分类： 地球科学 >> 地理学 提交时间： 2021-10-11 合作期刊: 《干旱区科学》
摘要： The ability of plants to safely retain seeds in the mother plant is an adaptive mechanism described in many desert plants. However, research about delayed seed dispersal species in the desert of the United Arab Emirates (UAE) is lacking. This study aims to identify these delayed seed dispersal species and assess the relationships of the presence of delayed seed dispersal with plant growth form, habit, spatial dispersal, antitelechoric mechanism, and seed release time. The relationships between the presence of delayed seed dispersal and the above studied traits were assessed by using the Pearson Chi-square test and Nonlinear Principal Components Analysis (NLPCA). Results showed that a total of 46 delayed seed dispersal species were recorded (15.0% of 307 studied species) and the highest incidence occurred in the Fabaceae family (17.4%). Delayed seed dispersal species were predominantly perennial plants (73.9%) with spatial restricted dispersal (67.4%), which released seed in the dry season (45.7%). The dominant groups of delayed seed dispersal species were persistent fruits species and synaptospermy (28.3%). All graminoids showed persistent lignified fruits, while prostrate annuals were basicarpic species with myxospermy. Sandy habitats had the highest number of delayed seed dispersal species (54.3%), whereas salt flats had the lowest (23.9%). In the desert of the UAE, delayed seed dispersal species spread seeds until the end of the dry and windy season, thus breaking seed dormancy at this time and ensuring seed germination in the next arrival of the rainy season. This morphological and ecological adaptation of delayed dispersal species is essential to the survival and sustainable development of vegetation in desert environments.
分类： 地球科学 >> 地理学 提交时间： 2021-10-11 合作期刊: 《干旱区科学》
摘要： Ridge-furrow film mulching has been proven to be an effective water-saving and yield-improving planting pattern in arid and semi-arid regions. Drought is the main factor limiting the local agricultural production in the Loess Plateau of China. In this study, we tried to select a suitable ridge-furrow mulching system to improve this situation. A two-year field experiment of summer maize (Zea mays L.) during the growing seasons of 2017 and 2018 was conducted to systematically analyze the effects of flat planting with no film mulching (CK), ridge-furrow with ridges mulching and furrows bare (RFM), and double ridges and furrows full mulching (DRFFM) on soil temperature, soil water storage (SWS), root growth, aboveground dry matter, water use efficiency (WUE), and grain yield. Both RFM and DRFFM significantly increased soil temperature in ridges, while soil temperature in furrows for RFM and DRFFM was similar to that for CK. The largest SWS was observed in DRFFM, followed by RFM and CK, with significant differences among them. SWS was lower in ridges than in furrows for RFM. DRFFM treatment kept soil water in ridges, resulting in higher SWS in ridges than in furrows after a period of no water input. Across the two growing seasons, compared with CK, RFM increased root mass by 10.2% and 19.3% at the jointing and filling stages, respectively, and DRFFM increased root mass by 7.9% at the jointing stage but decreased root mass by 6.0% at the filling stage. Over the two growing seasons, root length at the jointing and filling stages was respectively increased by 75.4% and 58.7% in DRFFM, and 20.6% and 30.2% in RFM. Relative to the jointing stage, the increased proportions of root mass and length at the filling stage were respectively 42.8% and 94.9% in DRFFM, 63.2% and 115.1% in CK, and 76.7% and 132.1% in RFM, over the two growing seasons, showing that DRFFM slowed down root growth while RFM promoted root growth at the later growth stages. DRFFM treatment increased root mass and root length in ridges and decreased them in 0–30 cm soil layer, while RFM increased them in 0–30 cm soil layer. Compared with CK, DRFFM decreased aboveground dry matter while RFM increased it. Evapotranspiration was reduced by 9.8% and 7.1% in DRFFM and RFM, respectively, across the two growing seasons. Grain yield was decreased by 14.3% in DRFFM and increased by 13.6% in RFM compared with CK over the two growing seasons. WUE in CK was non-significantly 6.8% higher than that in DRFFM and significantly 22.5% lower than that in RFM across the two growing seasons. Thus, RFM planting pattern is recommended as a viable water-saving option for summer maize in the Loess Plateau of China.
分类： 地球科学 >> 地理学 提交时间： 2021-10-11 合作期刊: 《干旱区科学》
摘要： Nitraria tangutorum nebkhas are widely distributed in the arid and semi-arid desert areas of China. The formation and development of N. tangutorum nebkhas are the result of the interaction between vegetation and the surrounding environment in the process of community succession. Different successional stages of N. tangutorum nebkhas result in differences in the community structure and composition, thereby strongly affecting the distribution of soil nutrients and ecosystem stability. However, the ecological stoichiometry of N. tangutorum nebkhas in different successional stages remains poorly understood. Understanding the stoichiometric homeostasis of N. tangutorum could provide insights into its adaptability to the arid and semi-arid desert environments. Therefore, we analyzed the stoichiometric characteristics of N. tangutorum in four successional stages, i.e., rudimental, developing, stabilizing, and degrading stages using a homeostasis model in an oasis-desert ecotone of Northwest China. The results showed that soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) contents and their ratios in the 0–100 cm soil depth were significantly lower than the averages at regional and global scales and were weakly influenced by successional stages in the oasis-desert ecotone. TN and TP contents and C:N:P in the soil showed similar trends. Total carbon (TC) and TN contents in leaves were 450.69–481.07 and 19.72–29.35 g/kg, respectively, indicating that leaves of N. tangutorum shrubs had a high storage capacity for C and N. Leaf TC and TN contents and N:P ratio increased from the rudimental stage to the stabilizing stage and then decreased in the degrading stage, while the reverse trend was found for leaf C:N. Leaf TP content decreased from the rudimental stage to the degrading stage and changed significantly in late successional stages. N:P ratio was above the theoretical limit of 14, indicating that the growth of N. tangutorum shrubs was limited by P during successional stages. Leaf N, P, and N:P homeostasis in four successional stages was identified as ''strictly homeostasis''. Redundancy analysis (RDA) revealed that soil acidity (pH) and the maximum water holding capacity were the main factors affecting C:N:P stoichiometric characteristics in N. tangutorum leaves. Our study demonstrated that N. tangutorum with a high degree of stoichiometric homeostasis could better cope with the arid desert environment.
分类： 地球科学 >> 地理学 提交时间： 2021-10-11 合作期刊: 《干旱区科学》
Laura B RODRIGUEZ
Silvia S TORRES ROBLES
Marcelo F ARTURI
Juan M ZEBERIO
Andrés C H GRAND
Néstor I GASPARRI
摘要： The quantification of carbon storage in vegetation biomass is a crucial factor in the estimation and mitigation of CO2 emissions. Globally, arid and semi-arid regions are considered an important carbon sink. However, they have received limited attention and, therefore, it should be a priority to develop tools to quantify biomass at the local and regional scales. Individual plant variables, such as stem diameter and crown area, were reported to be good predictors of individual plant weight. Stand-level variables, such as plant cover and mean height, are also easy-to-measure estimators of above-ground biomass (AGB) in dry regions. In this study, we estimated the AGB in semi-arid woody vegetation in Northeast Patagonia, Argentina. We evaluated whether the AGB at the stand level can be estimated based on plant cover and to what extent the estimation accuracy can be improved by the inclusion of other field-measured structure variables. We also evaluated whether remote sensing technologies can be used to reliably estimate and map the regional mean biomass. For this purpose, we analyzed the relationships between field-measured woody vegetation structure variables and AGB as well as LANDSAT TM-derived variables. We obtained a model-based ratio estimate of regional mean AGB and its standard error. Total plant cover allowed us to obtain a reliable estimation of local AGB, and no better fit was attained by the inclusion of other structure variables. The stand-level plant cover ranged between 18.7% and 95.2% and AGB between about 2.0 and 70.8 Mg/hm2. AGB based on total plant cover was well estimated from LANDSAT TM bands 2 and 3, which facilitated a model-based ratio estimate of the regional mean AGB (approximately 12.0 Mg/hm2) and its sampling error (about 30.0%). The mean AGB of woody vegetation can greatly contribute to carbon storage in semi-arid lands. Thus, plant cover estimation by remote sensing images could be used to obtain regional estimates and map biomass, as well as to assess and monitor the impact of land-use change on the carbon balance, for arid and semi-arid regions.
分类： 地球科学 >> 地理学 提交时间： 2021-10-11 合作期刊: 《干旱区科学》
摘要： Precipitation and temperature are the most abiotic factors that greatly impact the yield of crop, particularly in dryland. Barley, as the main cereal is predominantly cultivated in dryland and the livelihood of smallholders depends on the production of this crop, particularly in arid and semi-arid regions. This study aimed to investigate the response of the grain yield of dryland barley to temperature and precipitation variations at annual, seasonal and monthly scales in seven counties of East and West Azerbaijan provinces in northwestern Iran during 1991–2010. Humidity index (HI) was calculated and its relationship with dryland barley yield was evaluated at annual and monthly scales. The results showed that the minimum, maximum and mean temperatures increased by 0.19°C/a, 0.11°C/a and 0.10°C/a, respectively, while annual precipitation decreased by 0.80 mm/a during 1991–2010. Climate in study area has become drier by 0.22/a in annual HI during the study period. Negative effects of increasing temperature on the grain yield of dryland barley were more severe than the positive effects of increasing precipitation. Besides, weather variations in April and May were related more to the grain yield of dryland barley than those in other months. The grain yield of dryland barley was more drastically affected by the variation of annual minimum temperature comparing with other weather variables. Furthermore, our findings illustrated that the grain yield of dryland barley increased by 0.01 t/hm2 for each unit increase in annual HI during 1991–2010. Finally, any increase in the monthly HI led to crop yield improvement in the study area, particularly in the drier counties, i.e., Myaneh, Tabriz and Khoy in Iran.
分类： 地球科学 >> 地理学 提交时间： 2021-10-11 合作期刊: 《干旱区科学》
摘要： Zarrineh River is located in the northwest of Iran, providing more than 40% of the total inflow into the Lake Urmia that is one of the largest saltwater lakes on the earth. Lake Urmia is a highly endangered ecosystem on the brink of desiccation. This paper studied the impacts of climate change on the streamflow of Zarrineh River. The streamflow was simulated and projected for the period 1992–2050 through seven CMIP5 (coupled model intercomparison project phase 5) data series (namely, BCC-CSM1-1, BNU-ESM, CSIRO-Mk3-6-0, GFDL-ESM2G, IPSL-CM5A-LR, MIROC-ESM and MIROC-ESM-CHEM) under RCP2.6 (RCP, representative concentration pathways) and RCP8.5. The model data series were statistically downscaled and bias corrected using an artificial neural network (ANN) technique and a Gamma based quantile mapping bias correction method. The best model (CSIRO-Mk3-6-0) was chosen by the TOPSIS (technique for order of preference by similarity to ideal solution) method from seven CMIP5 models based on statistical indices. For simulation of streamflow, a rainfall-runoff model, the hydrologiska byrans vattenavdelning (HBV-Light) model, was utilized. Results on hydro-climatological changes in Zarrineh River basin showed that the mean daily precipitation is expected to decrease from 0.94 and 0.96 mm in 2015 to 0.65 and 0.68 mm in 2050 under RCP2.6 and RCP8.5, respectively. In the case of temperature, the numbers change from 12.33°C and 12.37°C in 2015 to 14.28°C and 14.32°C in 2050. Corresponding to these climate scenarios, this study projected a decrease of the annual streamflow of Zarrineh River by half from 2015 to 2050 as the results of climatic changes will lead to a decrease in the annual streamflow of Zarrineh River from 59.49 m3/s in 2015 to 22.61 and 23.19 m3/s in 2050. The finding is of important meaning for water resources planning purposes, management programs and strategies of the Lake's endangered ecosystem.
分类： 地球科学 >> 地理学 提交时间： 2021-10-11 合作期刊: 《干旱区科学》
YU Yang
CHEN Xi
Ireneusz MALIK
Malgorzata WISTUBA
CAO Yiguo
HOU Dongde
TA Zhijie
HE Jing
ZHANG Lingyun
YU Ruide
ZHANG Haiyan
SUN Lingxiao
摘要： Central Asia is located in the hinterland of Eurasia, comprising Kazakhstan, Uzbekistan, Kyrgyzstan, Turkmenistan, and Tajikistan; over 93.00% of the total area is dryland. Temperature rise and human activities have severe impacts on the fragile ecosystems. Since the 1970s, nearly half the great lakes in Central Asia have shrunk and rivers are drying rapidly owing to climate changes and human activities. Water shortage and ecological crisis have attracted extensive international attention. In general, ecosystem services in Central Asia are declining, particularly with respect to biodiversity, water, and soil conservation. Furthermore, the annual average temperature and annual precipitation in Central Asia increased by 0.30°C/decade and 6.9 mm/decade in recent decades, respectively. Temperature rise significantly affected glacier retreat in the Tianshan Mountains and Pamir Mountains, which may intensify water shortage in the 21st century. The increase in precipitation cannot counterbalance the aggravation of water shortage caused by the temperature rise and human activities in Central Asia. The population of Central Asia is growing gradually, and its economy is increasing steadily. Moreover, the agricultural land has not been expended in the last two decades. Thus, water and ecological crises, such as the Aral Sea shrinkage in the 21st century, cannot be attributed to agriculture extension any longer. Unbalanced regional development and water interception/transfer have led to the irrational exploitation of water resources in some watersheds, inducing downstream water shortage and ecological degradation. In addition, accelerated industrialization and urbanization have intensified this process. Therefore, all Central Asian countries must urgently reach a consensus and adopt common measures for water and ecological protection.
分类： 地球科学 >> 地理学 提交时间： 2021-10-10 合作期刊: 《干旱区地理》
摘要： 维持城市生态系统服务供需平衡是建设宜居城市、提高城市居民福祉的基础，同时对区域 经济与可持续发展具有重要意义。以西安市建成区为例，基于 2018 年遥感数据、统计数据和实地 调研等多源数据，构建粮食需求、水资源需求、固碳释氧、空气净化、高温调节、减弱噪声和休闲娱 乐服务需求测算模型，并应用 ArcGIS 等分析工具，对研究区城市绿色基础设施（Urban green infra⁃ structure，UGI）服务供需空间匹配关系进行评估和分析，最后运用最小累积阻力模型识别生态源地 和生态廊道，对西安市 UGI 空间格局进行优化。结果表明：（1）西安市建成区 UGI 分布不均匀，破 碎化程度高，连通性较差。UGI 提供的生态系统服务总价值小于居民对服务需求总价值，在空间上 表现为显著不匹配性。（2）不同生态系统服务供需匹配状况存在差异，高温调节服务、空气净化服 务和休闲娱乐服务供大于求，匹配状况较好；粮食供给、固碳释氧、水源涵养和减弱噪声服务供小 于求，供需赤字。（3）研究区生态系统服务供需具有显著空间异质性，随着人口集聚程度的提高，大 部分生态系统服务（如高温调节、减弱噪声等）供需的空间匹配程度显著下降，在空间上表现为由 城市中心的严重失调向边缘的良好匹配渐变。（4）研究区生态源地斑块面积较小，破碎化程度高， 连接度低，UGI 网络缺乏主干生态廊道。通过构建由沿渭河、秦岭北麓 2 个生态走廊，沣河、潏河、 灞河等 7 个生态保育区及沿道路绿化带等组成的 UGI 网络，可使生态系统服务供需空间关系更趋 协调。
分类： 地球科学 >> 地理学 提交时间： 2021-10-10 合作期刊: 《干旱区地理》
摘要： 阿克苏河流域作为西北干旱区内陆河，生态环境极为脆弱，研究其生态安全格局对优化区 域国土空间开发保护格局，推动生产生活方式向绿色转型，促进人与自然和谐共生具有重要战略 意义。基于研究区本底特征，运用空间主成分分析法（SPCA）对阿克苏河流域 1980—2018 年生态 承载力时空演变进行评估监测，利用最小累积阻力（MCR）模型提取生态廊道及生态节点，构建生 态安全格局。研究表明：（1）阿克苏河流域生态承载力空间差异明显，以中等承载为主，生态承载 优势区呈现由中东部向西部转移趋势。（2）阿克苏河流域生态承载力呈增长趋势。近 40 a 阿克苏 河流域整体生态承载力呈上升趋势，强承载区面积不断增加，弱承载区面积呈现波动下降趋势，表 明流域环境有所改善。（3）生态源地占整体面积较少，分布较为集中。根据生态承载力评估结果， 提取生态源地 23465.21 km2，约占研究区面积的 35.61%。生态源地集中分布于流域中部地区，北部 高山地区与西南部盆地、沙漠地区分布较少。（4）利用 MCR 模型及遥感影像，将阿克苏河流域划分 为 16 个生态安全格局分区，提取生态廊道 67 条，识别生态节点 71 处，并结合生态承载力评估结果， 对流域生态空间结构提出优化建议。
分类： 地球科学 >> 地理学 提交时间： 2021-10-10 合作期刊: 《干旱区地理》
摘要： 水生态文明建设是新疆干旱区生态文明建设的关键，中国特色社会主义事业“五位一体”总 体布局对生态文明建设做出了战略部署。目前对干旱区水生态文明建设应关注的问题，水资源如 何保障和服务水生态文明建设等问题并不清晰。本文从水生态文明建设的角度综述了干旱区水 资源开发的生态环境效应研究和水生态文明研究，重点探讨了新疆水生态文明建设需坚持的重要 原则，提出了协调经济社会系统和生态系统的水资源保护利用策略。
分类： 地球科学 >> 地理学 提交时间： 2021-10-10 合作期刊: 《干旱区地理》
摘要： 运用 ArcGIS 空间分析，揭示了 1990—2018 年西北诸河流域土地利用动态变化特征，采用 “压力-状态-响应”（Pressure-state-response，P-S-R）模型和熵权法对指标进行赋权，并分析了西北诸 河流域土地生态安全状况。结果表明：（1）西北诸河流域2015—2018 年综合土地利用动态度为 2.65%，土地利用变化剧烈。2000 年后城乡建设用地年平均单一动态度为4.16%，增长速度最快。 草地主要向沙地、耕地和其他未利用土地转出，流域荒漠区沙地和其他未利用土地之间转换稳 定。（2）西北诸河流域土地生态安全评价指标体系中状态层权重最高，为 0.4985，由指标权重排序 可知，经济社会发展、湿地面积和人口增长是影响西北诸河流域土地生态安全评价的重要因素。（3）1990—2018 年西北诸河流域土地生态安全指数呈递增趋势，1990—2014 年基本处于不安全 级，2015 年后转变为较不安全级，西北诸河流域土地生态安全状况有所好转。本研究为西北诸河 流域土地利用管理规划提供科学依据，为自然流域尺度的土地利用变化及土地生态安全性研究提 供实例。
分类： 地球科学 >> 地理学 提交时间： 2021-10-10 合作期刊: 《干旱区地理》
摘要： 绿洲是干旱内陆区的精华部分，也是生态文明建设的难点地区，加强绿洲生态治理研究对 推进区域生态文明建设具有重要的理论和现实意义。长期以来，绿洲生态治理研究强调通过技术 手段、经济措施促进绿洲生态系统恢复，对行动主体在生态治理中的作用重视不够，影响了绿洲生 态治理成效和可持续性。以额济纳绿洲为案例，在深入调研基础上，援引空间生产理论和区域治 理理论，通过政策工具组合分析，探究纵向嵌入治理下绿洲生态空间生产过程。结果表明：（1）中 央政府的机构嵌入打破了传统“以粮为纲”的水资源配置导向，流域用水制度从“粮食生产偏好”向 “生态保护偏好”转变，绿洲被建构为国家生态保育空间，成为中国北疆重要的生态安全屏障。（2） 中央政府的行政嵌入重塑了流域用水关系和水权秩序，促成了黑河干流水量调度，实现了绿洲来 水增多化，干涸多年的东居延海出现稳定水面被开辟为生态旅游景区，由戈壁沙漠湖泊湿地转变 为生态观光旅游胜地，重构了黑河尾闾生态空间。（3）中央政府的规则嵌入解决了绿洲工程建设中 资金短缺问题，通过对绿洲灌溉的人工化控制和绿洲生态保护区化治理，实现了绿洲河网渠系化 与绿洲空间功能化，绿洲由边境牧业生产生活空间转变为国家重点生态功能空间。
分类： 地球科学 >> 水文学 提交时间： 2021-10-10 合作期刊: 《干旱区地理》
摘要： 以兰州市安宁区金牛街码头附近距黄河约 10 m 的河漫滩为研究对象，对河漫滩土壤水的 氢氧稳定同位素进行分析并结合不同水体 lc-excess（Line-conditioned excess），研究了河漫滩土壤剖 面不同深度土壤水氢氧稳定同位素与土壤含水量的变化特征以及降水以活塞流、优先流模式对土 壤水的补给过程。研究表明：（1）兰州当地大气降水线（Local meteoric water line，LMWL）：δD=7.00 δ18O+3.81(R2=0.95，P80 cm）土壤水存在补给。（3）4、6、10 月观察到降水以活塞流模式对土壤 水进行了补给，5、9 月观察到降水以优先流模式对土壤水进行补给，即降水对河漫滩土壤水以 2 种 入渗模式共同补给。明晰土壤水特征对于准确分析降水在土壤中的入渗量、深入认识其补给过 程、准确评价地下水补给资源以及地下水污染分析具有重要意义。
分类： 地球科学 >> 地理学 提交时间： 2021-10-10 合作期刊: 《干旱区地理》
摘要： 近年来，水资源利用超载导致新疆生产建设兵团（下称“兵团”）生产生态问题频发，科学精 准评估水资源承载现状能够为兵团社会经济发展和生态环境治理提供重要参考。兵团社会经济 用水中绝大部分为灌溉用水，因此耕地面积数据精度显著影响水资源承载现状评价结果，然而现 实中耕地面积统计数据存在一定偏差，增加了水资源承载现状评估的不确定性。基于此，通过引 入 Google Earth Engine（GEE）大数据平台和净耕地系数，精确修订耕地面积；并模拟常规灌溉、膜上 灌溉和混合灌溉 3 种灌溉用水情景，构建三生用水核算体系，对兵团及各师水资源承载现状进行精 准评估。结果表明：兵团耕地校正系数为 1.27，说明兵团耕地面积有约 27%的偏差；在与实际用水 相近的混合灌溉情景中，基于耕地面积统计数据的兵团总需水量为 106.45×108 m3，相对兵团总引 水量尚有 9.20%余量；通过 GEE 校正耕地面积后，兵团总需水量为 125.64×108 m3，超载 7.16%，且 13 个师中仅四师和十师 2 个师用水量不超载，表明灌溉用水过度占用有限的水资源量、挤占大量生态 用水，是导致兵团水资源超载和生产生态问题频发的关键。本研究实现了对兵团水资源承载现状 的科学精准评估，能够为兵团水资源利用及优化配置、区域可持续发展提供参考。
分类： 地球科学 >> 地理学 提交时间： 2021-10-10 合作期刊: 《干旱区地理》
摘要： 水资源承载力的定量评估是确保干旱地区水资源可持续利用的关键前提。选取我国最大 的内陆干旱区流域——塔里木河流域为研究区域，结合其特殊的地理环境和供水与需水特征，构 建系统动力学模型，基于实地调研、统计年鉴与水资源公报数据，以水资源红线为约束，对塔里木 河流域水资源承载力的历史状况与未来趋势进行了定量评估和预测。结果显示：塔里木河流域及 其所属各地（州）历史期内（2008—2016 年）水资源均呈现轻度超载状态，且在未来（2017—2030 年） 将进一步加剧。在当前的政策背景下，如使该区水资源于 2030 年达到可承载的状态，则需在该地 区扩大农业节水设施建设规模并着力发展农业节水灌溉技术，并力争在 2030 年实现灌溉用水定额 达到 5.70×103 m3·hm-2 以下，农业灌溉面积降低至 2.60×106 hm2 以下。同时，农业节水与产业转型应 是该地区未来社会经济发展的 2 个需要重点考虑的方向。
分类： 地球科学 >> 地理学 提交时间： 2021-10-10 合作期刊: 《干旱区地理》
摘要： 随着生产力的发展，人类在开发活动中导致的植被破坏、水源污染、土壤污染等生态环境问 题日益突出，人类活动与自然环境之间的矛盾和保障人类社会的可持续发展已经成为急需解决的 问题。利用最小累积阻力模型（MCR）对 1990—2019 年卡拉麦里地区的生态安全格局变化规律进 行分析，并结合元胞自动机-马尔可夫模型（CA-Markov）对 2025 年本地区的生态安全格局进行预 测。结果表明：（1）将卡拉麦里地区的生态安全格局分为安全区、低安全区及不安全区，安全区的 面积在 2010—2015 年萎缩至 3237.31 km2，主要转化为低安全区及不安全区，这一时期的人类活动 严重影响到了本区的生态环境。（2）2019 年，安全区面积为 6265.91 km2，低安全区及不安全区基本 恢复为自然状态，生态治理工作取得良好效果。（3）预测可知，2025 年卡拉麦里地区景观格局变化 不大，仍以草地、未利用地为主。生态安全区面积 6421.88 km2，低安全区及不安全区面积有继续下 降趋势。（4）在卡山保护区中部的交通路线附近形成了一条带状低安全区，将成为今后保护区生态 监测与保护的重点区域。
分类： 地球科学 >> 地理学 提交时间： 2021-10-10 合作期刊: 《干旱区地理》
摘要： 疏勒河流域地处河西走廊最西端，是典型的干旱内陆河流域，生态环境极其脆弱，也是我国 重要的生态屏障之一。借助 Fragstats 软件从斑块和景观 2 个尺度，结合 2000—2018 年土地利用数 据，评价分析疏勒河流域景观生态风险时空变化特征，利用地理探测器定量分析了该流域景观生 态风险驱动因素。结果表明：（1）疏勒河流域主要景观类型为未利用地和草地，其斑块个数（NP）、 景观形状指数（LSI）、最大斑块指数（LPI）和聚集度指数（AI）值均较高；2000—2018 年蔓延度指数（CONTAG）值下降、香农多样性指数（SHDI）和香农均匀度指数（SHEI）值缓慢上升，流域景观破碎 度严重。（2）疏勒河流域景观生态风险空间分布呈现北高南低，2000—2018 年呈现流域景观生态风 险逐渐下降趋势，其中较高风险和高风险地区面积下降明显。（3）人为干扰度是影响景观生态风险 空间分布的主要因子，归一化植被指数（NDVI）次之，人口密度影响最小；景观生态风险的影响均为 双因子增强或非线性增强，无显著差异大多表现在自然和自然因子间，自然和人为因子之间存在 显著性差异。因此，对流域进行景观生态风险指数评价和驱动因素分析至关重要。
分类： 地球科学 >> 大气科学 提交时间： 2021-10-10 合作期刊: 《干旱区地理》
摘要： 以叶尔羌河流域上游河源区为研究区，构建嵌入了冰川模块的 SWAT 分布式水文模型，对 卡群水文站 1968—2017 年逐月径流进行模拟，评价该模型在研究区内的适用性，基于模拟结果分 析研究区冰川径流年际变化与年内分布情况，并定量核算气候和下垫面变化对径流变化的贡献 率。结果表明：该模型在研究区径流模拟中具有良好的适用性，校准期（1968—1992 年）与验证期（1993—2017 年）的决定系数（R2）分别为 0.77 和 0.86，纳什系数（NSE）分别为 0.76 和 0.85，均方根误 差与实测值标准差的比值（RSR）分别为 0.49 和 0.38，偏差百分比（PBIAS）分别为-7.4%和 0.6%。经 模拟，研究区近 50 a 冰川径流量总体呈增加趋势，且其占总径流量的比重约为 51.1%；年内冰川产 流主要发生在 6—9 月，占全年冰川径流量的 90.0%以上。气候和下垫面变化分别使月径流量增加 6.62 m3·s-1 和 0.41 m3·s-1，其中气候变化的贡献率为 94.2%，即气候变化对研究区径流的影响占主导 地位。研究成果可为理解研究区的历史径流变化成因及预测未来径流的演变趋势提供科学依据。
分类： 地球科学 >> 水文学 分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2021-10-10 合作期刊: 《干旱区地理》
摘要： 萨雷扎兹河发源于吉尔吉斯斯坦（以下称吉国），入境水量约占阿克苏河水量的44.3%，对 确保阿克苏地区经济社会的可持续发展具有重要的现实意义。近年来，吉国计划在萨雷扎兹河（阿克苏河上游）进行水资源开发，将会影响处于下游的我国境内阿克苏河流域的水资源量。基于 阿克苏河流域的径流数据，定量分析了萨雷扎兹河的径流变化特征和不同开发情景对阿克苏河下 游径流的影响。结果表明：在 1958—2015 年，萨雷扎兹河年径流整体呈显著上升趋势；径流的年内 分配差异较大，主要集中在 7、8 月；春、冬两季径流呈显著增长趋势，夏、秋两季呈微弱增长趋势；从 年代际变化看，除 1958—1959 年为偏枯水时段，1990—1999 年为偏丰水时段外，剩下的时间段均为 平水时段。吉国跨流域调水工程建设将对阿克苏河径流产生重大影响。从季节尺度分析，跨流域 调水工程建设将导致阿克苏河下游径流呈减少状态，其中夏季敏感性最高；从年尺度分析，跨流域 调水工程建设将导致阿克苏河下游径流呈减少状态，而且随着调水量的增多，阿克苏河下游径流 不断减少。研究结果可以为我国政府在处理吉国跨流域调水工程建设对阿克苏河径流产生影响 的问题上提供一定的参考。
分类： 地球科学 >> 地理学 提交时间： 2021-10-10 合作期刊: 《干旱区地理》
摘要： 利用 ITS_LIVE 数据、Landsat 数据提取了喀喇昆仑山北坡 42 条冰川的表面流速。将末端运 动与表面运动特征结合起来，分析对比了不同运动类型冰川表面流速的时空变化。结果表明：（1） 1989—2018 年，研究区 42 条冰川中，存在稳定冰川 16 条、前进冰川 6 条、退缩冰川 1 条、跃动冰川 19 条。空间上，流速分布符合冰川运动一般原理，可在积累区和冰舌上部发现明显的高值区域，这些 区域多出现在跃动冰川主干或支部，流速大小一般在 100.00 m·a-1 之上，如在音苏盖提冰川南分支， 其最大流速可达到 358.33 m·a- 1。（2）冰川流速分布与地形要素的关系密切。流速在海拔 4600~ 5000 m 之间达到最大（54.55 m·a-1），是冰川末端流速的 10 倍以上；分布在坡度 0~5°之间的 42 条冰 川平均流速最大，并且随着坡度的增大，流速逐渐减小；处于东向的冰川流速最大，处于西南向的 流速最小。（3）稳定冰川流速年际变化较稳定，不同年份相同位置的流速值较一致；而对于前进冰 川和退缩冰川而言，年际流速波动均较大；跃动冰川不同位置年际流速变化不同。末端发生前进 的跃动冰川表面流速变化不大，但末端变化速度却可超过 100.00 m·a-1，甚至可达到 500.00 m·a-1。（4）长度更长、面积更大的冰川易发生跃动。气候、雪崩和地形也是影响冰川运动速度变化的主要 原因。
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