Subjects: Biology >> Botany >> Applied botany submitted time 2024-07-31 Cooperative journals: 《广西植物》
Abstract： Newly emerged twigs are the most active part of plant branching systems and are most sensitive to changes in habitat such as light and temperature. Analyzing the differences in stem and leaf characteristics of the twigs and evaluating their growth status is crucial for understanding the growth and survival strategies of plants and their adaptability mechanisms. As an evergreen broad-leaved shrub, the crown of Kandelia obovata produces a certain number of the twigs in different seasons within a year. To gain a deeper understanding of the growth status and seasonal dynamics of the twigs of Kandelia obovata, this study investigated the growth traits of the stems and leaves of the twigs. Statistical methods such as variance analysis, multiple comparisons, and principal component analysis (PCA) were used to comprehensively evaluate the growth performance of the twigs in different seasons and to explore the growth and survival strategies of mangrove plants, represented by Kandelia obovata. The results were as follows: (1) The 14 trait indicators characterizing the growth status of the twigs showed significant variation, with a coefficient of variation ranging from 13.856% to 56.469%, and a strong correlation between the indicators. (2) The growth traits of the twigs varied significantly in different seasons, with the overall performance being highest in July followed by May, March, and October. Additionally, the importance of the growth traits was ranked as follows: leaf traits > biomass > stem configuration. (3) The total weight proportion of the 7 trait indicators such as leaf density, the ratio of leaf and stem biomass, leaf number, leaf biomass, large leaf area, stem length, and leaf area ratio was 87.146%, which were the key indicators characterizing the growth status of the twigs of Kandelia obovata. In conclusion, the growth status of the twigs reflects the adaptation strategy of the tree to resource levels, influenced by external factors such as light and temperature, as well as internal growth strategies. These research results provide insight into the response of the twigs to environmental changes in different seasons and offer a reference basis for the protection and sustainable development of Kandelia obovata population.
Subjects: Biology >> Botany >> Applied botany submitted time 2024-07-31 Cooperative journals: 《广西植物》
Abstract： Wheat is one of three major staple crops in the world, QTL mapping and candidate gene analysis of important agronomic traits are beneficial for breeding new cultivars. In this study, the excellent wheat varieties Shumai 969 and Shumai 830 were used to construct a recombinant inbred line (F7) population consisting of 89 lines, and the reduced representation genome sequencing technology was carried out to genotype this population and its parents. In field, the phenotype of plant height, internode length, awn length, spike length, flag leaf length, flag leaf width, tiller number, effective tiller number, thousand grain weight, grain length, grain width, and grain surface area were measured. The complete interval mapping method was employed to locate the QTL sites controlling these agronomic traits. The results were as follows: (1) A total of 27 QTLs were identified. These QTLs distributed on 13 distinct chromosomes, and could elucidate 3.74% to 26.7% of the phenotype variation of the agronomic traits. Among them, the QTL in the 608.58-609.12 Mb interval on chromosome 7B controlled both plant height and panicle length, which was identified by two years. The QTL in the 519.94-528.83 Mb interval on chromosome 5A controlled both tiller number and effective tiller number, and the QTL in the 437.38-439.30 Mb interval on chromosome 5D controlled both thousand grain weight and grain surface area. 7 QTLs located in the same positions as previously reported. (2) The gene function analysis showed 2 candidate genes associated with plant height traits, 4 candidate genes linked to tiller traits, and 3 candidate genes attributed to thousand grain weight within the mapped interval. The two candidate genes of plant height encoded a leucine repeat receptor-like protein kinase and a gibberellin 2-oxidase. The candidate genes of tiller encompassed a auxin response protein, a RING/U-box superfamily protein, and two F-box proteins. The candidate genes for the thousand grain weight encoded a leucine repeat receptor-like protein kinase, a protein kinase, and a chlorophyll a-b-binding protein. The identified QTLs and predicted major genes in this research established a foundation for the meticulous mapping and cloning of the major genes controlling the correspondent agronomic traits, and benefited breeding new wheat cultivars.
Subjects: Biology >> Botany >> Applied botany submitted time 2024-07-31 Cooperative journals: 《广西植物》
Abstract： NAC transcription factors play important roles in plant growth, development, and various stress responses. However, the molecular mechanism of the RdNAC72 gene in Rhododendron delavayi involved in the heat stress response was still unclear. To investigate the the roles of the RdNAC72 gene in heat stress response, we first designed primers for cloning the full length coding sequence of the RdNAC72 gene using PCR technology. Subsequently, the gene’s structure, function, and physicochemical properties were analyzed and predicted using bioinformatics method. The spatial and temporal expression characteristics of the RdNAC72 gene under heat stress and ABA were analyzed using real-time fluorescence quantitative PCR(RT-qPCR). The results were as follows: (1) The RdNAC72 gene had a full length of 1 005 bp, encoding 334 amino acids with a relative molecular weight of 37.415 kDa. Subcellular localization analysis showed that the RdNAC72 protein was located in the nucleus. (2) Multiple sequence alignment and phylogenetic analysis indicated that the RdNAC72 was most closely related to the RwNAC72 in R. williamsianum. Additionally, cis-acting element analysis revealed that the gene contains elements associated with hormone response, light response, anaerobic response, low temperature response, and heat stress response. (3) Heat stress could induce the expression of RdNAC72, exhibiting temporal and spatial expression specificity. After three days of heat stress treatment, the relative expression level of the RdNAC72 gene in leaves was significantly upregulated by 31.16-fold, while no significant changes were observed in stems and roots. After six days of heat stress treatment, the relative expression levels of RdNAC72 were significantly upregulated, with the highest observed in leaves (61.56-fold), followed by stems (50.14-fold), and roots (17.42-fold). Additionally, it was found that ABA was found to induce the expression of RdNAC72. (4) RT-qPCR analysis demonstrated a coordinated expression pattern between RdHSP17.2 and RdNAC72 with RdHSP17.2 containing multiple NAC recognition motifs (CATGTG) and core binding sequences (CACG) in its promoter region, suggesting it may be a downstream target gene of RdNAC72. Therefore, the RdNAC72, a transcription factor, localized in the nucleus, responds significantly to high temperatures and ABA, potentially activating the RdHSP17.2 expression to confer heat resistance. These findings not only understanding our comprehension of the biological functions of NAC transcription factors in response to stress, but also potentially guide future genetic and breeding strategies to enhance stress resilience in plants.
Subjects: Biology >> Botany >> Applied botany submitted time 2024-07-31 Cooperative journals: 《广西植物》
Abstract： Pogostemon cablin (Blanco) Benth. possesses significant medical and industrial values, as it can be used for medicinal purposes as well as for essential oil extraction. However, the yield and quality of P. cablin can vary depending on the ecological environment and artificial cultivation measures employed in different production regions and origins. In order to study the structural characteristics and compare the differences of the chloroplast genome of P. cablin of different origins, this study used the DNBSeq sequencing platform to sequence the whole genome of P. cablin, used getOrganelle to assemble the complete chloroplast genome, annotated the chloroplast genome through the OGDRAW website, and analyzed the basic structural characteristics, IR/SC boundary comparison, genome comparison and collinearity analysis, simple repeat sequences and interspersed repeat sequences, polymorphism analysis and relative usage analysis of synonymous codons. The results were as follows: (1)The full length of the chloroplast genomes of 20 different origins of patchouli was 152 461~152 510 bp, and 132 genes were annotated, including 87 CDS, 37 tRNA genes and 8 rRNA genes. (2)The mVISTA comparison found that atpF, atpF-atpH, rps16-trnQ_UUG, rpoB-trnC_GCA, accD, psaI-ycf4, petA-psbJ, rpl16, and rps15-ycf1 were hypervariable regions. (3) The sites with nucleic acid diversity greater than 0.002 were located in the trnM-CAU-atpB interval, ycf4, rpl32, and rpl32-trnL-UAC interval. (4)Analysis of the relative usage of synonymous codons detected a total of 64 codons encoding 20 amino acids, and there were 33 highly preferred codons, among which codons ending in A/U accounted for the majority. (5)74-76 SSRs, 15-18 palindrome repeat sequences, and 12-17 forward repeat sequences were detected. (6)After genetic distance analysis and phylogenetic analysis, only GSY_MLXY has a distant genetic relationship with other cultivated types. In this study, the genome structure and different sites identified of chloroplasts from 20 different sources of P. cablin were obtained, which provided basic data for the development of molecular markers and the selection of superior germplasm.
Subjects: Biology >> Botany >> Applied botany submitted time 2024-07-31 Cooperative journals: 《广西植物》
Abstract： In order to gain an understanding of the characteristics of soil inorganic phosphorus and bioavailable phosphorus fractions affected by land use types and hydrothermal conditions in karst ecosystems, the characteristics of soil inorganic phosphorus and bioavailable phosphorus fractions in karst ecosystems were analyzed and compared across croplands, artificial forests, and natural forests in low hydrothermal regions (Nanchuan District in Chongqing, Dushan and Suiyang Counties in Guizhou) and high hydrothermal regions (Huanjiang, Mashan County/Wuming, and Longzhou Counties in Guangxi). One-way analysis of variance, two-factor analysis of variance, and correlation analysis were used to explore the different characteristics and the relationship between soil inorganic phosphorus fractions and bioavailable phosphorus fractions under the influence of land use types and hydrothermal conditions. Redundancy analysis was used to explore the key inorganic phosphorus fractions influencing soil bioavailable phosphorus fractions. The results were as follows: (1) Soil inorganic phosphorus fractions were significantly affected by land use types. The contents of dicalcium phosphate (Ca2-P), octacalcium phosphate (Ca8-P), phosphorus adsorbed on the Al oxides surfaces (Al-P), phosphorus adsorbed on the Fe oxides surfaces (Fe-P), occluded phosphorus (O-P) and decalcium phosphate (Ca10-P) in the soils of croplands were found to be higher than those in the soils of artificial forests and natural forests. Furthermore, the contents of Ca8-P, Fe-P and O-P exhibited the order of croplands > artificial forests > natural forests, whereas the contents of Ca2-P and phosphorus extracted by hydrochloric acid (HCl-P) demonstrated the order of croplands > natural forests > artificial forests. (2) In high hydrothermal regions, Ca10-P and O-P contents of natural forests soils were significantly higher than in low hydrothermal regions, and phosphorus extracted by enzymes (Enzyme-P) contents of artificial and natural forests soils were the opposite. (3) Soil inorganic phosphorus fractions Ca2-P, Ca8-P, Al-P, Fe-P and Ca10-P contents were significantly and positively correlated with bioavailable phosphorus fractions CaCl2-P and HCl-P contents. Redundancy analysis showed that Ca2-P was the key factor affecting the bioavailable phosphorus fractions. The results indicate that land use types and hydrothermal conditions are key fraction influencing the characteristics of soil inorganic phosphorus fractions and bioavailable phosphorus fractions. Increasing the contents of inorganic phosphorus fractions has a positive effect on bioavailable phosphorus fractions. Therefore, consideration should be given to the potential effects of future climate change on the fractions and availability of phosphorus in soil, thereby promoting the restoration of karst ecosystems.
Subjects: Biology >> Botany >> Applied botany submitted time 2024-07-31 Cooperative journals: 《广西植物》
Abstract： In order to investigate the characteristics and release pattern of volatile components during flowering of Dendrobium chrysotoxum. In this study, solid - phase microextraction (SPME) combined with GC-MS was used to detect the volatile components of D. chrysotoxum in four periods: bud stage, first-flowering stage, full-flowering stage and last-flowering stage, and four parts of the labellum, sepals, petals and pistil column in full - flowering stage, and on the basis of this analysis, we carried out the analysis of principal components and the pattern of fragrance release. The results were as follows: (1) A total of 29 volatile components were detected in the 4 periods of D. chrysotoxum, consisting of 13 alkenes, 6 alcohols, 2 aldehydes, 2 esters, 2 alkanes, 1 phenol, 1 acid and 1 other, and a total of 39 volatile components were detected in the 4 parts of D. chrysotoxum during the full bloom period, consisting of 15 alkenes, 9 alcohols, 4 alkanes, 3 esters, 3 ketones, 2 aldehydes, 2 others and 1 acid. (2) The volatile components and content in D. chrysotoxum gradually increase and then decrease during the whole process from blooming to decaying, and there are up to 22 volatile components in the blooming period, mainly alkenes and esters. (3) The seven volatile components, namely, octyl acetate, loreleiene, (+) - α - pinene, (-) - β - pinene, laurolene, d - limonene and 1 - octanol, were important volatile components in D. chrysotoxum. Among them, octyl acetate and loreleiene were the most released in the full - flowering period, which accounted for 31.74% and 24.98% of the total content, and the contents of acetic acid, octyl ester were detected in the three periods of buds, primordia and full bloom, and the content was higher, (+) - α - pinene, (-) - β - pinene, myrcene, d - limonene and 1 - octanol were detected only in the early and full - flowering periods and their contents increased gradually with the opening of the flowers. (4) The types and contents of volatile components released from different parts of D. chrysotoxum also varied. The main odoriferous parts were petals and sepals, with 29 types of volatile components detected in sepals, 20 types of volatile components in petals, with the highest total content of 5 754.26 ng·g-1. In conclusion, this study shows that the volatile components released by different periods and different parts of D. chrysotoxum are different, and the results of this study lay a theoretical foundation for developing industry of daily chemical products of D. chrysotoxum flower. Keywords:
Subjects: Geosciences >> Geography submitted time 2024-07-30 Cooperative journals: 《干旱区地理》
Abstract：物流企业的空间布局不仅可以改变现有的物流组织形式，对重塑地区的产业空间格局也会产生重大影响。基于2006—2022年乌鲁木齐市物流企业空间数据，在对乌鲁木齐市物流企业区位时空演变分析的基础上，运用地理探测器和多尺度地理加权回归进一步探究物流企业区位选择的影响因素及其空间异质性，并提出优化物流企业空间布局的发展策略。结果表明：（1）乌鲁木齐市物流企业存在集聚分布特征，呈现出由“一主轴、一核心”向“三主核、两副核”演变的空间格局。（2）乌鲁木齐市地区间物流企业发展存在显著的正向溢出效应。（3）物流企业区位选择的影响因素中，物流企业数解释力度的均值为66%、地区GDP为48%、人口密度为49%、物流园区距离为28%；其中物流企业数和物流园区距离是空间异质性因素且其系数在空间上变化较大，地区GDP是具有正向影响的全局变量，人口密度是具有负向影响的全局变量。研究结果不仅拓展了企业区位理论的研究，而且丰富了研究案例，同时可以为乌鲁木齐市进行物流产业规划和高质量建设丝绸之路经济带商贸物流中心提供理论依据和实践参考。
Subjects: Geosciences >> Geography submitted time 2024-07-30 Cooperative journals: 《干旱区地理》
Abstract：银川市作为黄河流域重要的水源涵养区及国家重点生态功能区，其生境质量关乎区域生态安全和可持续发展。然而，针对银川市生境质量及其影响因子仍需深入研究。基于2000、2010年和2020年3期土地利用数据，耦合InVEST和Geodetector模型估算银川市20 a间生境质量，对研究区生境质量空间分布特征及影响因子进行分析。结果表明：（1）2000、2010年和2020年银川市平均生境质量指数分别为0.337、0.332和0.322，生境质量指数较低且20 a间略有下降，生境质量整体呈“南北高、中部低”的空间分布特征。（2）银川市生境质量在空间上存在着较强的空间集聚效应，莫兰指数呈下降趋势，集聚程度逐渐下降。（3）高程和土地利用类型是银川市生境质量的主要影响因子。各影响因子交互作用都存在增强效应，对生境质量的影响力随之增强，且以双因子增强为主，其次为非线性增强，其中高程与各因子的交互作用最为显著。研究结果可为银川市生态保护与高质量、可持续发展提供科学依据和决策支持。
Subjects: Geosciences >> Geography submitted time 2024-07-30 Cooperative journals: 《干旱区地理》
Abstract：通过对农业面源污染、农业净碳汇等变量测算构建指标体系，采用超效率SBM 模型、Malmquist指数模型方法计算2011—2020年新疆14个行政区农业水资源绿色效率值及其分解指数值，绘制标准差椭圆并构建马尔科夫链概率矩阵分析其空间格局变化，并用Tobit模型分析其影响因素。结果表明：（1）新疆各地州研究期内农业水资源绿色效率均值为0.865；各地区农业水资源绿色效率水平、提升效果及速度存在明显差异。（2）研究期内重心坐标始终在巴音郭楞蒙古自治州和静县巴音布鲁克镇内移动，先向东北移动后西南最终又向东北方向折回；较低、较高、高效率类型地区之间具有相互转移或跨类型转移的概率，低效率地区难以快速或跨类型增长。（3）经济发展水平、农业经济、供水结构对农业水资源绿色效率有显著的正向影响，资源禀赋与节水设施对农业水资源效率有显著的负向影响。研究结果对新疆农业水资源可持续利用、建设绿色高效农业具有重要的现实意义。
Subjects: Geosciences >> Geography submitted time 2024-07-30 Cooperative journals: 《干旱区地理》
Abstract：现有由行政单元主导的碎片化遗产保护体系忽视了黄河流域遗产资源的整体性与地域性。利用莫兰指数（Moran’s I）、核密度估计等方法揭示2022年即有黄河流域遗产资源的空间分布特征，并利用地理探测器分析其在不同地貌、气候与水体环境的空间分布差异。结果表明：（1）黄河流域遗产资源集聚分布特征显著，省际尺度呈层次化连片分布，市际尺度呈高值集聚分布，个体尺度呈“三主核心辐射成带、四次核心横向分散”的空间分布格局。（2）黄河流域遗产资源主要分布于一系列河谷盆地与冲积平原，暖温带气候下形成黄河一级以上支流的低海拔（0~849 m）连续地表“负性区”是其适宜分布的自然环境类型。（3）自然环境中，黄河流域遗产资源的空间分异受地貌要素影响最大，坡度、河网密度与其余因子交互的正向“耦合”效应显著，绝对海拔（0.33）、地貌面海拔（0.30）与温度带（0.18）是主导分异驱动因子。研究结果对深入认识黄河文化内涵、促进遗产资源可持续发展具有重要意义。
Subjects: Geosciences >> Geography submitted time 2024-07-30 Cooperative journals: 《干旱区地理》
Abstract：立足资源禀赋和发展阶段因地制宜提高农业生态效率是农业强国建设的必由之路。在借助非期望非径向SE-SBM模型测度2010—2020年中国西北地区市域尺度农业生态效率的基础上，综合应用差异系数、Dagum基尼系数、全局趋势分析、全局莫兰指数和空间误差模型等指标和方法探讨了中国西北地区农业生态效率时空分异特征及影响因素。结果表明：（1）2010—2020年中国西北地区农业生态效率的中位数在波动中由0.512上升至1.001，年均增长率约为6.93%，且市域间农业生态效率的差异程度呈现出缩小的态势。（2）中国西北地区农业生态效率呈现出梯次性的圈层空间分布特征，投影趋势线在南北方向呈现出“U型”特征，而东西方向则是在由西向东平滑上升的过程中逐渐显现出“倒U型”特征。（3）劳均耕地面积、农村居民人均可支配收入、城镇化水平对中国西北地区农业生态效率产生正向影响，而农业机械密度与化肥使用强度则对该地区农业生态效率产生负向影响。
Subjects: Geosciences >> Geography submitted time 2024-07-30 Cooperative journals: 《干旱区地理》
Abstract：为了快速准确地获取干旱地区表层土壤盐分信息，以沙井子灌区为研究区，利用地面采集的0~10 cm和10~20 cm深度的土壤盐分数据，以及同步获取的Landsat 9 OLI遥感影像上相应点位的波段反射率值，组合两波段和三波段光谱指数，建立低植被度覆盖下盐渍化监测SDI1、SDI2、SDI3、SDI4模型，并检验4类模型对不同土层深度土壤盐分的反演精度。结果表明：（1）当土层深度为0~10 cm时，4类盐渍化监测模型对土壤盐渍化等级分类精度分别为73.56%、66.35%、43.75%和74.52%；而当土层深度为10~20 cm 时，相应的分类精度分别为61.06%、62.50%、66.35%和64.42%，说明灌区内土层最佳反演深度为0~10 cm。（2）三波段光谱指数构建的SDI4模型优于双波段光谱指数构建的其余3种模型，能够有效反演沙井子灌区土壤盐渍化程度。研究结果可为灌区土壤盐渍化治理和防治提供有效的技术参考。
Subjects: Geosciences >> Geography submitted time 2024-07-30 Cooperative journals: 《干旱区地理》
Abstract：在农业生态系统中，根际微生物群落是土壤中养分和有机物质成功循环和转化的动力，对作物的生长、健康和营养状况起着重要的影响作用。为了探究天山北部不同生境苜蓿根际土壤真菌多样性以及形成差异的驱动因子。利用高通量测序技术对天山北部山地和平原2个生境的苜蓿根际土壤与非根际土壤中真菌多样性、结构、功能以及驱动因子进行分析。结果表明：（1）山地苜蓿根际土中土壤氮、钾、有机质和酶活性均显著大于平原苜蓿根际土，而电导率和pH显著小于平原苜蓿根际土。（2）山地和平原的真菌群落存在显著差异，平原苜蓿根际土壤的可操作分类单元（OTUs）、Chao1 和ACE 指数均显著大于山地苜蓿根际土壤，并且OTUs、Chao1、ACE 和香农指数（Shannon指数）均表现为根际土壤显著大于非根际土壤。（3）该区域的优势真菌门为子囊菌门（Ascomycota）、被孢霉菌门（Mortierellomycota）、担子菌门（Basidiomycota）和芽枝菌门（Blastocladiomycota），并且在不同生境存在显著差异。（4）基于FUNGuild真菌功能预测，山地中植物的致病真菌显著高于平原而外生菌根显著低于平原地区。（5）通过冗余分析（RDA）和Mantel检验发现土壤pH、全氮、全钾和速效钾是真菌群落结构差异分布的主要驱动因子。
Subjects: Geosciences >> Geography submitted time 2024-07-30 Cooperative journals: 《干旱区地理》
Abstract：2023年4月23日和5月6日阿克苏地区东部出现极端低温霜冻天气（简称“4.23”过程和“5.6”过程），尤其“5.6”过程库车市出现历史最晚终霜。基于常规观测、L波段探空、NCEP/NCAR1°×1°逐6 h再分析等资料，利用天气动力学方法对比分析2次极端低温过程环流背景，高低空配置、冷空气及冷平流强度、锋生作用等，探讨极端低温霜冻成因。结果表明：（1）两者有共性也有差异，共性表现在2次过程500 hPa阿克苏地区东部均受低槽（低涡）后部西北气流携带冷空气影响，且温度梯度大，锋区增强；均有深厚冷平流自阿克苏西部沿高层偏北气流向阿克苏地区东部低层下传；低温时段贴地层均有逆温和明显锋生，锋生与冷空气进入南疆盆地的路径及低温持续时间对应，且高层能量锋区较强，中低层锋区在增强过程中有斜压不稳定发展；均在霜冻出现前6 h冷平流强度增至最大，冷平流与8 ℃以上降温区域对应较好，且850 hPa温度降至3~4 ℃，对低温霜冻预报有一定指示性。（2）不同点在于“4.23”过程冷空气为西北路径，西翻和东灌冷空气共同影响阿克苏地区，贴地层逆温明显偏强，为辐射+平流降温；“5.6”过程冷空气为偏北路径，较强冷高压翻越天山进入南疆盆地，同时有东灌冷空气补充，影响范围大、逆温弱但整层降温明显，以辐射降温为主。（3）“5.6”过程低涡在新疆维持时间长，其冷空气及锋区强度、假相当位温梯度及影响时间均较“4.23”过程更强，灾害更重。
Subjects: Geosciences >> Geography submitted time 2024-07-30 Cooperative journals: 《干旱区地理》
Abstract：明晰区域农业水资源可承载灌溉面积能力，约束农业用水和控制农田灌溉面积扩张是解决河西走廊地区水资源可持续利用问题的战略选择。利用水量平衡原理和逐步回归模型，以当地水资源量、水资源利用情况、灌溉水有效利用系数等资料为基础，计算出河西走廊在不同发展情景下的水资源可开发利用量和可承载灌溉面积阈值。结果表明：（1）在经济优先发展情景下，河西走廊地区可开发利用水资源总量为48.22×108 m3，可承载灌溉面积阈值为58.92×104~67.16×104 hm2。（2）在生态优先发展情景下，可开发利用水资源总量为34.44×108 m3，可承载灌溉面积阈值为37.90×104~43.20×104 hm2。（3）在经济兼顾生态发展情景下，可开发利用水资源总量为41.33×108 m3，可承载灌溉面积阈值为48.41×104~55.18×104 hm2。（4）微灌面积占比与灌溉水有效利用系数呈显著正相关关系。研究结果可为河西走廊地区确定合理灌溉面积、优化水土规划和配水制度提供依据。
Subjects: Geosciences >> Geography submitted time 2024-07-30 Cooperative journals: 《干旱区地理》
Abstract：入湖冰川在喜马拉雅山地区广泛分布，其快速消融和末端崩解，是该地区冰湖溃决洪水最重要的触发因子和影响因素。近年来入湖冰川整体处于物质持续且加速亏损状态，1975—2000年入湖冰川物质平衡为-0.33±0.07 m w.e.·a-1，近10 a达到-0.56±0.08 m w.e.·a-1，其平均物质损失速率-0.45±0.08 m w.e.·a-1。入湖冰川物质损失速率明显高于其他类型冰川，末端消融及崩解是其主要原因。当前冰川末端水下物质损失仍无法准确估算，广泛应用于入海冰川末端消融模拟的羽流模型，为估算入湖冰川末端湖-冰物/热交换过程研究提供了可行方法，其中冰下融水径流量、冰川末端切面形态、湖水温度和密度是影响羽流模型估算结果的重要参数。基于羽流模型评估冰川末端水下消融特征，为准确评估未来情境下冰川物质变化奠定基础。
Subjects: Geosciences >> Geography submitted time 2024-07-30 Cooperative journals: 《干旱区地理》
Abstract：以阿克苏地区苏巴什水库为研究对象，采用多源降水融合数据、雨量站数据、数字高程模型（DEM）数据以及土地利用数据等资料，运用FloodArea模型对苏巴什水库典型暴雨山洪淹没过程进行精细化模拟，通过淹没深度和汇水量2个参量，对比分析2种降水数据源模拟效果，在此基础上，构建了降水-淹没深度关系模型，得出冲砂闸底板高程、汛限水位、泄洪闸堰顶高程和坝顶高程对应的致灾临界雨量阈值。结果表明：以多源降水融合数据驱动的FloodArea模型模拟苏巴什水库淹没深度和计算汇水量较雨量站模拟的精度更高，更接近真实值，多源降水融合数据和雨量站降水数据模拟得到的淹没深度误差率分别为8.59%和18.67%。苏巴什水库淹没水位达到冲砂闸底板高程、汛限水位、泄洪闸堰顶高程和坝顶高程对应累积4 h降水量的致灾临界雨量阈值分别为7.1 mm、20.1 mm、32.9 mm和44.7 mm。研究结果可为苏巴什水库暴雨山洪预警提供理论依据，并提升暴雨山洪预警能力。
Subjects: Geosciences >> Geography submitted time 2024-07-30 Cooperative journals: 《干旱区地理》
Abstract：卫星遥感降水产品已广泛应用于估算降水，尤其是在地面观测站点稀少的地区。然而，这些卫星降水产品较低的空间分辨率，限制了其在局部地区的应用。因此，提出一种基于块到点克里金插值算法（ATPOK）与地理权重回归克里金残差校准算法（GWRK）组合的融合降尺度框架，对2000—2019年青海地区TRMM 3B43进行空间降尺度，并结合地面观测站点数据、归一化植被指数（NDVI）、数字高程模型（DEM）、坡度及坡向等辅助因子进行校准，最终得到1 km分辨率的降水产品。结果表明：（1）本研究所提出的融合降尺度框架能有效提高TRMM 3B43降水数据的降尺度精度，但并不能消除TRMM 3B43降水高估的情况。（2）与ATPOK算法相比，采用降尺度的TRMM降水数据和辅助因子的GWRK模型能更好地估算年、月降水量。（3）基于对TRMM 3B43和NDVI相关关系研究，发现NDVI对降水的响应存在0~2个月的延迟。（4）基于对降尺度降水产品时空变化分析，发现青海地区降水在月尺度上存在显著增长，其中干月年际变化率3.33%，湿月年际变化率1.79%。
Subjects: Geosciences >> Geography submitted time 2024-07-30 Cooperative journals: 《干旱区地理》
Abstract：氢氧稳定同位素作为示踪剂被广泛用于水文循环过程研究。地表水是水循环的重要组成部分，是区域水汽来源和现代水文过程分析的有效载体。基于新疆第三次科学考察，于2018年8月至2023年8月在昆仑山北坡采集了地表水样本并测量其氢氧稳定同位素数据，同时汇编了区域以往的地表水同位素数据，分析了昆仑山北坡地表水氢氧稳定同位素的空间分布特征。结果表明：（1）昆仑山北坡地表水同位素值呈现出西低东高的空间变化特征，区域地表水线为δ2H=5.98×δ18O-6.86（R2=0.65，n=141）。（2）对比昆仑山北坡地表水和降水氢氧稳定同位素值发现地表水同位素平均值普遍低于加权降水同位素值。（3）昆仑山北坡地表水同位素空间格局受到西风携带的外来水汽和局地再循环水汽共同影响，此外蒸发也会改变区域地表水同位素值。
Subjects: Geosciences >> Geography submitted time 2024-07-30 Cooperative journals: 《干旱区地理》
Abstract：随着青藏高原气候变暖，高原湖泊数量和面积均表现出显著增加趋势，东昆仑-库木库里盆地湖泊扩张亦十分明显。阿牙克库木湖是库木库里盆地最大盐湖，新疆第三次综合科学考察表明，该湖泊已扩张为新疆最大湖泊。基于科考资料，结合遥感卫星资料，对阿牙克库木湖扩张及其流域冰川、冻土、气温和降水等要素进行分析，探讨湖泊水量及其补给水源的关系。结果表明：（1）1990―2023年，阿牙克库木湖面积从623.03 km2扩张至1141.67 km2，2002―2023年湖面水位上升了7.28 m，对应水储量增加了66.64×108 m3。（2）1990―2023年，阿牙克库木湖流域冰川面积减少了16.4 km2，体积减少了1.96 km3。截止2023年，流域分布冰川451条，总面积为324.26 km2。（3）2010年青藏高原冻土分布图显示，流域分布多年冻土12395 km2，季节冻土10652 km2。（4）水量平衡分析表明，冰川和冻土融水径流分别占阿牙克库木湖总入湖水量的9%和5%，季节冻土和多年冻土区降水径流占比为67%，湖面降水量直接补给占比为19%。总体而言，湖泊的扩张主要是流域降水量增加所致。研究揭示了库木库里盆地地表水文过程，可为当地政府优化水资源配置和管理提供参考。
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