Land use/land cover (LULC) changes have been observed in the Gaborone dam catchment since the 1980s. A comprehensive analysis of future LULC changes is therefore necessary for the purposes of future land use and water resource planning and management. Recent advances in geospatial modelling techniques and the availability of remotely sensed data have become central to the monitoring and assessment of both past and future environmental changes. This study employed the cellular automata and Markov chain (CA-Markov) model combinations to simulate future LULC changes in the Gaborone dam catchment. Classified Landsat images from 1984, 1995, 2005 and 2015 were used to simulate the likely LULCs in 2015 and 2035. Model validation compared the simulated and observed LULCs of 2015 and showed a high level of agreement with Kappa variation estimates of K_no (0.82), K_loc (0.82) and K_standard (0.76). Simulation results indicated a projected increase of 26.09%, 65.65% and 55.78% in cropland, built-up and bare land categories between 2015 and 2035, respectively. Reductions of 16.03%, 28.76% and 21.89% in areal coverage are expected for shrubland, tree savanna and water body categories, respectively. An increase in built-up and cropland areas is anticipated in order to meet the population’s demand for residential, industry and food production, which should be taken into consideration in future plans for the sustainability of the catchment. In addition, this may lead to water quality and quantity (both surface and groundwater) deterioration in the catchment. Moreover, water body reductions may contribute to water shortages and exacerbate droughts in an already water-stressed catchment. The loss of vegetal cover and an increase in built-up areas may result in increased runoff incidents, leading to flash floods. The output of the study provides useful information for land use planners and water resource managers to make better decisions in improving future land use policies and formulating catchment management strategies within the framework of sustainable land use planning and water resource management.

中文翻译：

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使用 CA-Markov 模型分析哈博罗内大坝流域未来土地利用土地覆盖变化：对水资源的影响

自 1980 年代以来，在哈博罗内大坝集水区观察到土地利用/土地覆盖 (LULC) 变化。因此，为了未来的土地利用和水资源规划和管理，有必要对未来的 LULC 变化进行综合分析。地理空间建​​模技术的最新进展和遥感数据的可用性已成为监测和评估过去和未来环境变化的核心。本研究采用元胞自动机和马尔可夫链 (CA-Markov) 模型组合来模拟哈博罗内大坝流域未来的 LULC 变化。1984 年、1995 年、2005 年和 2015 年的分类 Landsat 影像用于模拟 2015 年和 2035 年可能出现的 LULC。模型验证比较了 2015 年模拟和观察到的 LULC，显示与 K 的 Kappa 变异估计值高度一致_无(0.82)、K _loc (0.82) 和 K_标准(0.76)。模拟结果表明，2015 年至 2035 年，农田、建成地和裸地类别的预计增长分别为 26.09%、65.65% 和 55.78%。灌木地、乔木稀树草原和水体类别的面积覆盖率预计分别减少 16.03%、28.76% 和 21.89%。预计建成区和农田面积会增加，以满足人口对住宅、工业和粮食生产的需求，在未来的集水区可持续性计划中应考虑到这一点。此外，这可能导致集水区的水质和水量（地表水和地下水）恶化。此外，水体减少可能会导致水资源短缺并加剧已经水资源紧张的集水区的干旱。植被的丧失和建筑面积的增加可能会导致径流事件增加，从而导致山洪暴发。该研究的结果为土地利用规划者和水资源管理者提供了有用的信息，以便在可持续土地利用规划和水资源管理的框架内，在改进未来的土地利用政策和制定集水区管理战略方面做出更好的决策。