The Huangshui River,an important tributary in the upper reaches of the Yellow River,has been regarded as a mother river which gestates Qinghai civilization in China.This paper presents the results of hydrogen and oxyg...The Huangshui River,an important tributary in the upper reaches of the Yellow River,has been regarded as a mother river which gestates Qinghai civilization in China.This paper presents the results of hydrogen and oxygen isotopic and water chemical analyses for the summer and winter Huangshui River water to study its seasonal recharge and major dissolved solutes.Characteristics of hydrogen and oxygen isotopes suggest that precipitation in the Qilian Mountains is the original recharge of the Huangshui River.However,in winter,the basic flow of the Huangshui River only depends on spring recharge and spring water originates from melt and infiltration of bottom layer glaciers.In summer,besides spring water,much rainfall directly recharges the Huangshui River,thus making its flux increase greatly.Water chemistry shows that the processes affecting dissolved solutes in the Huangshui River are also different between summer and winter.In summer,major ions in the river water are dominantly derived from carbonate and evaporate dissolution and anthropogenic inputs.In winter,carbonate dissolution decreases greatly while anthropogenic inputs play a much more important role for dissolved solutes in the river.Hence,further measures should be taken to lay stress on the winter Huangshui River water in order to protect the environment of the Huangshui River and reduce effects of dissolved solutes on,or prevent their pollution toward the upper Yellow River.Moreover,some measures also need to be introduced to prevent the possibility of water eutrophication caused by agricultural activities or stock raising in summer.展开更多
With social progress and economic development, flood protection, water storage, and pollution absorption of urban rivers have been improved, but at the same time negative effects have been brought about. In urban area...With social progress and economic development, flood protection, water storage, and pollution absorption of urban rivers have been improved, but at the same time negative effects have been brought about. In urban areas, due to canalization or occupation of river, and forcible alteration of course of rivers, river waters area has been reduced. Natural capacity of rivers is seriously lacking, and the ecosystem services of rivers are gradually weakening. For planning, design and construction of urban landscapes, the concept of ecological restoration must be applied to protect and rationally utilize river landscapes. This paper takes the landscape belt of Huangshui River in Doba New City of Xining as an example to study the Huangshui River. Based on the theory of river course restoration, a “dynamic growth” river restoration system is established, and the restoration process of nature itself is as little as possible. In order to improve the water quality of Huangshui River, control the flow velocity and build the ecological environment, a set of perfect and self-repairing system is created for Huangshui River.展开更多
为尽可能地提高大气加权平均温度的估计精度,利用神经网络所建立的大气加权平均温度模型,却未顾及大气加权平均温度的长期变化趋势。因此,本文利用全球气候第五代再分析数据集和大气逐层数据,考虑大气加权平均温度的年际变化,基于多层...为尽可能地提高大气加权平均温度的估计精度,利用神经网络所建立的大气加权平均温度模型,却未顾及大气加权平均温度的长期变化趋势。因此,本文利用全球气候第五代再分析数据集和大气逐层数据,考虑大气加权平均温度的年际变化,基于多层感知器建立了湟水流域大气加权平均温度模型,并使用探空数据与已有的六种模型进行了比较验证分析。结果表明:本模型的年均偏差和均方根误差分别为–0.01 K、2.71 K;均方根误差相比于Bevis式、双因子、多因子、全球气压温度3(global pressure and temperature 3,GPT3)、改进的GPT3模型、谢劭峰等(2022)方法分别减小了32%、23%、15%、14%、7%、5%。验证了引入年际变化因子可进一步提高神经网络模型的精度,建立了目前湟水流域精度相对最优的大气加权平均温度模型。展开更多
选取植被健康指数(Vegetation health index,VHI)为农业干旱程度衡量指标,利用Mann-Kendall(M-K)检验法和小波分析法对河湟谷地2000—2020年农作物生长季(3—11月)干旱程度进行逐年和逐季节研究(以3—5月为春季、6—8月为夏季、9—11月...选取植被健康指数(Vegetation health index,VHI)为农业干旱程度衡量指标,利用Mann-Kendall(M-K)检验法和小波分析法对河湟谷地2000—2020年农作物生长季(3—11月)干旱程度进行逐年和逐季节研究(以3—5月为春季、6—8月为夏季、9—11月为秋季)。结果表明:(1)河湟谷地农业干旱区主要集中在大通河中游地区、湟水河干流区和黄河谷地。(2)河湟谷地农业干旱面积呈现明显的地域分异特点,由北到南农业干旱面积逐渐增大。(3)河湟谷地农业干旱面积在年际尺度上有在周期性波动中不断减小的趋势,2007—2008年是河湟谷地农业干旱面积发生突变的时间点,此后河湟谷地农业干旱面积开始急剧减少;春季是河湟谷地受农业干旱影响最严重的季节。研究结果对掌握河湟谷地农业干旱空间分布及变化趋势、促进青海省农业健康发展具有重要意义。展开更多
文摘The Huangshui River,an important tributary in the upper reaches of the Yellow River,has been regarded as a mother river which gestates Qinghai civilization in China.This paper presents the results of hydrogen and oxygen isotopic and water chemical analyses for the summer and winter Huangshui River water to study its seasonal recharge and major dissolved solutes.Characteristics of hydrogen and oxygen isotopes suggest that precipitation in the Qilian Mountains is the original recharge of the Huangshui River.However,in winter,the basic flow of the Huangshui River only depends on spring recharge and spring water originates from melt and infiltration of bottom layer glaciers.In summer,besides spring water,much rainfall directly recharges the Huangshui River,thus making its flux increase greatly.Water chemistry shows that the processes affecting dissolved solutes in the Huangshui River are also different between summer and winter.In summer,major ions in the river water are dominantly derived from carbonate and evaporate dissolution and anthropogenic inputs.In winter,carbonate dissolution decreases greatly while anthropogenic inputs play a much more important role for dissolved solutes in the river.Hence,further measures should be taken to lay stress on the winter Huangshui River water in order to protect the environment of the Huangshui River and reduce effects of dissolved solutes on,or prevent their pollution toward the upper Yellow River.Moreover,some measures also need to be introduced to prevent the possibility of water eutrophication caused by agricultural activities or stock raising in summer.
文摘With social progress and economic development, flood protection, water storage, and pollution absorption of urban rivers have been improved, but at the same time negative effects have been brought about. In urban areas, due to canalization or occupation of river, and forcible alteration of course of rivers, river waters area has been reduced. Natural capacity of rivers is seriously lacking, and the ecosystem services of rivers are gradually weakening. For planning, design and construction of urban landscapes, the concept of ecological restoration must be applied to protect and rationally utilize river landscapes. This paper takes the landscape belt of Huangshui River in Doba New City of Xining as an example to study the Huangshui River. Based on the theory of river course restoration, a “dynamic growth” river restoration system is established, and the restoration process of nature itself is as little as possible. In order to improve the water quality of Huangshui River, control the flow velocity and build the ecological environment, a set of perfect and self-repairing system is created for Huangshui River.
文摘为尽可能地提高大气加权平均温度的估计精度,利用神经网络所建立的大气加权平均温度模型,却未顾及大气加权平均温度的长期变化趋势。因此,本文利用全球气候第五代再分析数据集和大气逐层数据,考虑大气加权平均温度的年际变化,基于多层感知器建立了湟水流域大气加权平均温度模型,并使用探空数据与已有的六种模型进行了比较验证分析。结果表明:本模型的年均偏差和均方根误差分别为–0.01 K、2.71 K;均方根误差相比于Bevis式、双因子、多因子、全球气压温度3(global pressure and temperature 3,GPT3)、改进的GPT3模型、谢劭峰等(2022)方法分别减小了32%、23%、15%、14%、7%、5%。验证了引入年际变化因子可进一步提高神经网络模型的精度,建立了目前湟水流域精度相对最优的大气加权平均温度模型。
文摘选取植被健康指数(Vegetation health index,VHI)为农业干旱程度衡量指标,利用Mann-Kendall(M-K)检验法和小波分析法对河湟谷地2000—2020年农作物生长季(3—11月)干旱程度进行逐年和逐季节研究(以3—5月为春季、6—8月为夏季、9—11月为秋季)。结果表明:(1)河湟谷地农业干旱区主要集中在大通河中游地区、湟水河干流区和黄河谷地。(2)河湟谷地农业干旱面积呈现明显的地域分异特点,由北到南农业干旱面积逐渐增大。(3)河湟谷地农业干旱面积在年际尺度上有在周期性波动中不断减小的趋势,2007—2008年是河湟谷地农业干旱面积发生突变的时间点,此后河湟谷地农业干旱面积开始急剧减少;春季是河湟谷地受农业干旱影响最严重的季节。研究结果对掌握河湟谷地农业干旱空间分布及变化趋势、促进青海省农业健康发展具有重要意义。
