Mapping 20 years of irrigated croplands in China using MODIS and statistics and existing irrigation products

Abstract

As a routine agricultural practice, irrigation is fundamental to protect crops from water scarcity and ensure food security in China. However, consistent and reliable maps about the spatial distribution and extent of irrigated croplands are still unavailable, impeding water resource management and agricultural planning. Here, we produced annual 500-m irrigated cropland maps across China for 2000–2019, using a two-step strategy that integrated statistics, remote sensing, and existing irrigation products into a hybrid irrigation dataset. First, we generated intermediate irrigation maps (MIrAD-GI) by fusing the MODIS-derived greenness index and statistical data. Second, we collected all existing available irrigation maps over China and integrated them with MIrAD-GI into an improved series of annual irrigation maps, using constrained statistics and a synergy mapping method. The resultant maps had moderate overall accuracies (0.732~0.819) based on nationwide reference ground samples and outperformed existing irrigation products by inter-comparison. As the first of this kind in China, the annual maps delineated the spatiotemporal pattern of irrigated croplands and could contribute to sustainable water use and agricultural development.

Concurrent Precipitation Extremes Modulate the Response of Rice Transplanting Date to Preseason Temperature Extremes in China

“…Human management practices could be responsible for the insignificant differences, as they also respond to climate extremes. To investigate the irrigation impact on modulation effects, we used an annual 500‐m irrigated cropland data set across China from 2000 to 2018 (C. Zhang et al., 2022). This data set was generated by integrating statistical data, remote sensing, and existing irrigation products.…”

County‐Level Evaluation of Large‐Scale Gridded Data Sets of Irrigated Area Over China

“…Recently, the Irrigated Cropland in China (ICC) product was proposed by C. Zhang et al. (2022d). It is based on a synergistic mapping method using spatial information derived from vegetation indices of RS and the IA values of GCD.…”

Trimethylamine from Subtropical Forests Rival Total Farmland Emissions in China

“…After that, we divided the north and south routes into different drive sections based on their farmland and forest types to see if they differed in TMA emissions within the same route. In China, exact criteria and distribution maps for farmland types are available, allowing us to clearly classify the north route into irrigated dryland drive section in the north and paddy field (also belongs to irrigated farmland) drive sections in the south. Even so, we removed measurements from the 50 km section at their junction (bounded by 34.66°N) as a buffer zone between the two (Figure b).…”