Optimization of water-urban-agricultural-ecological land use pattern:A case study of Guanzhong Basin in the southern Loess Plateau of Shaanxi Province,China

Extensive land use will cause many environmental problems.It is an urgent task to improve land use efficiency and optimize land use patterns.In recent years,due to the flow decrease,the Guanzhong Basin in Shaanxi Province is confronted with the problem of insufficient water resources reserve.Based on the Coupled Ground-Water and Surface-Water Flow Model(GSFLOW),this paper evaluates the response of water resources in the basin to changes in land use patterns,optimizes the land use pattern,improves the ecological and economic benefits,and the efficiency of various spatial development,providing a reference for ecological protection and high-quality development of the Yellow River Basin.The research shows that the land use pattern in the Guanzhong Basin should be further optimized.Under the condition of considering ecological and economic development,the percentage change of the optimum area of farmland,forest,grassland,water area,and urban area compared with the current land use area ratio is+2.3,+2.4,-6.1,+0.2,and+1.6,respectively.The economic and ecological value of land increases by14.1%and 3.1%,respectively,and the number of water resources can increase by 2.5%.

Dataset of Comparative Observations for Land Surface Processes over the Semi-Arid Alpine Grassland against Alpine Lakes in the Source Region of the Yellow River

Thousands of lakes on the Tibetan Plateau(TP) play a critical role in the regional water cycle, weather, and climate. In recent years, the areas of TP lakes underwent drastic changes and have become a research hotspot. However, the characteristics of the lake-atmosphere interaction over the high-altitude lakes are still unclear, which inhibits model development and the accurate simulation of lake climate effects. The source region of the Yellow River(SRYR) has the largest outflow lake and freshwater lake on the TP and is one of the most densely distributed lakes on the TP. Since 2011,three observation sites have been set up in the Ngoring Lake basin in the SRYR to monitor the lake-atmosphere interaction and the differences among water-heat exchanges over the land and lake surfaces. This study presents an eight-year(2012–19), half-hourly, observation-based dataset related to lake–atmosphere interactions composed of three sites. The three sites represent the lake surface, the lakeside, and the land. The observations contain the basic meteorological elements,surface radiation, eddy covariance system, soil temperature, and moisture(for land). Information related to the sites and instruments, the continuity and completeness of data, and the differences among the observational results at different sites are described in this study. These data have been used in the previous study to reveal a few energy and water exchange characteristics of TP lakes and to validate and improve the lake and land surface model. The dataset is available at National Cryosphere Desert Data Center and Science Data Bank.

Methodology to determine regional water demand for instream flow and its application in the Yellow River Basin

In order to realistically reflect the difference between regional water demand for instream flow and river ecological water demand as well as to resolve the problem that water demand may be counted repeatedly, a concept of regional water demand for minimum instream flow have been developed. The concept was used in the process of determining river functions and calculating ecological water demand for a river. The Yellow River watershed was used to validate the calculation methodology for regional water demand. CaIculation results indicate that there are significant differences in water demands among the different regions. The regional water demand at the downstream of the Yellow River is the largest about 14.893 × 10^9 m^3/a. The regional water demand of upstream, Lanzhou-Hekou section is the smallest about -5.012 × 10^9 m^3/a. The total ecological water demand of the Yellow River Basin is 23.06 × 10^9 m^3/a, about the 39% of surface water resources of the water resources should not exceed 61% in the Yellow River Basin. Yellow River Basin. That means the maximum available surface The regional river ecological water demands at the Lower Section of the Yellow River and Longyangxia-Lanzhou Section exceed the surface water resources produced in its region and need to be supplemented from other regions through the water rational planning of watershed water resources. These results provides technical basis for rational plan of water resources of the Yellow River Basin.

Water Environmental Degradation of the Source Area of the Yellow River on Northeast Qinghai-Tibet Plateau

The issue on water environmental degradation in the source area of the Yellow River has been one of very serious ecological and socially economic problems. The temporal-spatial changes of water environment led to the decreasing of land capacity and river disconnecting. The status of water environmental degradation in this paper was analyzed based on the data and field investigation. The results indicated that the surface water area in the region has obviously decreased owing to the climate changes and human irrational use of water resources and the continuous lowering of the regional groundwater table and the steadily decreasing tendency of the flow rate in the source areas of the Yellow River.

Sediment discharge of the Yellow River, China: past, present and future——A synthesis

The Yellow River cut through Sanmenxia Gorge and discharged into the sea via the North China Plain in 150 ka BP; since then, around 86 000 × 108 t sediment has been transported passing Sanmenxia Gorge. Based on land use and land cover changes in Loess Plateau and other available evidence, an estimate of the Yellow River sediment budget is presented here： about 72% of the sedimentary material was trapped in the North China Plain and the remainder（i.e., 26%） escaped to the sea. At the present stage, 〈 0.2×108 t/a suspended sediment of the Yellow River enter the northern Yellow Sea. The transport pattern is determined mainly by the shelf current system. Annually 0.2×108–0.3×108 t of suspended particles are carried to the East China Sea; the materials are derived mainly from coastal and subaqueous delta erosion associated with the abandoned Yellow River on the Jiangsu coast. Since 1972, the lower Yellow River started to have a situation of continuous no-flow. During 1996–2000, the annual water flow and sediment discharge are only 19%, as compared with normal years（i.e., average for 1950–1979）. In response to global warming and increase of water diversion from the Yellow River for industrial and urban use, the sediment flux of the Yellow River to the sea will most likely remain small in the next two to three decades.

Different provenance of separate loess sites in Yangtze River Basin and its paleoenvironmental implications

The dust deposits in the Yangtze River Basin(YRB)have been widely distributed along the Yangtze River valley.Previous studies mainly concentrated in its provenance of each loess site,however,the differences in provenance of loess among different sites in this area have rarely been studied.Here,the geochemical characteristics of the<20μm fraction in the loess in separate Jiujiang,Xuancheng and Nanjing sites were analyzed.The result shows that the loess in Jiujiang and Nanjing sites,near Yangtze River riverway,share similar geochemical characteristics that may commonly derived from the detrital materials of Yangtze River.However,both sites have significantly different elemental compositions compared with Xuancheng site,which is^60 km away from the Yangtze River riverway.These sites share different geochemical characteristics with Eastern Qinling Mountains and Xifeng section on the Chinese Loess Plateau,North China.Combining the distribution of the aeolian sand hills and the loess in this area published by previous studies,we suggest that the exposed river valley floodplain caused by weak summer monsoon provided abundant materials to form local dust cells controlled by strong winter monsoon during the glacial periods.Therefore,those local loess deposits should be identified as the“valley-sourced loess”.These reveal the inherent connection between the monsoon system and the loess deposits in Yangtze River Basin.

黄河流域水资源-生态-城市-产业协同演进研究

为考察黄河流域水资源-生态-城市-产业协同的动态演进及其地区差异和来源,基于2016—2020年黄河流域76个主要地级市数据,采用协同度模型、核密度估计和Dagum基尼系数及其分解方法进行实证测度。结果表明:处于初级、中级和良好协同的城市数量分别为30个、33个和13个。各城市协同度水平呈现上升趋势,但城市间绝对差异在扩大,相对差异在缩小;除呼包鄂榆城市群外,其他六大城市群协同度绝对差异均呈扩大趋势。黄河上游和下游内部差异呈下降趋势,中游内部差异呈上升趋势;上游和中游间差异最大,且呈现进一步扩大趋势,上游和下游间差异逐渐缩小。呼包鄂榆城市群群内差异最小,关中城市群群内差异最大;关中城市群与山东半岛城市群群间差异最小,晋中城市群与山东半岛城市群群间差异最大。未来应进一步加强要素协同、区域协同,发挥各地区动态比较优势,因地制宜推进黄河流域生态保护和高质量发展重大国家战略深入实施。

黄河流域数字经济发展区域差异及动态演进

数字经济作为一种新经济形态,为社会经济发展带来了创新性的潜能和动力。黄河流域在发展中长期存在区域发展不平衡、产业结构不合理以及创新发展动力不足等问题,探讨和明晰数字经济对黄河流域区域发展的影响,对该区域高质量发展具有现实意义。本文以2011—2020年黄河流域73个地级及以上城市为研究对象,采用熵权法对各城市数字经济发展水平进行测度,在此基础上,采用Kernel密度估计法、Dagum基尼系数等方法对黄河流域数字经济发展的动态演进过程及其区域差异进行研究,并通过空间杜宾模型检验其收敛性。结果表明:在数字经济发展战略和行动的推动下黄河流域数字经济发展水平不断提高,且呈现下、中、上游梯度递减规律。黄河流域数字经济发展总体差异呈缩小的趋势,区域间差异是总体差异的主要来源。黄河流域整体以及上、中、下游地区均存在绝对β收敛和条件β收敛。

黄河水沙变化:历史、现状与未来

在现状防洪工程格局下,实现长治久安,核心在于黄河下游能否长期“河床不抬高”,而决定河床淤积抬高的关键因素是水沙条件。本文分析了2200多年来黄河下游决溢频次、黄土高原气候和社会环境变化,利用史料、前人研究成果和实测数据等,对不同历史时期黄河水沙的变化情况进行了分析。研究表明,从西汉时期至1970年代,黄河水沙量总体呈现为“水量越来越少、沙量越来越多”的趋势:在东汉故道行河的前837年(公元70—907年),黄河沙量只有4亿~5.5亿t/a、下游水量超600亿m^(3)/a,随后的127年黄河沙量增至7亿t/a左右、下游水量减至580亿m^(3)/a;1579—1918年黄河沙量增加到15亿t/a、下游水量减至570亿m^(3)/a;1933—1979年是黄土高原产沙最丰的时期,黄河潼关站实测输沙量为16.2亿t/a,若还原坝库拦沙后“天然”输沙量达19.2亿t/a。1980年代至今,黄河水沙呈现出“水沙均减”的趋势,其中,2000—2023年潼关站实测输沙量为2.34亿t/a,还原坝库拦沙后“天然”输沙量为5.5亿t/a,与唐代持平,下游实测径流量290亿m^(3)/a,是唐末的46%。未来,依靠持之以恒的水土保持,黄河沙量或许可以长期控制在4亿~5亿t/a,达到东汉故道行河前期的来沙水平,但因下游来水量难超270亿m^(3)/a,黄河下游现行河道的行河寿命难以比肩东汉故道。

基于多区域投入产出的黄河流域贸易隐含碳排放时空格局及结构分解

厘清黄河流域贸易隐含碳排放时空格局及其驱动因素,对于制定公平有效的减排方案,实现区域合作减排的重要目标至关重要。利用多区域投入产出模型深入研究2007—2017年黄河流域9个省区贸易隐含碳排放的构成,以及其在省级和行业层面的转移路径;通过结构分解方法,追踪黄河流域贸易隐含碳排放区域内外的影响因素,揭示其区域内外影响因素的异质性。结果表明:黄河流域整体呈净贸易隐含碳转出区域,主要由中间投入的贸易方式进入其他各省的生产需求时导致。该流域的生产供应和整体需求正向中西部和东北地区转移,而对东南沿海省份的供应和需求正逐渐减少。区域外的最终需求和本地的碳排放强度是影响转出贸易隐含碳的主要因素,区域内的最终需求和区域外的碳排放强度是影响转入贸易隐含碳的主要因素。此外,生产结构和最终需求是影响黄河流域贸易隐含碳排放的关键因素,前者对黄河流域贸易隐含碳排放起抑制作用,后者则主要起驱动作用。

黄河流域9省区经济发展、产业结构与环境污染的关系

研究经济发展、产业结构与环境污染之间的关系对实现黄河流域9省区生态保护和高质量发展有着重要意义。基于环境污染和产业结构升级指数,运用Eviews 10.0软件检验了经济发展和产业结构的关系,探讨了经济发展、产业结构与环境污染三者之间的关系。结论如下:(1)黄河流域9省区环境污染指数整体变化曲线呈现先升后降特征,青海、宁夏、甘肃、河南和山东5省区的环境污染指数变化曲线呈现倒“U”型,四川、内蒙古、陕西和山西4省区的环境污染指数变化曲线呈现倒“N”型;经济发展水平呈上升趋势,区域差异较大;产业结构升级系数呈波动上升趋势,其中除青海和内蒙古外的7省区的产业结构格局由“二三一”转变为“三二一”,青海和内蒙古的产业结构格局稳定在“三二一”。(2)黄河流域9省区经济发展与产业结构关系差异显著。四川、甘肃、宁夏、内蒙古、陕西5省区经济发展促进了产业结构升级,产业结构升级对经济发展影响不显著;山西产业结构升级推动了经济发展,经济发展对产业结构升级影响不显著;河南和山东的经济发展与产业结构升级相互促进,青海的经济发展与产业结构升级相互作用和影响较小。(3)黄河流域9省区经济发展与环境污染的关系曲线均呈倒“N”型,经济发展水平与环境污染的演变趋势不同,随着经济发展,环境污染状况改善得并不明显;青海、宁夏、甘肃、河南和山东5省区产业结构升级抑制了环境污染,四川、内蒙古、陕西和山西4省区的产业结构升级加剧了环境污染。优化调整产业结构、转变经济发展方式和加大治污投入等,有利于实现黄河流域9省区经济社会的可持续发展。

黄河流域制造业高质量发展的空间格局演化、地区差异及收敛性分析

基于2010-2020年黄河流域73个地市面板数据,通过AHP-熵值法测算各地市制造业高质量发展水平,综合运用标准差椭圆、Dagum基尼系数及β收敛模型考察流域内制造业高质量发展的空间格局演化、地区差异及其空间收敛特征.研究结果表明:1)黄河流域制造业高质量发展水平呈波动上升趋势,但存在显著的空间非均衡性,始终保持“下强上弱”的空间分布格局.2)制造业高质量发展的重心向西南方向偏移,并表现为东西向集聚、南北向扩散趋势.3)制造业高质量发展的总体差异略有增加,组间差异是总体差异的主要来源.4)流域整体及上、下游地区支持条件β收敛和绝对β收敛机制,但不同地区的收敛速度和影响因素存在差异.基于实证结果,从提升黄河流域制造业高质量发展水平、缩小地区差距、促进区域差异化发展等方面提出建议.

黄河流域数字经济对区域创新水平的影响研究

基于2012—2021年黄河流域九省的相关统计数据,构建数字经济评价指标体系,采用个体时点双向固定效应模型进行实证分析。研究表明:黄河流域数字经济与区域创新水平的发展均存在不平衡性,各地区之间存在明显的差异;黄河流域数字经济能够显著促进区域创新水平提升;黄河流域数字经济对区域创新水平的影响存在区域异质性,对上游地区的促进作用更为显著。

豫西黄河流域古地名源流及其文化内核

豫西黄河流域既是一个地理概念,也是一个文化范畴。在这一区域,黄河及其支流的自然山水、人文因素,催生了不少古地名。丰厚的历史文化积淀,使这一区域的地名源头,从遥远的上古时期延续到漫长的奴隶社会、封建社会乃至近代。地名作为历史的活化石,记载着这一区域的朝代更迭、历史变迁,记载着风云人物、风物传奇,也同样记载着民间百姓的生活和生存状态。豫西黄河流域古地名丰富的历史文化底蕴,主要生发于该区域文化内核——仰韶文化、殷商文化、秦汉文化、唐宋文化等,也得益于黄河这一华夏文明的摇篮。

黄河源区典型泥炭湿地地下水水位时空变化及流量过程

以黄河源区若尔盖盆地黑河上游的一个典型泥炭湿地小流域为研究对象,采用2018—2022年的地下水水位监测数据、气象数据和无人机航测地形数据,统计分析了泥炭湿地小流域内地下水水位时空变化,并推算了小流域沟道出口的断面水深与流量过程。结果表明:降水是泥炭湿地小流域地下水水位变化的主导因素,地下水水位与降水量变化趋势一致,且随降水与蒸散发之比的增大而上升;小流域中游地下水水位比上游波动更剧烈,且上游地下水水位均值高于中游,沟道中部泥炭湿地的蓄水能力在减退。根据水力学方法和地下水水位监测数据得到了泥炭湿地小流域的沟道断面水深-流量经验关系公式,可用于计算日流量过程线。

黄河流域水稀缺风险评价

基于黄河流域水稀缺特点及其成因,提出了综合考虑水量､水质和生态需水因素的流域水稀缺风险(WSR)评估框架,以此评估了2017年黄河流域90个地级市42个部门的直接水稀缺风险损失(DWSR),并通过构建城市尺度环境拓展多区域投入产出模型(MRIO),评估了城市间贸易驱动的间接水稀缺风险损失(IWSR).结果表明:流域DWSR和IWSR分别约为28941.49亿元和34464.08亿元,贸易导致的间接经济损失大于直接经济损失;各城市DWSR和IWSR整体上呈现一定的空间差异性,但高风险城市具有明显的空间集聚性和重合性,主要集中在流域中下游的山东､河南两省,如潍坊､淄博､郑州等;IWSR转移主要由各省内的城市间贸易产生,省际间的风险转移没有形成明显的热点区域;农林牧渔业､化学工业､石油加工､炼焦和核燃料加工业等部门的DWSR较高,同时也是主要的IWSR出口部门.建议结合识别出的重点城市､关键部门等全面加强WSR管理,协同推进黄河流域节水控水､水质改善和生态用水保障,促进流域水资源节约集约高效利用.

黄河九省(区)水资源绿色效率时空格局与影响因素研究

为探索黄河九省(区)水资源绿色效率,采用SBM-DEA模型和Tobit模型对黄河九省(区)99个地级市水资源绿色效率的时空分布及影响因素进行分析。研究结果表明:1)黄河九省(区)水资源绿色效率整体呈上升趋势,下游的中原城市群和山东半岛城市群水资源绿色效率较高,上游的兰西城市群和宁夏沿黄城市群相对较低;2)黄河九省(区)水资源绿色效率空间集聚分布显著,“高-高”型城市主要集聚在下游经济较发达的省份,水资源绿色效率呈显著的正向空间自相关,并存在集聚现象和溢出效应;3)第一产业和第三产业规模、水资源禀赋和节水水平对水资源绿色效率提升具有显著积极影响,外商直接投资对水资源绿色效率的影响较为消极。

黄河流域区域再生水循环利用的制约因素和对策措施探讨

区域再生水循环利用是破解水资源、水环境和水生态“三水统筹”治理难题,实现污水资源化利用的重要途径.通过调研黄河流域上中下游16个地级市区域再生水循环利用试点实施方案的推进情况,剖析了区域再生水循环利用模式在地方的认知度和融合度,从政策和技术层面梳理了影响黄河流域区域再生水循环利用体系构建的主要制约因素,并提出了相应的对策措施.旨在推动区域再生水循环利用体系在黄河流域更大范围内发挥更加显著的效益,为其他流域再生水利用提供借鉴.政策层面的制约因素表现在地方政府缺少对再生水利用比例的考核机制,人工湿地工程无法与当地再生水利用规划、城镇污水处理厂和管网建设充分衔接融合,再生水不能有效纳入水资源配置规划,对于再生水取用权和收益权亦缺乏明确的管理要求,再生水尚未纳入水权交易市场.再生水利用工程盈利能力较弱,在缺乏经济政策保障的情况下很难形成稳定的市场运营和长效运行机制.技术层面的制约表现在冬季低温条件下,人工湿地工程的处理效果对运维技术的依赖度较高.不少地方的人工湿地工程往往缺乏专业运维队伍,“重建设、轻运维”的现象较为普遍.黄河流域再生水用于农业灌溉的需求量大,潜力有待充分发掘,再生水盐分升高和水质安全利用问题需持续探索和研究.提出的对策措施包括四方面:一是强化地方政府相关职能部门的协作协同,加大再生水利用率在考核中的权重,鼓励基础较好的地区开展再生水水权交易制度建设试点;二是省级层面应加大对区域再生水循环利用工程的政策和资金倾斜,推动工程尽早开工建设和发挥示范效益;三是强化人工湿地用地保障和运维管理;四是鼓励地方政府出台支持再生水用于农业灌溉的政策,推动黄河流域内典型农业县城形成具有示范性的再生水农业安全利用模式.

黄河流域黄土高原生态质量时空演变格局及其驱动因素

[目的]量化分析自然与社会经济因素对黄河流域黄土高原生态质量格局演变的影响,为进一步提升黄河流域生态质量,促进区域生态可持续发展提供理论支撑。[方法]基于DPSIR模型框架,从社会经济状况、自然环境与生态治理方面选取14项指标,构建生态质量综合评价指标体系,采用层次分析法确定指标权重,采用加权平均法计算生态质量综合评价指数;构建岭回归模型,分析了其变化的驱动因子。[结果]黄河流域黄土高原生态质量具有明显时空异质性;生态质量较高区域集中分布在中游地区,较低区域集中分布在上游地区,整体呈“东南高、西北低”的空间格局;生态质量评估为中及以上水平区域面积占比由2000年的40.56%上升至2020年的70.36%;20年间生态质量提升的区域面积占研究区总面积的94.44%,提升的区县数量占总区县数的91.57%;岭回归模型可以解释生态质量99.4%的变异,植被覆盖度和年降水量对生态质量变化的相对贡献率较高。[结论]黄河流域黄土高原生态质量呈提升趋势,其时空分布格局主要受植被覆盖度和年降水量的驱动。建议在科学、合理增加植被覆盖度的基础上,进一步优化生态系统空间格局。

黄河流域城镇人口和用地变化的关联格局及地域类型

黄河流域城镇人口和城镇用地的关联格局及地域类型对人地系统协调发展具有重要指导意义。基于人口普查和城镇用地栅格数据,运用城镇人口变化指数、城镇用地扩展强度指数、标准差椭圆等方法,揭示2000—2020年黄河流域城镇人口和城镇用地时空分异动态特征,并构建城镇人口和城镇用地协同发展系数,划分城镇化地域类型。结果表明,(1)黄河流域2000—2020年城镇人口增长和城镇用地扩展均呈阶段式变化,城镇人口由中高速增长为主,转为以中低速增长为主,城镇用地面积呈现持续增加的趋势,同一城市不同阶段的城镇扩展强度具有由强变弱的特征;(2)黄河流域2000—2020年城镇人口和城镇用地的标准差椭圆长、短轴的差值不断增大,城镇人口增长和城镇用地扩张在时空格局上吻合性较强;(3)黄河流域城镇化地域类型可以划分为5类,2000—2010年城镇化地域类型呈现自西向东依次分布的趋势,2010—2020年呈现自东南向西北依次分布的格局。黄河流域新型城镇化发展应构筑区域协同发展体系,加快产业结构转型升级,统筹城乡发展,促进黄河流域人地系统可持续发展。