Antecedent Precipitation Index to Estimate Soil Moisture and Correlate as a Triggering Process in the Occurrence of Landslides

Landslides are highly dangerous phenomena that occur in different parts of the world and pose significant threats to human populations. Intense rainfall events are the main triggering process for landslides in urbanized slope regions, especially those considered high-risk areas. Various other factors contribute to the process;thus, it is essential to analyze the causes of such incidents in all possible ways. Soil moisture plays a critical role in the Earth’s surface-atmosphere interaction systems;hence, measurements and their estimations are crucial for understanding all processes involved in the water balance, especially those related to landslides. Soil moisture can be estimated from in-situ measurements using different sensors and techniques, satellite remote sensing, hydrological modeling, and indicators to index moisture conditions. Antecedent soil moisture can significantly impact runoff for the same rainfall event in a watershed. The Antecedent Precipitation Index (API) or “retained rainfall,” along with the antecedent moisture condition from the Natural Resources Conservation Service, is generally applied to estimate runoff in watersheds where data is limited or unavailable. This work aims to explore API in estimating soil moisture and establish thresholds based on landslide occurrences. The estimated soil moisture will be compared and calibrated using measurements obtained through multisensor capacitance probes installed in a high-risk area located in the mountainous region of Campos do Jordão municipality, São Paulo, Brazil. The API used in the calculation has been modified, where the recession coefficient depends on air temperature variability as well as the climatological mean temperature, which can be considered as losses in the water balance due to evapotranspiration. Once the API is calibrated, it will be used to extrapolate to the entire watershed and consequently estimate soil moisture. By utilizing recorded mass movements and comparing them with API and soil moisture, it will be possible to determine thresholds, thus enabling anticipation of landslide occurrences.

果树穴贮砖对南疆温室软籽石榴光合特性及氮素吸收的影响

为探究适用于南疆温室沙地土壤条件下的氮肥增效措施,以3 a生‘突尼斯’软籽石榴为试材,设置无果树穴贮砖(CK)、施加果树穴贮砖A(T1)和果树穴贮砖B(T2)共3个处理,研究施加果树穴贮砖对软籽石榴光合特性及氮素吸收的影响。结果表明:T1、T2处理显著增加了1个灌水周期内第1天的石榴叶片叶绿素指数及第3天和第5天的氮平衡指数,提高了叶片净光合速率、气孔导度、胞间二氧化碳浓度、蒸腾速率的日均值,总体上以T1处理较好;与CK相比,T1和T2处理的石榴茎、叶、根中的全氮、硝态氮含量均有显著提升,同时茎和叶中的铵态氮含量也有显著提升,总体表现为T1>T2>CK。综上,施加果树穴贮砖有助于提升南疆温室沙地土壤条件下软籽石榴植株光合性能以及氮素吸收,本研究以施加果树穴贮砖A处理效果最佳。

工业企业水平衡测试与节水分析

企业水平衡测试是促进工业节水的一项行之有效的方法,本文对某工业企业的取用水状况及水源之间的转换、回收利用的关系进行分析,将用水过程细化到单台设备,同时分工序、分厂区进行量化汇总,对可完善之处提出合理化的分析和建议。为健全企业用水档案,弥补和完善供用水基础资料,也为企业今后有序生产发展,提升用水管理水平提供依据和参考资料。

Water and Nitrogen Management Effects on Biomass Accumulation and Partitioning in Two Potato Cultivars

Biomass accumulation and partitioning into different plant parts is a dynamic process during the plant growing period, which is influenced by crop management and climate factors. Adequate knowledge of biomass partitioning is important to manage the crops to gain maximum partitioning of assimilates into plant parts of economic significance, i.e. tubers in potato. This study was conducted using two potato cultivars grown in a sandy soil with center pivot irrigation under full irrigation (FI;irrigation to replenish 100% of water loss by evapotranspiration [ET]) and deficit irrigation (DI;replenish only 80% ET) and two nitrogen(N) rates (pre-plant + in-seasonN rates of 56 + 112 or 168 + 336 kg/ha). Plant samples were taken on 22, 44, 66, and 98 days after seedling emergence (DAE). With high N rate, tuber biomass of ‘Umatilla Russet’ cultivar in relation to total plant biomass varied from 23% - 88% and 25% - 86% over 22 to 98 DAE for the FI and DI treatments, respectively. The corresponding partitioning ranges were 30% - 93% and 38% - 93% at the low N rate. With respect to the‘Ranger Russet’ cultivar, biomass partitioning to tubers ranged from 36% - 82% and 23% - 84% for the FI and DI, respectively, at the high N rate, and 29% - 87% and 39% - 95% at the low N rate. Overall, this study demonstrated that within the range of N rate and irrigation treatments the biomass portioning into tubers was largely similar in both cultivars.

基于实际蒸散量修订标准化降水蒸散干旱指数研究

为改进SPEI在农业干旱监测中的效果,从水分平衡的角度提出了一种修订的标准化降水蒸散指数(MSPEI).该指数通过计算降水与实际蒸散量的差值,并基于最长连续干旱时间对差值进行自适应修正,采用目视检查概率拟合曲线与Kolmogorov-Smirnov检验2种方法选择适宜分布函数,最后进行标准化转换生成干旱指数.干旱指数有效性检验表明:MSPEI能够准确反映不同季节间干湿状态的差异,在湿润比例低于20%的春季,MSPEI均低于-0.5;在反映干旱趋势时,MSPEI与SPEI具有高度一致性;MSPEI与植被指数具有稳定且较高的相关性,在0.57~0.78之间;在典型干旱过程监测中,MSPEI对旱灾发生、发展和解除过程的描述更符合实际.MSPEI适应于不同气候背景,无需选择时间尺度,即可较准确地反映农业干旱演化过程.

Spatial patterns of ecological carrying capacity supply-demand balance in China at county level

A balanced ecological carrying capacity and its understanding are important to achieve sustainable development for human kind.Here,the concept of ecological carrying capacity has been used for measuring the dependencies between human and nature.China＇s ecological balance between supply and demand has become a global concern and is widely debated.In this study the ＇Ecological Footprint＇ method was used to analyze the supply-demand balance of China＇s ecological carrying capacity.Firstly,the ecological supply and demand balance was calculated and evaluated,and secondly,the ecological carrying capacity index （ECCI） was derived for each county of China in 2007,and finally this paper systematically evaluated the ecological carrying capacity supply-demand balance of China.The results showed that ecological deficit appeared to be the main characteristic of ecological carrying capacity supply-demand balance in 2007 of China at county scale.In general,more than four-fifths of the Chinese population was concentrated in less than one-third of the land area and more than two-thirds of the land area was inhabited by less than one-fifth of the population.The spatial distribution of the ecological carrying capacity demand-supply was unbalanced ranging from significant overloading to affluence from southeastern to northwestern part of China.It appeared to be more dominant in regions located at coastal areas which are attracted by migrants and had a generally higher population density.Along with the rapid development and urbanization trends in China,ecological deficits in these regions will become more severe.

基于水资源刚性约束的城市节水潜力分析

为满足水资源刚性约束制度的要求,有效保障城市农业、生活及生产用水安全,以江苏省宿迁市为例开展不同规划年各来水条件情景下的节水潜力分析。用水总量控制管理是落实水资源刚性约束的重要标准,在节水潜力计算过程中,基于节水目标与强度设定了“基本方案”与“节水方案”,以区域用水总量控制指标为约束,构建了基于目标控制的节水潜力模型,从农业、第二第三产业、生活3个模块分析规划年宿迁市可节水量。结果表明:采用“节水方案”后,宿迁市基本能够满足水资源供需平衡,在P=95%的来水频率下,仅沭阳县处于轻度缺水状态;在P=50%来水频率下,发展至2025年及2030年,宿迁市全市节水潜力分别可达7.5069亿m^(3)和6.9293亿m^(3);在宿迁市两区三县中,沭阳县可节水量最大,未来应合理规划,充分挖掘地区节水潜力。研究成果可为区域节水潜力发展提供参考。

基于分层需水的水资源均衡配置研究

水资源配置是缓解区域水资源供需矛盾、均衡水与发展的关键措施。根据新时期水资源精细化管理的有关要求,以农业、工业、生活、生态用水户为对象,基于分层需水相关理论和已有成果,提出了刚性需水、弹性需水的计算方法;综合考虑社会、经济、环境效益,构建了面向分层需水的水资源优化配置模型,采用NSGA-Ⅲ算法与EMW-TOPSIS法求解得到4种效益配置方案;以用水基尼系数表征配置单元间、用水户间的用水公平性,对非劣解集内配置方案的用水公平性进行评价,筛选出兼顾用水公平和效益的均衡配置方案;最后以宁夏回族自治区为典型研究区,进行案例应用。结果表明:均衡配置方案下,2025年宁夏全区总缺水量为10.74×10^(8)m^(3),经济效益为2182.6×10^(8)元,污染物排放量为162.78 t,该方案对应的全区用水基尼系数为0.98,配置单元间、不同用水户间用水公平性较高;与现状年相比,均衡配置方案对应的全区地下水开采量减少了0.91×10^(8)m^(3),降幅超过16.1%,地下水供水量占总供水量比例下降1.3%,进一步优化了自治区供水结构。本研究提出的水资源均衡配置思路与方法可为水资源短缺地区均衡配置提供借鉴,也可为新时期落实水资源刚性约束制度提供技术支撑。

Spatio-temporal Evolution and Flow of Water Provision Service Balance in Jinghe River Basin

Quantifying the whole process of ecosystem services from generation through transfer to use,and analyzing the balance between the supply and demand of regional ecosystem services are of great significance for formulating regional sustainable development strategies,realizing regional ecosystem management,and effective resource allocation.Based on the SWAT model,InVEST model,ArcGIS,and other software,this study analyzed the supply-demand balance of water provision services in Jinghe River Basin,a typical region located in the Loess Plateau,using multi-source data.This research then analyzed the spatial-temporal distribution pattern and spatial matching characteristics of the supply and demand of water provision services in Jinghe River Basin from 2000 to 2015.On this basis,a spatial flow model of water provision service was constructed,the flow rules(flow paths)of the water provision service were explored at the subwatershed scale,and the spatial scope of the supply area and benefit area were depicted.The results show that:(1)Water resource supply and demand in the Jinghe River basin both showed increasing trends from 2000 to 2015.(2)The supply-demand balance of water resources was generally up to the standard,however,there were significant differences between urban and rural areas.The supply-demand balances of the central urban areas of each county were relatively low,and even exceeded the supply in the lower reaches of the Jingyang River,such as Gaoling County,Qindu District,and Jingyang County.In rural areas,due to the small population and industrial distribution,coupled with a better ecological environmental base,the supply-demand balance was relatively high,such as Pengyang County,Lingtai County,Huachi County,Huanxian County,Ningxian County,and Zhenyuan County.(3)From 2000 to 2015,the spatial matching pattern of supply and demand in the Jinghe River Basin showed a trend of decline with fluctuations.In 2015,the supply-demand ratios of more than 60%of the subwatersheds showed trends of decline,and the proportion of under-supply area increased by 55.7%in 2015 compared with that in 2000.(4)The supply areas of water provision service in Jinghe River Basin are distributed in the upper reaches of the basin,and the benefit areas are Huating County,Chongxin County,Yongshou County,Chunhua County,Ganxian County,Liquan County,Qindu District,and others in the middle and lower reaches.

干旱条件下南方红壤丘陵地区水分平衡

全球变暖背景下近些年中国南方地区干旱气候事件频发,水土资源匹配态势并不乐观。论文以吉泰盆地为案例区,采用标准化降水指数,系统诊断吉泰盆地近50a的干旱态势,识别干旱的类型与强度;构建水分平衡模型,重演历史干旱气候条件下南方红壤丘陵地区耕地、林地等主要用地类型的水分平衡。研究表明,1960-2010年,吉泰盆地近30%的年份发生了干旱,频率较高。其中,轻旱发生的频次最高,特旱位居其次,吉泰盆地干旱大多发生于伏秋期间;无旱气候条件下,吉泰盆地水分平衡量约为448mm,自然降水整体可以满足林地和耕地等主要用地类型的水分需求,水分盈余是其平衡关系的基本特征,盈余量整体呈现河谷、平原低于丘陵、山地的空间格局;轻、中、重和特旱气候条件下,吉泰盆地耕地水分平衡量由无旱态势下的盈余转为亏缺,林地的水分盈余量下降幅度在37.87%～77.80%;轻、中、重旱气候条件,吉泰盆地的水分平衡量较无旱时依次下降了55.07%、70.28%和96.08%;在特旱气候条件下,缺水量达72mm;随着干旱程度的加剧,吉泰盆地水分盈余量降低、亏缺量增加。

农灌区土壤次生盐渍化的防治方法及实例分析

系统提出灌区土壤产生次生盐渍化的防治方法 ,分析农灌区发生土壤次生盐渍化的研究实例 .认为盐随水来 ,但不易随水去 ;提高灌溉效率 ,加强排水 ,建立盐水土地处理系统 。

基于土壤水分平衡模型的广东干旱时空分布特征

根据广东省86个气象站1962-2006年逐日气象资料,基于土壤水分平衡模型,计算逐日土壤有效含水量,模拟土壤水分平衡状况,构建逐日干旱动态指数DI,根据DI分析广东近45a不同等级干旱的时空分布及变化规律。结果表明:(1)广东省全年干旱日数占28.7%,轻、中、重、极旱发生频率依次减少;(2)近45a平均干旱过程强度指数(DCI)的季节变化特征明显,汛期较低,汛期结束后DCI值迅速上升;(3)1962-2006年,年干旱日数和DCI值均显著上升,说明广东省干旱的发生频率和严重程度逐年上升;(4)DCI和全年干旱日数在全省范围内基本呈纬向分布,北低南高。粤北的连山附近是全省DCI值和干旱日数最低的区域,雷州半岛及东南沿海地区DCI值和干旱日数较高;(5)春季与秋季的DCI空间纬向分布基本相反,表现为春季南部较旱、秋季北部较旱;(6)秋季月平均DCI值高于春季,说明广东省秋旱情况重于春旱。研究结果对应对气候变化、开发利用气候资源、调整种植区划和农业生产布局具有重要参考价值。

基于ET管理的县域水资源合理配置研究

根据ET管理理念对水资源供耗评价指标体系进行整理,运用SWAT模型模拟ET,并以新乡县为例进行县域水资源供耗平衡分析和优化配置。结果表明,运用SWAT模拟所得到的ET比遥感ET能够更合理的反映实际耗水量,SWAT模拟ET的Nash-Sutcliffe效率系数(ENS)达0.75;根据SWAT模拟规划水平年(2010、2015、2020年)的可消耗ET,在社会、经济、环境和生态等目标中进行平衡后,再对新乡县水资源进行最优配置,可使新乡县2020年的水资源供耗达到平衡。

农田土壤墒情预报研究现状及不同预报方法的对比分析

土壤墒情预报是实施农田土壤水分有效调控的基础和前提。回顾总结了国内外土壤墒情预报研究发展的历史和现状,并对几种预报模型进行了重点对比分析。在此基础上,对现有研究中存在的问题及发展趋势和今后研究的重点进行了展望。

黑河流域水资源承载能力分析

黑河流域属资源性缺水地区,区域水资源难以满足当地社会经济发展和生态平衡的需要。随着西部大开发战略的逐步实施,西北干旱内陆河地区水资源的支撑作用将显得愈来愈重要。因此分析黑河流域水资源现状条件下对区域经济、社会发展的承载能力,显得极为重要。根据黑河流域具体情况,结合流域经济社会发展特点、生态环境状况,以遏制并逐步改善流域生态环境为基本前提,以流域水资源承载能力为约束。首先利用水资源承载压力指数计算了现状条件下黑河流域水资源承载压力度,得出目前黑河流域水资源承载能力属于超负荷承载。水资源将成为制约黑河流域社会经济发展和保证生态平衡的重要因素。当前必须立足于当地的水资源条件,按照以供定需的原则,合理安排生活、生产和生态用水,才能实现流域经济社会和生态环境的协调和可持续发展。然后针对超载现状,对黑河流域规划水平年(2010年)水资源承载能力作进一步的分析评价,根据相关预测资料设计了3种可能情景,利用流域评价的发展系数、协调系数、公平系数和可持续发展系数,从水资源开发利用方式、社会发展方式、经济发展模式、生态恢复程度等方面分析水资源承载能力,并计算其水资源承载压力度,同时结合水资源的可持续发展建立流域可持续发展评价指标体系,进行方案组合和各种发展模式的水资源优化配置。满足流域水资源支撑经济社会可持续发展判据的方案的承载能力指标即为该方案下的水资源可持续承载能力指标。通过对黑河流域现状及规划水平年的水资源承载能力及可持续发展度分析评价,利用水资源可持续发展战略分析,选取出了最优发展模式,为流域的可持续发展提供了基本依据。通过寻求情景方案中水资源承载能力和可持续发展度的最佳组合,实现了经济、社会与生态的可持续发展目标。结果表明:通过努力,谋求经济和社会与水资源承载能力协调发展是有可能实现的。

长武县水资源承载力分析计算与评价

水资源的用水结构和承载力的计算是当前人们普遍关注的问题,探讨县域水资源承载力是维持县域经济社会健康发展的重要环节。从长武县2007年水资源现状出发对县域范围内的用水结构及水资源承载力平衡指数进行计算与分析。结果表明:长武县用水结构中,农业、工业、生活、养殖业用水量比例分别为0.65∶0.29∶0.04∶0.01,农业用水占总用水量的1/2以上;长武县可利用水资源量大于总用水量,水资源承载力供需平衡指数大于0,说明长武县水资源供给充足,具备当前规模的经济社会系统的支撑能力。

利用气藏生产指示曲线计算凝析气藏水侵量

水驱凝析气藏在已开发的气田中占有一定比例,其在开发过程中会出现凝析油析出的特殊现象,导致该类气藏水侵量的计算更加复杂。凝析气藏作为一类特殊气藏,当气藏压力低于露点压力时,流体中会出现反凝析液相物。基于水驱凝析气藏的生产特征,推导出新型的水驱凝析气藏物质平衡线性方程,该方程考虑了当凝析气藏压力低于露点压力时析出凝析油对水侵量计算的影响。利用该方程绘制的生产指示曲线可方便、快速并准确地计算出水驱凝析气藏不同时期的水侵量。实例应用表明,与其他水驱凝析气藏水侵量计算方法相比,该方法更简便、快捷,而且计算结果准确,实用性强。

液体平衡和血管外肺水指数变化及腹内压变化对感染性休克预后的影响研究

目的分析液体平衡、血管外肺水指数（EVLWI）和腹内压（IAP）变化对感染性休克患者预后的影响。方法选择2011年3月—2012年8月杭州师范大学附属医院重症医学科收治的57例感染性休克患者,采集患者3d内的液体入量、尿量、脉搏指数连续心输出量（PICCO）及IAP。以存活28 d为界,将患者分为存活组（38例）和死亡组（19例）,分析两组患者液体平衡量的差异。分别以血管外肺水指数差值（ΔEVLWI）〈-3 ml/kg和腹内压差值（ΔIAP）〈-1 mm Hg（1 mm Hg=0.133 kPa）将患者分为效应组和非效应组,对比两组患者的病死率。结果存活组和死亡组患者入ICU 6 h内液体平衡量间差异无统计学意义（P〉0.05）,入ICU第1、2、3天总液体平衡量间差异有统计学意义（P〈0.0001）。存活组ΔEVLWI为（-3.91±1.21）ml/kg,死亡组ΔEVLWI为（-2.03±1.92）ml/kg,存活组ΔIAP为-1.0（-2.0～1.0）mm Hg,死亡组ΔIAP为1.0（0～2.0）mm Hg,两组ΔEVLWI和ΔIAP间差异有统计学意义（t=4.53、3.70,P〈0.05）。ΔEVLWI和ΔIAP与3 d内总液体平衡量间呈正相关关系（r=0.43,0.40,P〈0.05）;ΔEVLWI、ΔIAP效应组病死率明显低于非效应组（22%和55%,4%和53%）。结论感染性休克存活患者3 d内多出现液体负平衡,而死亡患者未出现液体负平衡,提示液体负平衡的出现能够改善患者预后,入ICU后3 d内ΔEVLWI减少3 ml/kg或ΔIAP减少1 mm Hg提示患者预后良好。

黄河流域1961—2012年蒸散发时空变化特征及影响因素分析

基于黄河流域1 500个0.25°×0.25°网格,应用可变下渗能力模型VIC-3L计算1961—2012年黄河流域水文过程,获得日尺度的实际蒸散发量和潜在蒸散发量数据。运用Mann-Kendall趋势检验方法和Budyko水分能量平衡公式,分析了实际蒸散发量、潜在蒸散发量、蒸散发率和干燥指数的时空变化趋势及蒸散发受水分能量供应条件限制情况。结果表明:总体上实际蒸散发量和潜在蒸散发量呈减小趋势,其中潜在蒸散发量减小趋势显著,但在流域不同区域的增减趋势不同;蒸散发率和干燥指数的变化不明显;黄河流域上游蒸散发主要受能量供应条件限制影响,而中下游受水量供应条件限制影响较大。

退耕还林还草过程中不同土地利用方式土壤呼吸作用及其碳收支评估

采用动态密闭气室法对黄土高原水蚀风蚀交错区9种土地利用方式植物生长季节内(2010年6—10月)土壤呼吸速率及其主要影响因子进行测定,分析不同土地利用方式间土壤呼吸的差异性和土壤呼吸对温度、土壤水分、叶面积指数等因子的响应,对7种土地利用方式土壤碳收支进行了估算。结果表明,植物生长季节内,不同土地利用方式下土壤呼吸速率呈多峰型变化趋势。裸地、农地、梯田农地、苜蓿地、撂荒地、长芒草地、荒草地、沙柳地、沙蒿地的土壤呼吸速率季节变化范围分别为0.18～1.05、0.30～2.08、0.50～1.71、0.53～2.78、0.26～1.08、0.39～1.93、0.30～2.27、0.43～1.43、0.39～1.26μmol·m-2·s-1。9种土地利用方式下土壤呼吸速率均与气温和5、10、15cm地温呈显著相关(P<0.05)或极显著相关(P<0.01),而与0～6cm土壤水分相关性不显著。9种土地利用方式下地温对应的Q10值均表现为15cm地温>10cm地温>5cm地温。研究区域内土壤呼吸速率与其地上植被叶面积指数呈极显著线性相关关系(r=0.679,P<0.01)。