COMPARISON OF PROCESS‐BASED AND ARTIFICIAL NEURAL NETWORK APPROACHES FOR STREAMFLOW MODELING IN AN AGRICULTURAL WATERSHED1

ABSTRACT: The performance of the Soil and Water Assessment Tool (SWAT) and artificial neural network (ANN) models in simulating hydrologic response was assessed in an agricultural watershed in southeastern Pennsylvania. All of the performance evaluation measures including Nash‐Sutcliffe coefficient of efficiency (E) and coefficient of determination (R²) suggest that the ANN monthly predictions were closer to the observed flows than the monthly predictions from the SWAT model. More specifically, monthly streamflow E and R² were 0.54 and 0.57, respectively, for the SWAT model calibration period, and 0.71 and 0.75, respectively, for the ANN model training period. For the validation period, these values were ?0.17 and 0.34 for the SWAT and 0.43 and 0.45 for the ANN model. SWAT model performance was affected by snowmelt events during winter months and by the model's inability to adequately simulate base flows. Even though this and other studies using ANN models suggest that these models provide a viable alternative approach for hydrologic and water quality modeling, ANN models in their current form are not spatially distributed watershed modeling systems. However, considering the promising performance of the simple ANN model, this study suggests that the ANN approach warrants further development to explicitly address the spatial distribution of hydrologic/water quality processes within watersheds.     

DEBRIS FLOW IN WEST DEVELOPMENT

ＴｈｅｗｅｓｔｅｒｎｒｅｇｉｏｎｓｏｆＣｈｉｎａ (ｏｒＷｅｓｔＣｈｉｎａ)ｉｎｃｌｕｄｅ 1 2 ｐｒｏｖｉｎｃｅｓ/ａｕｔｏｎｏｍｏｕｓｒｅ ｇｉｏｎｓ/ｍｕｎｉｃｉｐａｌｉｔｉｅｓ:Ｑｉｎｇｈａｉ,Ｇａｎｓｕ ,Ｓｈａａｎｘｉ,Ｓｉｃｈｕａｎ ,Ｙｕｎｎａｎ ,Ｇｕｉｚｈｏｕ ,Ｘｉｎｊｉａｎｇ ,Ｔｉ ｂｅｔ ,Ｎｉｎｇｘｉａ ,Ｇｕａｎｇｘｉ,ＩｎｎｅｒＭｏｎｇｏｌｉａａｎｄＣｈｏｎｇｑｉｎｇ .ＳｉｎｃｅｔｈｅＰｌｅｉｓｔｏｃｅｎｅｏｆｔｈｅＱｕａｔｅｒ ｎａｒｙＰｅｒｉｏｄ ,ｔｈｅｍｏｕｎｔａｉｎｓｉｎｔｈｅｗｅ…     

Integrated Assessment of Air Pollution Abatement Strategies in Urban Areas: Application to the Greater Athens Area

This paper presents an integrated system for the assessmentof technical and non-technical measures that are putforward in order to reduce air pollution levels in urbanareas. In contrast to the majority of the currentlyemployed assessment tools, this system allows for theevaluation of any proposed air pollution control measure interms of its combined impact on air quality and socialwelfare, by correlating the environmental and economicaspects of alternative air pollution abatement solutions.Based on the multi-pollutant, multi-effect concept, thesystem presented aims in providing policy-makers with areliable tool for the objective assessment of the mostcost-effective packages of measures, the latter beingallocated according to the particular features and needs ofthe areas examined.     

临夏回族自治州旅游客源市场分析与定位

本文在临夏州客源市场调查与分析的基础上,确定其客源市场应定位在周边地区,包括兰州、定西、甘南、青海省西宁、同仁等地市;在完善和发展观光休闲旅游的基础上,发展文化修学游、民族节庆体验游、生态休闲度假游、黄河三峡风情游、穆斯林民俗游、古生物考古游,并提出了相应的市场开发策略。     

快速断电安全技术中半导体中性点开关结构性能的研究

对我国目前半导体中性点开关的结构 ,工作过程 ,性能进行了分析 ;现行中性点开关所存在的问题为电路拓扑结构不合理 ,关断时间过长或过短 ,过长不满足快速断电安全技术的要求 ,过短又易引起过电压 ,使中性点开关失控。笔者提出了采用绝缘门极双极性晶体管 (IGBT) ,构成半导体中性点开关的可行方案。同时指出 ,开发新型快速断电安全技术装置 ,将大大提高我国煤矿安全技术水平     

构建煤矿职业安全卫生管理体系

安全生产是煤矿企业的头等大事。根据煤矿企业的实际特点 ,分析了煤矿安全生产管理的现状、特点和煤矿建立职业安全卫生管理体系的注意事项。讨论了建立煤矿职业安全卫生管理体系的步骤和方法     

攀钢烧结烟气脱硫技术研究

介绍了攀钢烧结烟气的特点，SO2的来源。根据国内外烟气脱硫技术现状， 提出了攀钢烧结烟气脱硫的技术要求。     

炼铁厂2#电除尘的设计与应用

新疆八一钢铁有限责任公司炼铁厂上料系统1^#转运站，1^#a转运站，2^#转运站及1^#、2^#高炉高道料仓在上料时，粉尘污染较为严重，为解决粉尘污染问题，1999年炼铁厂组织设计与施工了40m^2单室卧式3电场除尘器，工程投运后，收尘效果良好，岗位粉尘浓度与外排浓度均低于国家标准。     

桥梁抗震主动控制的稳定性研究

主动控制应用于实际结构 ,需要考虑其控制效果的稳定性问题 ,为此 ,分析了桥梁抗震主动控制中可能出现的计算模型误差和系统误差 ,并讨论了应用H2 控制和H∞ 控制两种算法的稳定性。理论分析和仿真计算表明 ,在频谱特性不同的地震激励下 ,H2 控制和H∞ 控制两种算法都可以取得满意的控制效果 ;对于计算模型误差 ,H2 控制和H∞ 控制两种算法的鲁棒性相当 ,控制效果稳定 ;对于系统误差 ,H∞ 控制算法比H2 控制算法鲁棒性强 ,在较大的误差下可以保持控制效果的稳定性     

江苏省城市防汛决策支持系统研究

在分析江苏省城市防汛问题的基础上，设计了其防汛决策支持系统；根据江苏省城市洪涝灾情特点研建和选用了适宜的数学模型，该模型可以迅速、可靠和正确地模拟城市雨情、水情、灾情的发展过程和可能后果，为城市防汛决策提供多层次的信息服务和多种支持手段。