Quantitative modeling of cyanobacterial concentration using MODIS imagery in the Southern Caspian Sea

The cyanobacterial harmful algal blooms have been observed, over the last decade, in several regions of the southern Caspian Sea, becoming a major threat to human health and aquatic life. The present study aims to develop two models to quantify cyanobacterial concentration in the Caspian Sea using artificial neural networks and multiple band linear regression. The models are based on Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery. Data were collected from the west, center, and east of the southern Caspian Sea between September 2015 and August 2016. The field dataset includes 123 samples in seven different transects and is used to define and evaluate the proposed methods. The Root Mean Square Error (RMSE), unbiased RMSE (URMSE), and correlation coefficient (R) values between Multiple Band Linear Regression Algorithm outputs and field dataset are 1.8 × 10⁻³ mg.m⁻³, 22.43%, and 0.73, respectively. For Artificial Neural Network (ANN), the outputs are 1.6 × 10⁻³ mg.m⁻³, 18.89%, and 0.81, respectively. The performance of the proposed methods is proven suitable under nearly all conditions of the southern Caspian Sea. However, numerical comparison and visual evaluation of the results show that the ANN method is less sensitive to small changes in the environmental conditions, leading to more stable results. Moreover, the ANN model provides accurate results in most cases, and the accuracy of this results are improved by increasing the training data. This study focused on the development and validation of an optimal algorithm for quantifying temporal and spatial variability phycocyanin concentrations in the Caspian Sea using daily satellite data.     

Optimal Water Allocation of Surface and Ground Water Resources Under Climate Change with WEAP and IWOA Modeling

Water Resources Management - The water evaluation and planning (WEAP) approach and the invasive weed optimization algorithm (IWOA) are herein employed to determine the optimal operating policies in...     

Ground Water-Surface Water Interface (GWSWI) Modeling: Recent Advances and Future Challenges

Ground water-surface water interface (GWSWI) represents the interconnection of ground water and surface water in the hydrologic continuum. Interactions between these two water masses result in unique gradients and/or transitions of contaminant concentration profiles, biological populations, chemistry, flow, mixing characteristics, redox potential, dissolved oxygen, organic content, and thermal properties across GWSWI. In addition, many unique biogeochemical processes occur in this zone that can have significant impact on the fate and transport of contaminants across the GWSWI. Prediction of the distribution and concentrations of contaminants across the GWSWI is challenging, but is essential for evaluating human health and environmental risk, including remedial alternatives at contaminated sites. The objective of this paper is to review and assess existing modeling capabilities to recognize (a) the need for development of new modeling tools, (b) knowledge gaps, and (c) challenges required to address contaminant transport within GWSWI. Currently, the most important needs for future model development are, (a) linkage between ground water and surface water models; (b) integration of process-level models within the framework of large-scale models; and (c) understanding ground water-surface water interactions within a spatial and temporal framework.     

灌溉水质及土壤初始含盐量对作物出苗的影响

为了研究灌溉水及土壤中含盐量对作物出苗情况的影响,采用盆栽的方式,选取了几种耐盐性不同的作物和牧草,对微咸水灌溉与土壤初始含盐量对作物的出苗率及出苗时间的影响展开研究。结果表明:随着灌溉水矿化度和土壤初始含盐量的增大,作物的出苗率逐渐减小,出苗时间逐渐变长;土壤初始含盐量和由灌溉水带入土壤中的盐分数量相当时,灌溉水矿化度对作物出苗率和出苗时间的影响都大于土壤初始含盐量对其的影响,且作物耐盐性越强,这种差别越明显。灌溉水中的含盐量对作物的影响要大于土壤中的含盐量,因此,对于矿化度较高的微咸水资源,不可以用于灌溉,但可以用于盐碱地淋洗盐分。     

灌溉定额与灌溉水矿化度对春玉米水分利用效率影响研究

通过在甘肃省石羊河流域开展春玉米咸水灌溉田间试验,研究了灌溉定额和灌溉水矿化度对春玉米耗水量及水分利用效率的影响.研究结果表明:春玉米耗水量随着灌溉定额的增大而增大,随着灌溉水矿化度的增大而减小.而从充分利用土壤贮水的角度考虑,非充分灌溉能够提高土壤播前贮水的利用量,而咸水灌溉则会降低土壤贮水利用量;非充分灌溉有利于提高春玉米的水分利用效率和灌溉水分利用效率,而咸水灌溉会降低春玉米的水分利用效率和灌溉水分利用效率.本次试验得到淡水轻度缺水灌溉处理的水分利用效率和灌溉水分利用效率最大值分别为2.90 kg/m~3和4.23 kg/m~3.与淡水充分灌溉处理相比,在研究区若采用灌溉定额为340 mm和灌溉水矿化度为0.71 g/L的灌溉方式,春玉米的水分利用效率和灌溉水分利用效率可提高25%以上,同时可节水170 mm.     

齐鲁石化公司堠皋地下水处理利用设计

简要介绍了齐鲁石化公司堠皋地下水处理利用项目设计 ,主要包括水源和处理水量、工艺流程、主要构筑物与设备选型、各处理单元去除效率以及自动控制等内容。     

Assessment of Water Resources and Salinity Intrusion in the Mekong Delta

Abstract

A methodology is presented for the assessment of water resources and salinity intrusion in the Mekong Delta in Vietnam. The flow and water salinity at different locations in the river network have been dynamically assessed by the developed three-step approach in which the hydrodynamic, advection-dispersion models, harmonic analysis, and regression techniques have been employed in the development of the relationships between the boundary conditions (upstream inflows and tides at river mouths) and the harmonic constituents of flow and water salinity. These relationships were subsequently used to determine the parameter values of harmonic constituents of flow and water salinity at specific locations under various hydrologic conditions and water allocation alternatives as needed for water management purpose. With known harmonic parameters, the flow and water salinity at the locations can be predicted by a harmonic analysis method and the river water available for agricultural use can then be determined. The advantage of this methodology is that the river water can be dynamically assessed without performing the hydrodynamic and advection-dispersion simulations in the water resources management process. Due to the limitation of data availability, a preliminary assessment of groundwater resources has been included. The results indicate that the use of groundwater as supplemental resources for agricultural production is possible     

地下水资料整编系统的应用开发

本文简要介绍了地下水资料计算机整编系统的特点与功能、系统开发的主要结构和系统操作要点。     

基于水资源合理配置的地下水开发利用研究

以焉耆县为例,采用趋势法、指标法、规划定额法、万元产值预测与回归分析等方法,从生活需水、生产需水、生态需水3个方面预测需水量。利用焉耆县近10 a的流量频率分析曲线,选取典型年,采用同倍比放大法,推求设计代表年内流量分配,并预测地表供水量。在供、需水计算基础上,采用定性用水定额法对研究区水资源供需平衡进行分析,计算出焉耆县各水平年全年缺水量及最大缺水月份;根据地下水水量平衡原理,得出焉耆县地下水补给与排泄处于均衡状态。研究表明,考虑研究区的地下水生态水位,确定利于灌区水资源合理配置的地下水开采量为2.47亿m3。     

龙江县地下水水质评价

通过评价龙江县地下水的生活用水、工业用水、农田灌溉用水,提出了生活用水应采取除铁措施,氟离子含量过高造成的危害及治理措施,农田灌溉用水需作增温处理等措施与建议。     

井灌区地下水动态模拟的面状井系--水均衡综合模型

以亳州市城北乡灌区为实例 ,采用面状井系模型和水均衡模型 ,来模拟灌区地下水动态变化 ,两个模型结果相互印证 ,所得的结果是可靠的 ,有实际应用意义 ,可推广应用于水文地质条件类似地区     

黄河流域与地表水不重复的地下水资源特征分析

黄河流域1956～2000年多年平均,与地表水资源不重复的地下水资源量为112．32亿m^3,其中山丘区为39．89亿m^3、平原区为72．43亿m^3;1980～2000年多年平均,不重复的地下水资源量为110．35亿m^3,其中山丘区为43．61亿m^3、平原区为66．74亿m^3。1980-2000年均值与1956—2000年均值相比,全流域不重复的地下水资源量有所减小,但山丘区由于近年浅层地下水开采量增加,使得不重复的地下水资源量有增大的趋势。     

盐度分层水域温排水流动特性的三维数值模拟

为了研究盐淡水分层水域温排水的水力热力特性,在物理模型试验的基础上,基于ECOMSED三维非线性水动力模式,在考虑上游径流和潮流共同作用的情况下,对温度和盐度相互影响的水流进行了数值模拟。在对该水域的潮流验证良好的基础上,通过模拟得到了温度和盐度的垂向分布、不同水深处全潮平均温升场,以及涨急、涨憩、落急、落憩四个典型时刻温度场的特征值,与试验值进行比较,分析温盐扩散的机理。结果表明,该数值模型基本反映了非恒定盐淡水交汇水域的温盐输运扩散规律。     

宝鸡峡灌区地表水与地下水联合调度研究

针对宝鸡峡灌区水资源开发利用中存在的问题,结合灌区作物种植结构、灌溉方式.建立了地表水与地下水联合调度模型,以灌区经济效益最大为目标,以供需水平衡、可供水量、地下水位等为约束条件,以优先利用地表水为原则,进行了模型求解.结果表明:丰水年、平水年、枯水年3种水文年份灌区灌溉水源均应以地表水为主、地下水为辅;增加地袁水供水的比例,有利于灌区经济效益的提高,可以起到以丰补枯、涵养地下水源、缓解水资源供需矛盾的作用.     

黄河水对下游两岸地下水质的影响分析

黄河下游沿黄两岸(河南段)埋藏有丰富的地下水资源,是沿黄城市供水的前景水源地。应用水文地质学理论,以郑州市“九五滩”水源地水质分析资料为依据,对比分析了黄河对两岸地下水的影响。结果表明：①黄河水化学成分中SO4^2-、Cl^-、Na^ 、NO3^-的含量明显高于地下水,Fe、Mn、HCO3^-的含量明显低于地下水,其他成分二者相近。②对地下水有影响的主要是Cl^-、SO4^2-,表现为距黄河越近影响越大、含量越高,越远影响越小、含量越低;随水源地开采时间的延长有增加趋势,但其绝对含量不会超过黄河水。     

黄河水对两侧地下水补给范围的初步研究

黄河下游黄河水补给地下水的范围在自然和人为双重因素的影响下变得非常复杂，至今在学术界也没有定论。通过系统研究黄河流域地下水的动态特征，划分了水型、水－气象型到气象－水型，逐渐过渡到气象型、气象－灌溉型和气象－开关型等动态类型，并于2000年和2001年进行了两次地下水流场统一调查和同位素测试分析。采用地下水流场分析法和同位素测试分析法综合研究，较准确地划分了黄河不同河段影响带的宽度，为黄河影响带地下水资源评价奠定了基础。     

GIS-Aided Modeling of Nonpoint Source Pollution Impacts on Surface and Ground Waters

An application of GIS-aided modeling is done at an area in South Florida. A Geographic Information System (GIS) is interfaced with a nonpoint source pollution model to facilitate data storage, management and display; derivation of model input parameters; and effective presentation of results. parameters, and to visually present results in maps. Results for current conditions and practices show that sediments, nutrients and pesticides are present in surface runoff and ground water. Two alternatives to minimize pollution levels are evaluated, i.e., reduction of fertilizer application to the minimum required for effective agricultural growth and replacement of fertilizers with sewage sludge. In addition, the impact of urbanization of the agricultural area to the pollutant levels is tested. Both alternatives and the urbanization result in overall reduction of pollution.     

黄河流域平原区地下水可开采量分析

根据本次（2002～2004年）全国水资源综合规划——《黄河流域水资源调查评价》成果，采用可开采系数法或实际开采量调查法评价黄河流域平原区浅层地下水可开采量，并将本次评价结果与上次（1982～1985年）评价结果进行对比分析。黄河流域平原区浅层地下水矿化度肼≤2g／L的计算面积为152485km^2，浅层地下水总补给量为161.94亿m^3，可开采量为119．39亿m^3；其中矿化度肼≤1g／L的可开采量为90．75亿m^3，占平原区地下水可开采量的76％。本次评价与上次评价成果相比，全流域平原区浅层地下水矿化度肼≤2g／L的计算面积减少了14522km^2，总补给量和可开采量成果基本接近。