Monitoring irrigation performance in Sri Lanka with high-frequency satellite measurements during the dry season
Monitoring irrigation performance in Sri Lanka with high-frequency satellite measurements during the dry season
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DOI：
10.1016/s0378-3774(02)00132-4
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发表时间：
2003-02
影响因子：
6.7
通讯作者：
K. Bandara
中科院分区：
文献类型：
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作者：
K. Bandara
现在可以从卫星数据中检索作物在不同栽培阶段的需水、用水、土壤湿度和植物生长的信息。本研究利用NOAA卫星数据评估了斯里兰卡1999年旱季（4 - 7月）三个大型灌溉系统Polonnaruwa、Kirindi Oya和Gal Oya的表现。Polonnaruwa系统的总供水量大于需求量；相对供水量（RWS）为1.88。种植系统只使用了总灌溉供水量的47.5%。在加尔奥雅系统中，总供水量为作物需水量的1.27%，而作物利用了总供水量的71.1%，表明灌溉效率很高。这表明，在某些情况下，灌溉不足可以使水管理更有效。其原因可能是灌溉用水通过排水网络回用和地下水净抽吸。对于这两个系统，水的生产力都很高：Polonnaruwa和Gal Oya每单位流入水（降水加灌溉）的生产力分别为0.29和0.40kgm - 3。在Kirindi Oya， RWS（2.71）高于其他两个系统，但灌溉效率明显较低（32.4%）。本文表明，遥感测量有助于客观地分析全国范围内的灌溉过程，并在每月的时间步长。这些定量灌溉数据及其近乎实时的可用性为灌溉部提供了以前没有的信息。
Information on crop-water demand, water use, soil moisture and plant growth at different stages of the cultivation can nowadays be retrieved from satellite data. In this research study, NOAA satellite data were used to assess the performance of three large irrigation systems in Sri Lanka during the 1999 yala (dry season from April to July): Polonnaruwa, Kirindi Oya and Gal Oya. The Polonnaruwa system has a total water supply that is greater than the demand; the relative water supply (RWS) is 1.88. The cropping system has used only 47.5% of the total irrigation supply. In the Gal Oya system, the overall water supply was 1.27 of the crop demand whereas the crop has utilized 71.1% of the total water supply indicating high irrigation efficiency. This shows that, in certain circumstances, under-irrigation can make water management more effective. The reasons may be the reuse of irrigation water through the drainage network and net groundwater draft. For both systems, productivity of water is high: Polonnaruwa 0.29kgm−3and Gal Oya 0.40kgm−3per unit of water inflow (precipitation plus irrigation). In Kirindi Oya, the RWS is higher (2.71) than in the other two systems and irrigation efficiency is considerably lower (32.4%). This paper shows that remote sensing measurements can help objectively analyze irrigation processes throughout the country and at a monthly time step. These quantitative irrigation data and its near-real time availability provides the Irrigation Department with information not previously available.