相关实验视频
Updated: Jul 21, 2025

12:44
Watershed Planning within a Quantitative Scenario Analysis Framework
Published on: July 24, 2016
8.1K
揭示贸易潜力,扭转区域淡水边界超标情况
Xu Zhao1, Siyu Hou2, Xinxin Zhang3
1Institute of Blue and Green Development, Shandong University, Weihai 264209, People's Republic of China.
Environmental science & technology
|July 26, 2023
概括
贸易模式加剧了中国地区淡水边界的超越. 目前的进口往往来自已经过度分配的地区,限制了贸易.
科学领域:
- 环境科学环境科学
- 水文学的水文学
- 水资源管理水资源的管理.
背景情况:
- 区域淡水边界 (RFB) 评估对于当地水资源管理至关重要,但面临不确定性.
- 贸易在缓解RFB超值方面的作用尚未得到充分研究.
研究的目的:
- 用多个水文模型估计RFB以减少不确定性.
- 制定一个框架,将RFB变化归因于消费和贸易.
- 分析贸易对中国省级RFB的影响.
主要方法:
- 来自15个水文模型的平均结果来估计RFB.
- 制定了一个框架,将RFB变化划分为消费和贸易组件.
- 将贸易贡献分为六种类型.
- 将框架应用于中国的各省.
主要成果:
- 中国目前的贸易模式并不能有效地缓解RFB的超值.
- 超过RFB的省份78%的进口来自其他超过RFB的省份.
- 仅仅增加进口不足以扭转省份的RFB超值.
- 进口增加可能导致国家淡水边界超越.
结论:
- 贸易必须进行战略管理,以支持RFB维护.
- 促进非RFB超标省份的出口和减少水强度是关键战略.
- 解决水资源不平衡需要地方和国家整合的贸易政策.
相关概念视频
Design Example: Analyzing Capacity Contours for Flood Risk Assessment
71
Flood risk assessment involves careful planning and analysis to ensure the safety of communities near water retention structures. Capacity contours are a vital tool in this process, as they illustrate the potential spread of water at specific levels in a given area. In the context of building a bund across a small valley, these contours play a critical role in evaluating the safety of nearby residential areas.In this example, the bund is intended to store stormwater in the valley. The engineers...
71
Underflow Gates
79
Underflow gates are vital for controlling water flow in irrigation canals. The three main types of underflow gates — vertical, radial, and drum gates — serve different purposes while ensuring effective flow management. Vertical gates move up and down, generating a free-flowing water jet; radial gates pivot to regulate the flow; and drum gates rotate for precise adjustments. The flow through these gates is influenced by downstream conditions, resulting in free or drowned outflow.Free and...
79
Hydraulic Jump
118
A hydraulic jump is a sudden rise in fluid depth in open channels, occurring when high-velocity (supercritical) flow transitions to low-velocity (subcritical) flow. This phenomenon requires an upstream Froude number greater than 1, as flows with Fr1<1 remain subcritical, making a hydraulic jump impossible due to the need for negative head loss, which violates thermodynamic principles.The characteristics of a hydraulic jump depend on the upstream Froude number and are classified as...
118
Conservation of Mass in Moving, Nondeforming Control Volume
1.1K
Stormwater detention basins are essential in managing runoff during heavy rainfall, particularly in urban areas where impervious surfaces increase the risk of flooding. Understanding the conservation of mass in these systems allows engineers to optimize basin performance, balancing inflow, outflow, and water storage.
In the context of a detention basin, the conservation of mass states that the total mass of water entering the basin must equal the mass leaving the basin plus any accumulation of...
In the context of a detention basin, the conservation of mass states that the total mass of water entering the basin must equal the mass leaving the basin plus any accumulation of...
1.1K
Rapidly Varying Flow
98
Rapidly varying flow (RVF) in open channels is characterized by abrupt changes in flow depth over a short distance, with the rate of depth change relative to distance often approaching unity. These flows are inherently complex due to their transient and multi-dimensional nature, making exact analysis difficult. However, approximate solutions using simplified models provide valuable insights into their behavior.Key Features of Rapidly Varying FlowRVF is commonly observed in scenarios involving...
98
Regulation of Water Output
340
The human body predominantly expels water through the urinary system. On average, an individual generates around 1.5 liters of urine each day. This amount can fluctuate based on how well a person is hydrated, but a critical minimum quantity of urine must be produced to ensure the body's proper functioning. Daily, the kidneys remove 600 to 1200 milliosmoles of dissolved substances, effectively excreting excess minerals and water-soluble toxins such as creatinine, urea, and uric acid from the...
340

