In this paper, according to the rule of unbalanced sediment transport and the analysis of field data, different water diversion schemes were theoretically studied, including the erosion and sedimentation trend as well...In this paper, according to the rule of unbalanced sediment transport and the analysis of field data, different water diversion schemes were theoretically studied, including the erosion and sedimentation trend as well as their impacts on the environment of the middle and lower reaches of the Hanjiang River. The results showed that the 95×10 8m 3 water diversion scheme will cause less erosion and water level decrease than the 15×10 8m 3 water diversion scheme. Using a water diversion scheme of 95×10 8m 3, the decrease of water quantity can impact the river hydrodynamic regime substantially and the environments of the middle and lower reaches of the Hanjiang River will be greatly affected. It is therefore necessary to develop new water resources or build projects to meet the need of the environment and the needs for navigation.展开更多
The factors influencing the water supply price of a hydraulic project include natural conditions and economic policies. This paper thoroughly demonstrates the water price of South-to-North Water Transfer Project from ...The factors influencing the water supply price of a hydraulic project include natural conditions and economic policies. This paper thoroughly demonstrates the water price of South-to-North Water Transfer Project from the viewpoint of economic policies. It is considered that if the project is assigned as a profitable one and built depending on commercial loan from bank completely or mostly, the water price will be too high to be undertaken by users,and if the project places the public good at first while considering the economic benefit, its investment mainly relies on the state (national or local governments) appropriation and self-raised funds and a little from the bank loan on favorable terms, the price determined according to the principle of satisfying the cost and reasonable profit will be relatively lower and can be undertaken by the users in the North China where water shortage is serious. The problem of higher water price of agricultural irrigation to the north of the Yellow River can be tackled by taking measures such as "compensating agriculture by industry" according to foreign practical experiences and relevant suggestions.展开更多
南水北调中线工程水源地(以下简称水源地)的固碳能力(净生态系统生产力,NEP)与气候变化密切相关。本文利用第二代基于个体树木的森林生态系统碳循环模型——FORCCHN2估算了水源地2002-2020年的森林NEP,并分析了森林NEP的时空变化特征及...南水北调中线工程水源地(以下简称水源地)的固碳能力(净生态系统生产力,NEP)与气候变化密切相关。本文利用第二代基于个体树木的森林生态系统碳循环模型——FORCCHN2估算了水源地2002-2020年的森林NEP,并分析了森林NEP的时空变化特征及其影响因素。结果显示:2002-2020年水源地森林NEP在像元尺度上平均值为308.88~761.22 g C·m^(-2)·a^(-1),辐射和温度变化是其主要影响因素。水源地森林NEP在19年间呈显著下降趋势,年均降低值为4.41 g C·m^(-2)·a^(-1),且空间变化趋势具有差异性。分析总初级生产力(GPP)、土壤呼吸(SR)、植被呼吸(VR)年际变化趋势及其与气候要素的逐像元相关性,结果表明,区域东部温度上升造成的SR增长速率高于GPP;另外,西北与西南区域太阳辐射的降低导致了该区域GPP的减少。展开更多
文摘In this paper, according to the rule of unbalanced sediment transport and the analysis of field data, different water diversion schemes were theoretically studied, including the erosion and sedimentation trend as well as their impacts on the environment of the middle and lower reaches of the Hanjiang River. The results showed that the 95×10 8m 3 water diversion scheme will cause less erosion and water level decrease than the 15×10 8m 3 water diversion scheme. Using a water diversion scheme of 95×10 8m 3, the decrease of water quantity can impact the river hydrodynamic regime substantially and the environments of the middle and lower reaches of the Hanjiang River will be greatly affected. It is therefore necessary to develop new water resources or build projects to meet the need of the environment and the needs for navigation.
文摘The factors influencing the water supply price of a hydraulic project include natural conditions and economic policies. This paper thoroughly demonstrates the water price of South-to-North Water Transfer Project from the viewpoint of economic policies. It is considered that if the project is assigned as a profitable one and built depending on commercial loan from bank completely or mostly, the water price will be too high to be undertaken by users,and if the project places the public good at first while considering the economic benefit, its investment mainly relies on the state (national or local governments) appropriation and self-raised funds and a little from the bank loan on favorable terms, the price determined according to the principle of satisfying the cost and reasonable profit will be relatively lower and can be undertaken by the users in the North China where water shortage is serious. The problem of higher water price of agricultural irrigation to the north of the Yellow River can be tackled by taking measures such as "compensating agriculture by industry" according to foreign practical experiences and relevant suggestions.
文摘南水北调中线工程水源地(以下简称水源地)的固碳能力(净生态系统生产力,NEP)与气候变化密切相关。本文利用第二代基于个体树木的森林生态系统碳循环模型——FORCCHN2估算了水源地2002-2020年的森林NEP,并分析了森林NEP的时空变化特征及其影响因素。结果显示:2002-2020年水源地森林NEP在像元尺度上平均值为308.88~761.22 g C·m^(-2)·a^(-1),辐射和温度变化是其主要影响因素。水源地森林NEP在19年间呈显著下降趋势,年均降低值为4.41 g C·m^(-2)·a^(-1),且空间变化趋势具有差异性。分析总初级生产力(GPP)、土壤呼吸(SR)、植被呼吸(VR)年际变化趋势及其与气候要素的逐像元相关性,结果表明,区域东部温度上升造成的SR增长速率高于GPP;另外,西北与西南区域太阳辐射的降低导致了该区域GPP的减少。
