A dynamic process like land use, if anthropogenically unsustainable, adversely affects the well-being of the land system. Worldwide, water bodies are facing imminent threat due to unsustainable anthropogenic activities. Water quality and ecology are the two characteristics of water bodies, if not preserved, shall have a direct consequence on the well-being of the human systems. Hence it is essential to understand the causes and consequences of the deteriorating water body systems. The condition is particularly grim in Himalayan water body ecosystems, where unplanned and unchecked urbanization has threatened their very existence. In the present study, the dynamics of land use/land cover (LULC) and its impact on the water quality of Dal Lake in Kashmir Himalaya, India has been assessed. We carried out a detailed study wherein changing LULC is analyzed against the deteriorating trophic status of the Dal Lake using time-series of satellite imagery of the lake’s catchment and its water quality data. Results indicated that the water quality of Dal Lake has remarkably deteriorated due to increased nutrient and sediment loads from the catchment, attributed to significant anthropogenic activities in the catchment. Due to unprecedented LULC changes in the catchment, the forest class shows a significantly negative change since the last four decades (1980–2018), corroborating with the ongoing deterioration of physicochemical characteristics of the lake. The analysis shows an increase in all the agents of eutrophication, such as NO₃–N, TP, and COD, from 1990 to 2018. The decrease in forest, agriculture, and floating gardens was observed to show a significant negative correlation with the increase in the decadal average values of the COD, NO₃–N, and TP for the same corresponding period. Similarly, a positive correlation was found between the increase in built-up, aquatic vegetation, bare surfaces, and these water quality parameters, establishing a strong relationship between the deteriorating condition of the lake and changing LULC. Our findings indicate that changing LULC of the lake’s catchment is one of the critical factors that has significantly contributed toward the deteriorating ecology and water quality of the Dal Lake. This study shall contribute toward the development of the robust conservation strategy in order to save this urban lake from its untimely death.

中文翻译：

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评估印度西北喜马拉雅山达尔湖的土地利用和土地覆盖动态对水质的影响

土地使用等动态过程，如果人为无法持续，则会对土地系统的福祉产生不利影响。在世界范围内，由于不可持续的人为活动，水体正面临迫在眉睫的威胁。水质和生态是水体的两个特征，如果不加以保留，将直接影响人类系统的福祉。因此，必须了解水体系统恶化的原因和后果。在喜马拉雅水域生态系统中，情况尤为严峻，那里未经计划和未经控制的城市化威胁了其生存。在本研究中，已经评估了印度克什米尔喜马拉雅山土地利用/土地覆盖的动态及其对达尔湖水质的影响。我们进行了详细的研究，其中使用湖泊流域的卫星图像及其水质数据的时间序列，针对Dal湖不断恶化的营养状况分析了变化的LULC。结果表明，由于集水区大量的人为活动，集水区的养分和沉积物增加，达尔湖的水质显着恶化。由于该流域前所未有的LULC变化，自最近四个十年（1980-2018年）以来，森林类别显示出显着的消极变化，这与该湖理化特性的持续恶化是一致的。分析显示所有富营养化因子（例如NO）均增加 结果表明，由于集水区大量的人为活动，集水区的养分和沉积物增加，达尔湖的水质显着恶化。由于该流域前所未有的LULC变化，自最近四个十年（1980-2018年）以来，森林类别显示出显着的消极变化，这与该湖理化特性的持续恶化是一致的。分析显示所有富营养化因子（例如NO）均增加 结果表明，由于集水区大量的人为活动，集水区的养分和沉积物增加，达尔湖的水质显着恶化。由于该流域前所未有的LULC变化，自最近四个十年（1980-2018年）以来，森林类别显示出显着的消极变化，这与该湖理化特性的持续恶化是一致的。分析显示所有富营养化因子（例如NO）均增加 证实该湖的物理化学特性不断恶化。分析显示所有富营养化因子（例如NO）均增加 证实了该湖理化特性的持续恶化。分析显示所有富营养化因子（例如NO）均增加_{3 –} N，TP和COD，从1990年到2018年。观察到森林，农业和水上花园的减少与COD，NO ₃的年代际平均值的增加呈显着负相关。-N和TP对应相同的时间。同样，在堆积的，水生植被，裸露的表面和这些水质参数之间发现正相关，从而在湖泊的恶化状况和LULC的变化之间建立了牢固的关系。我们的发现表明，湖泊流域的LULC变化是导致Dal湖生态和水质恶化的重要因素之一。这项研究将有助于制定强有力的保护策略，以保护该城市湖泊免于过早死亡。