Watershed classification in Taizi River 孔维静 Chinese Research Academy of Environmental Sciences Outline 1. Natural, geographical and freshwater ecosystem features in Taizi river watershed 2. Why classification 3. Method 4. Results 1.1Overview 40 29 -4140N 122 25 -124 55 E Temperate continental monsoon climate Area: 12,000KM2 Province: Liaoning DEM Geomorphology Soil type Annual average temperature Annual average rainfall Vegetation 1.2 Environment variables for Taizi river watershed Environment variables Rationale Temperature Determines the spatial pattern of species distribution Precipitation Related to watershed water cycle and water resource distribution, determining species distribution, ecosystem process and dynamics DEM Related to temperature, rainfall and hydrology, influencing species distribution, freshwater ecosystem type, spatial pattern and ecosystem process Soil Related to water cycle, influencing hydrological process, biogeochemical process and freshwater ecosystem structure and function Vegetation Offering habitat for freshwater organisms, related to water temperature adjustment, sunlight penetration, soil erosion and biogeochemical process; influencing freshwater ecosystem structure and function Slope Related to regional or local macro-habitat, influencing freshwater structure and function 1.3 Environmental variables and its ecological importance Environmental variables influence freshwater ecosystem 1.4 Freshwater ecosystem: Macroinvertebrate community structure Individuals Dominant species Species Individuals, species and dominant species for macroinvertebrate are different among Taizi river watershed 1.5 Freshwater ecosystem: Fish community structure Individuals Species Dominant Species Individuals, species and dominant species for fishes are different among Taizi river watershed 1.6 Freshwater ecosystem: Alage community structure Individuals Species Individuals and species for algae are different among Taizi river watershed 1.7 Results Environmental variables changes from the upper Taizi river to lower Taizi river Freshwater community structure changes from the upper Taizi river to lower Taizi river 2. Why classification Spatial heterogeneity of environmental variables Spatial heterogeneity of freshwater ecosystem structure Base for river health assessment Management demands 3. Method-classification scheme Data source：DEM，slope，aspect, vegetation type，soil type，annual average temperature，annual rainfall，annual evaporation；NDVI Qualitative analysis of spatial distribution pattern Geostatistic analysis Correlation Analysis between aquatic organisms and environmental variables Environmental Indices chosen for the classification unsupervised classification results Final classification map Small catchments boundary Modify with aquatic organisms cluster map aquatic organisms survey data Aquatic organisms cluster map cluster ISODATA 4.1 Results Relationship between freshwater organisms and environmental factors Environmental variables influences freshwater ecosystem structure, so its pattern can be used to reflect the freshwater ecosystem pattern in Taizi river watershed 4.2 Results DEM slope Annual Evaporation Annual Temperature Annual Precipitation NDVI Range 101.28 KM 84.43 KM 132.1 KM 87.28 KM 100.3 KM 92.37 KM Spatial autocorrelation range calculated from geostatistic DEM and precipitation were suitable for the classification DEM Annual average rainfall Database 4.3 Results ISODATA unsupervised classification results in ERDAS 4.4 Results Check with freshwater organisms and boundary revision Classification by natural attributes Small watershed boundary Mountainous forest region Hill forest region Plain agriculture region Freshwater organisms pattern Region Watershed features River feature Freshwater ecosystem Mountainous forest region Area: 4557KM2， Mean DEM: 511m； Annual average temperature: 2.28-7.75； Annual average precipitation: 786-954mm Mean river width 14.79 m (0.5-100m)；Mean substrate index: 3.6 (1-4.8)；Mean suspended solid: 33.7mg/L (3.5347mg/L)；Mean DO: 10.8 mg/L (4.315.6 mg/L); Mean conductivity: 183s/cm (11.7826s/cm) Dominant fishes: Leuciscus waleckii、Cottus pollux, Odontobutis obscurus; Dominant macroinvertebrate: Ecdyonurus viridis, Paraleptophlebia japonica；Above ground herbaceous biomass: 1.04kg/m2，belowground: 0.55 kg/m2，Total: 1.68 kg/m2 4.5 Mountainous forest region Region Watershed features River features Freshwater ecosystem Hill forest region Area: 3896KM2; Mean DEM: 282m； Mean annual temperature: 6.9 (4.38-9.22)； Mean annual average precipitation: 784mm(717-868mm) Mean river width: 44.4m (0.3-300m)；Mean substrate index: 3.4(1-4.4)； Mean suspended solid: 30.3 mg/L(5.581.5 mg/L) ； Mean DO: 9.4mg/L (3.514.6 mg/L)；Mean conductivity: 336.8s/cm (57566s/cm) Dominant fishes: Ctenogobius brunneus, Hemicculter Leuciclus, Squalidus chankaensis; Dominant ma