Comparison and Selection of Water Restoration Techniques for Artificial Landscape Lakes in Nantong City

As an important part of urban infrastructure,urban water system is of great and far-reaching significance for ensuring urban flood control and waterlogging safety,protecting ecological environment and building livable homes.Taking the urban water system of Nantong as an example,Nantong Water Resources Bureau issued R evision of Nantong Urban Water System Planning in 2017,and put forward the construction of the"two circles,eight lakes and nine veins"water system layout,giving new vitality to the urban water system.In view of problems existing in newly excavated artificial landscape lakes,such as fragile water ecosystem,strong eutrophication trend,poor environmental sensory effect and unsatisfactory water landscape effect,it is urgent to study the in-situ water ecological restoration technique of"algae-controlling zooplankton+submerged plant community"to build a"grass-type clear water"ecosystem for artificial landscape lakes,so as to improve the water sensory index and self-purification ability and finally realize the double improvement of"sensory effect and water quality"of artificial landscape lakes.

Impacts of climate change and human activities on water resources in the Ebinur Lake Basin, Northwest China

Changing climatic conditions and extensive human activities have influenced the global water cycle.In recent years,significant changes in climate and land use have degraded the watershed ecosystem of the Ebinur Lake Basin in Xinjiang,Northwest China.In this paper,variations of runoff,temperature,precipitation,reference evapotranspiration,lake area,socio-economic water usage,groundwater level and water quality in the Ebinur Lake Basin from 1961 to 2015 were systematically analyzed by the Mann-Kendall test methods(M-K)mutation test,the cumulative levelling method,the climate-sensitive method and land-use change index.In addition,we evaluated the effects of human activities on land use change and water quality.The results reveal that there was a significant increase in temperature and precipitation from 1961 to 2015,despite a decrease in reference evapotranspiration.The Wenquan station was not significantly affected by human activities as it is situated at a higher altitude.Runoff at this station increased significantly with climate warming.In contrast,runoff at the Jinghe station was severely affected by numerous human activities.Runoff decreased without obvious fluctuations.The contributions of climate change to runoff variation at the Jinghe and Wenquan stations were 46.87%and 58.94%,respectively;and the contributions of human activities were 53.13%and 41.06%,respectively.Land-use patterns in the basin have changed significantly between 1990 and 2015:urban and rural constructed lands,saline-alkali land,bare land,cultivated land,and forest land have expanded,while areas under grassland,lake,ice/snow and river/channel have declined.Human activities have dramatically intensified land degradation and desertification.From 1961 to 2015,both the inflow into the Ebinur Lake and the area of the lake have declined year by year;groundwater levels have dropped significantly,and the water quality has deteriorated during the study period.In the oasis irrigation area below the runoff pass,human activities mainly influenced the utilization mode and quantity of water resources.Changes in the hydrology and quantity of water resources were driven primarily by the continuous expansion of cultivated land and oasis,as well as the growth of population and the construction of hydraulic engineering projects.After 2015,the effects of some ecological protection projects were observed.However,there was no obvious sign of ecological improvement in the basin,and some environmental problems continue to persist.On this basis,this study recommends that the expansion of oasis should be limited according to the carrying capacity of the local water bodies.Moreover,in order to ensure the ecological security of the basin,it is necessary to determine the optimal oasis area for sustainable development and improve the efficiency of water resources exploitation and utilization.

Extracting water body data based on SDWI and threshold segmentation:A case study in permafrost area surrounding Salt Lake in Hoh Xil,Qinghai-Tibet Plateau,China

There are a large number of lakes,rivers,and other natural water bodies distributed in the permafrost area of the Qinghai-Tibet Plateau(QTP).The changes in water bodies will affect the distribution of water resources in sur-rounding areas and downstream areas,resulting in environmental impact and bringing potential flood disasters,which will induce more serious issues and problems in alpine and high-altitude areas with a fragile habitat(such as the QTP in China).Generally,effective,reasonable,and scientific monitoring of large-scale water bodies can not only document the changes in water bodies intuitively,but also provide important theoretical reference for subsequent environmental impact prediction,and disaster prevention and mitigation in due course of time.The large-scale water extraction technology derived from the optical remote sensing(RS)image is seriously affected by clouds,bringing about large differences among the extracted water result products.Synthetic aperture radar(SAR)RS technology has the unique advantage characteristics of all-weather,all-day,strong penetration,and not being affected by clouds,which is hopeful in extracting water body data,especially for days with cloudy weather.The data extraction of large-scale water bodies based on SAR images can effectively avoid the errors caused by clouds that become prevalent at present.In this paper,the Hoh Xil Salt Lake on the QTP and its surrounding five lakes are taken as the research objects.The 2-scene Sentinel-1 SAR image data covering the whole area on 22 August 2022 was used to verify the feasibility of extracting water body data in permafrost zones.Furthermore,on 22 August 2022,the wealth here was cloudy,which made the optical RS images,e.g.,Sentinel-2 images full of clouds.The results show that:using the Sentinel-1 image and threshold segmentation method to extract water body data is efficient and effective with excellent results in permafrost areas.Concretely,the Sentinel-1 dual-polarized water index(SDWI),calculated by combining dual vertical–vertical(VV)polarized and verti-cal–horizontal(VH)polarized data is a useful index for water extraction and the result is better than each of the VV or VH polarized images.

Diversity and Adaptations of Immature Diptera in Semiaquatic Habitats at Shorelines of Hypersaline Lakes in the Crimea,with a Brief Review of Diptera in Mineralized Bodies of Water

The order Diptera(Insecta)is one of animal groups most successful in the colonization of mineralized shallow aquatic and semiaquatic environments.At the same time,the taxonomic composition of Diptera,their role in

Climate effects on an inland alpine lake in Xinjiang, China over the past 40 years

Inland lakes are important water resources in arid and semiarid regions. Understanding climate effects on these lakes is critical to accurately evaluate the dynamic changes of water resources. This study focused on the changes in Sayram Lake of Xinjiang, China, and addressed the effects of climate fluctuations on the inland lake based on long-term sequenced remote sensing images and meteorological data from the past 40 years. A geo- graphic information system （GIS） method was used to obtain the hypsometry of the basin area of Sayram Lake, and estimation methods for evaporation from rising temperature and water levels from increasing precipitation were proposed. Results showed that： （1）Areal values of Sayram Lake have increased over the past 40 years. （2） Both temperature and precipitation have increased with average increases of more than 1.8~C and 82 mm, respectively. Variation of the water levels in the lake was consistent with local climate changes, and the areal values show linear relationships with local temperature and precipitation data. （3） According to the hypsometry data of the basin area, the estimated lake water levels increased by 2.8 m, and the water volume increased by 12.9×108 m3 over the past 40 years. The increasing area of Sayram Lake correlated with local and regional climatic changes because it is hardly affected by human activities.

Estimation of the rational water area for controlling wind erosion in the dried-up basin of the Ebinur Lake and its effect detection

埃比纳·莱克区域被描述为“一个格林迷宫”在“ Xinjiang MapRecords：河的记录“然而，在 1910 出版了在这个区域的生态学和环境严重由于人的活动的影响被堕落了在期间最近 40 年。渴起来，有 107.4 km^2 的一个区域的湖盆在它的西北的部分形成，是没有植被，盖住 byunconsolidated 淤泥沉积物，并且在北方 Xinjiang 成为了灰尘天气的主要灰尘来源之一，并且有 4.8x10 ~ 6t 的年度数量的灰尘被大风从有 164 天的 Alataw 山脉差距从这个区域吹一年里的发生的大风。为在弄干起来的湖盆在湖区域和有效地控制的风侵蚀改进生态学的埃比纳·莱克的合理的水区域和流入在在弄干起来的湖盆分析在沉积物的小粒的作文之间的当前的生态的问题和关系以后用水平衡方程被估计并且灰尘天气，和最近的年里的生态的效果被监视。为在弄干起来的湖盆在湖区域和有效地控制的风侵蚀改进生态学的 theEbinur 湖的水区域应该至少是 800 km^2，这被考虑，并且湖应该在 7.92x10 ~ 上的再装的表面流量和地下水的年度体积 8 m^3。

多特征多层次Sentinel-2影像辽宁省湖库水体提取

以辽宁省为研究区,本文基于GEE遥感云平台,使用Sentinel-2遥感影像,提出了一种多特征多层次的湖库水体提取算法。该算法选择自动水体指数(AWEI sh)和改进的归一化水体指数(MNDWI)提取水体,并利用归一化植被指数(NDVI)、归一化建筑指数(NDBI)、归一化差异红边指数(NDREI)、Sentinel-2的B8和B9波段及DEM数据多层次地消除暗地物和高亮地物噪声,对提取结果中被云雾遮挡而部分缺失的水体进行修复,最后将河流及细小像素剔除。利用此算法提取了辽宁省2017—2021年每年4、7、10月的湖库水体,并对比了不同水体提取算法及不同的水体数据产品。试验结果表明,本文算法在大尺度条件下提取水体具有良好的效果,总体精度达96%以上,可以较好地去除植被、阴影等暗像元表面,并且保证了水体信息的完整性,在大尺度水体提取方面具有一定的适用性和稳定性。

某湖区水质现状调查与富营养化分析

以某湖区水体为研究对象,参照《地表水环境质量标准》(GB3838-2002)及《地表水环境质量评价办法(试行)》,对2011-2020年该湖区高锰酸盐指数(CODMn)、化学需氧量(COD)、总氮(TN)、总磷(TP)、氨氮(NH4+-N)、叶绿素a(Chl-a)、透明度(SD)等水质指标进行调查与分析。结果表明:该湖区近十年水质除2017-2019年TP超标为Ⅳ类水外,其他时间基本稳定在Ⅲ类水质水平;TN近十年一直超过Ⅲ类,2016年达到最高值3.4 mg/L,之后下降至1.3 mg/L左右,但2018年之后又有略微上升的趋势;结合NH4+-N浓度不断下降的趋势,发现近十年该湖区有机氮和无机氮的输入不断增加。通过对湖区水质进行加密分析,发现TN、TP在东湖东岸边以及南岸附近浓度较高,Chl-a在东湖北部和西湖西北部圩区附近含量较高。通过富营养化状态指数分析可知,自2014年以来,该湖区富营养化程度呈明显上升趋势,且西湖有高于东湖的趋势。

1985−2020年太湖月尺度高精度水体面积提取分析

本研究选取太湖作为研究对象,使用长期高分辨率水体掩膜数据集,通过水体分类增强算法纠正数据中受到云、云阴影、地形阴影等污染的像素.本研究提供了长达30多年(1985−2020年)的太湖月尺度水覆盖图和水体面积数据,其中水体面积平均值为2421.00 km^(2),数据方差较算法纠正前锐减,平均面积增强率达20.76%,验证结果可靠.这些数据可以用来支持水资源分析和科学管理,并为维护该区域的生态平衡和持续利用水资源提供科学依据和数据支撑.

基于Landsat影像的鄱阳湖面积监测及其与水位关系研究

湖泊是陆地生态系统的一个重要的组成部分,湖泊水域的变化对环境和人类的生产活动都有着重大的影响。鄱阳湖作为中国第一大淡水湖,近年来多次出现洪旱灾害现象,因此对鄱阳湖进行动态监测意义重大。文章以2000—2021年鄱阳湖175期Landsat影像作为数据源,对比分析了归一化差异水体指数(normalized difference water index,NDWI)、改进的归一化差异水体指数(modified normalized difference water index,MNDWI)、自动水体提取指数(automated water extraction index,AWEI)、谱间关系法(spectrum photometric method,SPM)这4种水体提取方法,优选最适宜鄱阳湖的水体提取模型;利用175期面积数据分析了鄱阳湖2000—2021年面积的年际变化趋势,分析年内季节变化特征,同时结合2009—2013年和2017—2018年同时期的50组水位数据,建立面积-水位关系模型。结果表明:①AWEI模型提取水体精度优于其他3种,该文最终选用AWEI进行鄱阳湖水体提取;②鄱阳湖面积存在明显的季节性变化,且丰水季面积年际波动大,枯水季较平缓;③棠荫水位站湖泊面积-水位分段线性模型为最佳模型,从而可以根据鄱阳湖区域的实时水位观测值对水体覆盖面积进行预测,以弥补云雨天气时利用可见光遥感手段难以监测到湖泊水体淹没情况的不足。

四川省大型湖泊和水库水体长时序时空变化分析

采用2000—2020年欧盟委员会联合研究中心发布的逐年地表永久水体和季节水体数据集,分析了四川省30个大型湖泊和102个大型水库(水体面积在1 km^(2)以上)的水体时空变化特征,探究了水体与降水和陆地水储量的关系。研究结果表明,2000—2020年大型湖泊和水库整体均呈永久水体面积增加、季节水体面积减少的变化趋势;从个体尺度来看,12个大型湖泊的永久水体面积显著增加,7个大型湖泊的季节水体面积显著减少,89个大型水库的永久水体面积显著增加,43个大型水库的季节水体面积显著减少。大型湖泊和水库的永久水体与年降水量、陆地水储量均存在较高的正相关性,相关系数分别达到0.68和0.90。

河湖长制背景下黑龙江省小微水体污染分析与治理研究

作为地表水最小的单位部分和最基本的生态细胞-小微水体,在水循环中起着极其重要的作用,对人居生态环境质量发挥着重要的基础性功能和作用,但部分小微水体饱受长期无人问津、疏于管护以及“人进水退”、垃圾和污水随意丢弃、水质严重污染、生态系统崩溃等问题严重突出,已然成为水生态文明建设的“盲点”和“重点”。以黑龙江省小微水体治理管护为切入点,分析、研究并总结小微水体的定义、特征、分类和数量,系统介绍了小微水体污染来源,梳理了高效治理的对策和方法,为黑龙江省和国内开展小微水体污染治理提供参考。

基于环境一号卫星的吉林省松花湖2012—2020年面积变化监测研究

研究基于HJ-1A/1B卫星数据对松花湖2012—2020年夏季水域面积变化进行监测。利用卫星遥感专业ENVI软件对环境星数据进行预处理,再采用目视解译法识别松花湖水体,并进行不同年份松花湖水域面积的计算。最后分析松花湖2012—2020年间水域变化时空特点,松花湖在2012年和2013年间水体面积无明显变化,2014—2017年水体面积变化波动较大,该研究区2013年水体面积增大是因为发生区域性洪涝灾害,而2015年水体面积变化较大则是因为该年政府对于丰满水库的规划建设发生一定变化。2017—2020年间水体面积与范围无明显变化趋势。

巢湖水体自净过程中污染物降解速率与影响因素研究

为有效改善巢湖水体污染现状,实现水体的自净治理,本文以巢湖水体污染为研究切入点,从生活污水、农业面源污染、工业废水等方面梳理了水体污染的主要成因,并结合水体自净过程阐明了污染物降解速率的概念及水体自净的机制原理。针对巢湖水域特征,从不同条件分析了影响污染物降解速率的因素,并从水体条件、技术手段、污染来源监管等方面提出相应的建议,旨在为水环境的保护与治理提供参考依据。

The model study of water mass and energy exchange between the inland water body and atmosphere

Based on a one-dimensional eddy diffusion model,a model to study the water mass and energy exchange between the water body(such as lake and wetland) and the atmosphere is developed,which takes the phase change process due to the seasonal melting and freezing of water and the convection mixing process of energy caused by temperature stratification into consideration. The model uses enthalpy instead of temperature as predictive variable,which will help to deal with the phase change process and to design an efficient numerical scheme for obtaining the solution more easily. The performance of the model and the rationality of taking convection mixing into the consideration are validated by using observed data of Kinneret Lake in Israel and Lower Two Medicine Lake in Montana State in America. The comparison of model results with observed data indicates that the model presented here is capable of describing the physical process of water mass and energy between the water body(lake and wetland) and atmosphere. Comparison of the result from wetland with shallow and deep lakes under the same forcing conditions shows that the evaporation from wetland is much greater than that from lakes,which accords with the real observation fact and physical mechanism.

Water sources for typical desert vegetation in the Ebinur Lake basin

In arid and semi-arid environments,desert vegetation plays an important role in preventing soil erosion by wind and helps maintain the stability of desert and oasis ecosystems.Four types of typical desert vegetation,namely Populus euphratica,Haloxylon ammodendron,Nitraria sibirica,and Halostachs caspica,corresponding to different habitats(i.e.,river bank,sand dune,desert,and salt marsh)were chosen as the model vegetation in this research.Theδ^(2)H andδ^(18)O for rainwater,soil water,and plant water were applied to identify the water sources and quantify the proportions of different water sources used over the entire plant growth period(from March to October).The results showed that the precipitationδ^(2)H andδ^(18)O in the Ebinur Lake basin varied from-142.5‰to-0.6‰and from-20.16‰to 1.20‰,respectively.The largestδ^(2)H andδ^(18)O values occurred in summer and the smallest in winter.The soil waterδ^(2)H andδ^(18)O of the four habitats decreased gradually with increasing depth.Theδ^(2)H andδ^(18)O values of water extracted from the stems of the four plants had similar variation trends,that is,the maximum was observed in spring and the minimum in summer.Among the four plants,H.caspica had the highest stable isotopic values in the stem water,followed by N.sibirica,H.ammodendron,and P.euphratica.The water sources and utilization ratios of desert vegetation varied across different growth stages.Throughout the growing period,H.ammodendron mainly used groundwater,whereas the water source proportions used by N.sibirica varied greatly throughout the growing season.In spring,plants mainly relied on surface soil water,with a contribution rate of 80%-94%.However,in summer,the proportion of deep soil water used was 31%-36%;and in autumn,the proportion of middle soil water used was 33%-36%.H.caspica mainly relied on topsoil water in spring and autumn,and the proportion of soil water in the middle layer slightly increased to 20%-36%in summer.P.euphratica mainly used intermediate soil water in spring with a utilization rate of 53%-54%.In summer,groundwater was the main source,with a utilization rate of 72%-88%,and only 2%-5%came from river water,whereas in autumn,the river water utilization rate rose to 11%-21%.The results indicated that there were significant differences in water use sources during the growing period for desert vegetation in arid areas.This research provides a theoretical basis for understanding water use mechanisms,water adaptation strategies,and vegetation restoration and management in arid areas.

Distinguishing different subclasses of water bodies for long-term and large-scale statistics of lakes:a case study of the Yangtze River basin from 2008 to 2018

Long-term and large-scale lake statistics are meaningful for the study of environment change,but many of the existing methods are labourintensive and time-consuming.To overcome this problem,a novel method for long-term and large-scale lake extraction by shape-factorsand machine-learning-based water body classification is proposed.An experiment was conducted to extract the lakes in the Yangtze River basin(YRB)from 2008 to 2018 with the Joint Research Centre’s Global Surface Water Dataset(JRC GSW)data and OSM data.The results show:1)The proposed method is automatically and successfully executed.2)The number of river–lake complexes is between 3008 and 4697,representing 3.56%–5.70%of the total water bodies.3)The areas of the lakes and rivers in the YRB were obtained,and the accuracy of water classification in each year was stable between 90.2%and 93.6%.Comparing the back propagation neural network,random forest,and support vector machine models,we found that the three machine learning models have similar classification accuracy for the scenario.4)Fragmented and incomplete small rivers in the JRC GSW data,unchecked training samples,and overlapped shape factors are the three error sources.Future work will focus on addressing these three error sources.

考虑水体面积变化的鄱阳湖平原区地表-地下水相互作用模拟

湖泊的水情变化会影响其与地下水之间的物理水文过程和生态行为,鄱阳湖独特的“河湖相”转换特征使得该地区地表-地下水交换过程更加复杂。采用Visual MODFLOW构建三维非稳定流地下水流数值模型,利用LAK3子程序模块,通过输入五河入湖以及鄱阳湖流入长江的水量,实现湖水面积的动态模拟。结果表明,2019年湖水位模拟值与实测值的均方根误差为0.225 m,地下水水位模拟值与实测值的均方根误差为0.571 m;模型模拟鄱阳湖水面积环比变幅−41%~83%,与遥感影像结论吻合。该模型减少了湖泊作为边界条件的约束,可以有效刻画鄱阳湖频繁变化的湖水位和水体面积,准确模拟地下水流场和地表-地下水相互作用关系对湖泊水体高度动态变化的响应。枯水期主要由地下水补给湖水,交换量为2.03×10^(7)~10.58×10^(7) m^(3)/mon;丰水期湖水补给地下水,交换量为2.04×10^(7)~16.53×10^(7) m^(3)/mon,湖区及周边地下水水位相比枯水期平均抬升2~3 m,地下水由湖区流向周边地区。本研究为地表水体剧烈变化地区提供了有效的数值模拟方法,研究结果可为鄱阳湖平原区未来水资源管理和环境评价提供基础。

调水期风场对淮河入江水道浅水湖泊水动力水质的影响研究

为研究调水期风场对淮河入江水道高邮湖、邵伯湖输水流场的影响,采用MIKE21 Flow Model建立研究区域的二维风生流数值模型,在盛行风场作用下分析两湖泊的水动力变化与水质更新规律。结果表明:风荷载作用下,高邮湖内形成了多个形态迥异的风生环流,环流的流向、形状与风场的风向密切相关;新民滩控制线的上下级湖面是风涌增减水作用显著的区域,风速越高水位变幅越大,该水位变幅可能导致高邮泵站设计扬程与调水动力不足;风场的剪切拖曳作用对湖区水体与长江水体的更新置换规律也有影响,顺风条件下湖区水体水质的更新速度与程度显著提高,而逆风条件下水体更新强度则明显下降。

基于MIKE21的异龙湖水动力优化与水质改善研究

湖泊由于长期处于封闭或半封闭状态,水动力条件差,极易发生富营养化。为此,综合考虑降雨对异龙湖湖泊TN浓度的时空分布影响,构建了MIKE21水动力—对流扩散模型,模拟了不同入水口启闭情况和不同流量引水方案下的水动力条件,基于湖泊流场的流速分布探究了TN浓度的改善情况。结果表明,增设引水口和增大引水流量均能有效提升湖泊水动力条件与湖区水质,城河单独引水的整体效果比城河和龙港河共同引水的整体效果好;在城河单独引水的方案下将引水量增大1倍,湖泊整体流速提升了44.04%,TN浓度下降52.78%,水动力优化与水质改善效果最好,但单位补水量的水质改善效率有所降低。研究结果可为类似在建及规划项目提供建设思路。