Download Selection of Priority Areas for Hydrological Ecosystem Conservation

Selection of Priority Areas for Hydrological Ecosystem Conservation
in Hai Basin, China
HE Ping1, LI Xiangrong2, BAI Yin
1. Chinese Research Academy of Environmental Sciences, Beijing, China, 100012
2. College of Research Sciences& Technology, Beijing Normal University, Beijing, China, 100875
heping18@sohu.com
Abstract: Global climate change results in the reduction of precipitation. At the same time, the
socio-economic rapid development led to water shortage. In Hai Basin, the pressure on water resource
and hydrological ecosystem caused by above factors led to serious degradation in many ways–wetlands
dry up and serious pollution, groundwater funnel deepened, soil erosion, as well as habitat degradation.
Eighty-five hydrologic units were analyzed as basic evaluation unit in four aspects: river restoration,
biodiversity conservation, groundwater recovery and soil and water conservation. A matrix-based
approach is developed to characterize the priority areas based on the seriousness of ecosystem
degradation and the protection of importance on classification. According to this approach, the
mountains area of Yongding River, the plains of the North Four River, Cangzhou coastal areas, Tianjin,
as well as Tuhai& Majia River in Hai River were selected as ecological restoration priority regions. This
method can be used for the integrated river basin planning because of its simpleness and smartness.
Keywords: Priority Selection, Ecosystem Conservation, Hai Basin
1 Introduction
Global climate change results in the reduction of precipitation. At the same time, the socio-economic
rapid development led to water shortage in Hai Basin (Wang Chang-Yan, etc., 2006). The per capita
water resource is only 226m3 (Hai Basin Commission, 2006).Human disturbance and hardly guaranteed
ecological water use led to severe degradation of aquatic ecosystem in mountain, plain, surface and
underground water. There is little co-ordination among the administration departments of water
management–environmental protection department stressed the water quality protection, water
conservancy department stressed the protection of water resources, land department stressed the
groundwater protection, forestry apartment stressed the wetlands protection, and so on. The
implementation of river basin restoration planning is based on the water availability (for example,
upstream was given priority compared to downstream) and tradability (such as Beijing has bought water
resource from Hebei Province, or purchased water resource from other river basin). The integrated
management of water resources and water environment required to take water quality, water quantity,
surface and ground water, land and sea as a whole system to restore watershed ecosystem health. Taking
both degrees of ecosystem degradation and restoration needs into account, the object of this paper is to
determine the priority areas for protection and restoration at the scale of the whole system and also to
provide basis for decision making.
2 Method and data
*
Correspondence author, E-mail: heping18@sohu.com. This research is funded by GEF Integrated Water Resource and
Environment Management Project (IWEMP)in Hai Basin, project code: TF053183.
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This study starts from a holistic view on water cycle, and then divides both the surface and underground
into hydrologic units whose priority are determined based on their ecological problems. With all the
ecological problems integrated in the hydrological units, the comprehensive priority was put forward as
the basis for watershed planning and management.
By use of SWAT model and a 1:25 million DEM data, the Hai Basin was divided into 85 hydrologic
units as basic evaluation units.
There are 4 types of ecological problems involved–water and soil conservation, biodiversity
conservation, groundwater funnel restoration and river restoration. The principle for determination of
the protection priority is that the more seriously the ecology degrades, the more vulnerable the unit is,
and the more population there is, the higher priority it will be pushed. Specific framework was shown in
Figure 1:
on
Population density
Class of protection
Degree of threat for sensitive species
Groundwater remediation priority
matrix
Groundwater drawdown
River restoration priority
matrix
Status of river water quality
matrix
Water quality index based
function regionalization
Biodiversity conservation priority
Integrated river basin ecological restoration priority
Soil and water conservation priority
Erosion intensity of soil and water
Figure 1 Framework of Ecosystem Restoration Priority
2.1 Determination of Soil and Water Conservation priority
Soil and water loss intensity was evaluated by the application of watershed vegetation coverage and
slope (Soil and Water Conservation Monitoring Center, Ministry of Water Resources& Beijing Datum
Technology Development Co., Ltd, 2008). Vegetation coverage was estimated from the NDVI data
extracted from the MODIS remote sensing images (images in 2004, 250m resolution). Slope was based
on 1:250000 DEM data. Water erosion intensity classification was developed according to Soil Erosion
Classification and Grading Standards (SL 190-2007 Alternative SL 190-96) (Ministry of Water
Resources, Soil and Water Conservation Division, 2007).
The areas with annually accumulative velocity of sand movement, which is equal to or higher than 5m/s,
more than 200m/s or annually accumulative day of wind of sand movement more than 30 days, and
sandy soil areas with annual rainfall less than 300mm for many years are defined as Aeolian Erosion
Districts. The wind erosion intensity grade was determined according to vegetation coverage.
The average soil erosion intensity was calculated for each hydrologic unit, and the intensity values were
classified into six grades by the automatically-grade function of GIS. These six grades from severe to
faint erosion represent the priority of water and soil conservation.
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2.2 Determination of river ecological restoration priority
Water quantity and quality are the driving factors for the of river ecosystem status. The sandy rivers
were taken as the priority restoration river (Table 1). The restoration priority of running rivers was
determined according to the gap between current water quality (2005 Water Resources Bulletin) and the
water quality objective for the corresponding water function zone (Ministry of Water Resources Hai
River Water Resources Commission, 2002). The rivers which are important and easy to repair were set
higher priority (for example, drinking water source areas and protected areas with water quality
degraded to Class IV). However, if the water quality of drinking water source areas have been degraded
to the inferior class V, it is difficult to restore the setting function. Therefore, the priority will not be set
as the highest.
Table 1 Judgment Matrix for River Restoration Priority
Water Function Zone
Drinking water source zone
Conservation zone
Agricultural water zone
Fishery Water zone
Industrial Water zone
Landscape Entertainment Water zone
Reserved zone
Buffer zone
Polluted control zone
sandy
I
I
I
I
I
I
I
I
I
dry up
w
III
III
III
III
II
IV
IV
V
Water Quality Status
inferior V
V
IV
IV
II
I
II
II
I
II
III
IV
II
III
IV
II
III
IV
II
III
IV
III
IV
IV
III
IV
V
IV
V
V
III
II
III
V
V
V
V
V
V
V
II
III
IV
V
V
V
V
V
V
V
2.3 Determination of Biodiversity conservation priority
The conservation priority of the regionally-exist species were determined according to grades of both
endangering and protection (National, Provincial, City and County and Unprotected) (Table 2). There
are 5 grades for endangering degree of sensitive species and the status of ecosystem–Critical,
Endangered, Vulnerable, Relatively intact and Relatively stable, respectively. The grade of endangered
species refers from the World Conservation Union (IUCN Red List of Threatened Species, 2004) and
Chinese Red Data Book of Endangered Animals (1998). "Relatively intact" area refers to protected
wetlands, native forest ecosystem, natural secondary forest ecosystem, etc. "Relatively stable" area
includes protection areas of geological trace, plantations, etc. Species information was derived from the
data of constructed and proposed protection areas and local reports. Due to lack of information on
boundary of protection areas, the research is carried out according to administrative boundary.
Table 2 Judgment Matrix for Biodiversity Conservation Priority
Grade of Endangerment
Critical
Endangered
Vulnerable
Relatively intact
Relatively stable
Unprotected
I
I
I
II
III
Conservation Status
City and County Level
Provincial level
I
I
I
II
II
III
III
IV
IV
V
National level
II
III
IV
V
V
2.4 Determination of the recovery priority of groundwater funnel
The priority of groundwater recovery was determined according to the hydrogeology hazard of ground
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fissure and land subsidence probably derived from groundwater funnel and its impact on population
density (Table 3). According to research work of Bai Yonghui (2005) on relationship between land
subsidence and deep groundwater drawdown in Cangzhou, the deep groundwater drawdown were
divided into 5 rates of 0-40m, 40-60m, 60-70m, 70-80m and 80-90m as vulnerability class. On the basis
of division standard from the plain shallow groundwater level contour map of the Hai Basin, shallow
layer groundwater level is divided into five grade of vulnerability–0-10m, 10-20m, 20-30m, 30-40m and
40-50m, respectively. Taking administrative area as evaluation unit, population density was divided into
four grades: firstly, less than 100 people/km2; secondly, 100-500 people/km2; thirdly, 500-2,000
people/km2; fourthly, larger than 2,000 people/km2 (Ministry of Water Resources, 2007). The
population data is from the National Statistical Yearbook, 2005. Data of the shallow groundwater depth
contours in 2000 (Figure 2) and deep groundwater drawdown contour from 1958 to 1998 (figure 3) were
get from "the Survey of Hai Basin". Population density is statistic data of administrative unit, so the
priority study of groundwater funnel restoration is at county-level.
Table 3 Judgment Matrix for Regional Groundwater Restoration Priority
Population
Density
(People / km2)
>2000
500-2000
100-500
<100
Extremely
vulnerable
I
I
II
III
Status of Groundwater System
Relatively
Moderate
vulnerable
vulnerable
I
I
II
II
III
III
IV
IV
Figure 2 Shallow Groundwater Level
Contour of Hai River Plain, 2000
Slightly
fragile
II
III
IV
V
None
vulnerable
II
IV
V
V
Figure 3 Deep Groundwater Drawdown
Contour of Hai River Plain, 1958-1998
2.5 Comprehensive Evaluation
Based on the hydrologic units, the 4 types of priority–soil and water conservation, biodiversity
restoration, groundwater restoration and river restoration were scored in six degrees (0, 20, 40, 60, 80,
100), sum up the total score as well as level, and then the scores were summed up and classified. On the
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basis of the evaluation above, the ecosystem restoration priority of 85 hydrologic units in the Hai Basin
were determined comprehensively.
3 Evaluation results
3.1 Soil and Water Conservation priority
The water erosion of Hai Basin occurred in the western Taihang Mountain area. The upper reaches of
Yongding River and Hutuo River are relatively serious water erosion area, followed by the middle
Taihang Mountain area, the upper reaches of the Zhang River and windward slope of Taihang Mountain
area. And in northern three-river mountain area, Luan River Mountain area and southern plain area, it’s
relatively milder. Wind erosion concentrate in the northwestern farming-pastoral zone and the Yellow
River old course in the southeastern plains (Figure 4). Figure 5 is the priority of soil and water
conservation based on hydrologic units.
Figure 4 Water and Soil Erosion Intensity
Figure 5 Priority of Water and Soil
Conservation Based on Hydrologic Units
3.2 River ecological restoration priority
The rivers in Hai Basin Plain are sandy waterways or with water quality worse than class V and there
are reaches with deteriorated water quality in the upper Yongding River. The priority of river ecological
restoration determined by comparing to the requirements of water function zone is shown in Figure 6,
and then it was converted into priority based on hydrologic units (Figure 7). When a hydrologic unit
contains rivers with different classes of priority, the higher-grade was selected. The priority repairing
rivers include sandy rivers such as Yongding River, Ziya River, Zhang River and heavily polluted
watercourses, followed by rivers in plain and mountain area whose water quality failed to reach
standard.
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Figure 6 Priority of River Restoration
Figure 7 Priority of River Restoration
Based on Hydrologic Units
3.3 Biodiversity conservation priority
The priority evaluation results by judgment matrix are shown in Figure 8. If there are administrative
regions with more than one protection area or administrative regions of different priority in one
hydrologic unit, the higher protection class is selected to get higher restoration priority. The priority of
biological diversity conservation based on hydrologic units is shown in Figure 9.
Figure 8 Priority of Biodiversity Conservation
Figure 9 Priority of Biodiversity
Conservation Based on Hydrologic Units
There are some endangered species such as giant salamander(Andrias davidianus), brown-eared
pheasant(Crossoptilon mantchuricum), rhesus monkey(Macaca mulatta) and milu (Elaphurus
davidianus) in Priority I region. However, it is not protected duly. Priority II region is a number of
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counties and cities which have some conservation value and urgent needs to upgrade the protection level.
Priority III region is national nature reserves with great importance or improvement potential. Priority
IV region is the place where has certain degree of conservation value or currently has already been
protected. Priority V region has general protection value or is associated with nature conservation.
3.4 Repair groundwater funnel priority
The shallow groundwater funnel in Hai River Plain locates in urban exploitation area of the piedmont
plain and agricultural exploitation area in joint zone of piedmont and eastern plain (Figure 10). The deep
groundwater funnel locates in urban and agricultural centralized exploitation area in the eastern and
middle plain area (Figure 11). The integrated priority based on hydrologic units is shown in Figure 12.
The high-priority groundwater restoration areas are Beijing-Tianjin, Hufu plain and Cangzhou, followed
by most of the Hebei plain, and the groundwater situation in Luan River plain and Tuhai& MaJia River
Basin is good.
Figure 10 The Priority of County-Level
Administrative Unit of Shallow Groundwater Restoration
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Figure 11 The Priority of County-Level
Administrative Unit of Deep Groundwater Restoration
Figure 12 Priority of Groundwater Restoration Based on Hydrologic Units
3.5 Comprehensive priority
The evaluation result of ecological restoration priority based on hydrologic units was shown in Figure
13.
Figure 13 Priority of Ecological Restoration Based on Hydrologic Units
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The hydrologic units of ecosystem restoration priority class I are mainly distributed in the upstream of
Guanting Reservoir, downstream of the North Canal, Tianjin and coastal area in Cangzhou as well as
upstream of Tuhai& Majia River. The ones of class II is mainly distributed in the North Four River plain,
Daqing and Ziya River plain, upper Yongding River and Hutuo River as well as source of Luan River.
And the distribution of the ones of priority class III and IV is dispersive, and they are mainly mountain
areas with biodiversity conservation priority and the piedmont plain funnel area in Heilonggang
Yun-Dong Plain. From comprehensive perspective of the basin, Beijing and Tianjin, coastal area of
Cangzhou, Hufu River Plain and the Yongding River mountain area shouldbe as priority areas for
ecological restoration.
4 Discussion
(1) The priority judgment matrix takes both urgency and accessibility into consideration. The principle
for determination of soil and water conservation priority is that the serious erosion areas are preferential.
The biodiversity conservation priority judgment matrix puts importance on "rescue" which means the
areas without proper protection possess high priority. River restoration priority judgment matrix reflects
two principles: the greatest gap between status and objective priority and the accessibility priority.
Groundwater restoration priority judgment matrix takes the hydro-geological security into account.
(2) In order to reflect the differences between hydrologic units protection priority, various methods have
been adopted to converted data based on hydrologic units. In the process of space conversion, the
accuracy is different with different methods. On one hand, soil and water erosion grade based on
hydrologic units is determined based on the average value of grid data, and the linear priority of rivers
was directly converts into priority based on hydrologic units. On the other side, when the biodiversity
conservation and groundwater remediation priority based on administrative unit was converted to that
based on hydrologic units, methods of high-class preference, that is, when there are two different
priority values in one evaluation unit, the higher one is preferred, and extrapolation were used. And a
hydrologic unit possesses the same priority as that of the administrative unit inherent. There is an
increase of inaccuracy in the upscaling of judgment from small-scale linear or plaque aspect to
hydrologic units. The intermediate results from the matrix can be reference when an accurate result of
the ecological restoration priority is needed. Although there are some problems in the methodology, the
comprehensive priority conclusion based on hydrologic units accords with the actual situation of the
basin.
(3) Some mountain forest ecosystem plays an important role in biodiversity. Although these areas are
neither directly related to ecological restoration tasks nor need of water supply, ET water consumption
quota requires arrangement by the basin administrative department.
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