阿姆河流域耕地变化及水土匹配特征分析

基于中亚阿姆河流域4个分区1990—2015年间土地利用变化和水资源等数据,运用耕地变化速率、洛伦兹曲线和基尼系数法以及水土资源匹配系数对阿姆河流域耕地变化和水土匹配状况进行了综合分析。结果表明:1990—2015年阿姆河流域耕地以146.74 km²/a的速度在扩张,且各时期、各分区扩张的速度不同;在不考虑咸海来水不断减少、生态持续恶化的前提下,绿洲区匹配状况属比较公平和相对合理状况;阿姆河流域水土资源空间分布存在明显的错位现象;全流域生态用水被农业用水严重挤占,阿姆河流域灌溉面积、灌溉用水量成为影响咸海水量及面积变化的重要因素,是一种不可持续的用水方式。     

Optimizing Deficit Irrigation Scheduling Under Shallow Groundwater Conditions in Lower Reaches of Amu Darya River Basin

Water demand for irrigated agriculture is increasing against limited availability of fresh water resources in the lower reaches of the Amu Darya River e.g., Khorezm region of Uzbekistan. Future scenarios predict that Khorezm region will receive fewer water supplies due to climate change, transboundary conflicts and hence farmers have to achieve their yield targets with less water. We conducted a study and used AquaCrop model to develop the optimum and deficit irrigation schedule under shallow groundwater conditions (1.0–1.2 m) in the study region. Cotton being a strategic crop in the region was used for simulations. Capillary rise substantially contributes to crop-water requirements and is the key characteristic of the regional soils. However, AquaCrop does not simulate capillary rise contribution, thereby HYDRUS-1D model was used in this study for the quantification of capillary rise contribution. Alongside optimal irrigation schedule for cotton, deficit strategies were also derived in two ways: proportional reduction from each irrigation event (scenario-A) throughout the growth period as well as reduced water supply at specific crop growth stages (scenario-B). For scenario-A, 20, 40, 50 and 60 % of optimal water was deducted from each irrigation quota whereas for scenario-B irrigation events were knocked out at different crop growth stages (stage 1(emergence), stage 2 (vegetative), stage 3 (flowering) and stage 4 (yield formation and ripening)). For scenario-A, 0, 14, 30 and 48 % of yield reduction was observed respectively. During stress at the late crop development stage, a reduced water supply of 12 % resulted in a yield increase of 8 %. Conversely, during stress at the earlier crop development stage, yield loss was 17–18 %. During water stress at the late ripening stage, no yield loss was observed. Results of this study provide guidelines for policy makers to adopt irrigation schedule depending upon availability of irrigation water.     

Remote Sensing and Hydrological Measurements for Irrigation Performance Assessments in a Water User Association in the Lower Amu Darya River Basin

Irrigation water management in Central Asia is notorious for its inefficiency. We assessed the operational performance of the irrigation scheme in one Water Users Association (WUA), Shomakhulum, in Khorezm district, Uzbekistan, in 2007 to provide recommendations for strategic water management planning. Relative evapotranspiration (RET), delivery performance ratio (DPR), drainage ratio (DR), depleted fraction (DF), overall consumed ratio (OCR), field application ratio (FAR) and conveyance ratio (CR) were used as performance indicators. The components of the water balance were obtained through remote sensing techniques and hydrological field measurements. The surface energy balance algorithm for land (SEBAL) was applied to MODIS satellite data to derive actual and potential evapotranspiration. Inflows and outflows were quantified with field measurements in the irrigation and drainage network using discharge rating curves. Ponding experiments allowed determining canal seepage losses. Water balances at field level were established for application efficiency estimations. The indicator values were then compared to efficiency target values taken from the literature in order to assess the operational capabilities of the irrigation scheme. The general performance of the irrigation scheme is very poor. DPRs exceeding 1.0 indicate that more water is delivered to the system than is demanded. The seasonal DF of 0.4 is lower than the target value of 0.6. Losses during the field application averaged at 57%, which is 24% above target values. Seasonal DR, OCR, CR and RET are 0.55, 0.51, 0.76 and 0.82 against the target values of 0.1, 0.54, 0.84 and 0.75, respectively. We conclude that the distribution mechanism can be considerably improved. Besides improving water distribution (timing and equity) in the network, another recommended intervention would be to increase the DF, particularly by interventions at field level that raise the FAR, which in turn will improve DR and OCR. This can be achieved by introducing modern water management approaches such as laser leveling, double-sided irrigation, and control of inflow through flow-measuring devices installed at farm gates, and adequate water pricing.     

唐山曹妃甸建设中的生态环境问题

2006年3月,曹妃甸工业区被列入国家"十一五"发展规划。其发展目标是努力让曹妃甸变成现代工业先行区、腹地发展龙头带动区、经济增长方式转变创新区、与国际市场接轨的高开放区和循环经济示范区。经过近年来的大力开发,曹妃甸已经发生了翻天覆地的变化,当地经济得到了很大发展,GDP总量逐年上升,但与此同时,曹妃甸的生态环境也受到了一定破坏,引起了政府和开发商的重视,逐渐成为大众关注的问题。     

巢湖生态环境问题及治理措施研究

巢湖生态环境问题主要体现在3方面:主要由氮、磷引起的水体富营养化等严重环境污染;水土流失导致泥沙淤积加速湖泊的逆向演化;诸如气象、地质及生物等自然灾害.针对上述问题,作者提出相应整治措施:控制污染源头排放量,提倡清洁生产工艺;转变经济增长方式,推动产业结构由资源型向质量效益型过渡;实施湖泊生态工程措施,采用底泥生态疏浚、浮床种植陆生植物净化水体、兴建湖岸绿化植被带等;整治流域生态环境,种植生态涵养林,提高森林覆盖率,加强行政监督管理等;增强公众环保意识,完善相关法规.     

Ecological channel science: Research objective and problems

Conclusion Ecological channel science should have a bearing on achievements in general channel science (theoretical, and its natural-history branch — geographical) and simultaneously be closely related to engineering channel science. In this case, it treats both the ecological aspects of the natural evolution of river channels (including channels transformed as a result of economic activity), and also the ecological consequences of any interference in the evolution of channel processes and their factors.Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 12, pp. 4–7, December, 1992.     

迁安市矿山水土保持存在问题及治理措施

<正>一、概况迁安市位于河北省东北部,燕山南麓,是一个半山区县级市。迁安市地处京津唐一级开发区,位置优越,交通便利,资源丰富,经济发达,2009年名列全国百强县市第24位。迁安市的经济发展主要依托于丰富的铁矿资源。目前全市共有矿山企业134家,年生产铁矿石500万t。随着铁矿资源的大规模开发,迁安市经济发展迅猛,但同时亦带来了资源消耗和生态环境问题,急需采取有效措施进行全面综合治理。     

洞庭湖区湿地生态环境问题与对策

洞庭湖区湿地的生态环境在调蓄洪水、调节气候、涵养水源、净化水质、维护生物多样性等方面具有重要的作用。但是,多年来由于人类不合理的开发利用,给湖区湿地生态系统带来了许多负面影响,致使湿地生态环境严重退化。目前,洞庭湖区湿地存在诸多问题,主要表现在：湖区环境污染日益加剧;生物多样性减少,珍稀物种濒危;泥沙淤积严重,湖泊萎缩,洪水水位升高,调蓄功能下降;水文环境趋于恶化,洪涝灾害日益频繁;血吸虫病盛行,疫区面积有扩展趋势;湿地生态质量下降,功能衰退。针对这些问题,提出：严格控制环境污染,切实做好洞庭湖水质监测工作,保护湖区湿地水环境;实施退田还湖和生态防护工程,减少泥沙淤积,确保湖泊蓄洪、分洪功能;因地制宜,综合治理,恢复湿地生态系统结构和功能;强化生态保护的教育,提高人口素质,加快对湿地保护的立法;优化湖区产业结构,走可持续发展之路;加强流域统一管理,建立跨区域生态管理模式等对策,以期洞庭湖区湿地生态环境得到恢复并向良性方向发展。     

燕塞湖水库旅游开发中生态环境问题及保护措施

水库旅游是依托水库的人工建筑和自然山水、人文环境来发展旅游业[1～2].随着人们生活水平的提高,到水库旅游的人也越来越多,这给水库旅游业的发展带来的了无限生机,同时也给水库管理和库区环境问题带来严峻的挑战.文中概述了燕塞湖水库在旅游开发中面临的水库泥沙淤积、水位下降、水体富营养化、库区生态功能衰退、生态系统脆弱等生态环境问题,并针对这些问题提出了合理的保护和治理措施.     

水利工程中的生态问题与生态水利工程

以生态的科学内涵作基础,探讨如何正确认识水利工程对生态影响的双重性;要在水利工程规划、设计、施工的全过程中强化生态意识和环保意识,尽量发挥其保护和改善生态的正面影响,限制和减免其负面影响.提出了生态水利工程的概念,并从历史和现实分析说明生态水利工程的客观存在和对经济社会发展所发挥的巨大作用,今后还要建造更多以保护和改善生态为主要目标的生态水利工程.     

Effects of hydrological changes on cooperation in transnational catchments: the case of the Syr Darya

Water allocation along the Syr Darya River may be affected by climate change. Here we statistically model cooperation strategies, country profits, and sensitivity of cooperation, showing that the hydrological regime affects transboundary cooperation. Climate change in the twenty-first century may reduce glacial cover, and reducing stream flows, decreasing chances of cooperation and potentially raising conflicts. Comparison with other transboundary catchments in Central Asia indicates moderate-to-high risk of conflicts for the Syr Darya. A template is provided for assessment of the stability of cooperation in the Syr Darya basin, and in catchments similarly dependent on water availability.     

入湖浅水三角洲形成过程实验模拟分析

本文基于自然模型法,对入湖浅水三角洲的形成发展过程进行实验模拟,从河型和流场变化的角度,分析其河道演变过程规律。通过改变上游来沙和下游水位,研究不同边界条件对三角洲形成过程中河道摆动及河型发育的影响。实验结果表明:(1)河槽在顺直、分汊及无河槽的形态间交替演变,下游淤积的河坝会导致地形抬高、反水压力以及溯源淤积现象,促进河道发生周期性横向摆动。(2)三角洲表面流场形态及流速大小随河型变化,且与演变阶段有关。(3)上游多沙和下游高水位,都能使河型周期历时变短,主流摆动角度变大,摆动点位置向上游移动,较多来沙可以使河道形态由鸟足状向辐射状发育。在这一演化过程中,来沙影响占主导而水位影响居次要,水位变化条件不会从根本上改变河道形态的类型。