基于GIS的黄土丘陵区土壤水库蓄水数量特征及其生态供水潜力评价

ISWC OpenIR > 水保所知识产出(1956---)

	基于GIS的黄土丘陵区土壤水库蓄水数量特征及其生态供水潜力评价
其他题名	Quantitative analysis and Water Supply Potential of soil water reservoir in the Loess Hilly Region Using GIS Techniques
	焦峰
学位类型	博士
导师	李锐
	2006
学位授予单位	中国科学院研究生院
学位授予地点	陕西
学位专业	土壤学
关键词	Gis 黄土丘陵区土壤水库蓄水数量供水潜力
其他摘要	在干旱半干旱地的黄土丘陵区，深厚的黄土层蓄积了大量水分形成了“土壤水库”。一方面，土壤水库对降雨的三水转化有重要的影响，并对植被供水具有良好的水稳性和自动调节能力，从而成为区域生态环境建设评价的主要因素之一；另一方面，随着黄土高原植被恢复与生态工程的开展，生态用水量与用水结构发生了重大变化，客观上需要对“土壤水库”蓄水量特征及其生态供水潜力进行评价。本文依据生态学、水文学、空间统计学理论与方法，以GIS为平台，结合野外实地调查，对黄土丘陵区“土壤水库”蓄水数量特征、“土壤水库”蓄水时空分布特征和“土壤水库”生态供水潜力预测等进行了研究。经过两年多的理念开发、系统推理、实地考察、数量计算和综合分析，在以下几个方面取得了一些进展。1.对土壤水库的定义、功能、相关技术指标、研究深度和静态库容组成等进行了描述、界定和计算。研究认为：赋存于土体中的雨水资源量相当可观，雨水转化为土壤水资源贮存量为457mm，相当于地表水和地下水总量的10倍，研究区5m深土层土壤水库总贮量为1419.78mm/416156万m³；其中死库容为299.25mm/87714万m³，占土壤总库容的21.08%，重力库容为196.18mm/57505万m³，占土壤总库容的13.82%，有效库容为924.35mm/270939万m³，占土壤总库容的65.10%，最大有效库容为1120.53 mm/328442万m³，占总库容的78.92%。2. 建立了研究区专题数据库和土壤水分数据库参照有关黄土高原土壤水分等级分类结果，结合黄土丘陵区实际情况，采用田间持水量、凋萎湿度、植被生长阻滞点为指标，建立具有统一时空尺度和区域特征的土壤水分分级指标，以土地利用图、土地类型图和坡度分级图为基础，以ARCVIEW为平台，建立不同利用类型——土地类型——坡度分级的浮点型土壤含水率字段，根据野外实点采集的数据和土壤含水量分级标准，建立野外采样数据与图形数据库的对应关系，编制2003年雨季前后、1985年雨季前不同土层土壤水分含量分布图，建立了研究区专题数据库和土壤水分数据库。3.对研究区土壤水分剖面分布和动态变化情况进行了系统的统计和分析雨季前，研究区土壤水分总体处于极难效和难效状态，分别占总土地面积的19.12%和75.57%，说明经过干燥的冬春两季蒸发和消耗，土壤水分环境非常恶劣；雨季后，0-60cm和60-120cm土层，土壤水分补偿率高，土壤水分变化分别达到2983.59km²和2216.71km²，变化率分别达98.72%和75.63%，土壤水分变化和补偿自上而下降低趋势显著。如果将植被生长阻滞点作为土壤是否干燥化的分界线，那么0-500cm土层1985年到2003年土壤水分干化面积增加了821.61km²，增加幅度达42.05%。雨季前，研究区0-500mm深土层土壤湿度指数都在60的警戒线一下，总体处于干旱和半干旱状态；雨季后，0-500cm土层土壤湿度指数由雨季前干旱状态的47.90升高到67.34，增幅达到19.44，土壤湿度由半干旱状态上升到半湿润状态；1985年与2003年雨季前0-500cm土层土壤湿度指数剖面变化趋势基本相似，土壤湿度指数由雨季前1985年的49.88下降到2003年雨季前47.90，降幅为1.97，土壤湿度在降低。4.对研究区土壤水库蓄水数量特征和动态变化进行了统计和分析通过对不同土壤剖面土壤水库蓄水量统计分析得出，研究区土壤水库总贮水量/蓄水量为614.32mm/180065万m³，占土壤水库总库容的43.27%，土壤水库有效贮水量/有效蓄水量为315.07mm/92351万m³，占土壤有效库容的30.09%；经过冬春两干旱少雨季节的消耗，研究区土壤水库蓄水量达不到总库容的50%，处于中等偏下水平。雨季后土壤水库贮水量/蓄水量为788.87mm/231227万m³，比雨季前增加了174.55mm/51162万m³，增加幅度为28.41%；雨季后土壤水库有效贮水量/有效蓄水量为489.62mm/143513万m³，比雨季前增加了174.55mm/51162万m³，增加幅度为55.40%。0-60cm土壤水分速变层、60-120cm土壤水分活跃层和120-200cm土壤水分次活跃层的土壤水库贮水量/蓄水量达到了土壤水库总库容的60%以上，其有效贮水量/有效蓄水量也达到有效库容的近70%以上，雨季对土壤水库蓄水量的补偿沿表层向深层减低的趋势非常明显。1985年雨季前土壤水库贮水量/蓄水量或为626.55mm/183642万m³，2003年雨季前土壤水库贮水量/蓄水量为614.32mm/180065万m³，2003年雨季前比1985年雨季前减少了12.23mm/3557万m³，减少幅度为1.95%；1985年雨季前土壤水库有效贮水量/有效蓄水量为327.30mm/95928万m³，2003年雨季前土壤水库有效贮水量/有效蓄水量为315.07mm/92351万m³，2003年雨季前比1985年雨季前减少幅度为3.74%。5.根据土壤水分平衡性和有效性原理，对研究区不同土壤剖面土壤水库蓄水量和亏缺量进行统计研究区0-3m土层雨季前土壤水库亏缺量已达375.67mm，大于6-9月雨季降雨均量值（367.8mm）；0-500cm土层土壤水库有315.07mm/92351万m³的可调节水量，总亏缺量为609.28mm/178588万m³，亏缺率达65.91%，亏缺量相当于年均降雨量的1.21倍，土壤水分亏缺有自上到下降低的趋势。植被的参与大大强化了土壤水分的消耗过程，导致土壤水分亏缺量明显增加，几种土地利用类型土壤水库亏缺率大小顺序为：有林地>天然草地>荒坡地>果园>坡耕地；其中有林地0-500cm土层土壤水库仅有95.63mm的可调节水量，总亏缺量为828.72mm，亏缺率达89.65%；天然草地仅有123.75mm的可调节水量，总亏缺量为800.62mm，亏缺率达86.61%。6.应用里思模型的混合模型对研究区植被承载力潜力及土地利用调整目标进行了计算和分析在年均降雨量502mm，光能利用率在2%的条件下，研究区植被盖度可能达到的最大植被盖度为56%；按照研究区的降雨和光照要求，确定了 4：3：2：1是研究区草、灌、农、乔比较理想的建造模式，其中，草地目标值为：1172.45 km²，灌木林地目标值为：879.34 km²，农地目标值为：586.23 km²，乔木林地目标值为：293.11 km²。; Abundance moisture storing in profound loess layer forms soil water reservoir (SWR) in the arid and semiarid loess hilly region. On the one hand, because the SWR has important influence on the rain transformation of three water(the surface water, the soil moisture and the ground water),and its well stability and self adjustably to vegetation water supply，so it become one of the primary factors in area entironment construction evaluation. On the other hand, in the movement of vegetation restoration and entironment project in loess plateau，because of momentous chance in eco-water quantity and structure, we need valuate quantitative analysis and Water Supply Potential of soil water reservoir on impersonality. According as theory and methods of ecology, hydrology, and space statistics，using GIS, integrating field investigation, the author studied quantitative characteristic, spatio-temporal distributing and water supply potential of soil water reservoir in the Loess Hilly Region. Through three years studying, the paper had made progress in some aspects.1.Systematically expatiate on define, function and correlative technique index of soil water reservoir. Make certain research depth of soil water reservoir. Calculate static state capacity of soil water reservoir. The results showed that quite a few rainfall deposited in soil. About 457mm rainfall transform into soil moisture resource, and amount to 10 times of the surface water and the ground water. In 5m depth soil of research area, total holding capacity is 1,419.78mm/416.156 million m³. Thereinto, unavailable volumetric capacity is 299.25mm/87.714 million m³，being 21.08% of total holding capacity. Gravitational volumetric capacity is 196.18mm/57.505 million m³, being 13.82% of total holding capacity. Available volumetric capacity is 924.35mm/270.939 million m³, being 65.10% of total holding capacity. The greatest available volumetric capacity is 1120.53 mm/328.442 million m³，being 78.92% of total holding capacity. 2. Constitute special database and soil moisture database of study area. Extend theory and methods in soil moisture research area. Referring to relational results of soil moisture grading classified in loess plateau, combining with factual instance, adopting field capacity, wilting coefficient, inhibiting growth point as indicator，the author constituted soil moisture grading classified system with uniform spatio-temporal scale and area characteristic. Based on land use map, land style map and slope map, using ARCVIEW, according to field investigation sampling and soil moisture grading classified criterion, the author established floating-point soil moisture field of different land use——land style——slope grade，and compile soil moisture maps of different soil layers before and behind rainy season in 2003 and 1985, and building up special database and soil moisture database of study area. 3. Systematically statistic and analysis distribution of soil moisture and its dynamic movement in research area Before rainy season, soil moisture was in the bally difficult-available and difficult-available state in research area, being 19.12% and 75.57% of total land area respectively. This result showed that soil moisture state was very bad by evaporation and consuming of dry winter and spring. Behind rainy season, in soil layers of 0-60cm and 60-120cm, compensatory rate of soil moisture got well, soil moisture change being 2983.59km² and 2216.71km² respectively, and its change rate being 98.72% and 75.63% respectively. Depressed trend of change and compensatory rate of soil moisture were remarkable from up to down. If regarding inhibiting growth point as boundary of soil dryness, so in soil layer of 0-500cm, 1985年到2003年the dried area of soil moisture added up 821.61km² from 1985 to 2003，extent being 42.05%. Before rainy season, soil humidity indicator was below of watchful borderline 60 in soil layer of 0-500cm. It showed that soil moisture was in the arid and semiarid state. Behind rainy season, soil humidity indicator was from 47.90 before rainy season up to 67.34 in soil layer of 0-500cm, extent being 19.44. It showed that soil moisture was in the semiarid and semi wetness state. Soil humidity indicator was from 49.88 of 1985 down to 47.90 in soil layer of 0-500cm, extent being 1.97. It showed that soil moisture was depressed by degrees.4.Systematically statistic and analysis quantitative characteristic of soil water reservoir and its dynamic movement in research area Quantitative statistic and analysis of soil water reservoir in different soil section showed that total cumulating quantity of soil water reservoir was 614.32mm/180.065 million m³，being 43.27% of total holding capacity. Available cumulating quantity of soil water reservoir was 315.07mm/92.351 million m³，being 30.09% of total holding available capacity. This result showed that soil moisture state fell short of 50% of total holding capacity by evaporation and consuming of dry winter and spring, its being middling and hyponastic level. Behind rainy season, cumulating quantity of soil water reservoir was 788.87mm/231.227 million m³, adding 174.55mm/51.162 million m³ than that before rainy season, extent being 28.41%. Available cumulating quantity of soil water reservoir was 489.62mm/143.513 million m³, adding 174.55mm/51.162million m³ than that before rainy season, extent being 55.40%. In soil layers of 0-60cm,60-120cm and 120-200cm, cumulating quantity of soil water reservoir got to 60% of total holding capacity. Its available cumulating quantity of soil water reservoir got to 70% of total holding available capacity. Depressed trend of compensatory rate of soil water reservoir from rainfall were remarkable from up to down. Cumulating quantity of soil water reservoir was 626.55mm/183.642 million m³ before rainy season in 1985 and cumulating quantity of soil water reservoir was 614.32mm/180.065 million m³ before rainy season in 2003, decreasing 12.23mm/3557 million m³ from 1985 to 1985, extent being 1.95%. Available cumulating quantity of soil water reservoir was 327.30mm/95.928 million m³ before rainy season in 1985 and available cumulating quantity of soil water reservoir was 315.07mm/92.351 million m³ before rainy season in 2003, extent being 3.74%. 5. Systematically statistic and analysis deficit quantitative of soil water reservoir in research area based on theory of soil moisture balance and validity Before rainy season, deficit quantitative of soil water reservoir got to 375.67mm of 0-300cm in research area, bigger than mean value (367.8mm) from June to September. Deficit quantitative of soil water reservoir got to 609.28mm/178.588 million m³ of 0-500cm in research area, deficit rate getting to 65.91%, and amount to 1.21 times of annual rainfall. Depressed trend of deficit rate of soil water reservoir from rainfall were remarkable from up to down. Vegetation strengthened dissipative process of soil moisture in great, and led to obviously augment deficit quantitative of soil water reservoir. Deficit rate of soil water reservoir in land use styles from the big small was: woodland, natural grassland, wild land, orchard and slope farmland. Thereinto, the woodland merely had 95.63mm adjustable cumulating quantity of soil water reservoir of in 0-500cm, total deficit quantitative getting to 828.72mm，deficit rate getting to 89.65%. the natural grassland merely had 123.75mm adjustable cumulating quantity of soil water reservoir of in 0-500cm, total deficit quantitative getting to 800.62mm，deficit rate getting to 86.61%. 6.Calculate and analysis bearing capacity of vegetation and adjustable cause of land use applying omnibus model of Lieth in research area In terms of 502mm of annual rainfall and 2% of light energy used, the author calculated that the greatest coverage rate is 56% in research area. According to rainfall and light, the author thought that 4：3：2：1 is the most perfectly pattern of grassland, shrubbery land, farmland and woodland constructing in research area. Thereinto, the target value of grassland is 1172.45 km². The target value of shrubbery land is 879.34 km². The target value of farmland is 586.23 km². The target value of woodland is 293.11 km².
文献类型	学位论文
条目标识符	sbir.nwafu.edu.cn/handle/361005/4145
专题	水保所知识产出(1956---)
推荐引用方式 GB/T 7714	焦峰. 基于GIS的黄土丘陵区土壤水库蓄水数量特征及其生态供水潜力评价[D]. 陕西. 中国科学院研究生院,2006.