Calibration and Validation of the GR2M Hydrologic Model in the Kouilou-Niari Basin in Southwestern Congo-Brazzaville

The hydrologic simulation of a catchment area, described as the transformation of rainfall into runoff, generally uses hydrologic model. This work opts for the global conceptual hydrologic model GR2M, a monthly time step model, to study the Kouilou-Niari basin, the second most important ones of the Republic of Congo. This includes two parameters to model the hydrologic behavior of a catchment area. The choice of the conceptual model GR2M is justified by the reduced number of parameters and the monthly time scale. The objective of this study is to determine the characteristic parameters of the GR2M model, by a calibrating and a validating procedure. The use of these parameters enables to follow the evolution of the water resources from the climatic variables. It has been first carried out a characterization of some physical, geological and climatic factors governing the flow, by dealing with the main climatic variables which constitute the inputs of the hydrologic model. Then, a hydrologic rainfall-runoff modeling allows to calibrate and validate the model at monthly time scale. Taking into account the number of parameters involved in hydrologic processes and the complexity of the cathment area, this model gives acceptable results throughout the Kouilou-Niari basin. The values of the Nash-Sutcliffe criterion and those of the correlation coefficient obtained are greater than 80% in validation, which explains the performance and robustness of the GR2M model on this basin.

Hydrological Modelling of the Casamance River in Its Upstream Section (Basin at Kolda Level) to Predict Its Future States as a Function of Different Stresses

Flow records for stations in the Casamance basin are incomplete. Several gaps were noted over the 1980-2021 study period, making this study tedious. The aim of this study is to assess the potential impact of climate change on the flow of the Casamance watershed at Kolda. To this end, hydrological series are simulated and then extended using the GR2M rainfall-runoff model, with a monthly time step. Projected climate data are derived from a multi-model ensemble under scenarios SSP2-4.5 (scenario with additional radiative forcing of 4.5 W/m2 by 2099) and SSP5-8.5 (scenario with additional radiative forcing of 8.5 W/m2 by 2099). An analysis of the homogeneity of the rainfall data series from the Kolda station was carried out using KhronoStat software. The Casamance watershed was then delimited using ArcGIS to determine the morphometric parameters of the basin, which will be decisive for the rest of the work. Next, monthly evapotranspiration was calculated using the formula proposed by Oudin et al. This, together with rainfall and runoff, forms the input data for the model. The GR2M model was then calibrated and cross-validated using various simulations to assess its performance and robustness in the Casamance watershed. The version of the model with the calibrated parameters will make it possible to extend Casamance river flows to 2099. This simulation of future flows with GR2M shows a decrease in the flow of the Casamance at Kolda with the two scenarios SSP2-4.5 and SSP5-8.5 during the rainy period, and almost zero flows during the dry season from the period 2040-2059.

一类Z2^k—线性的二元码

我们记 Tk为 Galois环 GR( 2 k,m)到 Z2 k 的迹映射 ,ξ是 GR( 2 k,m)中的本原元 ,ξ2 m- 1 =1 ,τk,m={0 ,1 ,ξ,… ,ξ2 m- 2 },来讨论一类 Z2 k-线性码 {Tk( a0 x + 2 k- 2 a1 x3+2 k- 1 a2 x5) + b| a0 ∈ GR( 2 k,m) ,a1 ∈τk,m+ 2τk,m,a2 ∈τk,m,b∈ Z2 k}x∈τk,m 的广义 Gray映射下的象所构成的二元码 ,这类二元码也具有很好的参数性质 ,优于一些已知的二元码 ,例如广义的 Kerdock码或广义的 Delsarte- Goethals码 .

Z_2~k-线性负循环码

Wolfmann引进了 Z4-负循环码 .Zn4 上的负移位γ是指 Zn4上的满足γ( a0 ,a1 ,… ,an- 1 ) =( - an- 1 ,a0 ,a1 ,… ,an- 2 )的置换 ;长度为 n的 Z4-负循环是指 Zn4的子集 C满足γ( C) =C.他给出了在环 Z4[x]/( x2 + 1 )中多项式表示的 Z4-负循环码 ;证明了 Z4-线性负循环码 Gray映射下的象是二元距离不变量循环码等 .本文有两个目的 :一是给出在环 Z2 k[x]/( x2 + 1 )中的多项式表示的 Z2 k-负循环码及其对偶 ;二是由 Z4-负循环码在 Gray映射下的象构造出具有优良关连性质的二元周期序列族 .

塞内加尔河流域降雨径流模拟

针对塞内加尔河上游流量系列严重不足的问题,使用GR2M降雨径流模型,以模拟和延长其上游的水文系列。在计算流域降雨量、平均潜在蒸散量,以及最大、最小和平均土壤含水量的基础上,对模型输入的降雨量和土壤含水量数据进行了灵敏度分析。基于纳什-苏特克里弗标准,按流域选择了输入数据的最佳组合。根据输入数据,选择模型参数设置,最终完成模型交叉率定-验证测试。该研究延长了塞内加尔河上游的水文系列,为该河的梯级大坝建设提供了有价值的统计数据。

压力容器用钢板ASTM A 387M Gr.11 CL2的生产实践

介绍了重庆钢铁股份有限公司生产压力容器用ASTM A 387M Gr.11 CL2 24 mm钢板的生产工艺及实物性能。试验钢(/%:0.13C,0.56Si,0.56Mn,0.036Alt,0.005P,0.001S,1.02Cr,0.50Mo)300 mm×2010 mm铸坯粗轧开轧> 1 000℃,中间坯厚度72 mm,精轧开轧880~940℃,精轧终轧850~870℃,层流冷却后690~710℃,空冷至室温后890~910℃正火,空冷至室温后650~670℃回火。实践表明,研发的该钢板各项性能指标均符合技术要求,且具有良好的低温冲击韧性,试验钢-40℃冲击功149~172 J。

特厚临氢设备用钢12Cr2Mo1R(SA387Gr.22Cl.2)的试制

介绍了特厚临氢设备用12Cr2Mo1R(HIC)钢板的生产工艺和技术指标,详细研究了钢板热处理工艺与组织对模拟焊后热处理和回火脆化倾向等性能的关系。以118mm厚钢板为例,给出了化学成分及力学性能结果,结果表明该特厚临氢设备用12Cr2Mo1R钢板成分均匀、杂质元素含量低、综合力学性能优良、回火脆化敏感性低。

SA508M.Gr.3CL.2钢锭冶炼生产实践

SA508M.Gr.3CL.2钢主要用于生产制造核电装备的锻件钢锭,其对P、H元素和w(N)/w(Al)比值等要求严格。上海电气上重铸锻有限公司根据此钢种的成分要求,制定了冶炼生产工艺,通过采取严格控制配料、脱磷、脱硫、偏析以及真空脱气等工艺措施,成功生产了460t超大型SA508-3钢钢锭。锻件成品中w(P)≤0.004%、w(S)≤0.002%、w(H)≤0.8×10-6、w(O)<5.0×10^(-6),w(N)/w(Al)比值在0.6~0.9之间,C、Mn、Mo元素偏析控制较好,满足了此钢种的内控成分要求。