Organic Phosphorus in Shallow Lake Sediments in Middle and Lower Reaches of the Yangtze River Area in China

Thirteen sediment core samples(0-10 cm) were taken from the seven lakes in the middle and lower reaches of the Yangtze River to determine the contents and distributions of organic phosphorus(P) fractions in the sediments of the shallow lakes in the area.The organic P fractions in the sediments were in the order of moderately labile organic P(MLOP) > moderately resistant organic P(MROP) > highly resistant organic P(HROP) > labile organic P(LOP),with average proportional ratios of 13.2:2.8:1.3:1.0.LOP,MLOP,and MROP were significantly related to the contents of total organic carbon(TOC),water-soluble P(WSP),algal-available P(AAP),NaHCO3-extractable P(Olsen-P),total P(TP),organic P(OP),and inorganic P(IP).However,HROP was significantly related to OP and weakly correlated with TOC,WSP,AAP,Olsen-P,TP or IP.This suggested that organic P,especially LOP and MLOP in sediments,deserved even greater attention than IP in regards to lake eutrophication.In terms of organic P,sediments were more hazardous than soils in lake eutrophication.Although OP concentrations were higher in moderately polluted sediment than those in heavily polluted sediment,LOP and MLOP were higher in the heavily polluted sediment,which indicated that heavily polluted sediment was more hazardous than moderately polluted sediment in lake eutrophication.

Analysis of Water Resources Supply and Demand and Security of Water Resources Development in Irrigation Regions of the Middle Reaches of the Heihe River Basin, Northwest China

Based on the data for meteorology, hydrology, soil, planting, vegetation, and socio-economic development of the irrigation region in the middle reaches of the Heihe River basin, Northwest China, the model of balance of water supply and demand in the region was established, and the security of water resource was assessed, from which the results that the effects of unified management of water resources in the Heihe River basin between Gansu Province and Inner Mongolia on regional hydrology are significant with a decrease in water supply diverted from Heihe River and an increase in groundwater extracted. In addition, it was found that the groundwater level has been steadily decreasing due to over pumping and decrease in recharges. In present year （2003）, the volume of potential groundwater in the irrigation districts is far small because of the groundwater overdraft; even in the particular regions, there is no availability of groundwater resources for use. By 2003, water supply is not sufficient to meet the water demand in the different irrigation districts, the sustainable development and utilization of water resources are not secured, and the water supply crisis occurs in Pingchuan irrigation district. Achieving water security for the sustainable development of society, agriculture, economy, industry, and livelihoods while maintaining or improving the abilities of the management and planning of water resources, determining of the reasonable percentage between water supply and groundwater utilization and water saving in agricultural irrigation are taken into account. If this does not occur, it is feared that the present performance of water development and planning may further aggravate the problem of scarcities of water resources and further damage the fragile ecological system.

The Background of Regional Lead Isotopic Compositions and Its Application in the Lower and Middle Reaches of the Yangtze River and Neighbouring Areas

The paper systematically deals with the background of regional isotopic compo-sitions in the lower and middle reaches of the Yangtze River and neighbouring areas. It isshown that the lead isotopic compositions of different geological formations and units are con-trolled by the primary mantle heterogeneity, dynamic process of crust-mantle interchange,abundances of uraninm, thorium and lead of various layers of the earth and timing. Studies onthe background of regional isotopic compositions may offer significant information forgeochemical regionalization, tracing of sources of ore-forming materials, and regionalprognosis of ore deposits.

Impact of vegetation restoration on hydrological processes in the middle reaches of the Yellow River,China

Sediment discharge from the Yellow River originates mainly from the drainage area between Hekouzhen and Longmen, i.e., the Helong area. Spatial-temporal variations of the vegetation cover in this area during the 1981-2007 period have been investigated using GIMMS and SPOT VGT NDVI data. We have also analyzed the interannual variations in vegetation cover and changes in annual runoff and sediment discharge, the consequences from precipitation change and the Grain for Green Project （GGP）. The results show that vegetation cover of the Helong area has increased during the 1981-2007 period. The northwestern part the Helong area, where the flat sandy lands are covered by grass, has experienced the largest increase. The region where the vegetation cover has declined is largely found in the southern and southeastern Helong area, which is a gullied hilly area or forested. Although precipitation was relatively low during the 1999-2007 period, the vegetation cover showed a significant increase in the Helong area, due to the implementation of the GGP. During this period, the most significant improvement in the vegetation cover occurred mainly in the gullied hilly areas of the Loess Plateau, such as the drainage basins of the Kuyehe and Tuweihe rivers and the middle and lower reaches of the Wudinghe and Yanhe rivers. A comparison of the average annual maximum NDVI between the earlier （1998-2002） stage and the next five years （2003-2007） of the GGP indicates that the areas with increases of 10% and 20% in NDVI account for 72.5% and 36.4% of the total area, respectively. Interannual variation of annual runoff and sediment discharge shows a declining trend, especially since the 1980s, when the decrease became very obvious. Compared with the 1950-1969 period, the average runoff during the 1980-2007 period was reduced by 34.8 × 10^8 m3 and the sediment discharge by 6.4 ×10^8 t, accounting for 49.4% and 64.9% of that in the 1950-1969 period, respectively. There is a positive correlation between the annual maximum NDVI and annual runoff and sediment discharge. This correlation was reversed since the implementation of the GGP in 1999 and vegetation cover in the He- long area has increased, associated with the decrease in runoff and sediment discharge. Less precipitation has been an important fac- tor driving the decrease in runoff and sediment discharge during 1999 2007. However, restoration and improvement of the vegetation cover may also have played a significant role in accelerating the decrease in annual runoff and sediment discharge by enhancing evapotranspiration and alleviating soil erosion.

A PREDICTION ABOUT THE EFFECT OF THE BUILDING OF SHUIKOU HYDROPOWER STATION ON THE ECOLOGICAL ENVIRONMENT OF THE MIDDLE-LOWER REACHES OF THE MINJIANG RIVER

The building of Shuikou Hydropower Station in the Minjiang River is the largest one in the region of east China. Its install capacity is 1.4 million kw., and its generated energy of planning is 4.95 billion kwh each year. In accordance with a comprehensive survey of the valley of the middle-lower reaches of the Minjiang River and the characteristic of hydrography and in association with the specific type of the hydrography station, we can be sure that no harm will be done to the ecological environment when a hydropower station is built at Shuikou. Not only the deposition of silt within the reservoir must not be very serious, it is also more favorable than before for the irrigation of farmland on plains in the lower reaches of the Minjiang River and inland navigation.In addition, after the completion of the power station, the ecological environment will be the same as before both at the Minjiang River estuary and beyond it.

Two series of copper-gold deposits in the middle and lower reaches of the Yangtze River area (MLYRA) and the hydrogen, oxygen, sulfur and lead isotopes of their ore-forming hydrothermal systems

Based on studies on the geological characteristics of the copper-gold deposits in the middle and lower reaches of the Yangtze River area (MLYRA) and their hydrogen, oxygen, sulfur and lead isotope compositions, it is concluded that there existed two series of copper-gold deposits. They are evolutional products of two ore-forming hydrothermal systems in different geodynamic settings and geological era. Series I is stratiform or stratabound copper-gold deposits. These deposits were formed by submarine exhalation and sedimentation of hydrothermal solutions in Her-cynian tensional tectonic environment after bot brine ascending along contemporaneous faults and exhaled into the sea-floor. Series II consists of copper-gold deposits related to medium and acidic magmatic intrusions. Their mineralizations took place in Yanshanian in a tensional or a transitional period to the tensional tectonic environment from the composite of the tethys tectonic regime and the Paleo-Pacific ocean tectonic regime, as well as in the upper mantle doming and crustal thinning environment. Copper-gold deposits were formed from the hydrothermal fluids, mixtures of magmatic water and part of meteoric water, by complex water-rock interactions and coupling dynamic processes of transport-chemical reactions. Superposition is an important condition for the formation of the large-scale copper-gold ore deposits.

Effects of drip irrigation on components of water cycle in arid inland areas: A case study of Manas river basin in northwestern China

Compared to either drip irrigation or mulching with plastic film,the two methods together can reduce water requirements of crops grown in arid areas by more than 30%.Such a combination deployed on a large scale(1)reduced the loss of soil water by 31.8%compared to that from drip irrigation alone;(2)narrowed the range of annual evapotranspiration from 1582.4-1780.3 mm,which is average for the basin,to 222.2-294.8 mm;and(3)increased the overall humidity in the central plain of the basin.However,the surrounding regions in which drip irrigation is not combined with mulching are getting more arid;thus,as a result of the water-saving technology,both oases and the desertification of the river basin are increasing at the same time.The results of the study further the understanding of the effects of drip irrigation combined with mulching on water cycles in the basin of the Manas river and suggest ways to protect the ecology and the environment of the basin.

Corridor effect of the spatial changes of landscape patterns in arid areas:A case study of the river corridor areas in the middle and lower reaches of Tarim River

在 Tarim Riverare 的中间、更低的活动范围的河走廊区域在 Ruoqiang 从 Qara 水库 inYuli 县沿着河节由传统的绿走廊统治了到泰泰马·莱克县，它在 Tarim 河分水岭在社会、经济的发展起一个重要作用与一极其重要的生态的功能。对水路垂直的缓冲区地区从水路在 5-kminterval 开始沿着两个河边被定义(10 km 更宽) 用缓冲区地区分析的方法。每个缓冲区地区的风景模式索引被计算，并且主要风景模式的索引被分析以便在风景和补丁层次上揭示放射的效果和河走廊的特征。放射的宽度通常是在学习区域的 30 km 的结果表演，和罐头直到在潜水艇的 50-70 km -- 区域 FG1 因为学习区域位于二排水盆，与在他们之间的一个生态的空隙的地区。树林和沼泽地的 Thelandscapes 通常在 10 km 缓冲区地区以内被散布(它意味着缓冲区地区是离开水路的 5 km；一样此后) 沿着两个河边。而且，缓冲区地区越靠近到水路，补丁密度和最大的补丁索引是越多 higher。在为学习区域的生态、环境的新生，河走廊的生态的效果的程度必须充分被考虑，并且工程必须科学地并且讲道理地被计划并且设计。

数字经济产业区域协同发展机理及路径研究--基于江西与粤港澳、长三角、长江中游城市群协同发展视角

数字经济产业区域协同发展对推动区域经济效率变革、质量变革和动力变革具有积极推动作用。近年来,江西充分发挥毗邻粤港澳大湾区、长三角以及位居长江中游城市群的地理优势,积极推动数字经济产业区域协同发展,打造了赣深电子信息产业集聚区、承接长三角数字产业转移示范区、赣湘电子信息产业园等,为江西数字经济产业高质量发展奠定了扎实基础,但是在数字经济产业区域协同发展过程中仍然存在协同规划缺乏、协同层次偏低、协同结构失衡、产业数字化滞后、数字技术协同创新弱和数据要素共建共享不畅等问题。这需从强化规划引领、提高协同层次、优化协同结构、加快数字化转型、推动数字技术协同创新和促进数据互联互通共用等方面加以破解。

长江中下游小麦新品系条锈病抗性评估与抗病基因分析

由小麦条锈菌(Puccinia striiformis West. f. sp.tritici Eriks.&Henn.)引起的条锈病是世界范围内小麦的重要病害。长江中下游麦区是中国小麦主产区之一和重要的小麦商品粮基地,也是中国小麦条锈病流行的重点防控地区。准确评价该地区小麦品种(系)对当前小麦条锈病流行小种的抗性,了解抗条锈基因在各个品种及所处麦区内的分布状况,对及时调整抗病育种目标、指导抗病品种及抗病基因的合理布局与应用具有重要意义。本研究收集了2019-2021年间苏、皖、鄂等长江中下游麦区103份小麦材料,包括34份当地主栽品种和69份参加新品种区域审定试验的高代品系,于2021年分别在陕西杨凌混合小种(CYR32、V26-lab)人工病圃及四川江油自然诱发病圃进行成株期抗条锈性鉴定;以当前流行条锈菌小种条中32(CYR32)和G22致病类群(V26-lab)对参鉴品系进行苗期分小种鉴定,利用16个已知抗条锈基因的19个SNP标记进行分子检测,其中包括11个全生育期抗病基因[Yr5a、Yr5b (YrSP)、Yr6、Yr7、Yr9、Yr15、Yr26、Yr28、Yr81、YrZH84和YrAS1676]和5个成株期抗病基因(Yr18、Yr30、Yr78、Yr86和YrLT26),推测小麦品系可能携带的抗病基因。结果表明,34份主栽品种中,23份表现成株期抗病。在69份高代品系中,苗期对CYR32和V26-lab小种表现抗病的品系分别有11份和13份,对CYR32和V26-lab均表现免疫或者近免疫的品系仅有2份。根据品系成株期抗病DS值的聚类热图结果表明,在杨凌表现抗病的品系有44份,在江油表现抗病的品系有25份,在两地均表现环境稳定抗病的品系有17份。分子检测表明,参鉴品系中可能携带Yr5b、Yr6、Yr7、Yr9、Yr30、Yr78、Yr81、Yr86、YrZH84、YrLT26和YrAS1676,其中只有Yr6、Yr81和YrLT26显著影响抗病性,没有发现可能携带Yr5a、Yr15、Yr18、Yr26和Yr28的品系。此外,Yr78、Yr81、Yr86和YrAS1676组合表现可有效抗条锈病。长江中下游麦区小麦品系对小麦条锈菌当前流行小种的抗性整体水平较2010年前明显提高,抗病基因的使用呈多样化趋势。

长江中下游地区生态系统服务对景观占比的响应及其阈值

人类活动所导致的土地利用方式改变对区域生态系统服务有着显著影响,厘清区域内不同土地利用类型景观面积占比对生态系统服务的影响机制对区域景观调控与用地管理有着重要意义。以长江中下游地区为研究区,以二级流域为研究单元,基于InVEST模型、RULSE模型以及NPP数据,评估产水量(WY)、固碳量(CS)以及土壤保持(SC)3种生态系统服务的空间分布特征;使用分段线性回归探究生态系统服务综合指数(TES)对人类活动影响较为强烈的林地、建设用地和耕地面积占比的响应及其阈值。结果表明:(1)长江中下游地区林地占比较高地区分布在西部和南部,建设用地占比较高地区分布在东部和北部,耕地占比较高地区分布在东北部和中西部。(2)生态系统服务空间分布表现出明显的空间异质性,其中WY呈现出西南高,东北低的分布特征,CS呈现出南高北低的分布特征,SC高值区主要分布在植被覆盖率较高的山区,TES与SC分布呈现相似特征。(3)林地面积占比对TES有正向促进作用,其影响阈值为93.2%,当超过此阈值,促进作用会加强;建设用地和耕地面积占比对TES有着负向的作用,当面积占比分别超过8.7%和46.9%时,二者的负向作用会减弱,耕地在阈值前后的负向影响均弱于建设用地,因此,约束建设用地和耕地的开发,促进林地面积增加可以提升流域生态系统服务水平。研究结果可为长江中下游地区流域的景观调控和土地利用管理提供一定理论依据与参考。

黑河中游耕地变化与节水灌溉对地表耗水与地下水的影响

为探究黑河中游耕地面积变化与节水灌溉影响下地表水耗水及地下水动态演变特征,基于1985—2022年黑河莺落峡、正义峡水文站实测径流量月数据和中游地区49眼地下水观测井埋深月数据,结合对节水灌溉的实地调研结果,利用统计分析等方法,分析了地表水耗水和地下水埋深对耕地面积变化与节水灌溉的响应。结果表明:耕地面积变化、节水灌溉和水量统一调度多重影响下,黑河中游地表水耗水量略有下降;黑河中游地下水埋深总体呈增大趋势,扩耕较大的大满灌区东南部与东北部及友联灌区中部地下水埋深明显增大;不同灌溉方式对地下水埋深也有较大影响,河灌区地下水埋深随地表水入渗补给量变化,井灌区和混灌区地下水埋深随地下水开采量变化。

长江中游干流河段洲滩民垸行蓄洪能力研究

长江中下游洲滩民垸具有巨大行蓄洪能力,对保障重点地区防洪安全起重要作用。但是,洲滩民垸点多面广,地形数据缺乏,无法充分利用并有效构建数学模型分析行蓄洪作用。基于长江中下游高分辨率遥感影像数据,构建长江中游干流河段洲滩民垸数字高程模型,以生产水位-面积-容积关系成果,分区分类研究洲滩民垸的行蓄洪能力。结果表明:长江中游干流洲滩民垸行蓄洪能力强,但空间分布差异大,其中,荆江河段洲滩民垸面积及蓄洪容积占比最高,在面临大洪水时调度运用多。研究成果能够直观有效呈现长江中游干流洲滩民垸的行蓄洪能力,为洲滩民垸的调度运用打牢数据基础,为科学准确制定防洪决策提供有力支持。

南水北调中线供水区水域面积变化遥感分析

为更好地研究调水对供水区域水域面积的影响,利用遥感技术研究了南水北调中线工程调水前后供水区及其下游四季的水域面积变化情况及其动因。研究表明:在调水工程实施之后,汉江中下游区域出现了水域面积大幅度下降的情况,汉江流域水域面积从2011年到2015年整体减少,尤其是春夏季水域面积减少最多,春季减少52.6km^(2),夏季减少65.8km^(2),减少比例达到17.3%,秋季和冬季水域面积减少幅度较小,秋季水域面积减少23.4km^(2),冬季水域面积减少最少,为4.2km^(2)。

农业绿色转型约束下耕地利用生态效率时空分异特征及空间效应

[目的]基于农业绿色转型约束探究粮食主产区耕地利用生态效率时空分异特征及空间效应,可为制定生态耕种政策提供理论支撑。[方法]运用SBM-Undesirable模型对长江中游粮食主产区2005—2019年耕地利用生态效率进行评价,结合Dagum基尼系数和地理时空加权回归模型分析其时空特征及影响因素。[结果](1) 2005—2019年长江中游粮食主产区耕地利用生态效率总体由0.425上升至0.674,效率值空间差异较大但差异度有所下降;(2)耕地利用生态效率空间非均衡性显著且逐渐缩小,基尼系数由0.265降至0.185,地区空间非均衡程度表现为湖南地区>湖北地区>江西地区;(3)人均GDP、有效灌溉率和财政支农力度对研究区耕地利用生态效率呈正向影响,复种指数和城乡收入差距呈负向影响。[结论]长江中游粮食主产区耕地利用生态效率呈上升趋势,但空间非均衡性显著,受自然、经济社会、技术和政策多重因素影响。未来应激发农户耕地绿色生产积极性,降低污染排放量,以及推进耕地绿色利用技术均衡化,提高区域整体资源配置效率。

长江中游粮食主产区耕地碳源汇时空演化特征及驱动因素分析

辨识粮食主产区耕地碳源汇平衡特征及驱动因素,对推动耕地低碳生产跃迁和稳固粮食安全至关重要。该研究基于碳源-碳汇双重视角测度2005—2021年长江中游粮食主产区耕地利用净碳汇量,运用空间自相关、核密度估计和地理探测器等方法探究其时空演化特征及驱动因素,并提出固碳减排策略。结果表明:1)长江中游粮食主产区耕地净碳汇总量从2005年2674.09万t增加至2021年3757.58万t,年均增幅2.22%,碳汇功能愈发凸显,空间上各地市耕地净碳汇呈“低值区点状分散、高值区片状集聚”的差异分布态势;2)长江中游粮食主产区耕地净碳汇空间相关性存在“正集聚-负集聚-正聚集”交替变化规律,整体和省域耕地净碳汇均存在扩散现象且区域差异有所增强;3)长江中游粮食主产区耕地净碳汇时空格局演化受耕地利用和农业经济因素影响显著,其中,耕地规模和农业机械化水平是关键主导因素且影响力区域异质性明显;4)应推动耕地规模化与机械化经营、科学量化物资投入及重视耕地生产主体素质培养,带动长江中游粮食主产区耕地利用固碳减排。研究结果可为科学测度耕地碳源汇、完善耕地碳循环机制提供决策参考。

黑河中游荒漠化地区植被动态变化及其自然驱动因素分析

对2019—2023年黑河中游4个类型荒漠区样地植被生长状况和监测区气温、空气湿度、蒸发量、土壤含水率等自然因子进行监测,分析监测区植被动态变化及其与自然驱动因素的相关性。结果表明:降水量大、空气湿度大、蒸发量小、风速低的年份和月份,植被状况相对较好,盖度、高度、密度和生物量都比较高;相反,降水量小、空气湿度小、蒸发量大、风速高的年份和月份,植被状况相对较差。从年际变化趋势看,各样地植被变化规律很不稳定,总体来说由于降水、气温、空气湿度等关键气象因子数据的不稳定性,植被变化规律也表现出很大的不确定性。从月际数据分析,各样地均表现出5月、6月、7月、8月和9月盖度、生物量、高度较大的特性。4个样地之间植被状况存在很大的差异性,说明气象因子对不同类型荒漠化土地植被的影响是不同的。单从2023年数据看,4个样地植被状况和往年纵向相比有明显长势变弱的趋势,2023年出现持续高温、少雨现象,植被生长量下降,一些植物受高温、干旱影响而死亡,造成植被盖度降低。5年监测数据显示,土壤含水率不论年际还是月际数据变化都没有明显的规律性,只随降水量和蒸发量的变化而变化;土壤含水率明显降低的年份和月份,植被生长也相应缓慢,植被高度、盖度、密度和生物量均受到不同程度的影响。各类数据均表明,样地2土壤含水率明显高于其他3个样地,说明盐碱区(沼泽草地)土地的持水能力要好于其他土地。

A STUDY ON RELATION BETWEEN EAST ASIAN WINTER MONSOON AND CLIMATE CHANGE DURING RAINING SEASON IN CHINA

Based on the data of NCEP, OLR and rainfall of China, we studied the influences of the East Asian winter monsoon activities on the precipitation during the raining season over China by correlation analysis and composite analysis. The result shows that annual and interdecadal change of East Asian winter monsoon is distinct. It is strong from 1950s to the middle of 1980s but weak after the middle of 1980s. The effect of abnormal winter monsoon on the precipitation during raining season is significant over the middle and lower reaches of the Changjiang River basin. It is revealed that the precipitation will increase when preceding winter monsoon is weak but decrease when preceding winter monsoon is strong. In this paper, some appropriate reasons are given to explain the abnormal rainfall by analyzing the distribution of SSTA and the variation of summer circulation. It is pointed out definitely that the variation of SSTA and summer circulation is a primary cause for abnormal rainfall over the middle and lower reaches of the Changjiang River.

创建黄河中游水土保持高质量监管示范区的机制与模式

黄河中游地区是国家重要生态功能区、能源基地,防治水土流失、保护生态任务艰巨,迫切需要科学、精准、高效监管。针对黄河流域生产建设项目水土保持监管工作面广量大、监管能力不足、传统监管方式时效性不强等问题,提出了在晋陕蒙接壤地区创建水土保持高质量监管示范区的工作机制、模式等:一是创新工作目标,率先做到无违规项目;二是创新合作共建工作体制,构建目标一致、行动自觉、协同发力的工作机制;三是创新内生动力,以自律守约为核心,整体提升水土保持信用水平;四是创新认知提升路径,各级领导、建设单位、青少年、社会公众整体提升水土保持生态文明认知水平与能力,做到知行合一;五是创新高质量评价内涵,全面提升科技支撑水平;六是数字赋能,科学分类管理,创新智慧监管平台,使生产建设项目水土保持监管工作实现智慧技术指导、智慧跟踪、智慧预警。

三河与中国早期王都

司马迁在《史记·货殖列传》中所称“三河”,是指今天流经山西、河南境内的黄河中下游地区。河东位于今山西南部,襄汾陶寺遗址早期约早出夏代一二百年,或当传说中尧、舜、禹时期,陶寺中晚期已在夏代纪年范围之内,此时正是早期国家形成阶段;河内即今太行山东南麓为古黄河所环绕的地区,历史上为商人的主要活动区域;河南指晋、豫两省黄河以南,周公在此营洛邑,即成周与王城,是周人活动的主要区域。河东、河南、河内三个区域既成相对独立区域,又以黄河相连接,为当时“天下之中”“王者所更居”之地。夏、商、周三代王朝的更替与发展壮大都没有离开过古老的黄河流域,从这个角度看,夏、商、周三代中国早期国家的诞生不仅是黄河与黄河文化的馈赠,同时也把中国历史与中华民族的发展推进到了新的阶段。黄河中下游流域龙山时代形成的文化成果为夏、商、周三代早期国家的诞生奠定了坚实的文化基础,成为夏、商、周三代文明的始原。龙山时代之后不久,在黄河中下游地区诞生了中国历史上最早的国家形态和中华民族的雏形——华夏族。