Evaluation of the Effectiveness of Light Pollution Control in Shenzhen Xichong Dark Sky Preserve Based on Nighttime Light Remote Sensing
Received date: 2025-02-17
Revised date: 2025-05-03
Online published: 2025-08-31
Rapid urbanization in China has significantly exacerbated light pollution, disrupted the ecological balance, and imposed constraints on both astronomical observations and public access to stargazing. Therefore, addressing light pollution has become a critical issue in ecological conservation and sustainable development. Shenzhen's Xichong Community achieved a landmark milestone in 2023 by becoming China's first International Dark Sky Community certified by the International Dark-Sky Association (IDA). This designation makes light pollution control practices of Xichong significant for similar regions. This study aimed to systematically evaluate the effectiveness of light pollution control measures in the Xichong Community, providing a scientific basis for balancing conservation and development in comparable areas. This study innovatively utilized high-resolution nighttime light (NTL) remote sensing data acquired using the Sustainable Development Goals Satellite-1 (SDGSAT-1), integrated with NASA's Black Marble products, to establish a refined monitoring and assessment framework for light pollution. To address the challenge of radiometric inconsistencies inherent to multitemporal SDGSAT-1 NTL imaging, this study proposed a novel radiometric consistency correction method based on Random Forest Regression (RFR). During the preprocessing phase, the images were subjected to salt-and-pepper noise removal and absolute radiometric calibration. Subsequently, the RFR model was applied to achieve a radiometric consistency correction. A comparative analysis with traditional linear brightness normalization confirmed the superior accuracy and effectiveness of RFR approach in enhancing image comparability. By leveraging corrected, high-quality, time-series NTL imagery, this study quantitatively assessed the effectiveness of light pollution control measures implemented in the Xichong Community over a three-year period. The key findings were as follows. (1) Significant reduction in light pollution: the Xichong Community exhibited a markedly greater decline in overall light pollution intensity compared to other areas within the Dapeng New District. Pixel-level analysis verified the widespread nature of this decreasing trend, with the brightness values showing a pervasive reduction. (2) Effective control across functional zones: the core stargazing beach area witnessed a substantial brightness reduction (57%) in September 2024 compared with that seen in September 2022. Road-lighting intensity also decreased significantly (56%-70%). Among the residential zones, Xinwu and Xiyangwei villages achieved reductions exceeding 69%, whereas brightness in Nanshe village decreased by 55.7%. Getian and Xigong villages experienced steady declines, while Hesou, Yashan, and Shagang Villages saw fluctuating but overall decreasing trends. (3) Effective management of light pollution sources: although accommodation facilities remain the primary contributors to light pollution, their brightness coefficients decreased significantly (46.11%). Points of Interest (POIs) related to tourism saw reductions exceeding 45% in brightness, with overall POI brightness coefficients declining by 27.68%-74.45%. These results demonstrate that the stringent lighting management policies implemented by the Xichong Community effectively mitigated the adverse impacts of tourism development on the dark sky environment. This study not only successfully applied high-resolution NTL data from SDGSAT-1, but also developed an RFR-based radiometric consistency correction technique, significantly improving the comparability of multi-temporal NTL data. The established methodological framework enables fine-scale monitoring of nighttime lighting at the community level, specifically for areas pursuing "dark-sky conservation + ecotourism" models. Furthermore, this study provides a foundation for establishing a dynamic monitoring and quantitative assessment system for light pollution within existing dark-sky reserves. These advancements offer critical scientific foundations and technical support for balancing the imperative of dark-sky conservation with sustainable tourism development goals.
Xi Li , Bubuli·Yeerleke , Jianchuan Zheng , Lin Mei . Evaluation of the Effectiveness of Light Pollution Control in Shenzhen Xichong Dark Sky Preserve Based on Nighttime Light Remote Sensing[J]. Tropical Geography, 2025 , 45(8) : 1373 -1387 . DOI: 10.13284/j.cnki.rddl.20250084
表1 SDGSAT-1夜光影像的成像日期及时间Table 1 Imaging dates and times of SDGSAT-1 nighttime light images |
| 影像日期 | 成像时间 |
|---|---|
| 2022-03-07 | T 21:46:49.13 |
| 2022-04-03 | T 21:42:13.13 |
| 2022-04-08 | T 21:48:11.78 |
| 2022-09-02 | T 21:44:35.70 |
| 2023-02-28 | T 21:51:27.68 |
| 2023-07-24 | T 21:39:17.99 |
| 2023-08-03 | T 21:39:17.99 |
| 2023-08-14 | T 21:48:58.94 |
| 2023-11-20 | T 21:39:28.95 |
| 2024-01-19 | T 21:37:41.13 |
| 2024-02-10 | T 21:43:40.85 |
| 2024-05-05 | T 21:42:40.03 |
| 2024-05-16 | T 21:41:9.92 |
| 2024-08-10 | T 21:35:59.09 |
| 2024-09-01 | T 21:33:14.03 |
表2 SDGSAT-1微光传感器绝对辐射定标系数Table 2 Absolute radiometric calibration coefficients of the SDGSAT-1 glimmer sensor |
| 波段 | Gain | Bias | 波段带宽(W)/nm |
|---|---|---|---|
| R | 0.000 013 54 | 0.000 013 675 4 | 294 |
| G | 0.000 005 07 | 0.000 006 084 | 106 |
| B | 0.000 009 925 3 | 0.000 009 925 3 | 102 |
表3 椒盐噪声去除结果Table 3 Results of salt-and-pepper noise denoising |
| 日期 | 残差噪声熵(RNE) | 平均相对偏差(MRD)/% | |||||
|---|---|---|---|---|---|---|---|
| 红波段 | 绿波段 | 蓝波段 | 红波段 | 绿波段 | 蓝波段 | ||
| 2022-03-07 | 0.465 3 | 0.241 0 | 0.468 3 | 1.59 | 1.72 | 2.74 | |
| 2022-04-03 | 0.128 3 | 0.132 5 | 0.060 3 | 0.81 | 0.85 | 0.34 | |
| 2022-04-08 | 0.749 1 | 0.364 1 | 0.626 3 | 2.31 | 1.73 | 2.32 | |
| 2022-09-02 | 0.199 2 | 0.136 2 | 0.024 0 | 1.30 | 0.86 | 0.12 | |
| 2023-02-28 | 0.416 4 | 0.569 5 | 0.544 0 | 1.19 | 2.59 | 2.42 | |
| 2023-07-24 | 0.316 4 | 0.264 3 | 0.396 1 | 1.61 | 2.17 | 1.10 | |
| 2023-08-03 | 0.252 6 | 0.173 3 | 0.213 8 | 1.73 | 1.15 | 1.47 | |
| 2023-08-14 | 0.248 3 | 0.499 5 | 0.627 0 | 1.73 | 1.94 | 1.27 | |
| 2023-011-20 | 0.142 5 | 0.212 4 | 0.063 6 | 0.90 | 1.45 | 0.37 | |
| 2024-01-19 | 0.345 5 | 0.343 7 | 0.363 5 | 1.54 | 2.54 | 2.72 | |
| 2024-02-10 | 0.171 3 | 0.283 6 | 0.155 3 | 1.13 | 1.03 | 1.01 | |
| 2024-05-05 | 0.294 0 | 0.742 3 | 0.460 4 | 1.11 | 2.28 | 2.63 | |
| 2024-05-16 | 0.087 3 | 0.668 7 | 0.281 5 | 0.53 | 1.51 | 1.03 | |
| 2024-08-10 | 0.342 0 | 0.813 4 | 0.258 0 | 1.52 | 1.92 | 1.84 | |
| 2024-09-01 | 0.107 4 | 0.426 7 | 0.508 2 | 0.66 | 1.26 | 1.09 | |
图5 2023-07-24 SDGSAT-1影像椒盐噪声去除效果对比(a. 原始影像;b和c分别为a图中方框区域的放大显示;d和e分别对应b和c区域经去噪处理后的结果)Fig.5 Comparison of salt-and-pepper noise removal effects in SDGSAT-1 imagery (July 24, 2023) (a. Original image; b and c show zoomed-in views of the boxed regions in a; d and e present the denoised results corresponding to b and c, respectively) |
图6 经辐射一致性处理后的定标区域SDGSAT-1夜光遥感影像Fig.6 Radiometrically consistent SDGSAT-1 nighttime light imagery of stable light sources |
表4 VNP46A2数据与校正前后的SDGSAT-1数据之间的R²Table 4 R² values between VNP46A2 data and SDGSAT-1 data before and after correction |
| 影像日期 | SDGSAT-1数据 | 影像日期 | SDGSAT-1数据 | ||
|---|---|---|---|---|---|
| 校正前 | 校正后 | 校正前 | 校正后 | ||
| 2022-03-07 | 0.482 | 0.490 | 2023-11-20 | 0.363 | 0.381 |
| 2022-04-03 | 0.332 | 0.342 | 2024-01-19 | 0.462 | 0.475 |
| 2022-04-08 | 0.525 | 0.542 | 2024-02-10 | 0.393 | 0.414 |
| 2022-09-02 | 0.598 | 0.612 | 2024-05-05 | 0.472 | 0.479 |
| 2023-02-28 | 0.442 | 0.455 | 2024-05-16 | 0.385 | 0.403 |
| 2023-08-03 | 0.380 | 0.391 | 2024-08-10 | 0.482 | 0.536 |
| 2023-08-14 | 0.382 | 0.420 | 2024-09-01 | 0.564 | 0.578 |
表5 不同辐射一致性校正方法的RMSE与R²结果对比Table 5 Comparison of RMSE and R² Results from Different Radiometric Consistency Correction Methods |
| 影像日期 | 线性模型 | 随机森林回归法 | |||
|---|---|---|---|---|---|
| RMSE | R² | RMSE | R² | ||
| 2022-03-07 | 23.57 | 0.64 | 16.16 | 0.72 | |
| 2022-04-03 | 16.99 | 0.73 | 12.72 | 0.83 | |
| 2022-04-08 | 21.66 | 0.68 | 14.76 | 0.77 | |
| 2022-09-02 | 21.24 | 0.69 | 14.52 | 0.78 | |
| 2023-02-28 | 19.15 | 0.74 | 13.03 | 0.82 | |
| 2023-08-03 | 11.39 | 0.85 | 8.78 | 0.92 | |
| 2023-08-14 | 17.18 | 0.81 | 11.14 | 0.87 | |
| 2023-11-20 | 19.80 | 0.71 | 13.71 | 0.80 | |
| 2024-01-19 | 19.18 | 0.74 | 13.28 | 0.81 | |
| 2024-02-10 | 19.98 | 0.68 | 14.03 | 0.79 | |
| 2024-05-05 | 22.79 | 0.72 | 13.94 | 0.79 | |
| 2024-05-16 | 24.75 | 0.63 | 16.21 | 0.72 | |
| 2024-08-10 | 31.01 | 0.55 | 17.31 | 0.68 | |
| 2024-09-01 | 17.49 | 0.76 | 12.79 | 0.83 | |
图10 大鹏新区各街道与西涌社区夜光均值时序变化(2022年3月—2024年9月)Fig.10 Mean nighttime light time-series for Dapeng subdistricts and Xichong (Mar 2022 - Sep 2024) |
表6 基于Theil-Sen和MK检验的大鹏新区夜间灯光变化趋势Table 6 Nighttime light change trends in Dapeng New District based on Theil-Sen slope and Mann-Kendall test |
| 区域 | Theil-Sen斜率 | 年变化率/% | MK_Tau | MK检验P值 | 趋势显著性 |
|---|---|---|---|---|---|
| 西涌社区 | -0.084 2 | -27.37 | -0.50 | 0.000 069 1 | 显著下降 |
| 南澳街道 | -0.004 64 | -2.23 | -0.16 | 0.21 | 下降(趋势不显著) |
| 大鹏街道 | -0.020 17 | -2.55 | -0.17 | 0.18 | 下降(趋势不显著) |
| 葵涌街道 | -0.033 42 | -4.65 | -0.30 | 0.018 | 显著下降 |
1 https://www.sdgsat.ac.cn
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