results show that river water quality has significant temporal and spatial variations. Hierarchical cluster analysis(HCA) grouped 12 months into three periods(LF, MF and HF) and classified 10 monitoring sites into three regions(LP, MP and HP) based on the similarity of water quality characteristics. The principle component analysis(PCA)/factor analysis(FA) was used to recognize the factors or origins responsible for temporal and spatial water quality variations. Temporal and spatial PCA/FA revealed that the Nenjiang River water chemistry was strongly affected by rock/water interaction, hydrologic processes and anthropogenic activities. This work demonstrates that the application of HCA and PCA/FA has achieved meaningful classification based on temporal and spatial criteria.

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.

Using MaxEnt Model to Guide Marsh Conservation in the Nenjiang River Basin, Northeast China

Incorporating private and working lands into protected area networks could mitigate the isolation state of protected areas(PAs) and improve the efficiency of conservation.But how to select patches of land for conservation is still a troublesome issue.In this study, the MaxEnt model and irreplaceability index were applied to guide marsh conservation in the Nenjiang River Basin, Northeast China.According to the high accuracy of the MaxEnt model predictions(i.e., the average AUC value = 0.933), the Wuyuer River and Zhalong marshes in the downstream reaches of Wuyuer River are the optimal habitat for the Red-crowned crane and migratory waterfowls.There are 22 marsh patches selected by the patch irreplaceability index for conservation, of which 12 patches had been included in the current network of protected areas.The other 10 patches of marsh(amounting to 1096 km^2) far from human disturbances with high NDVI(up to 0.8) and close distance to water(less than 100 m), which are excluded from the existing network of PAs, should be implemented conservation easement programs to improve the protection efficiency of conservation.Specifically, the marshes at Taha, Tangchi, and Lamadian should be given priority for conservation and restoration to reintroduce migratory waterfowls, as this would lessen the current isolation state of the Zhalong National Nature Reserve.

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.

THE FLOOD OF THE NENJIANG RIVER AND THE SONGHUA RIVER IN 1998 AND THE COMPREHENSIVE MANAGEMENT OF THE RIVER BASINS

In the summer of 1998, an exceptionally serious flood, with the characteristics of high water level, large volume of flow, long duration and serious losses caused by the disaster, occurred in the Nenjiang River basin and the Songhua River basin. Greater flood peak occurred three times in the trunk stream of the Nenjiang River for the floods occurred in its tributaries one after another. At Jiangqiao Hydrometric Station, the water level was 141.90 m and the rate of flow was 12?000 m 3/s. The flood is ranged to a catastrophic one, which occurs once in 50 years. Ranged to a catastrophic flood at Qiqihar Hydrometric Station that occurs once in 400 years, its water level, 0.89 m higher than the former all time highest, was 149.30?m and the corresponding rate of flow was 14?800?m 3/s. The water level that exceeded the all time highest lasted for 7 days. At Harbin Hydrometric Station, the water level, 0.59?m higher than the former all time highest, was 120.89?m and the corresponding rate of flow was 17?400?m 3/s. The water level that exceeded the all time highest lasted for 9 to 10 days. The flood here is ranged to a catastrophic one, which occurs once in 150 years. The flood of the Nenjiang River damaged 456×10 4?ha of crops and 115×10 4 rooms and the direct loss of economy exceeded 40 billion yuan(RMB). The main reasons of the flood are great rainfall, long flood season, unreasonable land use, regional ecological environment degradation and lack of water control projects. It is obvious that the following measures are greatly needed: the comprehensive management of the river basins; the formulation of development planning of the river basins, especially the water control projects; the development of agriculture based on ecological security.

Impact of land use/land cover changes on ecosystem services in the Nenjiang River Basin, Northeast China

Introduction:The Nenjiang River Basin is an important foodstuff base and eco-environmental fragile area in Northeast China.With the rapid rise in human population,human-induced changes in land use/land cover form an important component of regional environment and ecosystem service change.At the local and regional level,the ecosystem service concept can act as a decision support tool for a stakeholder to reach sustainable land use management.However,the prevailing ecosystem service evaluation would produce a biggish warp when it is applied to concrete area.So,it is essential to evaluate ecosystem service change according to the local actuality.Method:According to 1:250,000 land use/land cover maps of China and the adjusted equivalent value per unit area of ecosystem services in the Nenjiang River Basin,we evaluated the ecosystem service change of the river basin from 1980 to 2005.Results:The forest and wetland,which are mainly located in the upstream mountainous area of the Nenjiang River Basin,were the two valuable land cover types,accounting for more than three quarters of the total ecosystem service value of the river basin.As for individual ecosystem service,besides the food production,all of the ecosystem service values declined from 1980 to 2005.The total decline of 2.43 billion USD was mainly due to the cultivation of grassland(14.34%of the area in 1980)and wetland(4.62%of the area in 1980)in the downstream plain.Conclusions:Due to the increase in population and the concomitant requirement of grain,the inconsistency between decision-making at the macro-level,and the objective of agricultural production at the micro-level,cultivated land was increased through zealous reclamation of grassland,marginal woodland,and even fallow land.Tremendous land use/land cover changes had caused great damages to the ecological environment such as land degradation and ecosystem service recession.So,the policies of the Grain for Green and Construction of Ecological Province projects should be well-implemented to optimize land use/land cover.

Change trend analysis of ammonia nitrogen in Nenjiang River main stream under fluctuating precipitation

将2004-2010年嫩江流域沿途13个气象站的降水量作为径流的主要考察因子，以嫩江最下游的自沙滩水环境监测站获得的氨氮监测数据为流域总体氨氮污染水平表征，分析了降水波动对嫩江流域氨氮污染变化的影响。结果表明，嫩江流域在年度内的氨氮质量浓度以枯水期最高，平均为（0．99±0．48）mg／L，在丰水期最低，平均为（O．58±0．08）mg／L。从年际总体变化趋势来看，2004-2010年嫩江流域氨氮浓度总体呈增加趋势。降水量的年内分布格局对嫩江流域氨氮浓度的影响在不同时期略有差别。在平水期，降水量变化对氨氮浓度的影响不显著；但在枯水期、丰水期，降水量的波动对氨氮浓度有较显著（Sig．〈O．05）的影响。从年尺度上看，随降水量增加，嫩江流域中氨氮浓度总体呈下降趋势。

Mountain Effect and Differences in Storm Floods between Northern and Southern Sources of the Songhua River Basin

In this study, the differences in annual rainstorm changes in the Second Songhua River Basin and the Nenjiang River basin and their causes were compared from the perspective of mountain effects. The following results were drawn: (1) Altitude effect is the primary factor leading to increased rainstorms in the southern source; (2) Slope effect primarily leads to differences of the weather systems in the two sources, and thus cause the difference of the rainstorms; (3) Slope effect is responsible for the greater fluctuation in the observed floods in the southern source. These landform differences eventually lead to the differences in the characteristics of floods in the southern and northern sources. Commensurability method was used to identify the period of rainstorms in the southern and northern sources. The results showed that although rainstorms do not appear at the same time in the two sources they are characteristic of a 10 years' period in both areas. These results can serve as hydrological references for flood control and long-term flood disaster predictions.

数字孪生嫩江防洪“四预”应用研究

推进智慧水利建设是推动新阶段水利高质量发展的六条实施路径之一,水利部组织54家单位开展数字孪生流域建设先行先试工作。水利部松辽水利委员会围绕流域特色,以防洪为重点选取嫩江干流开展数字孪生流域建设先行先试工作。通过升级完善天空地一体水利感知网、搭建多源多级数据底板、建设模型库知识库、强化信息化基础保障等,构建基于数字化场景的防洪“四预”应用体系,有效提升了流域水旱灾害防御科学化、精准化水平,为防洪调度决策提供重要支撑,在2023年洪水防御工作中发挥了重要作用。

数字孪生流域预演场景研究与运用——以嫩江干流为例

为加强数字孪生演练场景真实化,助力决策精准化,依托数字孪生流域建设思路,搭建数字孪生业务应用平台。分析孪生平台整体架构与关键技术,构建具备预报、预警、预演、预案功能的防洪“四预”全景可视化平台。以嫩江干流为例,分析数字孪生建设实际需求,以尼尔基水库防洪调度为预演场景,分析尼尔基水库上游与下游嫩江干流之间的淹没损失关系,得出最优调度防御安排及建议。结果表明:通过全景可视化平台进行场景演练,可呈现河道演进真实情况,保障河道行洪安全,避免淹没损失,为防洪安全决策提供科学支撑。

嫩江流域生态干旱影响因素及其时空演变格局

近几十年来,嫩江流域湿地大面积萎缩、土地盐碱化严重,干旱频发,严重威胁生态安全、水环境安全和社会经济可持续发展。为量化嫩江流域干旱对生态系统的影响,利用标准化生态缺水指数(SEWDI),结合旋转经验正交函数、累积和曲线和Pearson相关性分析法分析嫩江流域1980—2017年生态干旱的时空演变规律,并利用游程理论提取生态干旱特征。结果表明:(1)生态干旱与影响因子间的相关系数排序为相对湿度>归一化植被指数>径流>降水>气温,其中生态干旱和相对湿度相关系数最大且大于0.5,呈现显著相关性,其余因子的相关系数均小于0.5,呈现低度相关性;(2)从SEWDI变化曲线上看,1980—1999年干湿交替呈现出一定的周期性,生态干旱以轻旱和中旱为主,总体呈加剧趋势;2000—2017年极端干旱和极端湿润事件频发,生态干旱总体呈缓解趋势。从累积和曲线上看,1980—1995年为嫩江流域生态干湿状态的正常波动时期,1996—2009年为嫩江流域生态干旱期,2012—2017年为生态湿润期;(3)生态干旱的干旱历时和烈度显示流域西南部严重程度较大,长期干旱风险较高,而流域北部干旱强度较大,较易发生单次较为严重的短期干旱。

嫩江流域河间地块地下水和地表水补给关系研究

地下水和地表水的补给关系研究,是水资源管理、保护以及合理利用的基础。通过野外测绘、取样、室内试验测试以及数值模拟方法,分析了嫩江流域典型河间地块地下水和地表水的氢氧同位素、水化学特征以及地表水和地下水的补给关系。结果表明:地下水与地表水同位素均因蒸发分馏影响导致同位素富集,浅层地下水富集程度大于深层地下水,地下水富集程度大于地表水;水体中阴离子以HCO_(3)^(-)为主,阳离子以Ca^(2+)、K^(+)和Na^(+)为主,水化学类型主要以Na·Ca-HCO_(3)型或Ca·Na-HCO_(3)型为主;水体中Ca^(2+)与HCO_(3)^(-)主要来源于研究区气液变质成因的碳酸盐化岩类的风化/溶解,K^(+)、Na^(+)主要来源于长石类矿物的风化/溶解;地下水与地表水存在相互补给关系,地表水主要通过断裂通道向地下水进行补给,地下水通过径流补给至周边地表河流。研究结果可为嫩江流域的生态建设和水资源管理提供科学依据和数据支撑。

基于生态系统服务价值的嫩江流域生态补偿研究

生态补偿是大力推进生态文明建设的重要举措。本文以嫩江流域为例,基于改进的当量因子法,通过ARCGIS遥感解译,计算嫩江流域生态系统服务理论价值。再通过生态补偿优先级和生态补偿需求强度系数,计算最终的生态补偿总量。结果表明:嫩江流域实际生态补偿总金额为439.89亿元。流域范围内的内蒙古自治区生态补偿标准为340.115亿元,黑龙江省生态补偿标准为79.108亿元,吉林省生态补偿标准为20.667亿元。可见内蒙古自治区是嫩江流域重点生态补偿对象。本文内容可为研究其他地区生态补偿、生态环境保护提供参考依据。

1998年夏季中国暴雨洪涝灾害的气象水文特征

文章分析了 1 998年夏季我国长江、嫩江、珠江流域发生的严重洪涝灾害的气象、水文特征及其成因。 6月中、下旬珠江、长江、嫩江流域出现了持续性强降水 ,局部地区下了大暴雨 ;7月下旬长江流域出现了“二度梅” ,湖南、湖北和江西省普降暴雨 ;8月上半月嫩江流域再次出现持续性强降水。频繁的强降水使长江、嫩江、华南西江等干、支流水位迅猛上涨 ,支流河水不断涌入干流 ,使得干流洪峰迭起。雨水和洪峰迭加 ,引发了百年一遇的大洪水。1 998年 7月副热带高压南落是造成长江流域“二度梅”的主要原因。副热带高压、南海季风涌、中高纬冷空气和从青藏高原东移的中尺度对流系统 (MCS)等 4个因子的最佳组配 。

农村居民阅读的知与行——嫩江流域少数民族地区阅读情况调查

对于农村居民阅读少问题的研究,学界多偏重于农村阅读设施建设和服务模式等方面,关注农民自身的研究成果较少。笔者通过实地考察、现场问卷调查和家庭走访等方式,对嫩江流域51个民族村的阅读设施建设和居民的阅读情况进行调查,发现当前农村阅读中的突出问题是,认为阅读重要的人多而阅读的人少,争取阅读援助的人多而利用阅读设施的人少。这一现象误导了农村阅读设施反复投入和建设,并导致图书馆服务和研究进入误区。农村居民阅读少问题的根源在于农民阅读需求的复杂性。农村阅读中问题最多的是困难群体遭遇的各种障碍;其中难度最大的,是农民阅读需求的贫困与阅读行为的障碍。研究农村居民阅读认知和阅读行动的状况,对于图书馆抓住农村阅读服务关键,改善阅读服务途径和完善服务目标具有重要意义。表7。参考文献42。

嫩江流域近45年来径流演变规律研究

采用随机水文学方法对嫩江流域1956—2000年的年径流量序列演变特征进行分析。结果表明，嫩江流域径流的水文周期是32a，整体而言，45a径流序列不存在明显的趋势性。此外，对嫩江流域用水性消耗程度进行分析。结果表明，人类用水性消耗量对流域水循环整体影响程度为5％，但是在流域内部影响程度存在较大差异。洮儿河子流域影响因子达到16％，反映该地区人类取用水消耗量较大。从年际分析，整个流域在70年代的影响因子要高于其它年段，呈现出越是枯水年段人类用水影响程度越大的现象。

近50年嫩江流域径流变化及影响因素分析

根据嫩江主要代表水文站石灰窑、同盟、江桥、大赉1956-2006年51年的径流资料,应用数理统计、累积滤波器、Mann-Kendall秩相关法及小波分析法等多种方法,分析了嫩江径流年内、年际变化特征及其影响因素。结果表明:嫩江径流年内分配不均匀,主要集中在7、8、9月份。嫩江年径流量在1963年左右发生了一次全流域的减少突变,80年代径流有所增加,90年代中后期又发生了一次减少突变。嫩江径流主要存在8年的年际周期,20年及大于40年的年代际周期。径流变化的主要气候影响因素是降水,人类活动通过土地覆被变化及水利工程等对径流也有重大影响。

土地利用/覆被变化的驱动力模型研究——以嫩江中上游地区为例

通过遥感手段获取嫩江中上游地区 1 995年和 2 0 0 0年的土地利用 /土地覆被图及其变化图 ,在GIS支持下 ,生成两个时段该区的土地利用程度变化图 ,分析土地利用程度变化的驱动力 .选取的自然因子主要为高程 (e)、坡度(s)、人口 (Δp)、大牲畜头数 (Δl)、农业机械力投入量、土地覆被类型变化区距嫩江干流和居民点的最短距离等 ,利用空间相关分析筛选出主要影响因子为高程、坡度、人口、大牲畜头数 .利用空间多元线性回归函数求得本区土地利用程度变化模型ΔLa=1 1 .0 3 7-4 .51 2 e -0 .2 98 s + 0 .2 92 Δp + 2 .596 Δl.