本文選題：AnnAGNPS + 羅李村流域�。� 參考：《陜西科技大學(xué)》2017年碩士論文

【摘要】：隨著城市化的發(fā)展,世界范圍內(nèi)的供水危機(jī)日益嚴(yán)重,河流的水環(huán)境問題越來越受到人們的關(guān)注。分布式水文模型考慮了氣候和下墊面的空間異質(zhì)性,根據(jù)地形和水文特征將流域劃分為若干計(jì)算單元,基于此模擬的流域水文物理過程更接近實(shí)際�？茖W(xué)合理的模擬流域水文過程為研究流域水環(huán)境的可持續(xù)管理提供科學(xué)依據(jù)。灞河屬黃河支流渭河的一級(jí)支流,是西安市典型的城市河流。灞河流域地處西北半干旱區(qū),降雨是流域徑流的主要補(bǔ)給方式。AnnAGNPS分布式水文模型在灞河流域的應(yīng)用未見報(bào)道。本研究以灞河上游羅李村流域?yàn)檠芯繀^(qū),基于AnnAGNPS模型構(gòu)建流域日尺度徑流泥沙數(shù)據(jù)庫,探討流域最優(yōu)分室劃分,分割流域基流,分析徑流泥沙的敏感性參數(shù)。在此基礎(chǔ)上,運(yùn)行模型模擬流域的徑流過程和泥沙負(fù)荷并分析其模擬效果,評(píng)價(jià)Ann AGNPS模型在羅李村流域的適用性,為充分了解流域水文特征及合理管理流域環(huán)境提供理論參考。本研究取得的主要成果如下:(1)通過實(shí)驗(yàn)發(fā)現(xiàn)流域離散化參數(shù)初始源面積(CSA)為100 hm2,最小初始溝道長(zhǎng)度(MSCL)為70m,模型將流域劃分為1030個(gè)分室(Cell)和420個(gè)溝道(Reach),模型能夠較好的反映流域地形、土地利用、土壤類型等下墊面特征。(2)采用加里寧算法對(duì)流域基流進(jìn)行分割,得出流域基流指數(shù)為47.48%。(3)通過DSA進(jìn)行模型參數(shù)敏感性分析發(fā)現(xiàn):流域徑流敏感性參數(shù)從高到低依次為徑流曲線數(shù)CN、田間持水量、飽和導(dǎo)水率、溝道曼寧系數(shù)。泥沙敏感性參數(shù)依次為耕作后地表殘留物覆蓋率、地表覆被與作物管理因子、水土保持措施因子、土壤可蝕性因子、初始隨機(jī)粗糙度、田間持水量、年根系生物量、耕作擾動(dòng)面積、地表殘留物覆蓋率。此外,溝道曼寧系數(shù)對(duì)泥沙的輸出無影響。(4)通過對(duì)模型進(jìn)行率定和驗(yàn)證,模型在率定期(2001-2005年)和驗(yàn)證期(2006-2010年),年、月、日尺度徑流模擬效率系數(shù)Ens均大于0.51,決定系數(shù)R2均大于0.55,模擬值低于實(shí)測(cè)值但相對(duì)誤差Re均控制在10%以內(nèi)。月尺度徑流模擬效果最佳,Ens和R2均大于0.78。模型對(duì)大中等強(qiáng)度降雨事件的模擬效果優(yōu)于暴雨,降雨事件的模擬偏差隨降雨強(qiáng)度的增大而增大。徑流的空間分布顯示,流域內(nèi)耕地產(chǎn)流能力最強(qiáng),喬木林產(chǎn)流能力最弱。AnnAGNPS模型適用于羅李村流域的徑流過程模擬。流域河段水環(huán)境容量的計(jì)算結(jié)果表明,灞河干流COD和NH3-N的水環(huán)境容量分別為3814t/a和223t/a,干流對(duì)流域水體的面源污染有一定的調(diào)節(jié)作用。(5)由于輸沙過程的復(fù)雜性,與徑流相比,模型對(duì)泥沙的模擬精度偏低,Re在-30%左右。月尺度率定期Ens為0.35,R2為0.36,驗(yàn)證期分別為0.27和0.35。總體上模型可以反映流域輸沙量的變化。流域土壤侵蝕以微度為主。
[Abstract]:With the development of urbanization, the water supply crisis in the world is becoming more and more serious. The distributed hydrological model takes into account the spatial heterogeneity of climate and underlying surface and divides the watershed into several computing units according to the topography and hydrological characteristics. The hydrophysical process of the watershed based on the simulation is closer to the actual situation. Scientific and reasonable simulation of watershed hydrological process provides scientific basis for the study of sustainable management of watershed water environment. Bahe is a first-class tributary of the Weihe River, a tributary of the Yellow River, which is a typical urban river in Xi'an. The Bahe River basin is located in the semi-arid region of northwest China. Rainfall is the main recharge mode of runoff. The application of Ann AGNPS distributed hydrological model in Bahe River basin has not been reported. Based on AnnAGNPS model, the daily scale runoff and sediment database of the upper reaches of Bahe River was constructed, and the optimal partition of watershed basic flow was discussed, and the sensitivity parameters of runoff and sediment were analyzed. On this basis, the operation model simulates the runoff process and sediment load of the watershed and analyzes its simulation effect, and evaluates the applicability of the Ann AGNPS model in the Luoli village basin, which provides a theoretical reference for fully understanding the hydrological characteristics of the basin and for reasonably managing the basin environment. The main results of this study are as follows: (1) the experimental results show that the initial source area and minimum initial channel length are 100 mm ~ 2 and 70 m, respectively. The model divides the watershed into 1030 compartments (Cell1) and 420 channels (CSAs). The model can be compared with that of the model. A good reflection of the watershed topography, Land use, soil type and other underlying surface characteristics. The sensitivity analysis of model parameters by DSA showed that the runoff sensitivity parameters from high to low are runoff curve number CNN, field water holding capacity, saturated water conductivity and channel Manning coefficient. The parameters of sediment sensitivity were surface residue coverage, land cover and crop management factors, soil and water conservation measures, soil erodibility, initial random roughness, field water holding capacity and annual root biomass. Tillage disturbance area, surface residue coverage. In addition, the channel Manning coefficient has no effect on the sediment output. (4) through the rate determination and verification of the model, the model is at regular intervals from 2001 to 2005) and the verification period is from 2006 to 2010. The daily runoff simulation efficiency coefficients Ens and R ~ 2 are all greater than 0.51and 0.55 respectively. The simulated values are lower than the measured values, but the relative error re is controlled within 10%. The results of monthly scale runoff simulation showed that both Ens and R2 were more than 0.78. The simulation effect of the model is better than that of rainstorm, and the simulation deviation of rainfall event increases with the increase of rainfall intensity. The spatial distribution of runoff shows that the runoff production capacity of cultivated land in the watershed is the strongest, and the runoff production capacity of Arbor forest is the weakest. Ann AGNPS model is suitable for the runoff process simulation of Luoli village watershed. The results show that the water environmental capacity of 3814t/a and NH3-N are 3814t/a and 223t / a, respectively. The main stream has a certain regulating effect on the non-point source pollution of the basin water body. (5) because of the complexity of sediment transport process, compared with runoff, the water environmental capacity of the main stream of Bahe River is more complex than that of the runoff. The simulation accuracy of the model for sediment is about -30%. The monthly scale rate of the periodic Ens is 0.35 ~ 2 is 0.36, and the verification period is 0.27 and 0.35, respectively. On the whole, the model can reflect the change of sediment discharge. Soil erosion in watershed is dominated by microdegree.
【學(xué)位授予單位】：陜西科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：P333

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本文編號(hào)：2037305