In terms of per capita water availability, the Guanting Basin is .... Figure 8.7: Frequent phytoplankton taxa in the Yongding River and in Guanting reservoir; ...
E
Hydrology / Ecology / River Management
Schweizerbart
Konzepte für die nachhaltige Entwicklung einer Flusslandschaft ISSN 2366-8962 %DQG )UDQN:HFKVXQJ6WHIDQ.DGHQ0DUNXV9HQRKU-UJHQ+RIPDQQ-HQV 0HLVHO=KHQFL;X (GV
6XVWDLQDEOH:DWHUDQG$JULFXOWXUDO/DQG 8VHLQWKH*XDQWLQJ%DVLQXQGHU/LPLWHG :DWHU5HVRXUFHV SDJHV ¿JXUHVWDEOHVULEERQERRNPDUN KDUGFRYHU [FP ,6%1 ¼ ZZZVFKZHL]HUEDUWGH
In terms of per capita water availability, the Guanting Basin is one of the world’s most water scarce regions. The catchment of the Guanting reservoir (“Guanting basin”) covers an area of 43 605 km². With regard to administrative areas the western part belongs to the Shanxi Province while the eastern section is part of Hebei Province. Smaller portions extend into Beijing and Inner Mongolia autonomous region. The book presents research results of a Chinese-German scenario study that explored sustainable water and land use management strategies in the Guanting Basin. The basin, located northwest of Beijing, is facing dramatic water challenges. Originally, the research approach has been developed in the German landscape for the Elbe River. 200
Within the Guan ting project this approach – and model chain – was transferred to completely different conditions of an East Asian landscape and river basin. Together with Chinese project partners the German researchers adapted their climate, discharge, water balance and nutrient emission models to the regional conditions of the Guanting basin. Additional water quality monitoring, reservoir classification and socioeconomic methods as well as different future development scenarios for the region were produced. In the end, a regional integrated model setup has been composed to assess different adaptation options and their benefits to water and land use management under different climate and socio-economic scenarios.
201
from a bridge or a boat was not possible, a graduated jug was fixed on a 2 m stick or a rope and was used for water sampling from the shore.
H1 – Guanting, May 2010, shore sampling
210
Figure 8.1: Location of the monitoring sites (period 2000–2011).
Figure 8.2: Procedure Steps during the microscopic analysis. A) Unfiltered water sample with iodine rich Lugol’s solution glass bottles B) sediment chambers to let the algal particles settle C) examination of the samples for taxa determination and counting according protocol D) photo documentation of taxa
Sustainable Water and Agricultural Land Use in the Guanting Basin under Limited Water Resources
DJHV
H1 – Guanting, Sept 2011, boat sampling
211
and Cyclotella ozensis (Tanaka & Nagumo 2005) H. Tanaka (2007) comb. nova; Figure 8.9 pictures k – m. Cyanobacteria did not reach relevant proportion in terms of phytoplankton taxa number and total biovolume in 2010 and 2011. Microcystis wesenbergii, Planktothrix agardhii and Anabaenopsis cunningtonii were detected, but also indicators for a good status such us Aphanocapsa and Merismopedia. In Guanting reservoir the total biovolume of the phytoplankton ranged between 0.5 H2 – Bridge No 8, May 2010, high erosion H2 – Bridge No 8, Sept 2011, maize ize corn fields and 3.5 mm3/L, which corresponds to a low concentration of chlorophyll a ranging between 2 and 13 mg ∙ m−3. Total biovolume below 3.3 mm3/L and chlorophyll a concentrations below 11 mg ∙ m−3 indicate high status for polymictic reservoirs in mountainous regions with large catchment areas (German lake type 6.3). The taxa composition of the Guanting reservoir indicates a mesotrophic to slightly eutrophic status. In contrast to the reservoir, phytoplankton in the rivers had a high share of phytobenthic diatom taxa such as Achnanthes, Bacillaria paxillifer, Cymatopleura solea var. apiculata, Entomoneis paludosa, Gomphonema minutum, Surirella brebissonii, Gyrosigma spp, Surirella (see more taxa in Tables 8.5, 8.6). In Germany an assessment method is applied to all larger rivers, which is based on H3 – Shacheng Yang River – confluence nfluence of Yang River phytoplankton biomass and composition. This method is named PhytoFluss and is made H3 – Shacheng Yang River – confluence of Yang River (high sediment load) and Sanggan He, Sept 2011 and Sanggan He, Sept 2010 to implement the European Water Framework Directive (EC 2000). The test application of the assessment method with the German PhytoFluss-Index for plankton dominated rivers (Mischke et al. 2011) revealed a moderate status for the Yongding River. At station H2 the seasonal mean of the total biovolume was 8.2 mm3/L, which corresponded to 31 mg ∙ m−3 chlorophyll a in 2010. In the subsequent year, the phytoplankton biovolume was higher (7.1–15.5 mm3/L), which present a chlorophyll a concentration of 43 mg ∙ m−3. The concentrations of both years of investigation are indicating a good or moderate status, respectively, according the boundaries for good/moderate and moderate/poor status class set for the German river type 20.2 (Mischke et al. 2011). H4 – Baozhuang – Sanggan River ver – high discharge in H4 – Baozhuang – Sanggan River – construction works Within the Phyto-Fluss-Index, further biological parameters are used as indices Sept 2011 in May 2010 (metrics), which are based on the contribution of specific algal groups to total biovolume. In Yongding River, the share of chlorophytes (1 %) and of cyanobacteria (3 %) to total biovolume were low and both metrics are in the range of the good river status. The Pennales, a group within the algal class Bacillariophyceae (diatoms), are common in rivers with low nutrient status and near-pristine hydro-morphological conditions. In Yongding Monitoring of trophic status and phytoplankton in water bodies dies of the Guanting basin River the group of Pennales had a high contribution to total biovolume (18 %), which indicates a good status at station H2. In the Yongding River, taxa such as euglenids, Aulacoseira granulata, Cyclotella meneghiniana or Microcystis indicate a poor ecological status. A frequently found taxa Cymatopleura solea var. apiculata has no trophic score according to the German assessment method. In September 2011, an unusual bloom of the desmid Closterium cf. praelongum was observed (Figure 8.7 picture l). In the Yang River at station H5, the total biovolume ranged between 0.6 and 3.78 mm3/L in May to September 2011. The maximum was caused by an Euglena bloom in September 2011. In addition to the centric diatoms Cyclotella meneghiniana, Cyclotella atomus and Stepha-
Sustainable Water and Agricultural Land Use in the Guanting Basin under Limited Water Resources
OHS DPS
nodiscus minutulus, pennate diatoms such as Achnanthidium minutissimum, Gomphonema olivaceum, Navicula viridula and Nitzschia palea were also common (Table 8.4). The cyanobacteria Planktothrix agardhii and Pseudanabaena catenata were found (
