NPS MODEL PARAMETER UNCERTAINTY ANALYSIS FOR AN OFF-STREAM RESERVOIR1

ABSTRACT: Parameter uncertainties exert a significant effect on nonpoint source pollution (NPS) modeling results. A decision made on the basis of such results may thereby be inappropriate. In this work, the parameter uncertainty is analyzed to explore an improved modeling procedure. Drainage patterns generated from digital elevation data and rainfall are the major parameters examined. A case study for the watershed of the Posan off-stream reservoir is implemented. A significant spatial variation of NPS distribution simulated with a drainage pattern generated from varied methods is observed. The effects of rainfall randomness on the spatial loading distribution are assessed and computed based on a Monte Carlo simulation. The proposed procedure is capable of improving the quality of modeling results and the decision for an appropriate control strategy.     

三峡库区奉节县土地承载力与移民安置

人口环境容量的研究是提高移民安置工作科学性的基础，通过对四川奉节县人口及土地资源调查数据的分析，考察了三峡水库淹没对库区人口环境容量的缩减；对库区不同区域，不同类型的土地对人口的承载能力进行定量分析；研究了移民安置与环境容量的关系；探讨了通过大农业和通过城镇化、非农化等方式安置农村移民的对策。     

PRACTICAL IMPLICATIONS IN THE USE OF STOCHASTIC DYNAMIC PROGRAMMING FOR RESERVOIR OPERATION1

ABSTRACT: A stochastic dynamic programming model is applied to a small hydroelectric system. The variation in number of stage iterations and the computer time required to reach steady state conditions with changes in the number of storage states is investigated. The increase in computer time required to develop the storage probability distributions with increase in the number of storage states is reviewed. It is found that for an average of seven inflow states, the largest number of storage states for which it is computationally feasible to develop the storage probability distributions is nine. It is shown that use of the dynamic program results based on a small number of storage states results in unrealistically skewed storage probability distributions. These skewed distributions are attributed to “trapping” states at the low end of the storage range.     

涔天河水库灌区土壤资源特点及其合理利用

对涔天河水库灌区土壤资源现状，特点进行了调查研究，对土壤资源利用中存在的问题进行了剖析，并提出了合理利用土地资源，提高土壤生产力的措施。     

Longitudinal‐Vertical Hydrodynamic and Turbidity Simulations for Prediction of Dam Reconstruction Effects in Asian Monsoon Area1

Abstract: This research investigates possible impacts of enlarged water body according to dam reconstruction on the hydrodynamics and water quality of the reservoir using a laterally averaged, two‐dimensional hydrodynamic and transport model, CE‐QUAL‐W2. The lake was formed by the artificial dam in 1983 for agricultural water supply and is currently under consideration of reconstruction so as to expand the volume of reservoir for flood control as well as water supply in downstream areas. To calibrate and validate the model, field‐collected data were compared with model predictions for water level fluctuations and water temperature during the years of 2001 (from January to December) and 2003 (from March to November). The model results showed a good agreement with field measurements both in calibration and verification. Utilizing the model, impacts of dam reconstruction on the thermal hydrodynamics and turbid current were predicted. From the model results, dam reconstruction limited the depth of thermal stratification below 10 meter and formed steep temperature gradient between epilimnion and hypolimnion. The restricted thermal stratification persisted up to the end of September. This result indicated that thermal stratification would become stronger during summer and stay longer after dam reconstruction. In addition, the restricted thermal stratification caused vertical circulation of water mixing lower than 10 meter and isolated the upper water layer from the lower water layer which increased the volume of hypolimnetic water with low temperature. The vertical circulation near the surface also mitigated propagation of density plume within the depth of 10 m which would remain the hypolimnetic water clean.     

Effect of a seasonal di use pollution migration on natural organic matter behavior in a stratified dam reservoir

This article aims to describe the influence of di use pollution on the temporal and spatial characteristics of natural organic matter (NOM) in a stratified dam reservoir, the Daecheong Dam, on the basis of intensive observation results and the dynamic water quality simulation using CE-QUAL-W2. Turbidity is regarded as a comprehensive representation of allochothonous organic matter from di use sources in storm season because the turbidity concentration showed reasonable significance in a statistical correlation with the UV absorbance at 254 nm and total phosphorus. CE-QUAL-W2 simulation results showed good consistency with the observed data in terms of dissolved organic matter (DOM) including refractory dissolved organic carbon (RDOC) and labile DOC and also well explained the internal movement of constituents and stratification phenomenon in the reservoir. Instead turbidity and NOM were related well in the upper region of the reservoir according to flow distance, gradually as changing to dissolved form of organic matter, RDOM a ected organic matter concentration of reservoir water quality compared to turbidity. To control the increase of soluble organic matters in the dam reservoir, appropriate dam water discharge gate operation provided e ective measurement. Because of the gate operation let avoid the accumulation of organic matter within a dam reservoir by shorten of turbid regime retention time.     

新立城水库藻类水华环境因子分析及其预警监测

调查研究表明长春市新立城水库发生小范围藻类水华期间浮游植物藻类群落结构变化不明显,种群丰度增加。对监测数据进行了分析并与该地区非水华期间的监测数据相比较;同时对水质进行了环境因子相关性及对藻类水华的影响分析。结果显示溶解氧和温度是影响水库叶绿素a值变化的主要环境因子,且可以作为北方湖泊藻类水华预警的主要监测指标。     

辽宁大伙房水库水质评价

本文通过对大伙房水库主要污染物指标的分析,对大伙房水库的水质状况进行了评价,并对不同年份的评价结果进行了对比。     

丹江口水库入库河流总氮通量监测

针对丹江口水库总氮超标问题,对作为主要集水区的汉库入库各河流进行了一整年的水量和水质同步监测。结果表明:(1)主要河流入汉库总氮量共24503t/a,湖北和陕西两省入库总氮量比例总体上与水资源量比例相当,其中,汉江干流上游陕西来水入库总氮量占68.2%,湖北主要支流包括十堰堵河(18%)、神定河(7%)、泗河(4%)、官山河(0.9%)、浪河(0.7%)剑河(0.5%)和天河(0.5%)。(2)入汉库总氮总量月变化与入库总水量变化一致,总氮入库量主要集中在5~9月,占全年的77%。(3)根据各河流水环境容量和纳污特征,可将入库河流划分为容量型、点源污染型、农业面源型和混合型等四种类型。建议对不同类型河流应采取不同控制对策,点面结合,综合防治。     

松华坝水源区环境保护与管理规划中的搬迁措施

松华坝水源是昆明市极为重要的饮用水源。近年来,由于人类活动对其水质产生了重大影响．昆明市居民饮水受到严重威胁。本文提出了用搬迁措施解决水源地面临的环境和水资源问题的思路、方案和主要工程步骤;并确切提出了移民安置方案和方案实施政策。