Impacts of multi-scenario land use change on ecosystem services and ecological security pattern: A case study of the Yellow River Delta

The Yellow River Delta(YRD), a critical economic zone along China's eastern coast, also functions as a vital ecological reserve in the lower Yellow River. Amidst rapid industrialization and urbanization, the region has witnessed significant land use/cover changes(LUCC), impacting ecosystem services(ES) and ecological security patterns(ESP). Investigating LUCC's effects on ES and ESP in the YRD is crucial for ecological security and sustainable development. This study utilized the PLUS model to simulate 2030 land use scenarios, including natural development(NDS), economic development(EDS), and ecological protection scenarios(EPS). Subsequently, the InVEST model and circuit theory were applied to assess ES and ESP under varying LUCC scenarios from 2010 to 2030. Findings indicate:(1) Notable LUCC from 2010 to 2030, marked by decreasing cropland and increasing construction land and water bodies.(2) From 2010 to 2020, improvements were observed in carbon storage,water yield, soil retention, and habitat quality, whereas 2020–2030 saw increases in water yield and soil retention but declines in habitat quality and carbon storage. Among the scenarios, EPS showed superior performance in all four ES.(3) Between 2010 and 2030, ecological sources, corridors, and pinchpoints expanded, displaying significant spatial heterogeneity. The EPS scenario yielded the most substantial increases in ecological sources,corridors, and pinchpoints, totaling 582.89 km^(2), 645.03 km^(2),and 64.43 km^(2), respectively. This study highlights the importance of EPS, offering insightful scientific guidance for the YRD's sustainable development.

Evaluation of Coordinated Development of Urbanization and Ecological Environment in the Efficient Ecological Economic Zone of the Yellow River Delta

Based on the statistical data of urbanization development level and ecological environment in the Yellow River Delta during 2009-2014,a comprehensive index system for the coordinated development of urbanization and ecological environment was established to evaluate the coordinated development level. The results showed that the coordinated development level of urbanization and ecological environment in the Yellow River Delta was generally high during 2009-2014. The development level of urbanization was higher than that of ecological environment on the whole,that is,the development of ecological environment lagged behind. The development of urbanization in the region was relatively slow during 2009-2011 but rapid during 2012-2014. The development level of ecological environment was relatively stable and always increased.

Study on High-efficiency Ecological Agricultural Development Based on Science and Technology in the Yellow River Delta

Based on the analysis of the status, characteristics and technological functions of high-efficiency ecological agricultural development in the Yellow river delta, the paper pointed out technological bottlenecks of the high-efficiency ecological agricultural development in the Yellow river delta. Some suggestions were proposed including changing the development concept, implementing nine projects, increasing capital investment, focusing on demonstration, and strengthening human resources.

Measurement of Digital Economy Development Level in Yangtze River Delta and Its Influence on Ecological Efficiency

Based on the panel data of 41 cities in the Yangtze River Delta from 2007 to 2018,this paper empirically tests the impact of digital economy development on urban ecological efficiency in the Yangtze River Delta.The results show that the development level of digital economy in Yangtze River Delta urban agglomeration is fluctuating and rising;the development of digital economy has a significant positive role in promoting the improvement of urban ecological efficiency;there is significant regional heterogeneity in the promotion of ecological efficiency by digital economy,especially in central cities.

Critical effects on the photosynthetic efficiency and stem sap flow of poplar in the Yellow River Delta in response to soil water

To explore the critical relationships of photosynthetic efficiency and stem sap flow to soil moisture,two-year-old poplar saplings were selected and a packaged stem sap flow gauge,based on the stem-heat balance method,and a CIRAS-2 portable photosynthesis system were used.The results show that photosynthetic rates(P_(n)),transpiration rates(T_(r)),instantaneous water use efficiency(WUE)and the stem sap flow increased initially and then decreased with decreasing soil water,but their critical values were different.The turning point of relative soil water content(W_(r))from stomatal limitation to nonstomatal limitation of P_(n)was 42%,and the water compensation point of P_(n)was 13%.Water saturation points of P_(n)and T_(r)were 64%and 56%,respectively,and the WUE was 71%.With increasing soil water,the apparent quantum yield(AQY),light saturation point(LSP)and maximum net photosynthetic rate(P_(n)max)increased first and then decreased,while the light compensation point(LCP)decreased first and then increased.When W_(r)was 64%,LCP reached a lower value of 30.7µmol m^(-2)s^(-1),and AQY a higher value of 0.044,indicating that poplar had a strong ability to utilize weak light.When W_(r)was 74%,LSP reached its highest point at 1138.3µmol·m^(-2)s^(-1),indicating that poplar had the widest light ecological amplitude and the highest light utilization efficiency.Stem sap flow and daily sap flow reached the highest value(1679.7 g d^(-1))at W_(r)values of 56%and 64%,respectively,and then declined with increasing or decreasing W_(r),indicating that soil moisture significantly affected the transpiration water-consumption of poplar.Soil water was divided into six threshold grades by critical values to maintain photosynthetic efficiency at different levels,and a W_(r)of 64-71%was classified to be at the level of high productivity and high efficiency.In this range,poplar had high photosynthetic capacity and efficient physiological characteristics for water consumption.The saplings had characteristics of water tolerance and were not drought resistant.Full attention should be given to the soil water environment in the Yellow River Delta when planting Populus.

Evolution of Yellow River Delta Coastline Based on Remote Sensing from 1976 to 2014, China

Coastal regions are threatened by natural processes, such as erosion driven by storm surges and the effect of jetties, as well as by human behavior. The coastline of the Yellow River Delta(YRD) was monitored using the general high-tide line method, which combines Remote sensing(RS) and geographic information system(GIS) technology, using multi-spectral scanner(MSS), thematic mapper(TM), and enhanced thematic mapper plus(ETM+) images of the YRD from 1976 to 2014 as a data source. The results demonstrated that the shape and length of the YRD coastline has changed dramatically since 1976. The course of the Diaokouhe channel has resulted in mainly inland erosion in the north, and is primarily marine erosion; therefore, it was termed an erosion-type estuary. However, the coastline of the Qingshuigou course has moved seaward, demonstrating an accretion stage, and was therefore termed an accretion-type estuary. The coastline advanced forward before 1997 and shrank after 2003 in the southern part of the river mouth, which was due to the shift in the river mouth in 1996. It has continually extended outward in the northern part of the river mouth from 2003 onward. The coastline in the southern part of the river mouth has moved randomly, with the occurrence of both erosion and sedimentation caused by land reclamation and sea wave intrusion. In most cases, the coastline has extended offshore, especially in the northern part of the river mouth. The YRD coastline has changed frequently and rapidly from 1992 to 2014. The river mouth channel, river water and sediments, and precipitation were the major factors affecting the YRD. The YRD coastline was mainly in an accretion stage during flow periods. The erosion rate decreased and tended to be stable during a dry period. The coastline was basically stable when dry periods occurred over a long period. The location of Yellow River ports and sea erosion were the main factors driving coastline changes. The coastline was mainly influenced by the flow path of the Yellow River, with recent human activity also becoming a factor.

考虑生态耗水的干旱区绿洲灌溉用水效率评价指标与方法

针对现行干旱区绿洲尺度灌溉用水效率评价对生态服务效益考虑不足的问题,提出了在绿洲尺度上考虑生态耗水的灌溉用水效率评价指标和方法,并应用于宁夏引黄灌溉绿洲。结果表明:宁夏引黄灌溉绿洲农田蒸散消耗水量中的灌溉水量平均占比达74.7%,生态系统蒸散消耗水量中的灌溉水量平均占比达39.8%,灌溉水对生态系统的支撑作用显著;考虑生态耗水前后的灌溉用水效率差为0.052~0.074,占未考虑生态耗水灌溉用水效率的13.9%~16.1%,灌溉水的生态服务效益明显;提出的评价指标与方法合理可行,能客观反映干旱区灌溉用水的综合效益。

农业生态效率的演变特征与空间收敛——基于黄河流域47个城市的实证

基于2000—2020年黄河流域47个地级市的面板数据,构建黄河流域农业生态效率的投入产出指标体系,运用非期望产出的超效率SBM模型测算各市的农业生态效率,结合GIS空间分析、Moran’s I指数、ML指数等方法分析农业生态效率的演变特征,并进行空间收敛性分析。结果表明:黄河流域农业生态效率水平整体偏低,但正处于由低水平迈向高水平的“爬坡”阶段,其中下游地区的效率增长最快;效率增长的主要来源为技术进步,流域内农业规模化水平仍有较大提升空间;在空间关联格局上,效率的空间依赖性不固定,但空间聚集性总体增强;黄河流域农业生态效率呈现显著的空间收敛特征,且工业化水平、农业经济发展水平、农业机械化密度、财政支农力度、农业市场化程度会促进效率的空间收敛。

黄河“几字弯”都市圈土地利用效率与土地生态安全耦合协调研究

通过分析黄河“几字弯”都市圈土地利用效率与土地生态安全的时空演变特征,探索黄河流域土地利用与生态安全协同发展路径。利用Super-SBM模型、投影寻踪模型和耦合协调模型,以2002-2021年黄河“几字弯”都市圈15个城市作为研究对象,分别评估其土地利用效率、土地生态安全水平和二者之间的耦合协调度。结果表明:研究期内土地利用效率良好,平均值0.991,整体呈现逐年下降趋势,空间上以鄂尔多斯为高水平集聚中心;土地生态安全整体水平稳定,平均值为2.012,空间上以鄂尔多斯、榆林为高水平集聚中心;二者耦合协调均值为0.616,整体处于低度协调水平,大部分城市处于濒临失调状态,呈现“中心高,四周低”的空间分布特征。土地利用效率与土地生态安全存在较为明显的矛盾,因此,“几字弯”都市圈内各城市间应优化土地配置,提高土地利用效率,加强城市之间的经验共享与联动发展,共建差异化产业格局,协同推进黄河“几字弯”高质量发展。

黄河三角洲滨海湿地碳储时空演变及其生态补偿研究

近年来随着油气开采、港口建设、填海造陆等活动的开展,黄河三角洲滨海湿地面临生态服务功能降低、碳汇功能受损等问题。为改善黄河三角洲滨海湿地的生态功能及有效利用其碳储功能,研究突破了碳储生态补偿价值静态核算的局限性,充分考虑黄河三角洲滨海湿地的时空异质性影响,运用ArcGIS及InVEST模型计算并分析不同土地利用类型下的碳储量变化,探究如何对碳储量损失区域进行生态补偿,并提升黄河三角洲滨海湿地生态系统的碳储功能。研究表明:(1)2013—2020年黄河三角洲滨海湿地碳储量呈现下降趋势,8年间累计总损失6.36×10^(6)吨碳。(2)碳储总值的分布与土地利用类型密切相关。(3)黄河三角洲滨海湿地2013—2020年8年间碳储经济损失价值为164.92×10^(6)美元。

黄河流域农业水资源生态韧性与用水效率耦合协调及驱动因素研究

韧性与效率是可持续发展的两个核心要素,统筹农业水资源生态韧性和用水效率协调发展,对于推动黄河流域生态治理和农业高质量发展具有重要现实意义。利用熵权-Topsis法、超效率SBM模型对黄河流域农业水资源生态韧性与用水效率进行测度,构建耦合协调度模型分析两者间的协调发展水平,借助核密度估计、ArcGIS图示法、Dagum基尼系数和空间自相关考察耦合协调度的时空演变格局及空间集聚效应,并运用地理探测器模型识别其驱动因素。结果表明:①时空演化上:2007-2021年全流域耦合协调度均值呈现先降后升的“U”形演化趋势,良好协调区呈现由点到片、由北至西南、由外围向内部蔓延的空间格局。②区域差异上:中游区域内差异扩大,上游和下游区域内差异缩小但两者区域间差异最大。③空间集聚上:偏向于随机分布且空间集聚较弱,未形成连片效应。④驱动因素上:自然灾害、研发投入与产业发展是协调发展度的主要影响因子。针对协调演化发展现状,提出“中心带动边缘”、“技术协同管理”、“政府结合市场”的一体化、系列化、多元化发展策略。

“双碳”目标下黄河流域农业生态效率的动态演进与收敛特征

“双碳”目标下推进黄河流域农业生态效率提升,是推动实施黄河流域生态保护和高质量发展战略的重要途径。在农业减排固碳的发展要求下,以落实农业“双碳”目标为着力点,运用超效率SBM模型、Dagum基尼系数和收敛检验方法,测度2006-2021年黄河流域农业生态效率的时序演进、空间差异和收敛特征。结果表明:黄河流域农业生态效率整体呈波动上升趋势,但整体农业生态效率水平偏低,形成了“下游领跑、中游追赶、上游落后”的空间格局;黄河流域内农业生态效率差异逐渐扩大,差异主要源自超变密度,区域内差异由低到高依次为上游、下游和中游;黄河流域整体及上、中、下游的农业生态效率不存在σ收敛现象,但都存在显著的β绝对收敛和β条件收敛,种植业产值、机械化水平、农业产业集聚度、产业结构高级化水平等因素对β条件收敛的影响具有异质性。

基于适宜性和生态网络的沿海滩涂农渔业利用空间优化

对沿海滩涂区域农渔业国土利用空间进行布局优化,是推进我国“蓝色粮仓”建设和促进滩涂资源可持续利用的重要途径。本研究以黄河三角洲南部滩涂围垦地区为例,基于遥感和GIS技术揭示了研究区1995—2020年滩涂主要农业种植和海水养殖等农渔业空间利用格局演变特征,并将生态适宜性评价、生态网络构建与土地利用变化模型相结合,模拟预测2035年不同发展情景下滩涂农渔业主要土地利用变化格局,并提出空间布局优化调整建议。结果表明:研究期间滩涂农业种植与海水养殖利用总面积呈现先增后减的趋势,由1995年的924.62 km^(2)增长至2004年的1224.96 km^(2),2004年后规模开始缩减,2020年缩减至1129.38 km^(2);水田和养殖池塘空间分布格局变化较为明显,旱地空间聚集度增加,海域开放式养殖向远离海岸方向逐渐扩张,滩涂区域主要农渔业利用空间分布呈现明显的陆海梯度分异特征;滩涂农业种植和海水养殖现状分布的生态适宜性较好,但是农业种植未来增长空间受限,滩涂池塘养殖和开放式养殖仍有一定空间发展潜力。严格的湿地生态保护措施限制了滩涂农渔业利用空间的增长;在遵循生态保护优先的前提下,农渔业发展情景下滩涂农业种植与海水养殖土地利用规模会有明显增加,但需要重点关注未利用土地的合理开发、滩涂陆海生态连通性的提升和高效生态种养模式的应用推广。研究结果可以为黄河三角洲滩涂农垦区农渔业高质量发展提供决策支持。

基于OWBEI的黄河三角洲生态环境质量时空评价

黄河三角洲生态环境脆弱,受人类活动干扰,生态环境遭破坏,及时准确地对黄河三角洲生态环境质量进行评价,对于生态保护和政策制定至关重要。为解决湿地生态环境质量评价中植被要素精确监测的问题,将改进的高光谱植被指数(IHSVI)与顾及水效益的生态环境质量指数(WBEI)相结合,提出优化的顾及水效益的生态环境质量指数(OWBEI),以提高湿地生态环境质量反演精度。选取2000年、2006年、2012年、2017年和2020年的Landsat影像基于优化的顾及水效益的生态环境质量指数对黄河三角洲进行生态环境质量时空评价。结果表明:优化的顾及水效益的生态环境质量指数提高了湿地生态环境质量评价结果的反演精度,反演精度提升至90%;黄河三角洲生态环境质量在内陆农村地区优于黄河沿岸及沿海城市地区,且整体生态环境状况以2012年为转折点呈先上升后下降的变化趋势。

基于净初级生产力的珠江三角洲城市群生态可持续性评估

为确保经济的持续健康发展与生态环境的和谐共生,深入研究并评估该区域生态环境的可持续状态至关重要。借助净初级生产力(NPP)修正生态足迹模型,从生态可持续性、生态压力、自然资源利用效率等3个方面综合评估了珠江三角洲9个城市2000年至2020年的生态环境状态。结果表明:(1)珠江三角洲总研究区生态环境处于可持续状态,但出现持续降低的趋势。其中,珠海、中山一直处于不可持续状态,佛山、深圳、东莞由2000年的可持续状态变为2020年的不可持续状态。(2)珠江三角洲总研究区生态压力呈现中部高、外围低的分布态势。2000—2020年,生态压力最大的城市为东莞,最小的为惠州。(3)珠江三角洲总研究区及各城市的万元GDP生态足迹均呈现不同程度的降低趋势,表明区域资源利用效率越来越高。

宁夏沿黄城市带耕地碳排放时空特征和生态效率评价

[目的]研究宁夏回族自治区沿黄城市带2011—2020年耕地碳排放时空变化规律,评价生态效率,为构建低碳农业模式,推动农业碳减排,促进地区农业高质量发展提供支撑。[方法]采用耕地碳排放估算模型和ArcGIS计算分析宁夏沿黄城市带耕地碳排放的时空特征,采用非期望产出超效率模型SBM(松驰值测算模型)评估耕地生态效率值。[结果](1)2011—2020年宁夏沿黄城市带耕地碳排放总量总体呈下降趋势,化肥和农用柴油是耕地碳排放的主要来源。(2)宁夏沿黄城市带耕地碳排放呈现南北高,中间低的空间分布格局,其中平罗县和中宁县是最大的耕地碳排放城市。(3)宁夏沿黄城市带耕地碳排放强度呈先升高后下降的趋势与耕地碳排放总量变化相似。(4)宁夏沿黄城市带耕地利用生态效率总体呈波动状态,利通区耕地生态效率较低,需要调整农业生产过程中的投入要素。[结论]宁夏回族自治区沿黄城市带耕地碳排放时空分布不均匀,且生态效率不稳定,还需要进一步探索和巩固减排措施。

黄河三角洲生态用地质量状况及生态因子的相关性

近年来,黄河三角洲地区生态环境脆弱、变化剧烈,黄河流域生态保护和区域经济高质量发展已被列入国家“十四五”发展战略。以黄河三角洲地区为研究区,根据2002—2023年的陆地资源卫星数据与2023年7月份的野外调查数据,构建3种生态质量状况评价方案(方案Ⅰ、方案Ⅱ和方案Ⅲ),对比分析并确定了黄河三角洲地表生态质量评价的最适宜方案,并进一步分析综合遥感生态指数(I)与生态环境因子的相关关系。结果表明:(1)方案Ⅲ构建的地表生态质量评价模型增加了土壤信息在综合遥感生态评估中的贡献(R^(2)=-0.558),并涵盖了水体、土壤、温度和植被4个指标因子的92.17%的信息量。(2)2002—2023年黄河三角洲地表的生态质量状况表现为局部减退,林地作为主要的生态用地之一,生态质量平均值最高,生态质量稳定。所有变化区域均集中在综合遥感生态指数I≤0.4的区域范围内,主要由水体的波动引起生态质量退化;I>0.4的区域生态质量相对稳定。(3)黄河三角洲地表的生态质量状况与植被覆盖度呈极显著正相关关系(P<0.01),土壤的氮和土壤有机碳促进了生态系统的稳定性;土壤酸碱度的增加导致生态系统的稳定性下降。

基于改进的遥感生态指数的黄河三角洲生态环境质量时空变化分析

在黄河流域生态保护和高质量发展的背景下,为监测黄河三角洲整体生态环境变化,为区域未来发展提供合理建议,以黄河三角洲为研究区,选取5期Landsat影像为数据源,在遥感生态指数(RSEI)模型基础上,用盐度指数(SI)代替干度指标,同时引入空气质量指标(DI)构建改进的遥感生态指数(MRSEI),并结合景观指数,借助空间自相关分析方法,通过地理探测器进行驱动因子分析,定量评价黄河三角洲生态环境时空分异特征。结果表明:(1)与RSEI相比,MRSEI更接近生态环境状况指数(EI)值,评价结果与真实地表情况更为接近,更适用于黄河三角洲生态环境质量评价。(2)黄河三角洲生态环境表现为略微变差,生态指数均值由0.53降到0.51。生态环境质量差的区域主要集中在沿海滩涂附近,生态环境质量较好的区域分布在西南部与黄河沿岸地区,随着距海岸距离缩小生态环境质量逐渐降低。(3)不同等级的遥感生态指数斑块破碎度都不断上升,景观格局趋于破碎化。(4)各时期区域生态指数空间分布都存在显著的空间自相关性,局部以高-高聚集与低-低聚集为主,与MRSEI分布变化趋于一致。(5)土地利用是影响区域生态环境空间分异性的主要因素,各因子间的交互作用均表现为双因子增强。

黄河三角洲生态需水量计算及补水方案分析

黄河三角洲河-海-陆交互形成了独特的地理环境,但其水资源不足,供需矛盾突出,土地盐渍化形势严峻,盐碱地分布广且数量多,严重影响了当地的生态环境。选取黄河三角洲四个生态区域:黄河现行流路(自然保护区)生态区域、刁口河流路生态区域、黄河以北(除刁口河流路区域)生态区域和黄河以南生态区域,根据《河湖生态需水评估导则》及水量平衡方法计算得出四个区域的生态需水量。根据因地制宜、可持续发展原则,部署了具有针对性的区域生态补水方案,并提出后期监测评估工作和补水保障措施,可为改善黄河三角洲地区水资源、水环境,缓解湿地退化,避免生态系统破坏等起到重要的支撑作用,同时也为其他类似区域依靠水网工程改善生态环境提供了参考。

绿色生态效率时空分异特征及其影响因素研究——基于长三角城市群的实证分析

论文运用超效率EBM-GML模型测算了长三角城市群2008—2020年的生态效率,识别其时空分异特征及影响因素。研究发现:(1)长三角城市群生态效率在时间上呈波动上升趋势,在空间上呈“东高西低”的分布特征。(2)仅少数城市投入产出均有效率,其余城市效率不高,主要是源于能源利用率低、能源结构不合理和污染防治体系不健全。(3)Tobit模型结果表明经济发展、产业结构高级化、外商投资规模可以显著提高生态效率。(4)都市圈与城市规模差异对生态效率的影响效应存在异质性,经济发展对非上海大都市圈和小型城市生态效率正向作用更强烈。因此,要加快推动长三角一体化,促进各城市绿色协同发展。