基于生态保护红线的滇池流域生态空间管控

以滇池流域为研究区,采用GIS空间分析方法,明确生态保护红线与生态空间的内容及相互关系,基于空间分布特征及生态系统类型将生态空间类型划分为林地生态空间、水域生态空间、草地生态空间、荒地生态空间,根据不同管控等级以生态保护红线为界线确定滇池流域生态空间管控区为一级管控区和二级管控区,提出滇池流域生态空间四类两级九区的管制体系及规则,为构建以分类分级管控为导向的流域生态空间管控体系提供理论支撑和实践经验。     

基于水文水动力耦合模型的三江流域防洪模拟预报应用研究

为解决下游河网站点防洪模拟预报过程中存在预报精度偏低,以及采用水动力模型方法时所需资料数量过于庞大的问题,基于不同下垫面水文特征的分布式架构模型理论,通过对流域内山丘和平原区各阶段产汇流进行分解模拟的方式,建立了以交界面动量与通量交换实现互馈耦合的水文水动力一体化模型。以三江流域为研究区域,构建耦合了上游山丘区、平原区和下游长江水动力模型,利用代表站点开展了全流域一体化模型的率定与验证工作。对流域内 2016—2022 年降雨进行分析和场次降雨大于 100 mm 的多场洪水进行验证,结果显示耦合模型的模拟精度较好,在不需要大量资料的前提下有效提高了平原河网区预报精度及整个流域防洪调度能力,具有较强的借鉴意义,可为其他类似流域防洪模拟预报研究提供参考。     

Effects of muddy water irrigation with different sediment gradations on nitrogen transformation in agricultural soil of Yellow River Basin

Muddy water irrigation has been widely practiced in the Yellow River Basin for agricultural production and is an important method of economical and intensive utilization of water resources. In this study, the effects of sediment gradation, sand content, and soil moisture content on nitrogen (N) transformation were studied through a series of experimental tests. The results indicated that muddy water irrigation significantly affected agricultural soil physical and biological properties as well as N transformation. Soil bulk density, total porosity, pH, and microbial enzyme activities significantly correlated with N transformation as affected by the interaction between sediment and soil moisture. Sediment addition generally increased the soil bulk density and reduced the soil porosity and pH significantly, and the optimum moisture for promotion of the N transformation rate was 80% of the water-filled pore space. Therefore, muddy water irrigation has a potentially long-term influence on agricultural N cycles in semi-arid regions of northwestern China. This could provide a theoretical basis for scientific and rational use of muddy water for irrigation.     

Local and regional flood frequency analysis based on hierarchical Bayesian model in Dongting Lake Basin,China

This study developed a hierarchical Bayesian(HB) model for local and regional flood frequency analysis in the Dongting Lake Basin,in China.The annual maximum daily flows from 15 streamflow-gauged sites in the study area were analyzed with the HB model.The generalized extreme value(GEV) distribution was selected as the extreme flood distribution,and the GEV distribution location and scale parameters were spatially modeled through a regression approach with the drainage area as a covariate.The Markov chain Monte Carlo(MCMC) method with Gibbs sampling was employed to calculate the posterior distribution in the HB model.The results showed that the proposed HB model provided satisfactory Bayesian credible intervals for flood quantiles,while the traditional delta method could not provide reliable uncertainty estimations for large flood quantiles,due to the fact that the lower confidence bounds tended to decrease as the return periods increased.Furthermore,the HB model for regional analysis allowed for a reduction in the value of some restrictive assumptions in the traditional index flood method,such as the homogeneity region assumption and the scale invariance assumption.The HB model can also provide an uncertainty band of flood quantile prediction at a poorly gauged or ungauged site,but the index flood method with L-moments does not demonstrate this uncertainty directly.Therefore,the HB model is an effective method of implementing the flexible local and regional frequency analysis scheme,and of quantifying the associated predictive uncertainty.     

A distributed eco-hydrological model and its application

Eco-hydrological processes in arid areas are the focus of many hydrological and water resources studies. However, the hydrological cycle and the ecological system have usually been considered separately in most previous studies, and the correlation between the two has not been fully understood. Interdisciplinary research on eco-hydrological processes using multidisciplinary knowledge has been insufficient. In order to quantitatively analyze and evaluate the interaction between the ecosystem and the hydrological cycle, a new kind of eco-hydrological model, the ecology module for a grid-based integrated surface and groundwater model (Eco-GISMOD), is proposed with a two-way coupling approach, which combines the ecological model (EPIC) and hydrological model (GISMOD) by considering water exchange in the soil layer. Water interaction between different soil layers is simply described through a generalized physical process in various situations. A special method was used to simulate the water exchange between plants and the soil layer, taking into account precipitation, evapotranspiration, infiltration, soil water replenishment, and root water uptake. In order to evaluate the system performance, the Heihe River Basin in northwestern China was selected for a case study. The results show that forests and crops were generally growing well with sufficient water supply, but water shortages, especially in the summer, inhibited the growth of grass and caused grass degradation. This demonstrates that water requirements and water consumption for different kinds of vegetation can be estimated by considering the water-supply rules of Eco-GISMOD, which will be helpful for the planning and management of water resources in the future.     

Complexity analysis of precipitation in changing environment in Chien River Basin,China

The hydrological processes influenced by the multiple factors of climate,geography,vegetation,and human activities are becoming more and more complex,which is an important characteristic of hydrological systems.The different complexity distributions of precipitation processes of the Chien River Basin (a sub-basin of the Minjiang Basin) in two periods (from 1952 to 1980,and from 1981 to 2009) are illustrated using the fractal based on the continuous wavelet transform (CWT).The results show that (1) at the basin scale the precipitation process in the latter period is more complex than in the former period;(2) the maximum value of the complexity distribution moved from the east to the middle;and (3) through analysis of the time-information and space-information concealed in this complexity change,the precipitation characteristics in the changing environment in the basin can be illuminated.This study could provide a reference for research on disaster pre-warning in changing environments and for integrated water resources management in the local basin.     

Simplified SEBAL method for estimating vast areal evapotranspiration with MODIS data

The SEBAL (surface energy balance algorithm for land) model provides an efficient tool for estimating the spatial distribution of evapotranspiration,and performs a simple adjustment procedure to calculate sensible heat flux using the wind speed data set from only one weather station.This paper proposes a simplified method to modify the traditional SEBAL model for calculating the 24-hour evapotranspiration () in the Haihe Basin with data from 34 weather stations.We interpolated the wind speeds using the inve...     

Hydrological response to climate change and human activities: A case study of Taihu Basin,China

Climate change and human activities have changed a number of characteristics of river flow in the Taihu Basin. Based on long-term time series of hydrological data from 1986 to 2015, we analyzed variability in precipitation, water stage, water diversion from the Yangtze River, and net inflow into Taihu Lake with the Mann-Kendall test. The non-stationary relationship between precipitation and water stage was first analyzed for the Taihu Basin and the Wuchengxiyu(WCXY) sub-region. The optimized regional and urban regulation schemes were explored to tackle high water stage problems through the hydrodynamic model. The results showed the following:(1) The highest, lowest, and average Taihu Lake water stages of all months had increasing trends. The total net inflow into Taihu Lake from the Huxi(HX) sub-region and the Wangting Sluice increased significantly.(2) The Taihu Lake water stage decreased much more slowly after 2002; it was steadier and higher after 2002. After the construction of Wuxi urban flood control projects, the average water stage of the inner city was 0.16 e0.40 m lower than that of suburbs in theflood season, leading to the transfer of flooding in inner cities to suburbs and increasing inflow from HX into Taihu Lake.(3) The regional optimized schemes were more satisfactory in not increasing the inner city flood control burden, thereby decreasing the average water stage by0.04 e0.13 m, and the highest water stage by 0.04 e0.09 m for Taihu Lake and the sub-region in the flood season. Future flood control research should set the basin as the basic unit. Decreasing diversion and drainage lines along the Yangtze River can take an active role in flood control.     

气候变化对海河流域水文特性的影响

本文应用大尺度陆面水文模型——可变下渗能力模型VIC(Variable Infdtration Capacity)与区域气候变化影响研究模型PRECIS(Providing Regional Climatefor Impacts Studies)耦合,对气候变化情景下海河流域水资源的变化趋势进行预测。结果表明：未来气候情景下,即使海河流域降水量增加,年平均径流量仍将可能减少,预示海河流域的水资源将十分短缺;若考虑21世纪人口增长因素,海河流域的水资源形势将更加严峻;未来气候情景下,汛期的径流量增加,说明海河流域发生洪水的可能性将增大。     

在流域综合规划指导下加快水电建设

针对长江流域水能资源丰富,目前开发利用程度低,现有流域综合规划严重滞后的现状,指出长江流域是我国今后水电开发的主体,应加快开发;在河流上修建水电工程,涉及到水资源开发利用与生态环境保护的关系,水资源综合利用各部门之间的关系,河流上下游、左右岸之间的关系,因此,水电建设应在流域综合规划指导下合理、有序地的进行;应以科学发展观为指导,尽快修订长江流域综合规划,编制西南诸河流域综合规划,以促进水电事业快速、健康发展.