Upscaling Catchment Processes for Sustainable Water Management in Peninsular India

印度半岛的经济发展和人口增长导致土地使用、土地管理和水需求的迅速变化，这些都严重影响和退化了水资源。城市化、森林砍伐、农业集约化、灌溉农业和雨养作物之间的转换、地下水使用量的增加以及小规模地表水储存措施的扩散，如农田堤坝（通常用于保持田间土壤水分）和淤地坝（用于补充当地含水层），所有这些都促使集水区水文功能发生重大变化。这种变化和干预措施对当地水文过程的影响，如径流，地下水补给和蒸散，受到很大的限制，我们对这些不同的地方变化如何累积影响更广泛的流域规模的水供应的理解是非常有限的。专注于极具争议的州际Cauvery河流域（面积约80,000平方公里，Cauvery是印度最大的河流流域之一），我们的研究解决了代表印度半岛许多地方，小规模干预措施在更大规模的关键科学挑战。该项目将利用从农村和城市已建立的实验集水区获得的观测结果，首先探讨土地使用、土地覆盖、灌溉做法和小规模水管理干预措施的变化如何对当地水文过程产生影响。同时，我们将开发新的尺度放大方法，以在较大的子流域（Kabini，~ 10，000 km 2）和流域（Cauvery）尺度上代表模型中改进的过程理解。在这样做时，该项目将证明有能力在全流域水资源综合管理模式中概括地反映大量小规模变化的累积影响。将进一步模拟地方规模干预措施的影响，同时预测人口增长、气候和土地使用变化以及水需求，以评估未来对整个流域水安全的影响。关键利益攸关方参与项目的各个阶段，以确保项目产出反映他们的利益和关切，并为他们的决策提供有用的投入。

Economic development and population growth in Peninsular India have resulted in rapid changes to land-use, land-management and water demand which together are seriously impacting and degrading water resources. Urbanization, deforestation, agricultural intensification, shifts between irrigated agriculture and rain-fed crops, increased groundwater use, and the proliferation of small-scale surface water storage interventions, such as farm-level bunds (usually to conserve soil moisture in fields) and check-dams (to replenish local aquifers) all have contributed to significant changes in the hydrological functioning of catchments. The impact of such changes and interventions on local hydrological processes, such as streamflow, groundwater recharge and evapotranspiration, are poorly constrained, and our understanding of how these diverse local changes cumulatively impact water availability at the broader basin-scale is very limited. Focussing on the highly contentious inter-state Cauvery River basin (with an area of c.80,000 km2, the Cauvery is one of India's largest river basins) our study addresses the key scientific challenge of representing the many local, small-scale interventions in Peninsular India at larger scales. Using observations from established experimental catchments in both rural and urban settings, the project will first explore how changes in land-use, land-cover, irrigation practices and small-scale water management interventions locally affect hydrological processes. In tandem we will then develop novel upscaling methods to represent the improved process-understanding in models at the larger sub-basin (Kabini, ~10,000 km2) and basin (Cauvery) scales. In so doing, the project will demonstrate the capability to generically represent the cumulative impact of abundant small-scale changes in basin-wide integrated water resources management models. The impact of local-scale interventions will further be modelled alongside projections of population growth, climate- and land-use-change and water demand to assess future impacts on water security across the basin. Key stakeholders are involved throughout the different stages of the project to ensure that project outputs reflect their interests and concerns and provide useful input to their decision making.