【作者】 魏芳菲；

【导师】 刘成林；

【作者基本信息】 南昌大学 ， 水利水电工程， 2009， 硕士

【摘要】 绿洲灌溉农业是吐鲁番地区生存与发展的基础,农业的持续发展是决定吐鲁番地区经济发展的基础。农业是用水大户,水已经成为制约区域经济发展的首要因素。为了整个社会的持续稳定发展,必须进行节水农业以支持工业经济的发展。区域农业节水潜力的分析研究可为水资源的合理开发及利用,节水灌溉工程的建设提供科学依据,为今后节水型农业灌溉等生产实践提供科学理论基础。本文利用遥感这一先进技术手段,对农田蒸散发和作物生物量进行遥感定量估算,并在此基础上以作物水分生产率为衡量标准对棉田节水潜力进行了估算,进而对区域可采取的节水灌溉措施进行了分析。本文包括的主要内容如下:(1)利用ETWatch遥感模型结合吐鲁番地区的棉花分布图,对吐鲁番地区的棉田的物候期ET进行了估算。结果表明,吐鲁番地区的棉田耗水较大,这与目前该区仍大量采用的大水漫灌、串灌、深灌等大定额灌溉方式有很大关系。棉田耗水在时间上呈单峰分布,4～7月份耗水逐渐增大,8月份达到最大,9月份棉花趋向成熟耗水量回落,基本符合该地区棉田的耗水规律。(2)利用遥感数据基于生物量的产生机理对吐鲁番地区棉田生物量产量进行了估算。估算结果与统计数据比较吻合,相对偏差5.6%,与高产区产量相比,吐鲁番地区棉田单产偏低,平均值1450kg/ha,仅为高产田单产(3000kg/ha)的一半。(3)在遥感估算的棉田蒸散发和皮棉单产的基础上,根据本文作物水分生产率的定义计算了吐鲁番地区棉田的水分生产率。结果显示,吐鲁番地区棉田的水分生产率相对较低,尚有很大的提升空间,蕴藏着较大的节水潜力。(4)在对吐鲁番地区棉田的水分生产率进行频率分析后,综合分析国内外棉田的水分生产率水平与本区域的实际水平,将50%、70%累积频率处对应的水分生产率作为该区域近、远期的目标水分生产率,其对应的水分生产率分别为0.234kg/m~3、0.304kg/m~3。经分析计算,近期目标下,棉田节水潜力可达到2.24亿方;远期目标下,棉田节水潜力可达到4.63亿方。节水潜力随累积频率的增大而减小。低频区域的节水潜力大,高频区域的节水潜力小。若首先选择耗水量大、水分生产率水平相对较低的低产田进行节水改造,其节水效果最明显。(5)针对区域自然气候等特征,指出本区域棉田宜采用滴灌这一节水灌溉方式,并辅以农业节水措施如耕作保墒、水肥耦合、化学制剂保水保墒、覆盖保墒、高产栽培模式等以减少无效ET,提高作物的水分利用率。本文基于真实节水的概念,以作物水分生产率为出发点,将遥感这一先进技术手段运用到节水潜力的估算中来,其分布式的特征可以充分体现下垫面的空间变异性。由于每种作物的耗水特性、生理特性等都有所不同,故本文以单一作物的水分生产率代替区域综合粮食水分生产率进行分析,以当地的主要种植作物棉花为例,深入分析其耗水特性、生长规律等以使节水潜力的估算更加准确合理。更多还原

【Abstract】 Oasis irrigated agriculture is the basis for survival and development of the Turpan region, the sustainable development of agriculture is to determine the Turpan region’s economic development. Agriculture is the major water users; water has become a primary constraining factor in regional economic development. In order to sustained and stable development of society as a whole, water-saving agriculture must be carried out to support industrial economic development. And the analysis and research of the regional agricultural water-saving potential provides a scientific basis for rational development and utilization of water resources, the construction of water-saving irrigation project and a scientific theoretical basis for the future water-saving irrigation practices.In this paper, a quantitative estimation of farmland evapotranspiration (ET) and crop biomass have been made making use of advanced remote sensing technology. On this basis, estimated the water-saving potential of cotton farmland as measurement strategy of crop water productivity and then analyzed the available water-saving irrigation measures.The main elements included in this article are as follows:(1) Estimated the evapotranspiration of cotton field on the Turpan region making use of ETWatch remote sensing model and cotton distribution map of Turpan. The result showed that in the Turpan region the water consumption of cotton is higher which is related to the current irrigation method such as flood irrigation, string irrigation, deep irrigation and other large scale irrigation methods. The water consumption showed a single peak distribution with time. The water consumption is gradually increasing between April to July, got the maximum in August and dropped in September because of the cotton’s mature. These processes are basically in line with the local cotton’s water consumption discipline.(2) Estimated the biomass and yield of cotton field on the Turpan region based on biomass generation mechanism making use of remote sensing data and cotton distribution map of Turpan. The estimated result and the statistic data are neared with the relative deviation of 5.6%. Compared with the production of high-yielding areas, cotton yields in the Turpan region is low with an average value of 1450kg/ha, only a half of high-yield area (3000kg/ha).(3) Calculated crop water productivity in cotton fields of Turpan region on the base of the remote sensing estimation of the cotton evapotranspiration and lint yield, according to this definition. The result showed the level of water productivity of cotton field on Turpan region is relatively low, which implied that there is a considerable room for water productivity and a large potential for water-saving.(4) Carried out the frequency analysis on crop water productivity of cotton field in the Turpan area and a comprehensive analysis of water productivity levels in cotton fields at home and abroad with the actual level of the region. The crop water productivity corresponding to 50%, 70% of the cumulative frequency would be the short-term and long term goal of water productivity, respectively 0.234kg/m3, 0.304kg/m3. The result showed that the cotton field water-saving potential could reach 224 million square under the short-term goal; the cotton field water-saving potential could reach 463 million square under the long-term goal. With the accumulated frequency increasing, the water-saving potential is reduced. In the Low-frequency region the water-saving potential is high while in the high-frequency region the water-saving potential is low. If carried out water-saving transformation on large water consumption, relatively low levels of water productivity of low-yielding fields, the effect of water-saving would be most obvious.(5) Considering the regional characteristics of the natural climate, planting condition, pointed out that the water-saving irrigation measures should adopt the drip irrigation, supplemented by agricultural water-saving measures, such as farming preservation of soil moisture, water and fertilizer coupling, chemical preparation, covering preservation of soil moisture, high-yielding planting patterns in order to reduce the invalid ET and improve the crop water productivity.Based on the real water-saving concept, using the crop water productivity as the starting point, the advanced technological means of remote sensing was applied to water-saving potential the estimation, which distributed features can fully reflect the spatial variation of the underlying surface. Because each type of crop water consumption characteristics, physiological characteristics are so different, therefore, in this paper, single crop water productivity, instead of the regional comprehensive crop water productivity was analyzed. As for the main local crops of cotton, for example, a profound analysis of their water characteristics, growth pattern and so on were carried out in order to more accuracy and reasonableness estimation on water-saving potential.更多还原