With the rapid economy development and social civilization progress, the Chinese Government also is improving ecological environmental conditions. More efforts have been made to solve water problems through the implementation of stringent water resources management, as a key government policy on water. Thus, monitoring of water resources has been strengthened, being a main component of the hydrological work in recent years. Compared with routine hydrological monitoring, water resources monitoring pays more attention to the quantity and quality variations of regional waters, to reflect the status of water in river basins and administrative regions. In this paper, the overall layout of the hydrometric network in China is presented, monitoring efforts of the natural water cycle and water consumptions are analyzed, methodologies of water resources monitoring, which are commonly applied in the country, are summed up. Taking the hydrometric network planning on interprovincial boundary waterbodies as example, a summary of the planning at interprovincial boundary river sections is presented. The planning can meet the need of water resources management of administrative divisions. It can also improve the overall water resources monitoring for the country.
Water is not only an irreplaceable natural resource, but also an important
ecological and environmental element. According to the second National Water
Resources Assessment in China, the total amount of water resources of the
country was about 2841 billon m
With the impact of climate change and human activities such as urbanization in the country, water scarcity due to changes of surface conditions in the north and water pollution in the south have not been effectively curbed. Contradiction between water supply and water demand is yet outstanding, and water utilization efficiency is still poor in comparison with those in developed countries.
In recent years, the Chinese Government devoted to promote the country's ecological and environmental condition by implementing stringent water management as a key policy on water. Three “red lines”, i.e., (i) the control of total amount of water exploited, (ii) efficiency of water use, and (iii) water pollutions, have been set up in response to the increasing water problems across the country (Wang et al., 2015). To cope with the contradiction of temporally and spatially unevenly distributed available water and regional water consumptions, the Chinese Government also proposed the arduous task of inter-basin water transfer plans to realize regional water resources allocation. Above all, monitoring of water resources is the basis for the management of water. This paper introduces the overall hydrometric network in China, classifies the monitoring technology commonly applied in the country, and analyzes the comprehensive situation of water resources monitoring in China, taking the hydrometric network planning for interprovincial boundary rivers as an example. The distribution of monitoring stations at interprovincial boundary river sections is proposed to meet the needs of water resources management for provincial administrative divisions. The planning provides constructive guidance to the development of water resource monitoring of China.
Water resource monitoring involves, for example, analyzing the water quantity, water quality, distribution of water status, and water exploitation, water utilization and conservation of water resources (Yao et al., 2013; Zhang et al., 2015). A hydrometric network is the basis for water resources monitoring, investigation, analysis and evaluation (Maidment, 1993; WMO Secretariat, 1988).
At present, water resources monitoring in China can be generally distinguished into two forms: dynamic monitoring for the natural water cycle and monitoring for water utilization. Where, dynamic monitoring for natural water cycle focuses on the monitoring of hydrological features of water bodies, including rivers, lakes, water channels, as well as regional groundwater. Monitoring for water utilization focuses on the monitoring of water supply, water use and water consumption processes through human activities, including water supply sources, water pipelines, sewage outlets and so on. For a long time, the dynamic monitoring of natural water cycle was given priority in the work of the hydrologic sector, while measurement of the water utilization status remains to be further improved. Following the implementation of stringent water management in recent years, monitoring for inter-administrative boundary water sections become a new task to meet the needs of water resources management for administrative divisions. In addition, for those areas and water bodies without hydrological stations, water survey is usually carried out at a regular base, including both regional water quantity and water quality investigations.
Distribution of water resources in China.
After decades of development, China has established a comprehensive hydrological monitoring network all over the country, and accumulated a large amount of hydrological data, which provides a strong basis for the management of water resources. The hydrometric network has been long set up according to the needs of flood defence, drought relief and disaster reduction in river basins. Currently, there are in total 93 617 different kinds of hydrological monitoring stations (Deng, 2015). The structure of the country's hydrological stations is shown in Fig. 2.
Structure of hydrological stations in China.
Summary of the planned monitoring stations distributed by main river basins.
The dynamic monitoring of water resources based on existing hydrological
stations is carried out, as follows.
Monitoring of surface water flow. Traditional hydrological monitoring
stations are long deployed in line with the distribution of watersheds. The
average density of national hydrological stations is 1966 km Monitoring of groundwater level. There are 16 990 groundwater
monitoring stations in total, where 12 898 stations are basic stations,
which are monitored at a weekly base, and 4092 are supplemental stations,
which are monitored seasonally. These stations form the basic groundwater
monitoring network of China. Through monitoring, the dynamics of the regional
groundwater level can be thus outlined, and groundwater storage changes can
be estimated, which provide the basic needs of groundwater evaluation (Lin et
al., 2005; Wang, 2014). However, most of the existing groundwater monitoring
stations are distributed in northern China, and many are water extraction
wells and irrigation wells, which are manually monitored. The present network
density and regional layout cannot meet the increasing demand for information
on water resources management. To strengthen and improve groundwater
monitoring, the Ministry of Water Resources and the Ministry of Land
Resources jointly proposed a project to measure the groundwater state through
automatic monitoring systems (Qiao, 2009; Yang and Zhang, 2008). The project
plans to construct a total number of 20 401 automatic groundwater monitoring
stations. Monitoring for groundwater overdraft areas and different
groundwater sources are particularly strengthened. Effective monitoring will
be achieved for most of the country's plains, which cover an area of
3.5 million km Monitoring of water quality elements. There are more than 12 000
surface water quality monitoring sections, where, 596 sections focus on the
monitoring of interprovincial boundary waters (buffer zones), 1507 sites are
monitoring water supply sources, and 5064 sections are for the 4493
state-administrated water functional zones (areas defined according to the
natural water conditions and regional development targets) across the
country. In addition, water quality monitoring is carried out at both 4640
waste water outlets to rivers and 4115 representative groundwater monitoring
wells.
To strengthen and promote the work of water quality monitoring, the Ministry of Water Resources completed the national water resources conservation monitoring planning in 2013. A total number of 16 392 surface water quality monitoring sections are planned, providing a full coverage of the country's major water bodies. It can provide a strong support to the country's water conservation and protection goals by 2020.
Following the step-wise implementation of a stringent water resources
management, “three red lines” were formulated, i.e. a controlling index of
the total amount of water exploited, efficiency of water use, and water
pollutions for each administrative region. Among them, the controlling index
of total exploited water for the country is 670 billion m
To examine and evaluate the government performance on rational water
consumption and effective water conservation in the administrative regions,
the Ministry of Water Resources has put forward the intensive monitoring for
the trans-administrative boundary water bodies based on the monitoring
network planning (Zhang et al., 2012). The planning focuses at the
provincial administrative sections or at interprovincial boundary rivers.
New hydrological stations were further deployed in comply with the existing
hydrological monitoring network. Summaries of the planning are as follows,
as an example.
Principle of the planning. Monitoring stations at provincial
administrative sections of interprovincial boundary rivers are deployed to
comply with following principles: (a) major river stems and their first-order
tributaries, (b) rivers whose catchment area greater than 1000 km Outcome of the planning. Based on above principles, a total number of
841 monitoring stations are deployed at provincial administrative sections of
interprovincial boundary rivers. Summary of monitoring stations distributed
by main river basins are shown in Table 1. It is shown that, among the
planned stations, 359 sites are existing monitoring stations, accounting for
43 % of the total number, while 482 sites are new stations, accounted for
57 % of the planning. To promote the automatic monitoring capacity,
82 % of the new sites are either tour gauging or automatic monitoring
stations. To meet the requirement of monitoring regulations of water
resources, monitoring of water quality will be synchronized with monitoring
of water flow for all the 841 sites. Sketch map of the planned hydrological
monitoring stations for interprovincial boundary rivers is shown in Fig. 3.
In the planning, there are 367 interprovincial boundary rivers, whose
drainage areas are above 1000 km
Sketch map of the planned hydrological monitoring stations for interprovincial boundary rivers.
Monitoring for water use is usually carried out in real-time through
monitoring stations. However, for those areas without monitoring stations,
it can also be made through water investigation.
Monitoring for water consumptions. In comparison with the dynamic
monitoring of the natural water cycle, monitoring for water consumptions is
relatively weak in China. The monitoring ability is poor when compared with
those developed countries (Martin, 2008; Office of the Auditor General of
Canada, 2010; Wang et al., 2014). At present, a statistic method, such as
water consumption quotas, is widely used for the measurement of water
consumption in China. Nearly 30 % of industrial and 70 % of
agricultural water use have not yet been directly metered. Based on the
current monitoring situation, following principles are set up to strengthen
the real-time monitoring of water consumptions by focusing on those important
users: (a) centralized public and industrial users with annual surface water
consumptions above 300 million m Water investigation. Water investigation is carried out at regular
basis for those areas without monitoring stations. Investigation for water
flow is conducted once a year in general, and investigation for waste water
into rivers and lakes is generally conducted every 1 to 3 years. These
investigations are carried out in accordance with the Technical Guideline for
Water Resources Monitoring. The main technical work is as follows:
(a) investigation of natural water quantity, including river channel flow,
inflow and outflow of interprovincial boundary rivers, water storage and
groundwater, (b) investigation of water exploitation and utilization,
including surface water consumptions, groundwater exploitation, groundwater
recharge, mining drainage survey, and (c) specific investigations, including
industrial and domestic wastewater into rivers and lakes, irrigation return
flow.
Analysis shows that, a comprehensive hydrometric network has been developed
in China. The spatial distribution of hydrological stations is by far
rational and practical. The network distribution and monitoring elements are
basically consistent with regional economic and social development patterns.
However, due to the spatially and temporally unbalanced economic development
of the country, the hydrological monitoring network has also been unevenly
distributed. It is clear that, the monitoring network for water utilization
is still insufficient. Particularly, those monitoring stations for
inter-administrative boundary rivers are inadequate and monitoring for water
exploitation and consumption are poor. Demands for timely and fully
understanding of the regional water situation cannot be satisfied. There is
an urgent need to accelerate the implementation of the designed monitoring
network.
Traditional hydrological monitoring technology and methodology are fully
applied in the monitoring of water resources. With the rapid development of
modern science and technology, automatic monitoring technology has also been
widely introduced in water resource monitoring (Yao et al., 2013; Zhang et
al., 2003). Some examples of technology of main hydrologic elements
monitored are as follows:
Monitoring of water levels. Currently, automatic monitoring of water
levels is extensively applied in the country. According to statistics, more
than 90 % of the surface water levels in the country are automatically
monitored. However, about 90 % of groundwater monitoring is still
manually done. The capacity of automatic monitoring of groundwater will be
significantly improved after the implementation of the state automatic
groundwater monitoring system. For automatic water level monitoring, the
float type, pressure type and bubble type water level meters are the main
instruments applied for both surface water and groundwater. According to the
technical regulations on water level monitoring, some manual checks of the
water level is still necessary for the automatic monitoring sites. It is
mainly used to cross check the automatic measurement instruments by manual
readings. Monitoring of open channel flow. Open channel flow monitoring methods in
China is done through the velocity-area method, hydraulics methods, tracer
methods and volumetric methods (Yang et al., 1993). Velocity-area method is
the most commonly used monitoring technology. Where, the point velocity-area
method is the most widely applied one. Nearly 80 % of the current
national basic hydrological stations utilize the point velocity-area method,
whose most popular measurement instrument is the rotor type flow meters.
Application of the Acoustic Doppler Current Profilers (ADCP) in China has
constantly been increasing over the last decade (Liu et al., 2006). Up to
50 % of the hydrological stations in the recent monitoring planning for
small and medium-size rivers uses the velocity-area method of current
profiler type. In addition, when steady hydrological condition of the
monitoring cross sections can be achieved, and reliable and stable water
level-flow correlation can be established, then people are encouraged to make
use of the rating-curve instead of the direct flow measurement. Monitoring of pipe flow. Monitoring for pipe flow can also be
distinguished as velocity-area method and volumetric method in principle. For
the monitoring of industrial and domestic pipe flow, both methods are
extensively used. Types of popular instruments include the electromagnetic
flow meter, acoustic flow meter, water meter and others. For the monitoring
of irrigation water, above monitoring technology can generally be applied.
While for the measurement of groundwater exploitations, indirect measurement
such as electricity use, irrigation water meter and water consumption quotas
are the typical methods utilized. Monitoring of water quality. Water quality monitoring can generally be
divided into two kinds, one is the manual monitoring, and the other is
automatic measurement (Chen et al., 2014). At present, no matter if it is
surface water, groundwater, a natural water body or an artificial pipeline,
manual sampling in combination with laboratory analysis is still the main
method for water quality monitoring. Limited parameters are monitored through
automatic measurement of the electrode method and on-line analysis
technology. Monitoring of precipitation, evaporation and water storage. For the
monitoring of water storage, water levels are automatically monitored, and
the storage capacity of reservoirs and other water bodies are usually
obtained through the water level-volumetric correlations. For the monitoring
of precipitation, automatic monitoring has been realized for all stations;
while pan evaporation will remain to be manually monitored in general.
Water resource monitoring is important for better understanding of regional
water conditions and for evaluation of water resources. In this paper, the
overall hydrometric network in China is introduced, and the classification
of the monitoring network and monitoring technology commonly applied in the
country are presented. As an example, the monitoring network planning for
interprovincial boundary rivers is demonstrated to meet the increasing
demand of water management. It can be seen that in recent years, much
attention has been paid to the monitoring of water resources in China. The
water resources monitoring provides a reliable scientific basis for water
exploitation, utilization, configuration, protection and conservation.
Strengthening the monitoring of water resources is not only the requirement
of implementing stringent water resources management, but it also is an
important part of the development of hydrological work. In recent years,
China has been facing serious water problems, including water shortage,
water pollution, and inefficient water use, while water resource monitoring
still was fundamentally weak. Current monitoring cannot meet the actual
needs of water management yet. In view of the outstanding problems in
current water resources monitoring, the following suggestions are made on
the establishment of a systematic monitoring network:
Traditional hydrological monitoring mainly focused on the monitoring of
hydrological elements of the natural water cycle, including its spatial and
temporal distributions, to better understand regional water quantity and
quality conditions. Future monitoring of water resources should be put
forward to comply better with the regional water status. Synchronized water
quantity and water quality monitoring, regional water balance assessment in
combination with measurements and investigations, should be implemented in
water resource monitoring. Considering the relatively weak water resources monitoring, especially
the monitoring of water exploitation and consumption in the country, there is
an urgent need to accelerate the implementation of monitoring planning of the
interprovincial boundary river sections, as well as the planning of the water
resources monitoring capacity-building and automatic groundwater monitoring.
Thus, the monitoring network can be optimized, network density can be
improved, and water resources monitoring can be strengthened. Taking into account the cost of human resources for stationary
monitoring stations, it is required to actively promote automatic monitoring
to increase the water resources monitoring. Monitoring frequency and accuracy
could also been improved, to satisfy the growing demand for water resources
management.
The “Directory of rivers to be carried out for water allocation (monitoring and assessment)
during the period of 2013–2015”, which is the basic data for the work of hydrometric monitoring planning on inter-provincial boundary river sections is avaible in the
Supplement.
Access to the hydrometric network data in part1 of the manuscript is available on the government web
(
The work is supported by Zhang ShuAn from the Bureau of Hydrology of the Ministry of Water Resources. Special thanks to Henny A. J. van Lanen from the Wageningen University for his comments and revision to improve the paper.